wm *■*. .*i4 if; s * » w > 4 VV i&^E Journal of the Ropal Microscopical Societp CONTAINING ITS TRANSACTIONS AND PROCEEDINGS AND A SUMMARY OF CURRENT RESEARCHES RELATING TO ZOOXiOG-Y J^JSTJD BOTANY (principally Invertebrata and Cryptogaraia) MICBOSCOPY, &c. EDITED BY R. G. HEBB, M.A. M.D. F.R.C.P. WITH THE ASSISTANCE OF THE PUBLICATION COMMITTEE AND J. ARTHUR THOMSON, M.A. F.R.S.E. A. N. DTSNEY, M.A. B.Sc. Regius Professor of Natural History in the University of A berdeen FELLOWS OF THE SOCIETY A. B. RENDLE, M.A. D.Sc. F.R.S. F.L.S. Keeper, Depart»ient of Botany, British Museum HAROLD MOORE, B.Sc. RALPH ST. JOHN BROOKS, M.A. M.D. D.P.H. Woolwich Arsenal Assistant Bacteriologist Lister Institute Minimis partibus, per totum Naturae campum, certitudo omnis innititur quas qui fugit pariter Naturam fugit.— Linnceus. FOR THE YEAR 1914 TO BE OBTAINED AT THE SOCIETY'S ROOMS 20 HANOVKR SQUARE, LONDON, W. of Messrs. WILLIAMS & NORGATE, 14 Henrietta Street, London, W.C. and of Messrs. DULAU & CO., 37 Soho Square, London, W. * u *> Extra and informal Meetings are held on the 1st and 4th Wednesday evenings of the month. These Meetings are devoted to : — (1) Biology, Bacteriology, and Histology ; (2) Microscopical Optics and Microsope Construction. q oo % THE 1 flpl JJttqoicapical Established in 1839. Incorporated by Royal Charter in 1866. The Society was established for the promotion of Microscopical and Biological Science by tbe communication, discussion, and publication of observa- tions and discoveries relating; to (1) improvements in the construction and mode of application of the Microscope, or (2) Biological or other subjects of Microscopical Eesearch. It consists of Ordinary, Eonorary, and Ex-officio Fellows of either sex. Ordinary Fellows are elected on a Certificate of Kecommendation signed by three Ordinary Fellows, setting forth the names, residence, and description of the Candidate, of whom the first proposer must have personal knowledge. The certificate is read at two General Meetings, and the Candidate balloted for at the second Meeting. The Admission Fee is 21. 2s ; and the Annual Subscription 2/. 2s., pay- able on election, and subsequently in advance on 1st January annually. The Annual Subscriptions may be compounded for at any time for 31/. 10s. Fellows elected at a meeting subsequent to that in February are only called upon for a proportionate part of the first year's subscription. The annual Subscrip- tion of Fellows permanently residing abroad is 1/. lis. Qd. or a reduction of one-fourth. Honorary Fellows (limited to 50), consisting of persons eminent in Microscopical or Biological Science, are elected on the recommendation of five Ordinary Fellows and the approval of the Council. Ex-officio Fellows (limited to 100), consisting of the Presidents for the time being of any Societies having objects in whole or in part similar to those of the Society, are elected on the recommendation of ten Ordinary Fellows and the approval of the Council. The Council, in whom the management of the property and affairs of the Society is vested, is elected annually, and is composed of the President, four Vice-Presidents, Treasurer, two Secretaries, and twelve other Ordinary Fellows. The Meetings are held on the third Wednesday in each month, from October to June, at 20 Hanover Square, W. (commencing at 8 p.m.). Visitors are admitted by the introduction of Fellows. (See preceding page.) The Journal, containing the Transactions and Proceedings of the Society, and a Summary of Current Researches relating to Zoology and Botany (principally Invertebrata and Cryptogamia), Microscopy, etc., is published bi-monthly, and is forwarded post-free to all Ordinary and Ex-officio Fellows residing in countries within the Postal Union. The Library, with the Instruments, Apparatus, and Cabinet of Object*, is open for the use of Fellows daily (except Saturdays), from 10 a.m. to 5 P.M. It is closed for four weeks during August and September. Forms of proposal for Fellowship, and any further information, may be obtained by application to the Secretaries, or Assistant-Secretary, at the Library of the Society. 20 Hanover Square, W. a 2 Ration HIS MAJESTY THE KING. ilast-ihestbents. T" T Elected *Sir Richard Owen, K.C.B. D.C.L. M.D. LL.D. F.R.S. 1840-1 ♦John Lindley, Ph.D. F.R.S 1842-3 ♦Thomas Bell, F.R.S 1844-5 ♦James Scott Bowerbank, LL.D. F.R.S 1846-7 *George Busk, F.R.S 1848-9 •Arthur Farre, M.D. F.R.S 1850-1 ♦George Jackson, M.R.C.S 1852-3 •William Benjamin Carpenter, C.B. M.D. LL.D. F.R.S. 1854-5 "George Shadbolt 1856-7 •Edwin Lankester, M.D. LL.D. F.R.S 1858-9 ♦John Thomas Quekett, F.R.S I860 •Robert James Farrants, F.R.C.S 1861-2 ♦Charles Brooke, M.A. F.R.S 1863-4 *James Glaisher, F.R.S 1865-6-7-8 *Rev. Joseph Bancroft Reade, M.A. F.R.S 1869-70 ♦William Kitchen Parker, F.R.S 1871-2 ♦Charles Brooke, M.A. F.R.S 1873-4 ♦Henry Clifton Sorby, LL.D. F.R.S 1875-6-7 *Henry James Slack, F.G.S 1878 ♦Lionel S. Beale, M.B. F.R.C.P. F.R.S 1879-80 ♦Peter Martin Duncan, M.B. F.R.S 1881-2-3 ♦Rev. William Hy. Dallinger, M.A. LL.D. F.R.S. 1884-5-6-7 ♦Charles Thos. Hudson, M.A. LL.D. (Cantab.), F.R.S. 1888-9-90 Robert Braithwaite, M.D. M.R.C.S 1891-2 Albert D. Michael, F.L.S 1893-4-5-6 Edward Milles Nelson 1897-8-9 William Carruthkrs, F.R.S. F.L.S. F.G.S 1900-1 Henry Woodward, LL.D. F.R.S. F.G.S. F.Z.S 1902-i; DUKINFIELD II y. Scott, M.A. Ph.D. LL.D. F.R.S. F.L.S. 1904-5-6 ♦The Right Hon. Lord Avkkury, P.C. D.C.L. LL.D. F.R.S., etc 1907-8 Sir Edwin Rai Lankester, K.C.B. M.A. LL.D. F.R.S. F.L.S. F.Z.S 1909 J. Arthur Thomson, M.A. F.R.S.E 1910-11 Henry George Plimmer, F.R.S., F.L.S., F.Z.S., etc 1911-12. * Debased. COUNCIL. Elected 21st January, 1914. jprcstucnt. *Professor G. Sims Woodhead, M.A. M.D. LL.D. F.R.S.E. $ ice- ijjresiu cuts. *J. E. Barnard. Wynne E. Baxter, J.P. D.L. F.G.S. Edward Heron-Allen, F.L.S. F.G.S. F.Z.S. David J. Scourfield, F.Z.S. Crcasurcr. *Cyril F. Hill, M.Inst.M.M. Secretaries. *J. W. H. Eyre, M.D. F.R.S.E. *F. ShillinOxTON Scales, M.A. M.D. B.C.(Cantab.) (Oroinaru iiicmbcrs of dTounc *F. W. Watson Baker. Frederic J. Cheshire. *A. N. Disney, M.A. B.Sc. Arthur Earl and. *R. G. Hebb, M.A. M.D. F.R.C.P. John Hopkinson, F.L.S. F.G.S. F.Z.S. J. W. Ogilvy. Percy E. Radley. * Julius Rheinberg. *Charles F. Rousselet. A. W. Sheppard. E. J. Spitta, L.R.C.P.(Lond.), M.R.C.S.(Eng.). * Miinbers of the Publication Committer. EDITOR. R. G. Hebb, M.A. M.D. F.R.C.P. LIBRARIAN. Percy E. Radley. curators. Charles F. Rousselet. | Edward J. Sheppard. assistant secretary. A. E. Bull. CONTENTS. TRANSACTIONS OF THE SOCIETY. PAGE I. — The Binocular Microscope. By Felix Jentsch, Ph.D. (Figs. 1-3) .. .. 1 II. — The Binocular Microscope of the Past, and a New Form of Instrument. By Conrad Beck. (Plates I, II; 17 III.— Development of an Embiid. By J. C. Kershaw, F.Z.S. (Plates III, IV, and Fig. 4) 24 IV. — Notes on Shell-structure iu the Genus Lingula, Recent and Fossil. By Frederick Chapman, A.L.S., F.R.M.S. (Plate V) 28 V.— The President's Address. By G. Sims Woodhead 109 VI.— British Enchytrseids. By the Rev. Hilderic Friend, F.R.M.S. (Figs. 15- 19) 128 VII. — Some Observations on the Morphological Changes occurring in Beggiatoa alba on Staining by various Methods. By E. Moore Mumford. (Plates VI, VII) 233 VIII.— The Buzzing of Diptera. By P. A. Aubiu, F.R.M.S. (Plates VIII, IX, X) 329 IX. — Notes on some Focometric Apparatus. By Frederic J. Cheshire. (Figs. 52-5) 513 NOTE. Note on Sphierotilus. By E. Moore Mumford .. 433 OBITUARIES. Albert Grunow, Hon.F.R.M.S. By J. B. De Toni, Hon.F.R.M.S 236 Thomas J. Barratt. 1841-1914 237 John Davies Siddall. 1844-1914 238 Philippe Edouard Le'on van Tieghem, Hon. F.R.M.S. 1839-1914 335 vin CONTENTS. SUMMARY OF CURRENT RESEARCHES ZOOLOGY. VERTEBRATA. a. Embryology- PAGE Gray, J. — Electrical Conductivity of Ova .» .. .. 23 Oppermann, K. — Effect of lladium-rayed Sperms on Trout Ova 32 Wassermann. F. — Oogenesis of Zoogonus mirus 33 Palmer. R. W. — Development of Ear Ossicles in Foetal Perameles 33 Schl ei lit, Joseph — Early Development of Scale and Feather .. 33 Radford, Marion — Development of Pharyngeal Bursa in Ferret 33 IvanoW, E. — Artificial Insemination in Birds 34 Brachet, A. — Development of Rabbit's Embryo in Vitro 155 Bataillon, E. — Artificial Parthenogenesis in Amphibians 155 Levy, Fritz— Artificial Parthenogenesis in Frog 156 Hertwig, Gunther— Artificial Parthenogenesis in Frog and Toad 15b" Fuhrmanx. 0.— Hermaphroditism in Toad 15b" Williamson, A. ('has. — Eggs of Skates .. -• 157 Ballowitz, E.— Spermatozoon of Guillemot 157 Roule, Louis — Larval Phases of Nemichthydx 157 Jarojiir Wenig — Development of the Heart in Fishes and Amphibians 239 Saint-Hilaire, C— Yolk-granules of Amphibians 239 Buuin, P., & P. Ancel — Action of Corpus luteum on Mammary Glands .. .. 240 0'Donoghue : Chas. H.— Artificial Production of Corpora lutea 240 ., „ Corpus luteum in Marsupials 240 Bond. C. J. — Regeneration of Testes in Birds 240 Fraenkel, Manfred — Influence of Rontgen Rays on Ovaries 241 Firket, Jean — Development of Gonads in Chick 241 Jenkinson, J. W. — Development of the Centrifuged Egg of the Frog 244 Laet. Maurice de — Development of Mucous Membrane of Stomach 24."> Willey, Arthur — Blastocyst and Placenta of^Beaver 337 Curtis, M. R. — Reproduction in Domestic Fowl 337 Smith, Ltjot W. — Development of Columella auris in Chrysemys marginata | . . .. 338 Maki schi ik, M.-— Development of Lungs in Bombinator igneus 338 Keisek, W. — Development of Vascular System of Lamprey 338 Brachet, A.— Development of Chelonia 339 Tottov, A. Knyvett — Development of Caudal Skeleton in Pleuragramma antarcticum 340 "Wood-Jones, F. — Reproductive System of Female Mole 341 Seliumasn, C.G., & S. G. Shattock — Seasonal Changes in Testes and Plumage in Wild Duck 341 Witschi, E.— Development of Gonads of Frog 434 Pick. Ludwig— True Hermaphroditism in Man and Mammals 435 Tayssiere & G. Quintaret — Hermaphroditism in a Dogfish 435 Haff, R. — Blood-formation in Embryonic Liver .. .. 435 Haller. B. — Origin of Snpra-cleithral Bones from Epidermis 435 Lebedinskv, N. <;. — Development of Pectineal Pracest 436 Bogoljubsky, S. — Development of Lacertiliau Sternum and Pectoral Girdle .. .. 436 Houssay, F. — Embryonic Circulation in Axolotl .. .. 436 Ga i.e. Albert — Eggs and Egg-laying of Purple-striped Gudgeon 520 J/archetti, Laura — Observations on Development of Toad 521 CONTENTS. IX PAGE Lauche, Arnold — Pluripolar Mitoses in Regenerating Testes of Frog 521 Cole, I j. J, — Inheritance in Pigeons 521 Smirnowa, W. — Regeneration of Muscular Tissue in Metamorphosis of Frog .. .. 522 d' Antona, Serafino — Development of Connective Tissue] 522 Korff, K. von — Histogenesis of Cartilage 522 Gortner, R. A.— Chemistry of Development 523 Peyreger, E. — Permeability of the Sliell of Selachian Eggs .. .. 523 b. Histology. Schulze, Paul — Fine Structure of Cuticle 34 Hacigqvist, Gosta — Histology of Cold Spots in Human Skin 34 Ditlevsen, Christian — Peculiar Cells in Lingual Epithelium of Guinea-pig .. .. 34 Seguchi, Sakae — Mitochondria and Mitochondrial Strands in Epidermis Cells of Tadpoles 34 Ballowitz, E. — Chromatophores of Mullus 35 ,, „ Chromatophores of Gobies 35 Maximow, Alexander — " Mast" -cells of tlie Blood 35 Hdsen, Ebba von — Pecten of Bird's Eye 35 Tretjakoff. D. — Eye of Toad •• 36 Hulanicka, Pi.— Nerve-endings in Crocodile * 36 Kutchin. H. L. — Nervous System of Amphioxus .. 36 "Weber, A. — Degeneration of Nerve-cells in Embryonic Nerve-cord 36 Schneider, O. — Membranes of Notochord in Cychstomes and Fishes 37 Snessarew, P. — Stroma of Suprarenal Cortex 37 Boeke, J. — Double Innervation of Striped Muscle 37 Sohirokogoroff, J. J. — Mitochondria in Aduli f . Serve-cells 37 Retterer, E., & H. Neuville — Glans-penis of Felidx 37 „ „ „ Glans-penis in Bodents 38 ,, „ „ Penis of Bats 38 Oppel, A. — Active Movements of Epithelial Cells 157 Wichmann, S. E. — Miiller'* Epithelium 157 MacCordick, A. H. — Muscle-bands in Middle Coat of Arteries 157 Aigustin, Willy — Spongiosa of Cetacean Pelvis 158 Gran vik, Hugo — Structure of Preen Gland 158 Paris, P. — Structure of Preen Gland .. .. 158 Leplat, G. — Plastosomes of Visual Cells 159 Peterfi. Tlberius — Minute Structure of Amnion if Chick 159 Ogushi, K. — Histological Peculiarities of Turtle 160 Pusanow, J. — Development of Cartilage of Notochord in Lizards 160 Downey, Hal — Leucocytes of Amblystoma, ■ 160 Holmes, S. J. — Tadpole Epithelium cultivated in Plasma 245 Rehs, Jakob — Elastic Tissue of Hard Palate of Mammals .. 246 Holmes, S. J. — Isolated Living Pigment Cells '-46 Duesberg, J. — Regeneration of Intestinal Epithelium in Insects and Amphibians .. 246 Eguelino, H. v. — Femoral Pores 246 Laguesse, E. — Connective-tissue of Umbilical Con/ of Torpedo 342 Klein, Stanislaus — Primary Marrow-cell 342 Meves. Fr., & R. Tsukaguchi— Plastosomes in Epithelial Cells of Trachea and Lungs :'A'l Pfuller, Albert — Lateral Sense-organs of the Head in Macruridse 341! Liebe, Walther — Penis of Duck 343 Meves, Fr. — What are Plastosomes ? 437 Meek, C. F. U. — Dimensions of Chromosomes 437 X CONTENTS. PAGK Geigel, Richard — Movement of Chromosome* in Nuclear Division 437 Demoll, R. — Transformations and Excitability of Protoplasm 437 Swindle, Gaylord — Nuclear Substance in 11 elation to Fibrous Elements . . . . 438 Holmgren, Emil — Trophospongium and Reticular Apparatus in Spinal Ganglion Cells .. .. .. .. 438 Svent-Gyorgyi — Vitreous Humour in Amphibians ami Reptiles .. . . 438 Martynoff, W. — Nerve-endings in Pericardium of Man and other Mammals .. 439 Fritsch, C. — Structure and Innervation of Dentin 439 Bonnefon & Lacoste — Grafting Pieces of Cornea .. 439 Hofkr, Hermann — Hair of the Cat , .. .. 440 Botezat, E. — Phytogeny of Mammalian Hairs 440 Swindle, Gaylor — Nuclear Substance and the Origin of Fibres 524 Muhlmann, M. — Nissl's Granules 524 Axon, S. Walter — Structure of Vagus Nerve in Man 524 Stendell, W. — Minute Structure of Nerve-cord of Amphioxus 524 Marinesco, G., & J. Minea — Culture of Spinal Ganglia in vitro 525 Champy, C. — Culture of Tissues 525 Hulanicka, R. — Nerve-endings in Chelonia 526 Lange, W. — Comparative Study of Heart-muscle 526 Favaro, G. — Comparative Embryology, Anatomy, and Histology of the Vertebrate Heart * 526 Further, H. — Lymphatic Nodules of Birds 526 Rauther, M. — Structure of Swim-bladder of Umbra 528 Cole, F. J. — Vascular System of Myxine ' 528 Despax, R. — Vascularization of Shin in Newts 528 Marcus, H. — Structure of Muscle-columns 529 c. G-enerai. Unzeitig, Hans— Effect of Rontgen Rays on Organs of Chicken 38 Mozejko, B. — " Lymphatic System " in Fishes 38 Regan, (. Tate — Remarkable Cyprinodont 38 Bcdderbruck, W. v. — Statoeysts of Marine Invertebrates 39 Lapique, L., & R. Legendre — Relation between Diameter of Nerve-fibres and their Rapidity of Action 161 Toldt, K., Jun. — Pigmentation of Skin in Primates .. 161 Broman, Ivar — Ontogeny and Phytogeny of Pancreas 161 Orton, J. H. — Ciliary Mechanisms in Amphioxus, Ascidians, and Solenomya . . 161 Retteter, Ed., & F. de Fenis — Vro-patagial Stylet or Calcar in Bats 246 Brunner, H. L. — Respiration in Amphibians 247 „ „ Olfactory Sense in Amphibians 247 Fuhrmann, O. — Respiratory System of Thyphlonectes 248 Anthony. R, & I. Bortnowsky — Peculiar Air-sac in a Lemur 248 Phisalix, Marie — Poison-glands of Snakes 248 Magnan, A. — Modifications in Birds due to Changes of Diet 248 Shann, E. W. — Lateral Muscle of Teleostei 343 Petersen, Esben, & others — Relict Fauna 344 Burckhardt, G. — Plankton of Southern Alpine Lakes 344 Adloff, P. — Toothlessness of Myrmecophagidft 344 Orton, J. H. — Ciliary Mechanisms in Various Type* 344 Kafka, Gtjstav — Sense-organs of Invertebrates 441 Hirsch, Erwin — Influence of Salts 441 Johnsen, Sigurd— Lateral Glands of Shrews 441 CONTENTS. XI PAOK Beebe, C. W.— Effect of Postponed Moult 442 Allen, Glover M. — Pattern Development in Birch and Mammals 520 Neumann, Fr. — Study of Hooded Fowls 530 Svartz, Nanna — Nutrition of Striped Muscle 531 Koaf, H. E. — Physiological Theory of Muscle Contraction 531 Sanderson, E. D., & L. M. Pkairs — Temperature and Development 531 Halnan, E. T., & F. H. A. Marshall — Relation between Thymus and Generative Organs 532 Morgera, Arturo — Rectal Gland of Elasmobranchs and Appendix vermiformis in Man 532 Ritchie, James — Fauna of a Coal-pit at Great Depths .. 532 Lantzsoh, Kcrt — Nannoplankton of the Lake of Zug 533 ( olditz, F. V. — Plankton of the Manxfeld Lake 533 Tunicata. Huntsman, A. G. — Protostigmata in Ascidians .. ., 162 Duesberg, J. — Localization of Plastosomes in Ascidian Ovum 162 Huntsman, A. G. — Origin of Ascidian Mouth 163 Oka, A. — New Type of Compound Ascidian 163 Flitton, "W. A.— Central Nervous System of Tunica nigra .. 249 Meves, Fr. — Fertilization in Phallusia ;>33 Caullert, M. — Regeneration and Budding in Diazona 534 INVERTEBRATA. Mollusca. Cuenot, L. — Phagocytic Organs of Molluscs 443 a. Cephalopoda. Garaieff, W. — Minute Structure of Argonaut's Food-canal 39 Tippmar, F. B. — Minute Structure of Cuttlefishes 39 Schkaff; Boris — Nervous System of Myopsidae 444 •y. Gastropoda Meek, C. F. U. — Chromosomes in Snail 250 Shaw, H. O. N. — Structure of Conus 250 Kuhn, W. — Metabolism of Snail 250 Eckardt, Ernst — Structure of Vitrinia 251 Bzymowska, T. — Structure of Helix barbara . . . 345 Cuenot, L. — Alleged Nematocysts of Pleurophyllidias 346 Boszkowski, W. — Abyssal Fre*h-water Snails of the Lake of Geneva 444 Brygider, W. — Salivary Glands <>f Nudibranchs 445 Frank, E. J. — Structure of Trochidie 534 Kimakowicz-Winnicki, M. v. — Study of the Clam ilium 535 S. Lamellibrancliiata- Alverdes, Fr. — Structure of Pearls 40 Siebert, W. — Epithelium of Anodonta cellensis 40 Herbers, Karl — Development of Anodonta cellensis 163 Schwanecke, G. — Vascular System of Anodonta cellensis 164 Xll CONTENTS. PACK Bruck, A.— Insertion of Muscle on Shell -J5 1 Karny, H. — Structure of Bivalve Shell 846 Fernav. Wilhelm — Structure of Kidney of Anodonta 846 Bruck, Artur — Musculature and Muscles of Anodonta cellensis 445 Fernau, Wilhelm — Kidneys of Anodonta 445 Arthropoda. a. Insecta. Hansel, S. — Histogenesis of Wing-musculature in Diptera 40 Mitzmain, M. Bruin — Horse-fly of Philippines 10 Keuchenius, P. E. — Genitalia of Diptera 11 Shiwago. 1'. — Vesicular Secretion of Malpighian Tubes 41 Sorokina-Agafonowa — Changes of Peripheral Nerve* (hiring Metamorphosis .. 41 Krizenecky, Jar. — Embryonic Malformation in Meal-worm 41 Bordas, L. — Excretory System of Gryllidse 41 Cummings, Bruce F. — Crop of Mallophaga 42 Winter. L. de — Oogenesis in Podur ids 42 Govaerts, Paul — Structure of Oviry in Insects ,, 164 Wilson, Edmund B. — Cliromatoid Body in Spermatogenesis of Pentatoma .. .. 164 Kuhnle, K. F. — Comparison of Nervous Systems of Insects 165 Silvestri, F. — New Order of Insects , 165 Athanasiu, J., & J. Dragoiu — Tracheal Capillaries among Fibres of Wing-muscles 165 Casper, Alois — Skin and Glands of Dytiscus marginalis 165 Frbahn, Ernst — Odoriferous Organs of Female Lepidoptera 166 Tragardh, Ivar — Tropin of Leaf-miners 166 „ Larva of Egle spreta 166 Marshall, W. »S. — Development of Wings in a Caddis-fly 167 Rosen, Kurt von — Eyes of Termites 167 G i rhardt, Ulrich— Spermatophores of Gryllidx and Locustidae 167 Jordan, Karl — Study of Lomechusa and Atemeles 168 Bugnion, E.— Eyes of Nocturnal Insects _!.">_! He<;ner, Robert W. — Germ-track Determinants in a Parasitic Hymenopteron . . 252 Grandi, G. — Parthenogenesis in Otiorhynchus 253 Hollande, A. Ch. — Contents of Adipose Cells of Caterpillars 253 Chulodkoysky, X. — Structure of Necrobia ruficollis 251 Evans, W. — Anoplura of Forth Area 251 Kerschner, Th. — Development of Male Copulatory Apparatus in Mealworm .. .. 254 Paine, J. H. — New Genus of Mallophaga 255 Cerf, F. Le— Remarkable Caterpillar , . . . 255 Keilin, D. — Peculiar Psychodid Larva 255 Koch, Albert— Structure of Psychoda albipennis 255 Kellogg, Vernon L. — Ectoparasitic Insects on Mammals 256 Brocher, Frank— Respiratory System in Water-beetles M47 Feuriere, Ch. — Tracheo-parenchymatous Organ of Aquatic Hemiptera :!47 Carpenter, G. H., & Thomas R. Hewitt — Reproductive Organs and Larvae of Warble Fly 348 Veri.aine, L. — Spermatogenesis in Lepidoptera :!4S Malaquin, & A. Moitie — Hymenopterous Parasites of Aphis evony mi 349 Zawarzin, Alexius— Optic Ganglia of Dragon-fly Larvae 44ti Pampel, W. — Female Reproductive Organs in lchneumonidx 447 Gorka, A. von— Malpighian Tubes of Beetles 447 CONTENTS. xiii i L'AGE KlEFFEB, J. J., & others — Gall-wasps and Saw-flies of Central Europe 4-17 Waterhouse, C. O. — Acridiid.se of British India 448 POYAHKOPF, E. — Pupation of Holometabolic Insect* 448 Puschnig, R. — Reduction of Wings in Orthoptera 448 Mar i in, Fhiedrich — Development of Poly embryonal Chalcidians 449 Graham-Smith, G. S. — Flies and Disease .' ;,35 Eltringham, H. — Urticating Properties of Porthesia similis 535- Brass, P. — Tenth Abdominal Segment of Beetle Larvae 536 Hozawa, Sanji — New Termitophilous Beetle from Formosa 53b' Grandi, Gdido — Irregular Cyclical Parthenogenesis in a Weevil 536 Cheavin, H. S.— Structure of Water-beetle .. 530 Grove, A. J., & C. C. Gho.-h — Life-history of Psylla isitis 537 Chapman, T. A. — Egg-laying of Trichipsoma 537 Watlrston, James— Bird-lice of British Auks 538 Crawford, David L. — Monograph of Jumping Plant-lice of the New World .. .. 538 Mobice, F. D. — Saws of Female. Dolerids 538 Zimmeumann, K. — Faceted Eyes of Librlluliils, etc 539 Rimsky-KorsakoW, M.— Spinning Apparatus of Embiidse 539 Geuhakdt, Ulrich — Copulation and Spermatophores of Gryllidn and Locustidse .. 539 3. Myriopoda. Chamberlin, Ralph V. — Genus Walobius 540 Brolemann, H. W. — New Caveruicolous Myriopod. 540 7- Pi-ototracheata. Bries, C. T. — New Form of Peripatus 42 Webster, D. H. — Integument of Peri patu* 168 Kemp, Stanley — New Peripatus from India .. .. ' 168 Brdes, Charles T. — New Peripatus from Colombia 540 3. Arachnida. Pop>>vici-Baznosanu, A. — Study of Triohotarsus osmise 42 Painter, Theophilus S. — Dimorphic Males 168 Webster, D. H. — Food-canal of Li mulus 169 Schimkewitsch, W., & V. Dogiel — Regeneration in I 'antopoda 169 Dogiel, V. — Development of P antopoda .. 169 Soar. C D. — Two New British Water-Mites 256 Scheuring, Ludwig — Eyes of Arachnoids 349 Viets. Karl — Reproduction in Acercus 349 Haller, B. — Second Pair of Lung-boohs in Mygalomorph Spiders 449 Berland, Lvcien- Muting of Spiders . . 450 King, L. A. L.— Littoral Mites 540 c. Crustacea. De.mbowski, J. — Eye of Ocypoda Ceratopldhidmu 43 Woodland, W. F. N.— Maxillary Glands of Squilla 43 Marsh, C. DwiGHT — Abnormalities in Copepods 43 Muli.er-C ale, Kurt — Development of Cypris incongruens 13 Gi R.N ey, Robert — Thersitina gasteromda ulvx 545 Wharton, L. D. — Thalassema and a New Related Genus 545 Incertse Sedis. Gerwertzhagen, A.— Nervous System of Cristatella mucedo 175 Stiasny, Gustav — Development of Balanoglossus clavigerus _'<;_' Murray, James— Gastrotricha 262 Caullery, M. — New Variety of Rhopalura pelseneeri 356 yon Wenck, Wanda— Development of Tard/grada 357 Caullery, Maurice— New Invertebrate Type 454 XVI CONTENTS. Echinoderma. FAGJ. Mortensen, Th. — Development of some Echinoderms 47 Rosen, F. — Ova of Echinaster sepositus 47 Ublsch, L. v. — Development of Sea-urchins 47 Tenn ant, David H. — Echinoderm Hybridization 175 Dj aronov, A.— Viviparity and Growth in Amphiura squarnata 262 Scott, John W. — Evisceration and Regeneration in Thy one briareus 263 Herlant, M. — Artificial Parthenogenesis in Sea-urchin Ova 357 Haanen, W. — Minute Structure of Mesothuria intestimdis 546 Jordan, H. — Musculature and Skin of Holothurian* 546 Meves, Fr. — Fate of Middle Piece of Echinoid Spermatozoon 547 Ritchie, Jamis, & J. A. Todd — Abnormal Sea-urchins 547 Wood, Elvira — Crinoid Arms in Phytogeny 547 Ccslentera. Drzewina, Anna, & G. Bohn— Study of Eleutheria 47 Apstein, J. — Germ -cells of Leptomedusse 48 Faure-Fremiet, E. — Nematocysts of Polykrikos and Campanella 48 Arndt, W. — Fat in Sea-anemones 176 Walton, Ch as. L, & Olwen M. Rees— Structure of Sea-anemones 176 Kinoshita, K. — Axis of Alcyonarians 176 Gravier, Cm..— Incubation in Antarctic Alcyonarians 176 Schvlze, P. — Hypertrophy of Tentacles in Hydra 264 Billard, A. — Siboga Plumularids ., .. 264 Bale, W. M.- Australian Hydioids 264 Benoit, P. — Formation of Gonophore in Tubuluria and Myriothela 261 Light, S. F. — Structure of Eudendrium grifjini 264 Robson, Joyce H. — Abnormal Ephyra of Cyanea capillata 265 Krasinska, Sophie — Histology of the Medusas 265 Cale, K. M€ller — Development of Thccaphore Hydroids 266 McMurrich, J. Playfair -New Aciimians from British Columbia 266 Broch, Hjalmar— H ydrozoa henthonica 357 Muller, H. C. — Symbiosis in Hydroids 358 Bourne, Gilbert — Alcyonarian with Simple Tentacles 358 Niedeismayer, Albert — Minute Structure of Veret ilium 454 Tsdkaguchi, R. — Minute Structure of Ovarian Ovum of Aurelia aurita 455 Lochmann, L. — Development of Siphonophora 456 Robson, J. H. — New British Gymnoblastic Hydroid 548 Light, S. F. — Philippine Alcyonarians 548 Poriiera. Suhwan, A. — Hexactinellid and lladiolarian Spicules .. .. 48 Lebwohl, Fr. — Japanese Tetraxonid Sponges 456 Penaro, E. — Remarkable In fusorian 45y Sharp, R. G. — Diplodinium ecaudatum 457 Alexeieff, A. — Life-history of lchthyosporidium gasterophilum 458 Tregodboff, G. — Life-history and Relationships of Stenophora 45,s Crawley, Howard — Sew Sarcosporidia 459 „ „ Development of Sarcocystis muris 459 CONTENTS. XV11 Protozoa. Jennings, H. S., & K. S. Lashley — Inheritance of Size in Paramecium .. .. 48 Woodcock, H. M., & G. Lap age — Remarkable Protistan Parasite . 49 Cosmovioi, N. L. — Ureolaria synaptas 4!) Tregouroff, G. — New Chytridiopsid 49 Lebailly, C. — Spirochasts of the Intestine in Birds 50 Nagler, Kurt — Schizotrypanum cruzi f>0 Sweli.exgrebel, N. H. — Schizogony of Female Gametocytes of Lavernia malarise.. 50 MacKinnon, Doris L. — Flajellates of Larval Tipula '. .. 50 Faure-Fremiet, E. — Antarctic Foraminifera 177 Thomson, J. G., & D. Thomson — Tertian Malarial Parasites 177 Blacklock, R.. & Warrington '/orke — Trypanosome of Dourine 177 Reichenow, E. — Life-history of Karyolysus lacertx .... 177 Faure-Fremiet, E. — Nematocysts and Trichocysts of Pohjhrikos auricularia . . .. 177 Lucet, Adrien — Coccidia of the Rabbit ' 178 Schellack, C. — Development of Adelina dhnidiata 178 Noc, F. — Latent Life in Protozoa 267 Heron-Allen, Edward & Arthur Earland — North Sea Foraminifera . . . . 267 „ „ „ Clare Island Foraminifera .. .. 267 Sidebottom, Henry — Pacific Ocean Species of Lagena 267 Collin, Bernard — Degeneration in a Parasitic Infuscrian 267 Fermor, X. — Encystation in Stylonichia pustulata 268 Walkek, E. L. — Balantidium colt 268 Sant'And, J. Firmino — Studies of Trypanosomes 268 Mermod, G. — Infusorians of Peat-bogs 268 Andre, E. — New Infusorians from the Lake of Geneva 268 Baitsell, G. A. — Reproduction of Hypotrichous In fworians .. 268 Pixell-Goodrich, Helen L. M. — Sporogony and Systematic Position of Aggregata 269 Galli-Valerio, B. — New Pyroplasmid in Mole . . 269 Awerinzew, S. — New Myxobolus 269 WasiiiLEWSKI, Th. v., & Alfred Kuhn — Structure and Division oj the Amozba Nucleus 358 Chation, E. — Cnidofysts of Peridinids 359 Keilin, D. — New Schizogregarine 359 Regnard, Emile— Peculiarities of Metamera schubergi 36(1 Stempell, W. — Function of Contractile Vacuoles 548 Collin, Bernard — Studies on Protozoa 549 Thornton, H. G., & Geoffrey Smith — Nutritive Conditions Determining Growth of Protista 549 Edmondson, C. H., & R. H. Kingman— Japanese Fre*h-water Protozoa 550 Ishii, S. — Four Species of Gregarine from one Species oj Beetle 550 Dec. 16th, 1914. XVlii CONTENTS. BOTANY. GENERAL, Including- the Anatomy and Physiology of Seed Plants. I'AGE Mottier, D. M., & M. Nothnagel — Chromosomes of Allium 51 Samuels, J. A. — Relation between the Nucleus and Crystal-formation 51 Iwanowski, D. — Function of Yellow Pigment in Chlorophyll 179 Gates, R. R., & N. Thomas— Cytology of Oenothera in Relation to Mutation .. 3f>l Lewitsky, G. — Chondriosomes in Fungi '51 Scherrer, A. — Chroma tophores and Chondriosomes of Anthoceros 551 Guilliermond, A. — Mitochondrias and their Transformation into Plastids .. .. 552 Lowsohin, A. M. — Mitochondrias of Higher Plants 552 Richter, E. — Statolith-theory 553 Obekstein, O. — Tannin-idioblasts in Mese-mbrianthemum 553 Structure and Development. Veg-etative and Reproductive. Vouk, V. — Movements of Plasmodia 52 Mager, H. — Cutinization of Roots 52 Tiegs, E. — Root-cap of the Leguminosse 52 Schoute, J. C. — Secondary Growth in Palms 53 Pickett, F. L. — Embryology of Arissema -. •• 54 Donati, G. — Embryology of the Euphorbiacese 54 Perotti, R.— Embi yology of the Dianthacess 54 Baar, H . — Anatomy and Germination of Heteromorphou* Seeds 54 Moreau, L. — Anatomy of Tubers of Tropical Orchids and other Plants 179 Brockmann-Jerosch, H. — Structure of Leaf-sheaths of Grasses 179 Fccsko, M. — Fruit-wall of the Papilionarese 180 Ernst, A. — Embryo-formation in Balanophora J 80 Brick, E. — Anatomy of Bud-xcale* 270 Schips, M. — Dehiscence of Anthers 270 Lkbard, P. — Opening of Achenes in the Liguliflorse 271 ^'ienzieheu, S. — Development of Xyr is 271 Schlosb, H. — Morphology and Anatomy of Hyilrostachys 272 Soueges. R. — Embryogeny of the Cruciferse . . 460 Renner, O. — Fertilization and Embryology in Oenothera 460 Zaepfel, 10. — Distribution of Stomata in Graminese .. .. 461 Arber, A. — Amilosis in Root- development of Stratiotes 461 ^IcLean, 11. C. — Amitosis in Parenchyma of Water-plant* 46'^ Guilliermond, A. — Evolution and Physiology of Mitochondria 462 Neeff, F. — Cell-arrangement 554 Li ndegardh, H. — Growth of Root-tip 555 Koketsu, K. — Lactiferous Vessels and Cells ">55 Holden, R. — Anatomy of Mesozoic Conifers 556 Martin, J. X. — Morphology of the Leguminosse 556 McAiiisTiat, F. — Embryo-sac of the Convallariacese 557 Tournois, J. — Sexuality of Humulus 557 Roy ale, V. — Projection of Seeds of Oxalis ">58 CONTENTS. XIX Physiology. Nutrition and Growth. pagr Koressi, F. — Nitrogen-assimilation by Plant-hairs 361 Boudois, G.— Influence of Water on Roots of Trees 558 General . Schcbteb, I. V., & V. Ulehla — Organisms in Nectaries 55 CRYPTOGAMS. Pteridophyta. Bower, F. O. — Phylogenetic Studies of Ferns 55 Schoute, J.O. — Dichotomy and Lateral Branching in Pteropsidx 181 Wilson, W. J. — Lepidostrobus mintoensis 181 Beer. R. — Spore-development in Equisetum 1S2 Bosch, R. B. Van den — Synopsis Hemenophyllacearum 182 Frye, T. C..& others — North American Ferns 182 Lang, W. H. — Embryo of Helminthostach'ys 273 Wand, A. — Apical Growth and Branching in Selaginella 273 Kashyap, S. R. — Prothallus of Equisetum debile .. 274 Gwynne-Vaughan, D. T. — Mixed Pith in Osmunda regalis 274 Tidestrom, I. — Botrychium 274 Bertkand, P. — Corynepteris and Zygopteris 274 Maxon, W. R. — Tree-ferns of North America 275 Maxon, W. R. & Slosson, M. — Tropical American Ferns 275 Johnson, T. — Bothrodendron kiltorhense 362 Morton, F.—Phyllitis 362 Marsh. A. S. — Azolla in British Isles 363 Copeland, E. B. — New Papuan Ferns .. 363 Bower, F. O. — Phytogeny of the Filicales 463 Sinnott, E. W. — Jurassic Osmundacese from New Zealand 463 Watson, D. M. S.—Ulode?idroid Scar 464 Hill, J. Ben — Anatomy of Epiphytic Lycopodiums 465 Lignier, 0. — Stigmaria 465 Zeiller, R. — Lepidostrobus 466 „ „ Weald.ian Plants from Peru 466 Campbell, D. H. — Macraglossum 559 Benedict, R. C. — Vittaria 559 Copeland, E. B. — Sumatra Ferns 560 Bryophyta. Black, C. A. — Riccia Frostii 56 Dixon, H. N. — Tetraphidopsis 56 „ Ditrichum and Thuidium 56 „ Dicranoloma 56 Andrews, A. Le R. — North American Sphagnum 67 Boresch, K. — Filamentous Formations in Moss-cells 1S2 Ubisch, G. v. — Sterile Moss-cultures 183 Warnstokf, C.,& others — Fresh-water Mosses 183 Graham, M. — Nuclear Division in Preissia 183 Zodda, G. — New Hyophila from Tripoli 183 62 xx CONTKNTS. l'A'.E Ltjibikb,.A. — Triquetrella in Europe 183 Jennings, O. E. — New Brachylhecium Schiffner, V.— Bryological Notes Arnell, H. W.— Siberian Bryophyta 18i Brotheru*. V. F.— Mosses of East and South Africa 181 Bovrs, Cn.— Inflorescence of Cephaloziellacese 276 Schiffner, V. — Cephalozia -'° Grun, C. — Treubia insignia ^ ID Loeske, L. — Grimmiacese " u Familler, I. — Moss-galls *•"' Garjeanne, A. J. M.— Influence of Water on Alicularia 277 Roth, G. — Exotic Mosses • •• 2 ' 7 Britton, E. G. — West Indian Mosses 277 Brixton, E. G. & Williams, K. S. — Central American Mosses •• 277 Cardot, J. — Mosses of Japan and Corea 278 Muller, K. — European Hepatics 278 Rhthert, W. — Eyespot of Algse and Flagellates 278 Faure-Fremiet — Erythropsis agilis 278 Pavillard. J. — Diplosalis and the Neighbouring Genera .. 278 „ Three Diatoms 279 Virieux, J. — Plankton of the Victoria \yanza.. 279 „ Plankton of the Lac des Settons 279 Mangin, L— Phytoplanklon of St. Vaast-la- Hougue '-80 Guyer, O. — Plankton of Grief ensee 280 Carlson, G. W. F. — Antarctic Fresh-water Algse 280 Borge, O. — Swedish Fre*h-water Algie 280 Treboux, O. — Fresh water Algae from Riga .. .. 281 Printz, H. — The Genus Oocystis 281 Thomas, N. — Epiphyllous Algse 281 Blanchard, F. N. — Stigonema •• •• 281 Schmidt, E. W. — Spirogyra 281 Bkand, F. — Prasiola crispa 281 Kvfferath, H. — Porphyridium cruentum 282 Svedelius, N. — Nitophyllum punctatum 282 Killian, K. — Development of the Florid ese 282 Bonnet, J. — Alternation of Generations in Algse 283 TDovix, 11.— Fruit-braring Receptacle of Marchantiese 363 Meyer, K. — Corsinia marchantioides 361 Manning, F. L.— Life-history of Porella 361 Muller, K. — European Hepaticse •• • 364 Evans, A. W. — Peruvian Hepaticse 364 Wager, H. A. — South African Mosses 365 Duuin, R. — Ephemerum intermedium 365 Dismier, G. — Philonotis seriata ; '65 „ Phitonotis falcata and P.turneriana 365 Douin. C. — Sporoyonium of Cephaloziell'icese 466 Atw ell, Ruth S. — Polar Bodies in Autheridia of Ricciocarpus 466 Duuin, C. — Propagules of Hepatics 467 Douin, R.—Riella 467 Dismier, G. — Lophozia Hatcher i 467 Holzinger, J. M. — Hypopteryium 467 Dixon, H. N. — Sematophyllum acutirameum 468 Jewett, H. S. — Amblystegium 468 CONTENTS. XXI PAGE Nicholson, W. E. — New British Hepatic* .. .. 468 Campbell, D. H., & F. Williams — Morphology of Pallavieinia 560 Maybrook, Annie C. — Fegatelln without Air-cham'jers 561 Watson, W. — Xerophytic Adaptations of Bryophytes 561 Kashyap, S. R. — Aitchisoniella, a- New Himalayan Hepatic 562 Dixon, H. N., & others — Neva Indian Mosses 562 Thallopliyta. Algae. Gran, H. H. — Oceanic Plankton 57 Antonelli, G. — Diatom* in Sea-urchins 57 Merriman, M. L. — Nuclear Division in Spirogyra 57 Yexdo, K. — Haplosiphon filiformis 58 Hardy, A. D. — Melbourne Fresh-water Algae 58 Williams, J. Lloyd — Laminaria Zoospores 59 Yamaxouchi, S. — Life-history of Zanardinia 59 Faber, F. C. von — Iridescent Ftoridea; 60 Cotton, A. D. — Irish Marine Alga; 60 Tom, G. B. de— Marine Algae 60 Davis, B. M. — North American Marine Algae .. 61 Lucas, A. H. S. — Australian Marine Algae 61 YtNDO, K. — Neiv Japanese Algae 61 Schiller, J.— Plankton of the Adriatic 184 Moreau. Madame — Metachromatic Bodies in Algae 185 O'Donohoe, T. A. — Diatom Structure 185 Rocppert, K. — Two Plankton-diatoms 185 Hoffmann, K. — Bohemian Diatoms 1 85 Lacsny, J. L. — Algae of Thermal Waters 186 Pantocsek, J. — Bacillarieae from Hungarian Strata .. 186 ., „ Fossil Diatoms 186 Forti, A. — Italian Fossil Diatoms .. 186 McAllister, F. — Nuclear Division in Tetraspora lubrica . . '. 186 Printz, H. — Oocytis 187 Wille, N. — Notes on Microscopic Algae 187 Cedergren, G. R. — Swedish Fresh-water Algae 187 Brinnthaler, J. — Egyptian Fresh-water Algae 188 Langer, S. — New Spirogyra 188 Faber, F. C. von — Spirogyra tjibodensis 188 Mirande, R. — Siphonales 189 Petkoff, S. — Characeae of Bulgaria 189 Lemoine, Madame — Growth of Cmstuceous Algae 190 „ „ Melobesieae of Ireland • • 1 90 Bosse, A. Weber van — Rhodophyceae of the ' SeaktrJc ' 190 Borgesen, F. — Sargassum 190 Mazza, A. — Marine Algae . . .. ■■ .. 191 Collins, F. S. — Marine Algae of Vancouver Island 191 Okamura, K. — Japanese Marine Algae .. .. 191 Pascher, A. — Flagellates a ud Algae • 366 Schiller, J. — Vegetation of the Adriatic 366 Mangin, L. — Plankton of St. Vaast-la-HogtK 361 Krmpotio, I. — Microfauna of the Plitvic Lakes • • 367 XX11 CONTENTS. PAGE Naumann, E. — Colouring of Fresh-water by Algie 367 Kaiser, P. E. — Algal Flora of Traunstein and the Chiemgau 368 Gbeguss, P. — Diatoms of Surian :;,; 8 Hustedt, F. — Tetracyclus 368 Lobik, A. J. — Russian Desmids 368 Schmid, G. — New Oscillariacem 368 Chodat, R. — Fresh-water Algie in Culture 369 Hoffmaxn-Grobety, Amelie — Unicellular Algae .. .. 369 Wittmack, L. — Bed Snow 369 Kobniloff, M. — Gonidia of Cladonia 369 Buder, J. — Cldoronium mirabile 369 Lutkemuller, J. — The Genus Cylindrocystis 370 Blanchard, F. N. — Stigonema 370 Plimecke, 0. — Gonium pectorale 371 Conrad, W. — Eudorina elegans :; 71 Sauvageau, C. — Cladostephus 371 Svedelics, N. — Spores on Sexual Plants of Nitophyllum punrtatum 372 „ Delesseria sanguinea 372 Mazza, A. — Marine Alga? . 373 Kofoid, C. A.— Symmetrical Prvtophyte 468 (Jhatton, E. — Autogenesis of Nematocysts 468 „ Structure of certain Parasitic IHnoflagellates .. 469 Pascheu, A.— Fresh-water Algse (Flagellatm) .. 469 Naumann, E. — Notes on Fresh-water Algae 469 Woloszy^ska, J. — Fresh-water Species of Ceratium .. 470 Paschkb, A. — Flagellata) and Cyanophycem 470 Burton, J.— Flagellum of Euglena 470 Conrad, W. — Eudorina elegans 470 Acton, Elizabeth — Cytology of the Chroococcarese 471 Conrad, W., & H. Kufferath — New Protococcacem 472 Brown, N. 'E,.— Structure of Diatoms 472 Pavillard, J — Coscinodiscus oculus-Iridis 472 Laubt, A.— Fossil Diatoms 473 Handmann, R., & F. Y. Schiedler — Austrian Diatoms 473 Com ere, J. — Fresh-water Algx in relation to Medium 473 Kasanowsky, U., & S. Smirnoff— Spirogyra 474 Moheau, F. — Division of Mitochondria in Vaucheria 474 Virieux, J. — Dichotomosipliou and Mischococcus 474 Kufferath, H. — Porphyridium cruentum .. 474 Iltis, H. — Symbiosis between Planorbis and Batrachospemum 475 Setchell, \V. A.— Parasitic Floridex 475 Yendo, K. — New Japanese Algae 475 Gain,!,. — Algae of Atlantic Islands 475 Hy, F.— Characex of France 476 Playfaib, G. I.— Planlcton of Bichmond Biver, N.S. W 562 Spargo, M. W— Chlamydomonas 563 Brown, N. E.— British Diatoms 563 Mangin, L. — Polymorphism of certain Antarctic Diatoms 563 Meyer, K. — Microspora amcena 564 Getman, M. R. — Oogenesis in Hormosira 564 Borgesen, F. — Marine Algae of the Danish West Indies 564 Segers-Laureys, A. — Officinal Algae 565 Howe, M. A.— Marine Algae of Peru 565 CONTENTS. XXlli Fungi. PAO B Sartobt, A., & H. Sydow — Morphological and Biological Study of Uhizopus Artocarpi 61 Matheny, W. A. — Study of Sclerotinia 62 Theiszen, T. — Study of Lembosia 62 Kunkel, Otto — Germination of JEcidiospores 62 Olive, E. W. — Study of Perennial Rusts 62 Fbaser, \V. P. — Busts of Nova Scotia 63 Will, W. — Contribution to a Knowledge of Black Yeasts 63 Price, S. R. — Culture of Polyporus squamosus 63 Hohnel, F. von — Mycological Notes •.. .. 64 Kunkel, Otto — Toxicity of Nitrates to Monilia sitophila 64 Goddard, H. N. — Fixation of Nitrogen by Soil Fungi .. .. , 64 Beau, I'. — Tuberization in Spiranthes autumnalis 65 Farquharson, (. 0., & others — Plant Diseases 65 Nemec, R. — New Genus of Ch ytridiacese 191 Nemec, B. — New Genus of Saprolegniacex 191 Melhus, I. E.— Perennial Mycelium of Fhytophthora infestans 192 Diedicke. H. — Leptostromacese 192 Theiszen, F. — Microtltyriacew , .. 192 Schilbersky, K. — Morphology ami Physiology of Penicillium 192 Robinson, W. — Notes on Puccinia malvacearum .. .. 193 Gdinier — Busts on Hybrid Plants 193 Hils, E. — Mycelial Formation in Ustilago Jensenii 193 Lloyd, C. G. — Synopsis of the Genera Cladoderris and Stereum 193 Petch, T. — White Ants and Fungi 194 Moesz, G.— Fungus Teratology 194 Bornand, M. — Influence of Metals on the Development of Aspergillushiiger . . . 194 Blakeslee, A. F., & Rose Aiken — Toxin of Bhizopus' nigricans 194 Winge, O. — Cytology of the Plasmodiophoraceas 194 Boyd, D. A. — Buteshire Micr of ungi 195 Stevens, F. L. — Fungi which cause Plant Disease 195 Cook, M. T. — Diseases of Tropical Plants 195 Krause, F — Fungi occurring in Potato Plants 196 Prior, E. M. — Snap-beech Disease 196 Shear, C. L., & others — Diseases of Plants 197 Maire, Rene — North African Laboulbeuiacese 284 „ Systematic Position of Microstroma and Helostroma 284 Pethybridge, G. H. — Observations of Phytophthora erythroseptica 284 Faes, H; & A. Istvanffi — Development and Treatment of Mildew 285 Klebahn — Germination of Teleutospores 285 Eriksson, J. & Hammerland, 0. — Experiments with Puccinia malvacearum . . .. 286 Butler, E. J. & Dietel, P. — Uredinese 286 Matruchot, Louis — Culture of Tricholoma nudum 286 Kirchmayr, H. — Parasitism of Polyporus frondosus and Sparassis ramosa .. .. 286 Bambeke, C. van — Polymorphism of Ganoilerma lucidum 287 Dittrich, G. — Poisonous Properties of Agarics 287 Sydow, H. & P. — Philippine Fungi .. 287 Beauverie, J. — Culture of Entomophytic Fungi 287 Dale, E.— Soil Fuugi 288 Salmon, E. S. — American Gooseberry Mildew .. 288 Massee, G. — Plart Diseases 289 XXIV CONTENTS. i-AGB Weese, Joseph — Study of Nectriella 373 van der Wolk, P. C. — New Endomycete 37,3 Theisskn, F., & H. Sydow — Studies of Dothideacex :;74 Dodge, B. O. — Relationships of Florideie and Ascomycetes 374 Ramsbottom, J. — British Discomycetes 375 Poeteren, N. Van — Wintering of Mildews 375 Tonghini, C. C. — Recent Itesearhes in Jjaboulbeniacem 375 Tkaverso, G. B.— Oidium of Huta graveolens H75 Njenburg, Wilhelm — Development of Poly stigma rut tram 376 Brown, Horace T. — Studies on Yeast . . 377 Thaxter, Roland — Asoosporic Condition of Aschersonia 377 Beauverie, J. — Studies of Microscopic Fungi 378 Bubak — New Bhizosplnv ra 378 Robinson, W. — Effect of External Stimuli on Sporidia .. 378 Grebelsky, F. — Position of Sorus of Uredinese on tin' I. i-tif 378 Ramsbottom, <1. — Uredinem 379 Wehmer, C. — Culture Experiments with Merulius Spores 379 Cotton, A. D. — Imperfectly-developed Spores in the Agarieaceas 379 Buller, A. H. R. — Fruit-body Mechanism of Botbitius , .. 380 Overholts, L. O. — Poly poracem of Ohio 380 Baccarini, P. — New Podoxon* 380 Wakefield, E. M. — Corticium porosum Berk, and Curt 380 Brooks, F. T. — Observations on Pure Cultures ofsone Ascomycetes and Basidiomycetes 381 Brenner, Widar — Nitrogenous Food of Filamentous Fungi 381 Cotton, A. D., & others — British Mycology 381 Ramsbottom, J. — Record of Cytological Work 383 "Wehmer, C. — Resistance of Oak-wood to the Attack of Dry-rot 383 Bloohwitz, Adalbert — 'Influence of Light on ! ungus- development 383 Sydow, H. & P. — Fungi from Formosa and Japan 384 „ „ New Microscopic Fungi 384 Prinet, A., & others — Plant Diseases , 384 Fischer, A. — New Chytridiacese 476 Seaver, F. J. — Observations on American Discomycetes 476 Arthur, J. A., & F. D. Kean — Species of Per idermium .. 476 Coupin, Henri- New Eyphomycete 477 Zeller, S. M. — Development of Stropliaria ambigua 477 Bhisch, E. — Mycorhiza of Asclepiadacese .. .. 477 Lindner, Paul — Atmospheric Fungus Spores 477 AYilson, <;. W. — North American Peronosporales 478 Keene, M. L. — Cytology of Sporodinia 478 Boddier, E. — Oil Drops in Discomycete Spores 478 Guilliermond, A. — West African Yeasts 479 Fromme, F. D. — Morphology and Cytology of the jEcidium Cup 479 Fischer, E. — Biology of Uredinese 480 Montemartini, L. — Wintering of Uredospor es 480 Beauverie, J. — Internal Spores of Rusts 480 Eriksson, J. — Mycoplasm 481 Young, V. H. — Artificial Cultures of Basidiomycetes 481 Matrvciiot, L. — Variations in Tricholoma nudum 482 Thom, C — Conidium Production in Peuicillium 482 Sydow, H. & P. — Fungi from Northern Palawan 482 Grove, W. B. — Fungi from West Australia 483 Ramsbottom, J. — New Discinella 483 CONTKNTS. xxv I'AOl Cotton, A. D.—Atichia 483 Thaxter, R. — Fungus Parasites of Living Insects . 565 Rawitscher, F. — Sexuality of Tilletia Tritici 566 Eriksson, J. — Sort and Mycelium of Rusts in the Caryopses of Cereal* 566 Lange, J. E.— Mycena 566 Wheldon, H. J. — Fungi of Sand-dunes 567 Wakefield, E. M. & G. Massee — New Species of Fungi 567 Wakefield, E. M. — Nigerian Fungi 567 Graff, P. W. — Philippine Basidiomycetes 567 Massee, I. — Hibernating Mycelium in Tomato Seed 568 Massee, G. — Saprophytic Fungus becoming Parasitic 568 Pethybkidge, G. H., & H. A. Allard— Plant Diseases 568 Lichees. Howe, H. Hebeu — Study of Usneacese S6 Erichsen, F. — Swedish Lichens 386 L yxge, Bebst— Lichens from Brazil 387 Poulton, Ethel M. — Verrucaria maryacea 388 Lettau. G. — Lichen Acids 483 Bioret. G. — Contribution on the Study of the Apothecium of the Graphidese .. . . 484 Lesdain, Bouly de— Lichens on Flint 484 Mycetozoa. Meylan, Ch. — Myxomycetes from the Jura Mountains . . .. ... 198 N hinz, Hans — Myxogastres 292 Meylan, Ch. — Snovi Species oj Mycetozoa 388 Harper, R. A., & B. O. Dodge — Formation of the Capillitium in certn in Myxomycetes 388 Schwartz, E. J. — Plusmodiuphoraceee and their Relationship to the Mycetozoa and Cliytridete 389 Schizophyta. Schizomycetes. Rappin — Bacillus hypertoxicus ., 67 Schiller, J. — Amylolytic Microbe.-: of the Intestinal Flora of the Elephant .. .. 67 Lixde, P. — Cladothrix dichotoma 07 Venulet, F., & L. Padlewski— Bacillus septicaemias ranaruni 68 Shimidsa, K.— Morphology of Gram-negalive Bacilli '. 68 Lautenbach, B. B. — Contagious Abortion in JI ares 68 Revis, C. — Physiological Properties of Bacillus coli l!8 Viehoever, A. — Bacillus Urese 69 Wulff, A. — Flora of Pasture and Mill: 69 Cavara, V. — Kei atomy cosis Mucorina 69 Rosenow, E. C — Streptococcus-pueumococcus Transmutations 198 ., „ Etiology of Acute Rheumatism 1!W Kligler, I. J. — Indol Production of the Colon-typhoid Group 199 XXVI CONTENTS. PAGE Kennedy, J. C. — Agglutinins for Micrococcus melitensis in London Milk .. .. 199 McIntosh, J., & J. McQueen — Inagglutinable Typhoid Bacilli 199 Knowles, R., & H.W.Acton — Kurloff Bodies 200 Shaxby, J. H., & E. Emrys-Roberts — Brownian Movement of Bacterial Spores .. 200 Kellebmann, K. F., & others -Identification and Classification of Cellulose- dissolving Bacteria -01 Patrick, A. — Bacilluria in Typhoid Fever 201 Williams. R. S., & W. R. Wade— New Foetid Coccobacillus 202 Hottomley, W. B. — Bacterial Treatment of Peat 202 Dumas, M. T., & others— Staphylococcus aureus 292 Henri, Mdme. Victor — Action of Ultra-violet Light upon Anthrax Bacilli .. .. 292 Foktineau, L. & C. — Treatment of Anthrax with Pyocyaneus Cultures 293 Twort, F. W. & G. L. Y. Ingram — Cultivation of Johne's Bacillus 293 Brooks, R. St. J. — Phagocytosis of Plague Bacilli 293 Rowland, S. — Morphology of the Plague Bacillus 294 Metchnikoff, E. — Intestinal Flora of Infants 294 Martin, C. J., & A. W. Bacot — Mechanism of the Transmission of Plague by Fleas 295 Aragao, H. De B., &G. Vianna — Calymmato-hacterium granulomatis 295 d'Herelle, F. — Coccobacillus of Locusts 390 Tsiklinsky, Mdlle. — Intestinal Flora of Bats 390 Eisenberg, P. — Studies in Bacterial Variation 391 Bornand, M. — Contribution to the Study of Bacillus salmonicida 391 Haphael, Mdlle. A.— Note on Bacillus perfringens Veillon 391 Danielopolu, D. — Researches on the Etiology of Acute, Polyarticular Rheumatism . . 392 Roussel — Atypical Paratyphoid Bacilli '. isolated by Blood-culture 392 Lumiere, A., & J. Chevrotier — Vitality of Gonococcus Cultures .. .. -. •• 392 Grey, E. C. — Decomposition of Formates by Bacillus coli communis 392 Lockett, W. T. — Oxidation of Thiosulphate by certain Bacteria in Pure Culture.. 393 Barber, M. A. — Cockroaches and Ants as Carriers of the Vibrios of Asiatic Cholera 481 Northrup, Z. — Bacterial Disease of the Larva of the June Beetle, Lachnosterna . . 485 Schroeder, H. — Bacterial Content of Coal •• 485 Mautner, H. — Parendomyces Pulmonalis (Flaut) 185 (Jantacczene, M. J. — Micro-organism isolated in Scarlatina 486 ('astellani. A. — Bacterium col umbense 486 Markl, J. G. — Mutations of Plague Bacilli 487 HuNEiJ, J. A. — Flies in Relation to the Transmission of Leprosy .. .. .. .. 487 Drennan, Jennie G. — Pigment-forming Vibrio 187 Duval, C. W. — Behaviour of the Hansen Bacillus in vitro 569 Ualt, H. M.. & C. C. Isles— Boas-Oppler Bacillus 569 Good. E. S., & W V. Smith — Bacillus abortivus equinus in Infectious Arthritis of Colts 569 Landford, J. A. — Diphtheroid Organisms isolated from Lymphadenomatous Struc- tures 570 Wherry, W. B., & B. H. Lamb — Infection of Man with Bacterium tularense .. 570 Fimuin, Albert, & D. Roudsky — Bactericidal and Antitoxic Action of Lonthanum and Thorium Salts on the Cholera Vibrio 570 Hanjawa, J. — Nitrogen Fixation ly Azotobacter in Substrata Poor and Rich in Nitrogen 571 Henri, Victor, & Mme. Victor Henri — Metabiotic Action of Ultra-violet Rays. Theory of the Production of New Microbic Forma by the Action 0)i the Different Nutritive Functions 571 Holmes, J. D. E. — Bursati 572 Young, M. C. W. — Variability among Bacteria 572 CONTENTS. XXV11 MICROSCOPY. A. Instruments, Accessories, etc. Cl? Stands. i"age Watson's Vulcan Metallurgical Microscope (Fig. 5) 70 Winder's Special Metallurgical Microscope for Observing Structure of Metals under Strain (Fig. 6) 71 Watson and Sons' Micrometer Microscope (Fig. 7) 72 Leitz' Double Microscope (Fig. 8) 74 Leitz' Stereoscopic Binocular Microscope for Metallurgical Purposes (Figs. 20, 21) 208 Beck's (R. & J.) New Binocular Microscope (Figs. 22-26) 205 Watson & Sons' No. 2 Metallurgical Microscope (Fig. 27) 210 Old French Microscope by Joblot (Fig. 29) 297 Emich, F. — Greenough Binocular Microscope 300 I .ehmaNN, H. — Luminescence Microscope : its Construction and its Applications 300 Ives, F. E. — Binocular Microscopes 488 Watson & Sons— Watson-Conrady " Bicor " Binocular Attachment (Figs. 56. 57) . . 576 ,, Agricultural Microscope (Fig. 58) 579 „ Grand Model Van Heurck Microscope (1914 Model) (Fig. 59) .. 579 (2) Eye-pieces and Objectives. Zeiss' New Homogeneous Immersion 1/7 301 Healy's Comparison Ocular 301 Nelson, E. M. — Measurement of the Initial Magnifying Powers of Objectives (Fig. 34) " 394 (3) Illuminating 1 and other Apparatus. Lowe, F. — Zeiss Pocket Iiefractometer for Mineralogists and Jewellers (Fig. 9) .. 75 Watson-Conrady Condenser Vertical Illuminator (Fig. 10) 77 Wychgram's New Low-current Microscopical Lamp 78 Heath, C. E. — New Safety Device for High-power Lenses and Cover-glasses (Fig. 1 1) 78 Freihekr, W. — New Epidiascope 79 Huldsschinsky, K. — Simple Method for Obtaining Photomicrographs (Fig. 12) .. 79 Brandt, R. — Neio Electrical Heating Apparatus applicable to any Microscope (Fig. 30) 301 Berek & Jentzsch's Small Intense-light Monochromator (Figs. 31, 32) 303 Grundy, J. — Improved Form of Cheshire's Apertometer (Fig. 35) 396 Cheshire, F. J. — Two Simple Apertometers for Dry Lenses (Figs. 36, 37) .. .. 398 Ainslie, M. A.— Variation of Cheshire's Apertometer (Figs. 38, 39) 400 Draper, B. Bt. — Dark-ground Illumination with the Greenough Binocular .. .. 402 Akehurst, S. C. — Changer for Use with Substage Condensers (Figs. 40, 41) .. .. 40:! „ „ Substage Illumination 405 Levy, F. — New Microscope Illuminators 405 Zoth, A. — Application of Direct Coolers to Projection 405 xxviii CONTENTS. (4) Photomicrography. Hind, H. Lloyd. & W. B rough Randles— Handbook of Photomicrography .. .. '-2 10 Walker, Elda R.— Photographic Dark-box for Field Work (Figs. 42. 43) .. 406 Bchepfek, E. W. — Mirror-reflex Camera for Photomicrography; Microscope-table for Subjective Observation and Photography 488 Eminy, C. F. — Obtaining Density in Photomicrograph]i 489 (5) Microscopical Optics and Manipulation Ambbon, H., & H. Siedentopf — Exercises in Scientific Microscopy 80 Bibliography .. 80 Ambronn, H.— Demonstration Experiment on the Abbe Theory of Microscopical Perception 304 (6) Miscellaneous. Quekett Microscopical Club 81 Bibliography •• 82 Quekett Microscopical Club 210 Wychgram. E. — Output from Optical and Mechanical Workshops 306 Quekett Microscopical Club '06 J< hi \nnsen, Albert — Manual of Petrographic Methods 408 Blake. John M. — Possible Methods of Ruling used, by Nobert 490 Chalmers. S. D. —Glass for Optical Purposes 581 B. Technique. CD Collecting- Objects, including- Culture Processes. Linpe, P. — Cultivation of Cladothrix Dichotoma 82 Besrekda, A.. & F. Jcpille — Egg-broth .. 82 Hata, S. — Cultivation of Spirochseta recurrent 83 I. on ere, Aug., & J. Chevrotier — Mew Medium for Cultivating Gonococcus .. So Harris, G. T. — Collection and Preservation of Hydroida 211 Walton. A. J. — Cultivations of Adult Animal Tissues in vitro 212 Ki.itschewsky, J. L. — Thermos Apparatus in Laboratory Work 213 Ogata, M., & M. Takenouchi — Neiv Anaerobic Methods 213 Gildemeister, E.. & Gunther — Diagnosis of Diphtheria 213 Lubjiere, A., & J. Chevrotier — Cultivation of (Jouococcus 306 Lebour, M. V., & T. H. Taylor— Collecting Eelworms (Fig. 33) .. 307 8] liber, G. — Casein as a Cultivation Medium 307 Pitbchusin, P. L— Cultivation of Plasmodium Vivax 308 Henxingfeld, F. — Isolation of Single Trypanosomas 308 Barber, M. A. — Single Cell Cultures 308 Akkiu'kst, S. C. — Trap for Free-swimming Organisms (Fig. 44) 409 ThaLHIMER, \V. — New Hsemoglobin-agar Medium for the Cultivation of Bacillus influenzae 411 Konrich — New Method of Investigating Anaerobic Stab Cultures 411 Reichstein, S. — Demonstration of Streptococci in the Flowing Blood 412 Rosenow, E. C. — Simple Method of Preparing Tissue-cultures 492 Besrldka, A., & F. J vpillk— Egg Agar 493 Thomson, D. & J. (i. — Cultivation of Human Tumour-tissue in vitro 493 CUNNINGHAM, J. — Estimation of Gas produced by Gas-forming Bacteria, 493 Buchanan, R. M. — Inset Absorption Appliance for the Test-tube Culture of Anaerobes 494 CONTENTS. XXIX PAGP Jansen, A. M. — Disinfectant Action of certain Bacterial Stains 494 Emrys-Roberts. E. — Use of Glucose-agar for restoring lost Pigment- producing Properties ■ 494 Smith, J. F. — Isolation of Bacillus Diphtherias by means of a Simple Medium con- taining Potassium Tellurate 4'.»4 Hall. J. W., & F. Nicholas— Modified Fermentation Tube and a New Medium for Gas-forming Organisms 495 Miller, A. H. — Change of Form of the Tubercle Bacillus when grown on Sperm-oil and Glycerin-egg Medium 4 C .>5 Hall, I. Walker — Purification of Crude Silk Peptones 583 IMcLkod, J. W., & A. R. B. Soga — Cultivation of Pathogenic Spirochetes .. .. 583 Allen, E. J. — Culture of the Plankton Diatom Thalassiosira gravida 583 Thornton, H. G., & G. Smith — Growth of certain Fresh-water and Soil Protista 584 Douglas. S. R. — Method of Making Cultivation Media without Prepared Peptones 584 „ Peptone-free Medium for the Cultivation of the Tubercle Bacillus.. 585 (2) Preparing' Objects. Torraca, L. — Demonstrating Presence of Choudriosomes in Cartilage 214 Licwin, K. R.. & 0. H. Martin — Fixation of Soil Protozoa 214 Schluchterer, B. — New Method of Examining the Cells in the Cerebrospinal Fluid 309 Beattie, E. — Washing Pieces of Tissue for Histological Purposes 309 Boring, Alice M., & R. Pearl — Demonstrating the Chromosomes of the Fowl .. 309 Smith, B. G. — Preparing Tel eost Embryos for Class Use .. 310 Green, Bessie R. — Preservation of Bryozoa .. .. 310 Woodworth. O. W. — New Self-regulating Paraffin Bath (Figs. 48, 49) 495 Blake, John M. — Improved Method of Cleaning Diatoms 497 Darling, E. R. — Method for Cleaning Diatomaceas 500 Wolff, M. — New Water-jet Air-pump, and the Fixing and Embedding of Micro- scopical Objects in vacuo 501 Deudy, A. — Gametogenesis of Graidia compressa 586 (3) Cutting 1 , including Embedding- and Microtomes Leitz' New Sledge Microtome (Figs. 13, 14) 83 Kull, H. — Modification of Altmami' s Method of Staining Chondriosomes .. .. 85 Luzzani, Lena Negri — Diagnosis of h'abies .. . . 86 Hance, Robert T. — Paraffin Ribbon-carrier (Figs. 46, 47) 412 Beghek, S. — Leitz" s New Rotary Microtome (Figs. 50, 51) .. .. ' 501 C4) Staining- and Injecting-. Holmes, J. D. E. — McFaydean Staining Reaction for Anthrax Bacilli 215 Krtjger, P. — Staining Connective-tissues 215 Fulleborn, F. — Staining Methods for Microfilaria 311 Alverdes, F. — Staining Pearls in Mussels 312 Giemsa, G. — Rapid Romanowsky Stain 312 Thulin, J. — Studying the Musculature of Flies 312 Schnitzler, J. G.— Modification of Pal's Method of Staining Medullated Nerves . . 312 Fritsch, (J. — Demonstrating the Structure and Innervation of Dentine 313 Liperovsky, L. — Demonstrating Elastic Fibres 313 Biut, C. — Staining Spirochasta pallida 314 Neal, H. V. — Morphology of the Eye-muscle Nerves 314 Thurn, O. — Viability of Dried Bacterial Preparations (Stained and Unstained) .. 415 XXX CONTENTS. PAGF Bassos, 8. W. — Demonstrating the Structure of Mixes! Serves 416 Bell. E. T.— Differential Staining of Fats 503 Sztts, A. V'X — Xeic Hematoxylin Solution 503 K. H. Malone — Employment of Fat Stains for Differentiation in Preparing Museum Specimens 5 04 Tayl r. M >nica — Chromosome Complex ff Culex pipiens 5S6 Martis>tti, L. — Xeic Reaction of Fat* 587 K 5 Mounting, including Slides, Preservative Fluids, etc. Stansell, L. W. — Use of Glycerin-jelly in Mounting Microscopical Objects . . .. 87 Mironisoo, T. — Mounting Preparations of Amyloid Material 215 FinlaY; >. R. — Circular Slide for Ijpaque Objects Fig. 28) 216 Legenlre. R. — Simple Derice for obtaining a Moist Chamber 216 kover. C. — Celluloid Covers for Large Microscopical Slides 316 Plaut. M. — Venetian Turpentine as a Cover-glass Cement 316 Bubton, J. — Metliod of Marking a given Object for Future Reference on a Mounted Slide 116 Blake, J. M. — Picking Out an 1 Mounting Diatoms 11" Junes. Chaps; an — Mounting of Diatoms in Realgar 504 Burton. J. — Mounting Microfungi 58? C6 Miscellaneous. Beaumont, (i. H. — Crystallization of Coumarin 88 Glynn, E., & others — Enumeration of Bacteria 217 Letvis. F. C. — Electro-chemical Disinfection 317 Savage. W. G. — Bacteriological Examination of Food and Water 317 Walsen. G. t van— simple Method of Collecting Centrifugates 508 Morgan. W. De, & G. H. Drew — Study of Restitution Masses 587 Dumimcis. Angelo de — Diascopy of Traces of Blood 5S7 Kratzmann. E. — Micr>'hemical Detection of Aluminium 588 Metallography, etc. J'LIbois. P..& P., Thomas — Arsenic in Commercial Copper 89 Robin. F. — Acicular Constituents of Alloys 89 Arrivaut. G. — Manganese-silver Alloys 89 Iiawdvn. H. S. — Microscopical Examination of Standard Steels 89 Obeehoffer. P. — So-called Fibrous Structure in Steel 89 Hanemann, H., & C. Lind— Cold-rolling of Steel 90 | 'lerhoffer, P. — Annealing of Steel Castings 90 Fuchsel, M. — Structure of a Broken Axle 90 MArwEiEFF — Microstructure of a Boiler Plate 91 Babochine — Fluidity of Rails 91 Bauuann. R— Cracked Boiler Plates 91 Klugh, B. C. — Microstructure of Sintered Iron-bearing Materials 91 Rosenhain, W. — Metah, Crystalline and Amorphous .. ., 91 Mathe"W?on, C. H.. 4' Z. Jeffries — Micrometry as applied to Alloys 91 Robin. F. — Long-focus Microscope, and its Applications in Metallography .. .. 92 Weight. F. E. — Improved Vertical Illuminator 92 CONTENTS. XX xi 1 AGE Haxemanx, H., & K. Exdeli. — Microscopical Examination of Met alt by mean* of Polarized Light Rose. T. K — Annealing of Gold 218 Rig<;. G., & G. M. Williams — Metallography of Commercial Zinc 218 Hott, S. L. — Copper-rich Kalchoids 218 Raydt. U., & G. Tammass — Molybdenum-cobalt Alloys 218 JohxS'X, F. — Silicon in Arsenical Copper 219 Hiege, K. — Manganese-cobalt Alloys 219 CAMPBELL, W. — Lead-tin-antimony and Tin-antimony-copper Alloy? 219 L'Resz. R.. & D. Pltmbbidge — Alloys of Zinc, Tin. and Cadmium 219 Kerxakow. X., <£ cithers — Thall i um-bitmuth Alloys 219 Read, A. A. — Influence of Pliosphorus on Copper-aluminium Alloys 220 Garland, H. — Egyptian Metal Antiquities 220 DesCH, C. H., & S. Whtte — M'n rochemUtry of Corrosion Rcek. R.. & K. Raxeko— Iron-cobalt System 221 Raydt, U.. & G. Tammaxx — Structure of Zinc-iron Alloys 221 Ruer. R.. & K. Fick — Iron -copper System 221 Nbad, J. H. — Heat-treatment o] Steel 221 Hall. J. H. — Heat-treatment of Hypoeutectoid Steel Castings 221 Rusexhaix, W. — New Etching Reagent for Steal 222 Endell. K., &: H. Haxemaxx — Optical Orientation of some Cast Metals .. .. Mathewsox, C. H. & C. H. Stokesbcky— SiVrer and Cuprous Oxide 318 Yog el. R. — Alloys of Cerium icith Silicon and Bismuth 3]>. Kremaxx, R. & others — Metallography of Electrolytically-de posited Alloy .. .. 818 Mataveepf — Protective Oxidized Coating on Sheet-iron 318 Stead, J. E. & H. C. H. Carpexter — Crystallizing Properties of Electro-deposited Iron 318 Balaiew. N. T. — Researches on the Structure of Steel 319 Ewex, D. — Structural Changes of Iron during Annealing 319 lirERTLER. W.— Damascene Steel 319 ., .. Iron-carbon System 320 Haxemaxx. H.— Hyper-eutectic Iron-carbon Alloys >tead. J. E. — Ternary Alloys of Iron. Carbon, and Phosphorus Rogers, F. — So-called " Crystallization through Fatigue" 321 Campion, A. & J M. Ferguson — Preparing Sections of Fractures of Steel lor Microscopic Examination 321 Beilbt, G. T. — Transparence or Translucence of the Surface Film Produced in Polishing Metals .. .. 321 1'ortevix, A. — Microscopic Metallography in Three Dimensions 322 Guertler, W. — Cohesion of Metal Mattet 322 RiGG. G. — Colour-photomicrographt of Ore* 322 Whyte. S., & C. H. Desch — Microchemisiry of Corrosion 421 Dcxx. R. J., «.V 0. F. Hcdsox — Vanadium in Brute 421 Stead. J. E., \\ i'st, F., & H. Meissner — Influence of Manganese in Cast iron 426 Ridge, W. A. 1>. — Meteoric Iron 126 Desch, C. H. — Solidification of Metals ., 426 Robin, F. — Processes of Solidification and Grain Growth in Metals 427 Hanemann, H. — Metallographi'c Laboratory IJ7 Meyer, R, & others — Oxidation of Type-metal . . 509 Ki.emann, R., & others — Electrolytically-produced Alloys 509 Heyn, E., & 0. .Bauer — Antimony-lead-tin- Alloys . .. 509 Steinberg, S. — Sulphide Inclusions in Steel 509 Stadeler, A. — Changes in Mild Steel caused by Annealing 510 Arnold, J. O., & A. A. Reed — Tungsten Steels and Nickel Sted* 510 Vondracek, R. — Hardness of Iron-carbon Alloys 510 Storey, O. W. — Malleable Cast-iron 511 Gullet, L., & V.Bernard — Diffusion in Solids 511 Scott, J. — Micro-actions of Acids and Metals 512 Rtgg, Gr. — Structure of Fire-brick 512 National Physical Laboratory 512 Lamplough, F. E E., & ,1. T. Scott - Growth of Metallic Eutectics 588 Edwards, C. A, & H. C. H. Carpenter— Hardening of Metals 5S9 MVance, A. — Theory of Hardening 589 Zimmerschied, K. W. — Cast-iron of Unusual Structure 589 Comstock, GL F. — Titanium Nitride in Steel 589 Hadkiei.d, R. A, & B. Hopkinson — Structure of Manganese Steel 590 Houghton, S. A. — Failures of Heavy Boiler Shell Plates 590 Aknold, J. O., & G. R. Bolsover— Sulphides in Steel Ingots 590 Chapplli , C. — Re-crystallization of Deformed Iron 591 National Physical Laboratory 591 Rosenhain, W., & J. L. Haughton — New Reagent for Etching Mild Steel .. .. 592 PROCEEDINGS OF THE SOCIETY. Meeting, December 17, 1913 94 January 21, 1914 101 February 18, „ 223 March 18, „ 228 April 15, „ 323 May 20, „ 326 „ June 17, „ 428 October 21, „ ' 593 „ November IS, „ 59!) General Index to Volume <;03 JOURNAL OF THE ROYAL MICROSCOPICAL SOCIETY. FEBRUARY, 1914. TRANSACTIONS OF THE SOCIETY. I. — The Binocular Microscope. By Felix Jentzsch, Ph.D. (Bead December 17, 1913.) Figs. 1-3. 1. The Employment of Binocular Microscopes in the Past. Ever since optical instruments were known, people have tried to make them suitable for use with both eyes. There was no special reason for this, nor had they any very clear idea of the require- ments which such an instrument should fulfil, but one was quite contented with the somewhat obvious experience of daily life, that a man with both eyes intact is better than one who is blind on one side. Thus, for instance, in the beginning of the seventeenth century the Dutch spectacle-lens maker, Lippershey, was granted a patent for a double telescope. This instrument was provided with all sorts of improvements during the ensuing decades ; as, for instance, an arrangement for placing the two objectives in a convergent position. In 1677 Cherubin d'Orleans hit on the idea of fitting up the Microscope as a binocular instrument. Whether his arrangement was ever carried out or not we do not know. At all events, and in spite of further experiments by Zahn in 1701, the whole question was lost sight of, and we have to place on record that for the next 150 years not the slightest interest was taken in binocular Microscopes. It only came up again when C. H. Wheatstone developed his epoch-making ideas on stereoscopic vision. This gave the lead for an extended period in the development of binocular microscopy, Feb. 18th, mi 4 b 2 Transactions of the Society. for now every maker aimed at the construction of a stereoscopic Microscope. In fact, at that period a plethora of new types appeared simultaneously, some of which produced pseudoscopic, while some attained orthoscopic effects. These effects were ob- tained in some cases by means of double Microscopes, in others by the use of a single objective, in which case a geometrical or physical division of the pencils of rays was produced. The history of these different types, numbering about twenty altogether, which appeared in the course of a very few decades, is admirably compiled by M. von Kohr * in his work of reference, " The Binocular Instru- ments." While the Continental workers did not take very kindly to these types, the stands of English instruments were for a long time regularly provided with binocular fittings. The type most widely used was the one permitting the binocular arrangement to be thrown out of use in order to change to the ordinary monocular method of observation. This device could, however, be used only for quite low-power systems, otherwise two images were obtained differing widely in their coefficient of light intensity. With all forms of this construction the quality of the image suffered more or less deterioration, so that after the purely aesthetic pleasure of seeing stereoscopic views had passed by, it was realized even in England that for scientific investigations the monocular Micro « scope was always superior to these types. Later on, in Germany, E. Abbe f devised an arrangement with his stereoscopic eye-piece, which threw all previous types into the shade. Nevertheless, this eye-piece appears even to this day to enjoy a very restricted use. It is well known there has been in existence since 1897 a perfect type of instrument for low magnifications, namely, Greenough's Microscope. As a matter of fact, in view of optical law, the importance of viewing stereoscopically diminishes in the same ratio as the magnifi- cations and apertures in use are increased. Already, with medium magnifications and apertures, the penetrating power reaches values, so far as they can be calculated from purely dioptric data, which approach the limits of resolution of the Microscope, so that no further information of any importance bearing on the spatial structure of the specimen can be obtained. Taking physiological and psychological effects into consideration, the foregoing results will differ widely, which will be explained later. Many micro- scopists, especially in England, retained the binocular construc- tion even with higher magnifications, in order to be able to use both e}'es, as this was said to be less tiring. In spite of this, * The Binocular Instruments. Berlin, 1907. t Description of a New Stereoscopic Eye-piece, with general remarks on the conditions governing Micro -stereoscopic Observation. Kais. Zeit. f.Mikr.,ii. (1880) pp. 207-34 ; see also Ges. Abhand., i. pp. 244-62. The Binocular Microscope. By F. Jentzsch. 3 (hiring all this period, no one seems to have recognized clearly the great importance an instrument would have which, while being con- structed for binocular use, should be definitely non-parallactic, but whose function should be to present to the eyes two identical or congruent images, and not two pictures which differ in their perspective. On the contrary, one reads frequent complaints * that a particular stereoscopic instrument is no good, or is even harmful, because it only produces simple binocular images. In recent years interest in this question, which had died out, seems to be reviving : thus, J. Amannf expressed quite definite requirements three years ago with regard to a purely binocular Microscope. The instru- ment which is to be described here was constructed, as far as the chief features are concerned, in the winter of 1909-10. In the year 1912 it was entirely reconstructed. 2. Geometrical and Physical Division of the Eays. The designs hitherto adopted are unsuitable for meeting the con- ditions required. It may be noted that the chief advantage of obser- vation by the binocular method only becomes specially apparent with very high magnifying powers and arduous examinations, such as are required for dark-ground illumination and ultra-microscopy. It is just in these cases that -the earlier types fail. The Greenough Binocular is known to be suitable only for very low apertures, up to about • 15. For higher magnifications larger apertures are necessary : these require, however, very short focal distances only obtainable by using one objective, therefore the division of the pencils of rays must be carried out above the objective. This can be done geometrically or physically, either by conducting certain groups of the rays, which leave the objective towards one eye and the remaining groups to the other eye ; or by splitting each single ray into two parts, thus reproducing two images. The geometrical division can be performed in very different ways. The most obvious method is to divide the circle of the objective into two semicircles by using reflecting prisms (45° prism, J. L. Eiddell, 1852 ; 60° prism, Nachet, 1853; or by refrac- tion (Wenham, 1860). Moreover, it has also been attempted (many years ago by the firm of Leitz) to divide the opening into one or more annular circles or into several rectilinear zones. "With all these methods of construction, that is in every kind of geometrical division, a reduction of the aperture takes place, and consequently there must be a diminution in the resolving power of the instru- ment. Moreover, all the .spherical and chromatic defects of the objective become much more marked with these diaphragms. ( It * Proc. R.M.S., No. 1 (1878) p. 149. t Das Binokulare Mikroskop. Zeit. f. wiss. Mike., xxvii. (1910) pp. 488-93. B 2 4 Transactions of the Societ//. may be noted here that this disability obtains with all ordinary opaque illuminators whenever prisms are employed.) Further, it may be pointed out that the division must take place in the upper focal plane of the objective, if a uniform illumination of the field of vision is desired. This, however, becomes an impossibility with dry lens systems of higher magnifying power, as in all systems known to me the upper focal plane is situated within the lens, where no mirrors or reflectors can be located, even if, as was done in several English types, the objective mounts were made very short. All these objections disappear with the physical method of splitting up the pencils of rays, so that generally speaking this method is considered the more advantageous one. The aperture is not reduced, the field of vision is equally illuminated. There are several types which make use of this method of division, viz. (1) The binocular arrangement of Powell and Lealand,* where the partial reflection from a thick glass plate is employed ; (2 ) The so-called Wenham f-Schroder objective-prism, made by Eoss and Co., of London ; and (3) the previously mentioned stereoscopic eye-piece of Abbe. The last two named types divide the rays at a thin film of air which transmits and reflects at the same time, and this arrangement, just as with Powell and Lealand's type, unavoidably causes a marked difference in the light intensity of the two fields of vision. This difference, which amounts to a ratio of about 1 : 2*5, with Abbe, and which is higher still with Powell and Lealand, is under some circumstances even a desirable factor for a stereoscopic effect such as is sought for in those types, while for purely binocular examinations it is undesirable. In addition to this it follows, at least with Abbe's arrangement, that two eye- pieces of different construction have to be used, one a Huyghenian and the other a Eamsden, and that only one degree of magnifica- tion in the eye-piece is available. A further disadvantage of Abbe's eye-piece is, that the two tubes are placed in a converging position (see pp. 6, 7). 3. The New Binoculak Miokoscope. The problem before us, therefore, was to construct a binocular Microscope which can be used with any desired pair of eye-pieces, in which the two fields of vision shall have equal intensity of * Described by L. Dippel, Das Mikrcskop und seine Anweudung. [2nd ed., 1882, p. 55G. t F. Wenham, On a Binocular Microscope for High Powers. Trans. London Micr. Soc, No. 14 (1866) pp. 103-6. Wenham himself does not appear to have carried out this type of construction. In mentioning the Wenham-prism, with English Microscopes, a different type, employing geometric division, is always alluded to. The Binocular Microscope. By F. Jentzseh. 5 light, and with which the employment of all objectives, including the most powerful oil-immersion lenses, shall be possible ; so that Pig. l. 6 Transactions of the Society. it would also include normal binocular ultra-microscopy. This problem has been solved, and it should be observed, that a notice- able deterioration of the image, which was to be feared owing to the large bodies of glass necessary, has not taken place Fig. 1 shows the external appearance of the instrument. The tube has become a flat box containing the system of prisms. At the upper end are situated the two eye-pieces, whose distance apart can be regulated to suit the eyes of the observer by means of a milled head which actuates two toggle levers inside the box. The distance apart can be varied between 54 and 74 mm. The eye- pieces slide in guides so constructed that no dust can enter the prism-box owing to this movement. On the left-hand side is a millimetre scale, permitting the correct setting to be made for observation. As the two eyes are generally of unequal strength, it was found necessary to fit an independent adjustment on one of the eye-pieces. This can be placed in the right- or left-hand eye-piece. The usual way is to focus by coarse and slow adjustment, using the fixed eye-piece only, then the proper setting apart is given to the two eye-pieces, and finally, if necessary, a further adjustment by the movable eye-piece is made. All kinds of eye-pieces may be used. The eye-piece corresponding to the eye which is more shortsighted is of course set a little lower than the other. The simple internal arrangement is shown in fig. 2. In the cemented prism nearest to the objective will be found a semi- transparent coating of silver, which effects the above-mentioned physical division of the pencils of rays. There is nothing novel about the arrangement of the prisms ; on the contrary, it has been variously applied to optical apparatus in this and other modifica- tions. It is derived from the so-called " Swan cube." The semi- transparent film of silver also finds application in physical instruments. It is technically possible to adjust the film of silver so exactly that the transmitted and reflected light are practically of equal intensity. The thickness of the glasses is chosen so that the length of the optical paths are equal both to the right and to the left, thus securing equal magnification. The new Microscope has another peculiarity, namely, that the two eye-pieces are parallel. We know that in the human eye the actions of accommodation and adjustment for convergence are coupled so as to work together. A convergent action generally calls for an effort of accommodation corresponding to an approach of the object under observation nearer to the eyes, and vice versa. If, therefore, the eyes are forced to convergent action a certain accommodating effort is forced upon them, and this one would prefer to avoid because the eye-pieces of Microscopes are designed for the emergence of parallel rays, that is for an unstrained eye. Such observational work is very tiring when continued for any The Binocular Microscope. By F. Jentzsch. 7 length of time, principally owing to the fatigue of the muscles of the eye. Nevertheless, this method of construction for stereoscopic purposes is defensible at least in one respect, inasmuch as the pur- pose is to assist the purely optical effect by adding auxiliary psychological perceptions, in this case by convergence. For a purely binocular instrument, on the other hand, convergence of the optical axes of the eyes loses all its importance. We would rather require each eye to work as far as possible without effort of accom- modation, that is without strain, and that the point of convergence Fig 2. of the axes of the two eyes should be as distant as possible : in other words we prefer to place the two eye-pieces parallel. With this arrangement everyone * can succeed in making the two images coincide, and this is accomplished the sooner the more effectually one avoids any sort of strain in working. If the coinci- dence of the images takes place under conditions of complete re- laxation, the tranquillity and steadiness of the image is surprising. The distance at which the image is located varies in individual cases as with the ordinary Microscope. * It is a fact that anyone, who can see at all with both eyes, can use any properly designed and well-constructed binocular Microscope without previous practice. $ Transactions of the Society. 4. The Hygienic; Importance of Binocular Observation. We know that in most " Introductions " on the use of the Microscope one is advised when working to change about from one eye to the other, and we likewise know that it is the custom not to follow this good advice ! On the contrary, most microscopists have accustomed themselves to such an extent to the use of the one eye, that if they have to use the other eye for any length of time they experience acute discomfort. Very often they cannot use it at all. When stopping work after hours of tiring observa- tion, everyone has probably noticed that it is not the eye which one has been using which is most tired, but the one which has been out of service and which was apparently idle. Some observers have even assured me that after working for a long period with the right eye they have noticed a disturbance in the sight of the left eye which has for some time hindered them when reading. An explanation of this fatigue of the unused eye, which, by the way, is noticeable with any form of continuous observation with one eye, might be sought in the fact that the unemployed eye, in seeking a suitable point to focus on, causes the muscles or accom- modation to be continually on the move, backwards and forwards so to speak, thus sustaining much more fatigue than the other eye, whose accommodation remains practically unchanged during the whole period of observation. It may, however, be just as likely that the seat of fatigue is more central, i.e. in the brain, for while we are working with the Microscope we have to ignore entirely the images received by one eye while concentrating our attention on the images received by the other. The idle eye has to be continually " called to order," i.e. it has to be forced into inactivity, a process which absorbs a good deal of " energy." However, this last-named discomfort only affects the beginner. With continued practice the impressions received by the one eye are suppressed unconsciously and without difficulty. It is no concern of the science of optics to decide which of these or perhaps other explana- tions is the correct one. Owing to this fatigue not only is the period of observation reduced, but perhaps its value is diminished. At any rate Amann * considers that it is not improbable that, owing to the constant brain-effort which is required, the power and the discriminating efficiency of the working eye might be injuriously affected. Asa matter of fact I found it possible to carry on observations with the new binocular Microscope for a much longer period. It is astonishing how comfortable and how little fatiguing it is. Especially with dark-ground illumination the difference between monocular and binocular observation is remarkably great. * Das Binokulare Mikroskop. Zeit. f. wiss. Mikr., xxvii. (1910) p. 492. The Binocular Microscope. By F. Jcntzsch. 9 5. The Superiority of Binocular Observation. The appearance of the microscopic image differs qualitatively from that with the monocular type of instrument. The first consideration is that in binocular observation one generally sees better than otherwise, and moreover one is able to detect more detail. It must, however, be admitted that there are marked differences in this respect in individual cases. The fact that more detailed examination is possible leads one to think that possibly an actual increase in visual power takes place in binocular work. Certain experiments tend to support this theory, but I have tried to explain the effect in the following manner. According to the Duplex vision theory of von Kries, we possess two entirely different methods of vision, i.e. " daylight vision " and "twilight vision." Now the sensitive surface of the retina consists of two different sets of organs, the rods and cones, of which the former receive principally colour impressions while the latter are acted on by differences of light intensity. According to the above mentioned Duplex vision theory the cones are the organs for daylight vision and the rods for seeing in the semi-darkness. Now it is often pointed out that the rods are missing from the macula lutca, therefore with direct vision only the colour-dis- criminating cones are employed and the rods only play a part in indirect vision or possibly only in the twilight. This is not stating the case quite correctly. The rods do not disappear entirely in the region of direct vision. They are not absent from the whole area centralis* but only from the innermost spot, the fovea centralis, that is a region which externally only covers a field of vision of about 1° to 1'5°. Round about this region the rods make their appearance without any marked boundary line and varying greatly in individual cases. They increase in number farther away from the centre while the number of cones decreases. Besides these there are certain qualitative differences to be noted. At the points where the rods commence to diminish the cones gradually assume the shape of the former. This similarity is most marked in the fovea centralis itself. During normal vision (excepting perhaps with very high light- intensities) the cones and rods act at the same time ; only that the rods have a greater capacity for adapting themselves to darkness, so that a weak intensity of light suffices to excite the action of the rods but is insufficient to affect the cones. In the same way when one is using the Microscope both these organs are generally active. In addition to the differences in intensity of light we have * This expression is considered to be more suitable than the synonymous macula lutea, as according to Gullstrand the yellow colour of the so-called yellow region only refers to a post-mortem effect. 10 Transactions of the Society. above all things to observe fine colour differences or shades. Now as both eyes are rarely equally efficient, it may happen that one eye is more fitted for the one, while the other eye is particularly well equipped to do the other kind of work. Thus if we are in a position to use both eyes we can also utilize their respective strongest points. Everyone who makes much use of binocular instruments is aware that the two eyes assist each other to a much greater extent than would be expected from general consideration. With this method of observation there is not only a, continual movement of accommodation, as is the case in monocular instrument working, in virtue of which as is known the penetrative efficiency of the instrument is increased, but the attention, the perceptive organs of the main cerebral centres, turn from one eye to the other as it were, thus combining the delicate shades of colour as seen by one eye with the fine contour lines of the image as seen by the other. The process as described need not take place actually in such a simple manner. The capacity of our sense of sight is not ex- hausted by the mere perceptions of colour and light intensity. In analysing the sense of sight one would rather bracket the light- and colour-sense together as one factor and would then add the optical sense of space and position-perceptions, and finally the capacity for optical resolution and the sense of form. Although with the ordinary phenomena of sight all these senses come into action simultaneously, there will, nevertheless, generally speaking, always be differences between the two eyes of any individual with re- spect to these different phases. There may also be differences in the degree of sensitiveness of corresponding points on the retina. It may here be mentioned that the unpractised eye is generally less sharpsighted than the practised eye, while having greater sensitiveness to light. All these differences are naturally less noticeable with the binocular method of observation than with the monocular, so that we can now more easily realize how it is that one can make better observations with a binocular than with the ordinary Microscope. Moreover, this conclusion holds not only for the Microscope but also for many measurements made by the aid of optical instruments, especially in photometric work. Observa- tions in all these cases are directly comparable with normal binocular observations on far distances. It is common experience that long distance observations made from an isolated mountain peak or from a balloon are rendered much more effective by using both eyes. It will also be necessary to take into consideration the binocular summation of stimuli and the so-called " vividity " of perception. The Binocular Microscope. By F. Jentzsch. 11 6. The Summation of Stimuli in Binocular Vision. Although one generally has rather too much than too little light in the Microscope, it is necessary that we should be quite clear about the conditions of light intensity in the new instru- ment, as one might easily expect a certain amount of obscuration. First of all only about half the light transmitted by the objective reaches each eye-piece.* Further, a certain percentage is absorbed in its passage through the prisms and lost by reflection. Experience teaches us that if there be any obscuration at all in the new binocular Microscope as compared with the ordinary Microscope, this does not appear to be as great as calculation would lead one to expect. This cpuestion of light intensity has to be handled with a certain amount of caution. For when we have arrived objectively at the determination of a certain degree of illumination, we have still to deal, in the case of an optical instru- ment, with its use considered subjectively, for here the sensibility to light impressions has to be taken into account. It is known that in ordinary vision the same impression of light intensity is obtained with two eyes as with one. One can easily convince oneself of this by closing one eye when observing an illuminated surface. If the proper precautions are taken no obscuration will be observed. We know that in an experiment of this kind the pupil of the open eye becomes dilated. It is not possible, however, that this should simply make up for the loss of light. For, owing to the comparative slowness of this reflex action, a slight shadow should appear to cover the image during the first moment. This, however, is not the case. The experi- ment, moreover, only succeeds in a good light, and only then it the object is so far distant that it can be observed easily and well by both eyes, and provided that the person making the test is not accustomed to observe with one eye only, which happens rather often. The opposite result, namely that the apparent illumination of a surface is greater when observed with two eyes than with one, is generally arrived at if a diaphragm be interposed in such a way that one eye sees only part of the test surface. On making the fields of vision coincide, the part seen by both eyes appears brighter than the other. According to this, therefore, binocular summation of light stimuli obtains in everyday life. I do not, however, consider this experiment to be decisive, for a fusion with the * The light absorbed by the silver coating may be entirely neglected. No colouring of the images can be observed, although from theoretical considerations this might be expected owing to dispersion from the silver. 12 'Transactions of the Society. usually less bright image of the diaphragm itself takes place on the apparently darkened portion of the field of vision. According to modern physiology, the binocular summation of stimuli only takes place with the eye adapted to obscurity, and in the case of vision in full light it is entirely absent. It appears to me, however, that there are certain transition stages, and that a very high degree of full light adaptation must indeed be necessary to entirely eliminate any summation of stimuli. It may even be discovered that the conditions of " twilight vision " are already entered upon at much higher intensities than has hitherto been supposed. I do not wish to go any further into this question in all its bearings, but only wish to emphasize that, according to my personal experience, this is actually the state of the case with the new binocular Microscope. We know that a summation of stimuli takes place within one eye when the object is very small, and when the image approaches the size of an optical sensory element. In this case the intensity of light is proportional in the first instance to the number of sensory elements covered, but it will not increase as soon as the stimulated surface has reached a certain size. I suppose, there- fore, that also in binocular vision an analogous summation of stimuli takes place (even with adaptation to bright light), as the objects to be examined are very small. This would explain the fact that on using both eyes in the new binocular Microscope a marked increase in the impression of light intensity is noticeable. However, it is also possible that this feature is greatly due to another phenomenon generally experienced, the so-called "vividity." 7. Vividity. In using the new instrument, one has another observation to make which is not so easy to put into words. Perhaps the best way of giving expression to it is to say that everything appears more alive, more life-like than otherwise, so that the term " vividity " is perhaps the most suitable. The expression " vividity " was introduced in psychological terminology by Richard Semon in order to characterize the vivacity of perception. Vividity is a quality of perception clearly dif- ferent from " intensity " but not completely independent from it. For we are able to perceive an object of very small intensity, such as a distant light on a dark night, with great vividness (vividity), and on the other hand the effect which a brilliant arc lamp has may be one of very slight penetration. We hear, for instance, the steps of a person carefully coming nearer on tiptoes with great vivacity and distinctness though as something quite noiseless. On the other hand, the fortissimo of a noisy open-air The Binocular Microscope. By F. Jentzsch. 13 concert to which we listen only inattentively is the example of an intense but not vivid perception. The difference seems to be related to the difference between attentive and inattentive observation, although it is not identical with it. For the greater impressiveness of a perception under equal objective intensity may, apart from the question of attentive- ness, be conditioned by a multiplication of the areas susceptible to stimuli. The orchestra does not become less loud if we hear it through only one ear, nevertheless we feel the desire to increase its vividity by listening with both ears. Also, we do not always see more intently with two eyes than with one, but more vividly. I am convinced that this holds good for all kinds of binocular instruments : thus the advantage of prismatic binocular field-glasses over the so-called " prismatic monoculars " lies not merely in their stereoscopic effect, which is in any case only apparent with com- paratively near objects, but especially in the vividity, that is, the general increase in the " lifelikeness " of the impression, which is brought about by binocular as against monocular vision. In the new Microscope this advantage is similarly noticeable. Now I will go a little further, and should like to make the suggestion that in the impression of vividity is included also a part of the sense of depth, that is, those psychological factors which occur only in binocular vision. For the sense of depth (spatial effect) is known to be not only a function of the impres- sions on the senses, but is composed of actual optical factors and of physiological and psychological effects. If you remove by any method the immediate perception of depth by submitting to the two eyes two identical images, the remaining physiological and psychological factors can still produce a conception of depth (spatial effect). The estimation of the distance of a thing takes place according to the size of objects of a known extension : one judges from the appearance of the perspectives (covering, cast-shadows, intensity of colours, so called " air-perspectives ") and many other incidental facts. Further physiological features may be mentioned, such as, the straining of accommodation and the convergence of the two visual axes. In the new instrument not only are the purely optical con- ditions for depth- effect absent (the two images are identical) but the physiological factors are also eliminated (both eyes are parallel and are accommodated to infinity). The psychological effects which accompany an impression of depth may, however, be pro- duced by some conditions and so give rise to a certain depth- effect. The majority of these accessory impulses in connexion with the sense of depth are also to be considered in connexion with monocular vision : some, however, only appear with binocular vision. Thus, for many observers, the stimulus for the conception 14 Transactions of the Society. of depth lies in the fact that they are observing with both eyes. The certain expectation that "Now I shall see objects stereoscopic- ally," suffices to induce the apparent effect. This suggestion, with i lie impression of greater viridity, produces, by the binocular Microscope, the impression of stereoscopic effect and life-like appearance. 8. l'AKALLACTIC EFFECTS. Although parallactic perception of depth is out of the question with the new instrument, and the effect which sometimes astounds the observe)' is only psychological with higher magnifications, nevertheless conditions may be obtained with the binocular Micro- scope resulting in proper parallactic vision, and what is more both orthoscopic and pseudoscopic. This takes place when the eyes of the observer are not centred with the eye-pieces. One has only to take care that the half of the rays emanating from the object should reach each eye, and, moreover, on account of inver- sion in the Microscope, the rays from the left half of the object must be led to the right eye, and from the right half to the left eye if you desire an orthoscopic effect. In the reverse case we have pseudoscopic effect, i.e. parts which stand in relief appear to be depressed, and so on. These conditions were first made clear by Professor Abbe in 1882.* As is shown in fig. 3,f this screening has to be done in the upper focal plane of the objective. It could, however, be moved to an image of this focal plane — the only one available in the ordinary Microscope being the Eamsden disk. There one would have to apply to the " exit pupil " as has been done by Abbe, * On the Conditions of Orthoscopic and Pseudoscopic effects in the Binocular Microscope. Journ.R.M.S., 1881, pp. 203-11. t Figure 3 shows the path of the rays in the Microscope from the image of an object P Q to an eye which looks into the Microscope from a position out of the direct line of the principal axis. The rays from P are indicated by dotted lines, those from Q by continuous lines. Both points are represented on the retina, hence the field of vision will not be limited. Of the eight rays proceeding from the object, pairs may be taken together which are parallel in front of the objective and therefore intersect in the upper focal plane of the objective. This focal plane is represented by means of the eye-piece in the Eamsden disk of the whole Microscope. If the eye of the observer is out of the line of the principal axis, some of the rays are prevented by the iris from reaching the inner eye. This is the case with all those rays in the figure which pass through one half of the focal plane of the objective, that is to say, only such rays contribute to form the image of the object PQ as run in a certain direction. In the example given in the figure only the shaded part of the path of the rays reaches the eye. If the other eye of the observer is so placed that it receives the other half of the path of the rays, then the two eyes receive two images of different perspective, and all the conditions of a stereoscopic perception of depth are fulfilled. If on this assumption the eye in the figure is a right eye, the observer will receive a pseudoscopic image ; if, on the other hand, it is a left eye, the observer will receive an orthoscopic one. (We suppose ourselves to be opposite the observer.) The Binocular Microscope. By F. Jentzsch. 15 a semicircular diaphragm* in order to obtain all the desired effects! With normal microscopic observation, however, this is the spot where the " entrance-pupil " of the observer's eye should be placed so that inconvenience with the eye would be unavoidable ; this would Q P 1 Pupil of eye, \ Ramsden disk | Eye-lens Eye-piece diaphragm Field-lens of eye-piece JB §SU- Upper focal plane of \ objective. / j Eye (turned out of the \ microscopical axis). r Ocular. > Objective. Object. also be the case, for instance, with Abbe's stereoscopic eye-pieces. For a stereoscopic Microscope it would therefore be better to pro- duce another image of the Ramsden disk between the objective and eye-lens of the ocular, and to do the screening there. This neces- * It may be interesting to note that F. H. Wenhani already in 1854 made a proposal of this kind. Quart. Journ. Micr. Sci., ii., pp. 132-4. If) Transactions of the Society. sary screening can, however, be done more conveniently in another way, by placing the pupil of the eye in a special way in the path of the rays. For example, if we make the space between the oculars somewhat less than the distance between the observer's eyes would be for parallel vision ; but if, nevertheless, his eyes remain parallel and wholly without strain, then he must necessarily per- ceive an orthoscopic effect; on the other hand, pseudoscopic effects must be expected if the oculars are farther apart than the mean distance between the observer's eyes. This consideration, which is a direct result of Abbe's theories, was proposed by A. C. Mercer.* Observation confirms its truth entirely for low power magnifications. With higher powers the Eamsden disk becomes so small that, probably owing to the move- ments of the eye, it cannot be observed in part but can only be taken in entirely or not at all. This phenomenon can, however, best be observed with incident light, as the production of cast shadows is most conducive to an increase of stereoscopic effect. Besides all granular preparations, for instance, somewhat thicker test preparations of Macroglossa stdlatarum are most suitable for observing this effect. The oblique illumination is best obtained in this case by fitting a concave Microscope mirror with spindle into one of the holes for the speci- men clamps ; the light may then be directed obliquely on to the preparation, the individual scales throwing shadows on each other and even at times on themselves. Coins are also very suitable with low-power magnifications. For this case with a suitable adjustment of the distance between the eye-pieces, one sees the lettering stand out with remarkable parallactic effect. In conclusion, it may again be remarked that with medium and still more high power magnifications there can be no question of an actual parallactic effect. The advantage of the binocular Microscope lies in such cases in the qualitatively enhanced im- pression produced in different ways, and above all in its hygienic importance. * Stereoscopic Vision with non-stereoscopic Binocular arrangements. Journ. R.M.S., 1882, p. 271. TYPE 1 fe f^/dl -.-tP 7 1 RlDDELL 0G& 2 Wenham-Riddell "- r 3 Stephenson JOURX. R. MICR. SOC. 1914. PI. I. TYPE 2 W 6 Powell & Lealand 7 Wenham-Powell 8 Abbe 4 Nachet 5 Wenham I R 9 Leitz 10 Beck London Etching Co., Ltd., Eng. II. — The Binocular Microscope of the Past, and a New Form of Instrument. By Conrad Beck. (Bead December 17, 1913.) Plates I, II. The paper by Dr. Jentzsch has suggested that an exhibition oi the chief types of binocular Microscopes of the past and present might be interesting. To illustrate the construction I show on Plate I diagrams of the optical arrangement of the various forms. Dr. Jentzsch has made a happy classification of binocular Micro- scopes into two kinds, and, adopting this classification, I would add a third. I. The first type of binocular Microscope is that in which the light from a single object-glass is geometrically divided and half directed into each eye. The beam of light is bisected. This type includes in order of priority : 1. llic Biddell (Plate I, fig. 1). — My example of this is a small dissecting compound Microscope, made by Smith and Beck. 2. The Achromatic Prism of Wenham and Biddell (Plate I, fig. 2). — I can only obtain one of the prisms of this type, but I have a simple achromatic Microscope on this priuciple made by Smith and Beck. 3. The Stephenson Prism (Plate I, fig. 3). — An example of this has kindly been lent by Mr. Bousselet, and another by Mr. Curties. 4. The Nachet (Plate I, fig. 4). — Sir Frank Crisp has kindly lent us a sample of this form. 5. The Wenham Binocular (Plate I, fig. 5). — I have two examples of this, one in use with a low power and the other in use with a high power mounted very close to the prism. I have also an old experimental one, in which the prism is actually mounted in the back cell of a ^ object-glass so as to be practically in contact with the back lens, and another prism only mounted on an arm which projects down into the interior of a high-power object-glass. The Wenham form of binocular Microscope has been sold in thousands and is the only binocular Microscope that has had very great popularity. II. The second type of binocular Microscope is that in which the light from a single object-glass is divided into two beams in a Feb. 18th, 191^ c 18 1\ 5 of the Society. manner described by Dr. Jentzsch as "physically." The beam of light is not bisected, but is as ir were sifted into two so that - ne light from each portion of the beam goes to each eye. Powell and Zealand (Plate I, fig. 6). — The earliest type will demonstrate this. The whole of the light impinges on the first surface of the thick plate No. 1. and while some enters the plate and passes through to form the direct image some is reflected at the first surface, am night by prism N . 2 and reflected at an angle up the second tube of the Microscope. I have om of these instruments, kindly lent by Mr. Muiron. 7. The Wenham Modification of Powell and Zealand (Plate I, fig. 7) cuts off the top of prism 1 and place- it below between prisms 1 and 2, leaving an air space between prisms 1 and 2, and slightly alters the angle of these prisms to get a larger proportion of the light reflected. I have been unable to obtain a specimen of one of these, and it is doubtful if any but experimental instruments were made. 8. The Abbe Binocular Eye-piece (Plate I, fig. 8) is optically exactly the same as the Wenham -Powell, except that he divided prism 2 and altered its angle so as not to cross the right- and left-hand beams over. By his construction the length of path of the two beams of light had been much altered. He used a Huyghenian eye-piece on the left-hand body and a Eamsden eye- piece on the right-hand body to correct this, as a Eamsden eye- piece has its focus (F) at a much lower position than that of a Huyghenian. Abbe, instead of using this instrument nearly over the object-glass, placed it near the eye-piece. 9. Dr. Jentzsch now describes the New Zeitz Binocular (Plate 1, fig. 9), which makes use of a half-silvered him cemented between two glass prisms to divide the beam. 10. I have devised a still further form (Plate I, fhj. 10), which I am exhibiting here to-night, which is somewhat on the lines of the Wenham-Powell No. 6, but I am making use of the half- silvered film for dividing the lisjlit, and am not crossing over the beams for certain important mechanical reasons, and I also use a parallel block of glass on one of the prisms for equalizing the optical path of the two rays, so that both come to a focus at the same position in the eye-piece. III. The third type of binocular Microscope consists of two complete Microscopes pointed obliquely at the same object, and is only useful for low powers. The Greenough Microscope, as made by Mr. C. P.aker, has kindly been lent me bv Mr. Curties to illustrate this form. The paper by Dr. Jentzsch is a most admirable and interesting comment on most of these instruments, and the qualities may thus be summarized. JOUKN. R. MICK. SOC. 1914. PI. II. .'i London Etching Co., Ltd., Eng. The Binocular Microscope of the Past, and a New Form. 19 Properties of the First Type of Binocular Microscope, which has a geometrically bisected beam, one half going to each eye. 1. Resolution. — As compared to monocular vision this type is not equal to a monocular, because the diffraction image of a point is increased in consequence of the aperture of the light forming each individual image being half that of the object-glass, and each image has less detail in it on this account. The fact that the two images are combined in the brain does not fill in the detail when it has once been lost in the images in consequence of the half- size bundles of light. 2. The geometrical bisection of the beam must take place near the back nodal or equivalent plane. Dr. Jentzsch says it should take place at the back focal plane of the object-glass, but this is a mistake. It is even worse, as it should be at the back equivalent plane in order to ensure a proper sub-division of the rays, which come from the right-hand and left-hand sides of an object-point respectively, otherwise these rays have become mixed up and cannot be sub-divided except at the Kamsden disc outside the eye-pieces, which will be referred to later. For this reason this first type of instrument can only be used with low-power lenses, unless the high powers are specially mounted exceedingly close to the bisecting prism ; even when this is done great care must be taken with the illumination to ensure equal lighting to both halves of the object-glass. I am exhibiting to-ni^ht a binocular form of the well-known Wenham make, with a y 1 ^ oil-immersion mounted specially short showing tubercle bacilli, and you will noti-je that the performance is extremely satisfactory and the stereoscopic relief very marked, but the resolution is not equal to that of a monocular instrument. The change from binocular to monocular vision in this form by simply pushing the prism out of place is so quick and simple that I do not think the lack of resolution has been the only reason why this form has not more generally been used for high-power work. 3. The illumination in each tube in this type is similar in brilli- ance if the illumination is such that the two halves of the object glass receive equal amounts of light. 4. Stereoscopic Relief. — This type of instrument, excepting forms 1 and 2 which give pseudoscopic images, gives a stereoscopic relief of a very marked kind, indeed, of what is strictly a somewhat exaggerated character. This fact has at times been disputed, it has been stated that the stereoscopic effect is purely an illusion. The small diagram (Plate II) renders the reason for the stereoscopic relief clear. Suppose that represents the objective, and that an object at X consists of a fine blade of material placed on end, all the light from the left hand of this blade which enters the object glass 20 Transactions of the Society. at all reaches the left hand of the lens only and from the right hand side of X reaches the right hand side only. If the light from the lens is geometrically divided and passed to one eye at A and the other at B, a perfect stereoscopic picture will result, as though the eyes were looking on both sides of a card held in front of them in the well known experiment on binocular vision. It must, how- aver, be remembered that a Microscope inverts the image, and con- sequently to pass the correct image to the eyes to obtain the stereoscopic relief the two beams must be crossed over as in Form 4 the Naehet, and Form 5 the Wenham, or else the images must be re-erected as in Form 3. 5. The images are viewed in Form 1, Type I, with the two eyes parallel, in the other forms of this type with the eyes con- verging to a greater or less degree. Properties of the Second Type of Binocular Microscope, which has a Physically Divided Beam. 1. TJce resolution of this type is in all cases equal to that of a monocular provided the surfaces of the prism are perfect, because each eye receives a full size beam of light. 2. The prisms may be placed in any position in the beam of light between the object glass and eye-piece, and need not be placed close to the back lens. 3. The relative illumination in the two eyes in No. 6 Powell and Lealand, No. 7 Wenham Powell, No. 8 Abbe, is very unequal. In the Leitz and my own form it is equal in the two eyes, and no special care is required as to the equal illumination of the two halves of the object glass. Even if a single beam of oblique light be used for resolving a diatom, which enters the object glass from only one side, the second type of binocular is as efficient as the monocular. In type 6, Powell and Lealand, the light when it reaches the first face of prism 1 is divided into a reflected beam and a transmitted beam, the latter being about five times as bril- liant of that of the other. Wenham, in his modification of the above, by placing his reflecting surface at a greater angle to the incident light, increased the brilliance of the reflected light, but even then the relative intensity differed from about 1 to 3. Abbe adopted Wenham's modification in this respect ; he claims that an unequal illumination is advantageous for those microscopists who, before taking to the use of a binocular Microscope, have already reduced the sensitiveness of one eye with a monocular instrument. This argument is one that is difficult to follow, for if the binocular Microscope should come into general use, which, now that the correct type of instrument is being designed is extremely probable, it is important that it should be constructed for the normal The Binocular Microscope of the Past, and a New Form. 21 observer whose eyes have not been previously damaged by the use of a monocular instrument. It is possible to suit special cases, in either the Leitz or my own new model, by constructing instruments in which the brilliance of the respective eyes is varied by varying the amount of the reflecting silver deposit, but it is probably not desirable. 4. Stereoscopic, Belief, — Dr. Jentzsch says that the Abbe binoc- ular eye-piece threw all previous models into the shade, though he states also that it had a very restricted use. Probably in Germany, where the Wenham Binocular was not popular, this is accurate, but in this country and also in America no instrument has yet thrown the Wenham binocular into the shade, and it may be said to be the only binocular instrument that has hitherto been made in large quantities. The Abbe eye-piece is a difficult instrument to keep in adjustment, and has various disadvantages, but it was of great interest from a scientific point of view on account of the controversy that it occasioned as to whether it gave a stereoscopic picture. To elucidate this problem, Abbe pointed out that the Eamsden circle of a Microscope is the conjugate image of the aperture of the object glass, and that if the beam of light entering the eye were divided at the Eamsden circle instead of at the aper- ture of the object glass, exactly the same rays would be excluded from each eye, and the optical effect would be the same. Suppose in Plate II d represents the object glass and b c the eye-piece of the Microscope, z the Eamsden disk, which is the conjugate image, i.e. a small picture of the lens d, a shutter cutting off half the lens D or a smaller shutter cutting half its image at z allows just the same rays to enter the eye. Thus Abbe proved that a stereoscopic effect can also be obtained with any of the second type instruments, provided a diaphragm be placed in the Eamsden circle of each eye- piece which cuts out half the rays. It could be turned into a pseudoscopic effect by cutting out the wrong half of the rays or no stereoscopic effect at all by making use of the whole aperture. If by means of a lens held above the eye-pieces the Eamsden disks of a Wenham binocular Microscope be examined, they will be found to be half discs in each eye, small pictures of the back of the bisected object glass, whereas in binocular Microscopes of the second and third type the Eamsden circle is a complete disk. Abbe pointed out that if in these Microscopes that give a complete disk, a D- shaped diaphragm be placed over the Eamsden circle, the same stereoscopic result would be obtained as in the so-called stereoscopic binoculars, except that half the light would be wasted. Theoretic- ally this is quite correct, but there is a serious practical drawback. The proper use of the Microscope necessitates that the observer's eye should be placed so that the Eamsden disk is inside the eye very close to the pupil, and the diaphragm made by Abbe cannot therefore be placed in the right position. In consequence of the 22 Transaction* of the Society. observer's eyelashes it cannot be placed nearly at the correct position, and consequently many observers denied that any stereo- scopic relief was obtained with his binocular eye-piece. The use of his eye-piece diaphragms with any but very low power eye- pieces is unsatisfactory, because the Eamsden disk is very close to the Microscope, except in the case of eye-pieces of either very low power or of special construction. But there is another way of stopping out the portions required to give a stereoscopic picture, and that is by placing the eye-pieces slightly too near or too far apart, so that the pupils of the observer's eyes form the necessary diaphragms to cut down the Eamsden disk ; and as the stereoscopic effect Avith a high power object glass is generally exaggerated, a very slight movement of the eye-pieces is often sufficient to cause the necessary stereoscopic effect, and very little loss of light is occasioned. 5. In Types (5), (7), (8), and (10) the two eyes are converged to a point generally about 12 or 15 in. from the observer. Dr. Jentzsch states that to ensure comfort the eye should be looking out parallel. This is not borne out by experience, as the Wenham binocular of the ordinary form gives perfect rest to the eyes when used for hours at a time, and I am inclined to expect it will always be found more comfortable to use an instrument with the eyes con- verging at an angle of about 10° to 15°. One thing is certain, that the convergence must not be more than 18° and probably not so great, as this is an angle to which the observer is not accustomed. It will be noticed that with the Wenham binocular (Form 5), and the Powell and Lealand (Form 6), if the angle of convergence of the bodies is not to exceed the above convenient amount, the tubes must be long in order that the eye-pieces may be at the required distance apart. It is this fact, together with the trouble of illu- mination and loss of resolution, which has prevented the Wenham and Powell and Lealand (Forms Nos. 5 and 6) from being even more extensively used than has been the case. It is since the time of short tube-lengths that the popularity of binocular Micro- scopes has ceased to advance. Any binocular Microscope that is to be universal must have all the advantages of the monocular. In my design of binocular Microscope which I am showing for the first time to-night, I have been able to retain the small convergent ansle of about 14° for the two tubes and yet use a tube-length so short that even with a triple nose-piece attached it does not exceed the 160 mm. standard short tube-length. You will notice that the apex of the triangle at which the optic axes of the tubes meet is 3£ in. below the prisms (see Plate II). This advantage is gained by altering the construction of the Wenham Powell model so that the rays do not cross over when deflected from the prisms into the tubes. It will also be noticed that if for certain purposes monocular vision is required, the prism may be pushed out of position with The Binocular Microscope of the Past, and a New Form. 23 a touch and either binocular vision with half light in each eye or monocular vision with full light in one can be employed as desired. The question of slightly convergent versus parallel tubes for a binocular Microscope is one which depends on whether the observer who uses the Microscope uses his accommodation or not. It is, of course, well known to oculists that convergence and accommoda- tion act together, not that they are actually interconnected, but that by long habit when the accommodation is used the eyes con- verge, and vice versa, and if when the accommodation is used the eyes are obliged to look out parallel, considerable eye-strain and fatigue are occasioned. For telescopes, which are used when the observer is viewing objects at a distance, the eyes are naturally looking out parallel, and parallel tubes should be used, but where the Microscope is employed, alternately with the examination of objects on the table along side it, at a distance of say 12 or 15 in. the observer's eyes are converged to this distance, and it would ap- pear reasonable that such would be the angle at which the Micro- scope tubes should be set. A further advantage of this method of constructing the tubes is that by a slight movement of the head backwards or forwards the observer can obtain stereoscopic, flat, or pseudoscopic vision. The distance apart of the eye-pieces of the Microscope is varied by rotating one tube with the finger and thumb. They should be set at such a distance apart that the complete Eamsden disk of each eye-piece is central with the pupil of each eye. Under these cir- cumstances the full resolution and no stereoscopic relief is obtained. Xow if the eyes be placed a little closer to the eye-piece the observer's pupils cut off the margins of the Eamsden disks and the stereoscopic effect is obtained ; on the other hand, if the eyes are drawn back a pseudoscopic image is seen. Under the Microscope which is on exhibition will be seen a number of Coscinodiscus showing the spines whose composition created discussion some time back m the Society. When the observer examines these, moving his eyes towards or from the Microscope, a pair of individ- ual specimens, which are on different planes will completely change over their relative positions, at one time a specimen being behind, at another time in front of its neighbour. Thus an observer using this instrument for resolution under the most perfect conditions can instantly obtain the perception of the relative depth of the parts by a slight movement of the head. in working with this Microscope so far I have found no disad- vantage as compared with a monocular instrument, but even if such should sometimes exist, a touch slides the prism out of position and it is then exactly the same in every respect as the ordinary monocular Microscope. 24 Transactions of the Society-. III. — Development of an Erribiid* By J. C. Kershaw, F.Z.S. {Read November 19th, 1913.) Plates III, IV, and Pig. 4. These insects feed chiefly on the inner but dead part of the bark of the trees where they live and spin their webs, but they some- times eat remains of insects and other dead animal matter. The male, except when breeding, seems to live under a separate web, and the proportion of males to females is only about one to fifty. The males fly fairly well, chiefly at night it would appear, since I have had two or three come to light. The egg -batch is laid on the surface of the bark, or beneath a loose piece or crevice thereof. When the webs and tunnels are near the ground they are usually carried down between the bark and the earth and grass, and the eggs are often laid on the bark * This Embiid is E. uhrichi de Saussure. See Note sur la Tribu des Embiens, par Hemi de Saussure, Bull. Soc. Ent. Suisse, ix. (1896) p. 8. It is a very common insect in Trinidad, B.W.I. EXPLANATION OP PLATES III and IV. Fig. 1. — Longitudinal section through primitive band, and front view thereof. ,, 2. — Longitudinal section ; band sinking into yolk, and amnion and serosa growing over it ; front view thereof ; beneath, a transverse section. ,, 3. — Longitudinal section through egg (embryo itself not in section), ap- pendages budded ; below, a transverse section. ,, 4. — The same, tail just recurved ; to the right, anterior end of embryo un- rolled, showing bi-lobed labrum ; below, a transverse section. ,, 5. — The same, more advanced (embryo in section) ; to right, view of a maxilla ; below, a transverse section. Section i-j is through an embryo of still later date, when the ventral part of the amnion has disintegrated, and it is growing around the yolk laterally and dorsally. ,, 6. — Longitudinal section, embryo revolved ; below, a transverse section. ,, 7. — Embryo in egg ; only egg-shell (chorion) and embryonic membranes in section ; below, transverse section showing appendages embedded in the disintegrated material. ,, 7a. — Longitudinal section of anterior part of embryo at a later date, show- ing absorption of serosa and amnion. N.B. — In all but fig. 7 the chorion, or egg-shell, is not shown. Lettering of Figures: — am, amnion : at, antenna; cli, chorion; cu, cuticle; ec, ectoderm; I, leg; Ibr, labrum ; m, mandible; mi, mid-intestine; mx 1 , first maxilla ; mx'-, second maxilla ; o, oolemma ; pel, procephalic lobe ; pr, proc- todeum ; rs, remains of serosa ; s, serosa ; ss, membrane secreted by serosa ; st, stomodffiurn ; y, yolk ; ys + as, substance formed by remains of part of the yolk and amnion ; la, 10a, and 11a, first, tenth, and eleventh abdominal segments. JOURN. R. MICR. SOC, 1914, PI. III. co CM OJ © Development of an Embiid. By J. C. Kershaw. 25 in this position. Before oviposition the female gnaws the chosen spot fairly smooth. The eggs are laid with their posterior poles touching the bark, but the interstices between the eggs are filled up with excrement to the level of the lids. The female searches for the dry pellets of excrement which are plentiful beneath the Embiid welts. She chews it up and probably salivates it, and plasters the material around the eggs as they are laid with her jaws and palpi, now and again intermingling a little silk with a rapid scratching actipn of the front tarsi. The eggs are not all ■%-ex' Fig. 4. Eggs. — A. View looking on top of part of egg-batch, the blanket of webs and excrement removed B. Longitudinal section (eggs not in section) through part of egg-batch. b, bark ; ex\ excrement between the eggs ; ex 2 , blanket of excrement over the eggs ; to 1 , first silk web ; w-, second silk web (only a small piece of second web and blanket shown). laid the same day, though the excrement, etc., is added as they are laid. When all are laid, a thin web is spun over the top of the batch, a layer of excrement spread over this, and another web spun over the blanket of excrement. The whole affair is included under some part of the owner's large general web and tunnels. The female watches over her egg-batch like an earwig, but, of course, cannot shift the eggs about as the latter insect often does. The number of eggs in a batch varies greatly — from forty to eighty — and any number between these figures is common ; below 26 Transactions of the Society. and above these numbers is less frequent. One female in confine- ment laid three or four eggs on June 16, but the batch was not completed till the 25th, when it consisted of forty-five eggs. Thus, on an average five eggs per diem were laid. The first nymphs hatched out on July 25, the last on August 8, or, roughly speaking, the nymphs hatch out in about 40 days. The number of antennal joints in the just-hatched female nymph is nine ; the number of adult joints appears to be twenty-two. I have not run the nymphs through from hatching to adult, but they must take a long time maturing, since a batch which hatched on April 26 are still (September 10) not yet adult. I have not noted the moults, but believe they devour the shed skins, as they certainly eat away some of the eggs soon after hatchiug. There is no revolution of the embryo, the head throughout development remaining on the ventral side of the egg, although the embryo changes its position. The primitive band at first forms about the middle of the ventral side of the egg (Plate III, fig. 1), but later the head moves towards the posterior pole, and the band grows around the pole and up the dorsal side of the egg. It soon reaches nearly to the anterior pole, and the posterior end of the band recurves (Plate III, fig. 4), whilst the head is in its lowest position at the posterior pole of the egg. At this time the appendages have already budded out, the antenna? and labrum being first distinct, afterwards the mandibles and maxilhe, and finally the legs. The labrum is at first very markedly lobed (Plate III, fig. 4). The amnion and serosa around the head region of the embryo are in close contact, but early in the recurved stage the posterior part of the embryo sinks somewhat back into the yolk, so that — except around the head region — there is yolk between the amnion and serosa. At a later recurved stage the serosa secretes a complete outer membrane (Plate IV, fig. 5, section i-j) which separates from the serosa. The amnion tears or disintegrates down the median ventral line of the embryo and commences growing afresh laterally and dorsally, fusing to the dorsal remnant of the serosa (the ventral part of which disinte- grates as well as the ventral part of the amnion, the remains — together with some yolk which was enclosed between the amnion and serosa — forming the secretion in which the appendages of the embryo are embedded up to the time of hatching). The dorsal remnant of the serosa thus serves to surround the yolk whilst tiie amnion grows around and encloses it, which it quickly does, and the amnion itself is soon followed up by the ectoderm, which quickly encloses the whole yolk : the remains of the serosa and amnion gather dorsally near the head (Plate IV, fig. 7a), and are absorbed into the gut with the remnant of yolk as the ectoderm closes over and completes the back of the embryo. But the total absorption of the amnion and closure of the ectoderm over the JOURN. R. M1CR. SOC, 1914, PI. IV. ^ <0 + 1 CO v \^ 1 Development of an Embiid. By J. C. Kershaw. 27 whole dorsal region does not take place until just after the embryo has assumed its final position in the egg, as it appears just previous to hatching. This final movement of the embryo must take place within a very short time, since out of many sections made of batches of eggs consisting wholly of late recurved and final position embryos, only two or three were in the intermediate position. Probably the movement is effected within an hour or two. After this semi-revolution the insect remains some 16 days in the egg whilst the musculature, etc., develops, and then hatches out in the earl y "morning. * The nymphs appear to remain with the female under the same web for weeks. As all the eggs are not laid the same day, but with an interval of about ten days from first to last, it is difficult to fix exactly the length of the various embryonic stages, but the following dates compiled from a number of egg-batches are approximately correct : — Egg laid Primitive band discernible Tail just recurved ... Ready to revolve In position as at batcbing Hatcbes 6tb 12tb 24tb 24tb 40tb day There is, properly speaking, no real revolution of the embryo, since the head from start to finish is always on the ventral side' of the egg, though right at its posterior pole, But, as may be seen from the figures, there is a considerable movement of the embryo. In, conclusion, from what we have observed of the habits, anatomy and embryology of this Embiid, we have no doubt what- ever that it is really an Orthopterous insect (probably near the Earwigs) and should not be included in the Neuroptera. * Tbe nympb, just at batcbing, is tbus enveloped in three membranes :— tbe oolemma ; tbe membrane secreted by tbe serosa ; a cuticle moulted by tbe nympb. Tbese tbree membranes are left witbin tbe egg-shell on batcbing-out. 28 Transactions of thi Society. IV. — Notes on Shell-structure in the Genus Lingula, Recent and Fossil. By Feedekick Chapman, A.L.S. F.K.M.S. (Palaeontologist to the National Museum, Melbourne.) (Bead November 19th, 1913.) Plate V. In a recently published paper on fossil (Silurian) species of Lingula, one of which showed well-preserved shell-structure,* I commented on the apparent discrepancies between Carpenter's and Gratiolet's descriptions of shell-structure in this genus of Brachiopods, and promised some further remarks on the question. By the courtesy of Mr. C. J. Gabriel, who enabled me to examine microscopically the shells of some recent Lingulse in his collection, I have studied the minute structure of these shells by means of flakes and vertical sections, and submit the results herewith as being of some scientific interest. Two recent species of Lingula were examined, namely, L. albida Hinds and L. anatina Lamarck. Carpenter s Description of Lingula Shell-structure. — This author states f that "The structure of the shells of Lingula and Orlieula% is equally peculiar, but very different from that which has been now described. These shells are almost entirely composed of laminae of horny matter, which are perforated by minute tubuli, closely resembling those of ivory in size and arrangement, and passing obliquely through the laminae. Near the margin of the shell, these tubuli may be seen lying nearly parallel to the surface." In this description Dr. Carpenter did not say which species of * Proc. Roy. Soc. Victoria, n.s., xxiv. (1911) pt. 1, pp. 181-3, pi. xlv, figs. 3-5. f On the Microscopic Structure of Shells. Rep. British Assoc. 1844 (1845) p. 18. See pi. ix, fig. 22, of that paper. % Orbicula Sowerby, 1830 = Distinct Lamarck, 1819. EXPLANATION OP PLATE V. Pig. l. —Vertical section of shell of Lingula (Lilottidia) albida Hinds. Showing predominant corneous structure, x 150. „ 2. — Vertical section of shell of L. anatina Lamarck. Showing predominance of calcitic layers, x 150. n 3. — Vertical section of shell of fossil Lingula (L. lewisii Sowerby yar. flcmingtonensis Chapman) of Silurian age. Showing dark calcitic layers and fibrous corneous layers, x 190. JOUKX. R. MICK. SUC. 1914. PI. V . i* * if ■ 1 LVV - BJJ * ' . London Etching Co., Ltd,, Kng. SHELL STRUCTURE IX RECENT AND FOSSIL LINGULAE. Shell-structure in the Genus Lingula. By F. Chapman. 2!> Lingula was examined, but, judging from the present study, it was probably a species closely related in structure to L. albida* He did not differentiate the horny from the calcareous layers, although the two structures are presumably apparent in all species of the genus. Gratiolet' s Description of Lingula Shell-structure. — In his ex- haustive and classical paper on Lingula anatina^ Gratiolet states % that the shell is composed of alternate layers of corneous or horny, and shelly or calcareous lamina?, the thickness of each varying in the different parts of the shell. He notes that the horny layers prevail towards the external surface, and the shelly layers towards the internal surface. The structure of the horny layers is simple, transparent, and varying from yellow to green in the species examined. Gratiolet further states that he found no traces of the canaliculi in the horny layer, even after the action of caustic potash, and that it is composed entirely of parallel fibres. The shelly layer is described as recalling the shell of the Terebratulida?, being traversed by a multitude of microscopic canals, and covered besides with stria? of extreme fineness. The mean diameter of the canaliculi in the shelly layer in L. anatina as given by Gratiolet is 0-0008 mm. Gratiolet takes exception to Carpenter's statement that the corneous layers in Lingula and Discina (" Orbicula ") predominate over the shelly layers. Correlative Evidence in regard to the Observations of the abort' Authors. — A vertical section of the shell of Lingula albida Hinds, from Long Beach, California, taken from the central region of the valve, shows the corneous layers to greatly predominate over the shelly or testaceous layers in thickness ; and this is in accord- ance with the evidence of Dr. Carpenter, who, it is assumed, must have examined a closely-allied, if not the identical species, when he made the above-cpioted observation. In the section before me, the horny layers are from four to eight times the thickness of the shelly layers. The horny layer is, as Carpenter stated, perforated with very fine canaliculi, obliquely set to the lamina?, and closely resembling those of ivory. These canaliculi are much finer than those seen in the same section traversing the shelly layer, which are comparable to the coarser tubules found in the Terebratulidse. In this section of L. albida the tubules of the shelly layer measure 0-00132 mm. in maximum diameter, and the * This species is now placed by Dr. Dall in a new genus, Glottidia, in which the pedicle valve hears two diverging parietal ridges, and the brachial valve a median ridge of about the same length. It appears to represent the genus Lingula in American seas. (See Hall and Clarke, Pal. New York, viii. (1892), Pal. Brach. pt. 1. p. 14. t Studies anatomiques sur la Lingule anatina (L. anatina Lam.) Journ. de Conch, ser. 2, iv. (I860) pp. 49-172, pis. vi.-ix. X Etudies anatomiques sur la Lingule anatina (L. anatina Lam.) -Journ. de Conch, ser. 2, iv. (I860) pp. 59-60. 30 Transactions of the Society. average measurement is much the same as in L. anatina, for which Gratiolet gives ■ 0008 mm. On the other hand, a marked difference of detailed structure is seen in L. anatina : firstly, in the general predominance, as Gratiolet points out, of the shelly layer ; and, secondly, in the non-structureless appearance of the horny layers, which are in this section composed of parallel fibres of a transparent character. The Nature of the Shell structure in a Fossil (Silurian) exam///' of Lingula. — Considering the immense age of this fossil,* it is surprising to find the shell retaining so much of its original struc- ture, not only physical but chemical. In regard to the latter point, the shell, when tested, gave a decided reaction for phosphoric acid.t The structural details of this fossil shell shows the calcific and horny layers to be in about equal proportional thickness. It is therefore about as corneous as in L. anatina, and decidedly more shelly than in L. alhida. The layers are slightly flexuose, and tend to separate between the horny layers. Occasionally the vertical tubes passing through the calcific layers have been pre- served, and they are seen to be rather larger than those of either recent species quoted, measuring ■ 0026 mm. in diameter. This entirely bears out the statement by Hall and Clark,:}: who remark on the comparatively large pores in the shell of a Lingula from the Waverly Sandstone (Lower Carboniferous) of Ohio, and suggest therefrom, " That these vertical canals have sometimes attained a greater development in the extinct than in the living species." In the present examples of L. lewisii var. flemingtonensis, the shells are of a purplish-brown colour, and still show a chill horny texture like that of polished cow-horn, and under a tolerably high power is seen to be finely-punctate. This Australian Silurian example of the genus appears to be the oldest known Lingula, which still retains much of its original structure. Flakes taken from the horny layers show a vermiculated tubulated structure nearly identical with Carpenter's figure, but of a more irregular character. As in Carpenter's example, these canaliculi are set obliquely to the lamina: and tend to branch. Summaky. 1. The shell-structure of the living Lingulse, as shown by the two species examined, are very diverse in their detailed characters, the horny layers being predominant in one, the calcareous in the other. 2. In Lingula (Glottldia) alhida the horny laminae are canali- * Lingula lewisii J. de Sowerby, var. flemingtonensis Chapman, from the Silurian (Melboumian stage) of Flemington, near Melbourne. t Chapman, loc. cit., p 183. % Pal. New York, viii. (1892) Pal. Braoh., pt. 1, p. 17. Shell-structure in the Genus Lingula. 31 oulate, whilst in L. anatina they are fibrillate and otherwise structureless. 3. In the recent species of Lingula, as far as seen, the tubules are finer in the living than in the Palaeozoic species, as previously pointed out by Hall and Clarke. 4. It is obvious from the foregoing observations on L. albida, that Dr. Carpenter had examined either that or an allied species, when remarking on the predominant horny structure in the genus, and on the canaliculate character of the horny layers. SUMMARY OF CURRENT RESEARCHES RELATING TO ZOOLOGY AND BOTANY (PKINCIPALLY INVEETEBRATA AND CRYPTOGAMIA), MICROSCOPY, Etc.* ZOOLOGY. VERTEBRATA. a. Embryology. t Electrical Conductivity of Ova.J — J. Gray has tested the electrical conductivity of fertilized and unfertilized ova of starfish and sea-urchin. He finds that the entrance of the sperm into the egg causes an increase in the electrical conductivity of the egg. This condition usually attains its maximum within ten minutes of adding sperm to ripe eggs. The increase in conductivity is followed by a process which returns the con- ductivity of the fertilized egg to or towards that of the unfertilized egg. The changes may be purely physical or purely chemical, or both. The egg in the unfertilized state is remarkably impermeable to electro- lytes, and can almost certainly be regarded as being enclosed within a semi-permeable membrane. In its unstimulated condition this surface must necessarily be polarized. If now this polarization be destroyed, the membrane must become more permeable to ions than before. On this view the entrance of the sperm effects the depolariza- tion of the plasma-membrane. After about fifteen minutes this mem- brane must become polarized again, but the mechanism whereby this is effected is not at present clear. On the other hand, if the sperm carries an enzyme into the egg, which acts on some constituent of the egg-cytoplasm, then a rise in conductivity may occur as the result of the liberations of ions from un-ionized substances, while a reversal of this reaction will have an opposite effect. Effect of Radium-rayed Sperms on Trout Ova.§— K. Oppermann gets results similar to those obtained in regard to frog's ova by 0. and G. Hertwig. The spermatozoa exposed to radiations produce abnor- * The Society are not intended to be denoted by the editorial " we," and they do not hold themselves responsible for the views of the authors of the papers noted, nor for any claim to novelty or otherwise made by them. The object of this part of the Journal is to present a summary of the papers as actually pub- lished, and to describe and illustrate Instruments, Apparatus, etc., which are either new or have not been previously described in this country. f This section includes not only papers relating to Embryology properly so called, but also those dealing with Evolution, Development, Reproduction, and allied subjects. % Journ. Marine Biol. Assoc, x. (1913) pp. 50-59. § Arch. Mikr. Anat., lxxxiii. (1913) 2te Abt., pp. 141-89 (3 pis. and 10 figs.). ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 33 malities in development, such as spina bifida in various degrees. Deteriorative effects are also predominantly seen in the spinal cord, the eyes, and the muscle-plates. These vary greatly in amount. There may be slight displacements in the brain, or there may be general disruption of the tissues. Oogenesis of Zoogonus mirus.* -F. Wassermann gives a detailed account of the oogenesis in this Trematode. He especially discusses the origin of the reduced chromatin elements, the early displacements of the chromatin, and the maturation divisions. His results neither prove nor disprove the theory of the continuity of the chromosomes. "Nor is he able to convince himself of the applicability of the " hetero-homceo- typic reduction-scheme " to the maturation divisions in this type. It does not seem probable that the first maturation division is a reduction division, and the second is certainly an equation division. Development of Ear Ossicles in Foetal Perameles.f— R. W. Palmer finds evidence that the manubrium of the malleus is a secondary and later developed process of the malleus, that the tympanic is a triradiate bone, that the quadrate and incus are homologous, and that the Mam- malian tympanic bone is the modified angular of the Reptiles. Early Development of Scale and Feather.}— Joseph Schleidt finds that the scales on the chick's feet have primordia like those of Reptilian scales. On the trunk of the grass snake and of the chick, and on the feet of the chick, there are very similar structures, small bilaterally symmetrical papillae, passing without definite limits into one another, and forming what Ficalbi described as an " ondulazione in toto." They consist of a proliferation of epidermis and dermis. When feathers are going to develop there is on the second day a proliferation of epidermis at the apex and steep side of the papillae, and the feather primordia become circumscript as if the " ondulazione in toto " was smoothed out. The foot of the chick and the fore limb of the blackbird show embryonic down-feathers on scales. At a very early stage the down- primodia are seen as special differentiations on the scale primordia. The author inclines to the conclusion that there is not an homology between scales, embryonic down-feathers, and definitive feathers. Development of Pharyngeal Bursa in Ferret.§— Marion Radford concludes from her observations that the anterior end of the notochord, i.e., Sessel's pocket, loses connexion in the ferret embryo with the main chorda, which at this stage ends blindly close to the pharyngeal wall ; and that this anterior portion develops characteristics which would point _ to its identity with the pharyngeal bursa as described in human and pig embryos. * Arch. Mikr. \nat., lxxxiii. 1913) 2te Abt., pp. 1-140 (4 pis. and 43 figs.). t Anat. Anzeig., xliii. (1913) pp. 510-15 (4 figs.). X Arch. Mikr. Anat., Ixxxiii. (1913) lte Abt., pp. 118-29 (1 pi.). § Anat. Anzeig., xliv. (1913) pp. 371-7 (6 figs.). Feb. 18th, 19 U D 34 SUMMARY OF CURRENT RESEARCHES RELATING TO Artificial Insemination in Birds.*— E. Ivanowhas effected artificial insemination of hens and pheasants, and reports that a small percentage of the hens laid fertile eggs which developed. b. Histology. Fine Structure of Cuticle.f — Paul Schulze has made a study of the various types of structure in the cuticle of beetles, and distinguishes the limiting lamella, the upper or main plate, the pillars and the Tower plate, which may bear spinules. Between the limiting lamella and the main plate there may be (1) an alveolar seam of rods at right angles to the surface ; and (2) a lac-layer. The last named layer has typically an hexagonal areolation, corresponding to the shape of the formative "cells. When chitinization occurs a more or less distinct fibrillar structure is often to be seen. The surface relief of the elytra of Cicindelids— con- sisting of papillae, hexagons, etc.— dissolves away in caustic potash, and cannot therefore consist of chitin. Histology of Cold Spots in Human Skin.J— Gosta Haggqvist finds beneath a cold spot (fifteen cases) a thick bundle of smooth muscle- fibres, occurring at about the level of the rete cutaneum of the skin- vessels. The muscle is not connected with a hair-follicle or with the corpus papillare ; it lies always at the same level. It is very unlikeh that it is an arrector pili, as is shown in detail. It seems to be a muscle not previously recognized. The author did not find the muscle in pieces of skin without cold spots. It perhaps contracts reflexly when a cold object is placed on the skin, and constricts the local blood flow. Peculiar Cells in Lingual Epithelium of G-uinea-pig.§ — Christian Ditlevsen describes the occurrence of peculiar elongated spindle-shaped cells with long nuclei, sometimes arranged in narrow bands or in bows. They end in extremely fine prolongations to both sides, and these may branch. They have a strong affinity for basic stains. They are probably peculiar epithelial cells, and there are some intermediate forms which link them to the typical epithelial cells. Mitochondria and Mitochondrial Strands in Epidermis Cells of Tadpoles. || — Sakae Saguchi finds that the chondriosomes of the epidermic cells, before the appearance of the so-called Eberth's intracellular structure, are usually threads, the chondriokonts of Meves, which, though intricately twisted, are on the whole vertically disposed. There are not often granules or rows of grannies or chrondriomites. What look like granules turn out to be twisted chondriokonts. Up to a certain stage in the larval development, the chondriokonts or mitochondria persist, representing Flemming filar mass. At a certain point the zig-zag chondriokonts dispose themselves vertically and horizontally. They become coalescent, and primary mitochondrial * C.R. Soc. Biol Paris, lxxv. (1913) pp. 371-4. f Ver. Deutsch. Zool. Gesell., 1913, pp. 165-95 (37 figs.). t Anat. Anzeig., xlv. (1913) pp. 46-63 (12 figs). § Anat. Anzeig., xliii. (1913) pp. 481-500 (5 figs.). II Arch. Mikr. Anat., lxxxiii. (1913) pp. 177-246 (5 pis. and 5 figs.). ZOOLOGY AND BOTANY, MICKOSCOPY, ETC. 35 strands unite into secondary strands. They are disposed passively m cell-division. It seems probable that the homogeneous basal layer of the pyramidal cells is due to the horizontally disposed mitochondrial strands. and becomes the connective-tissue of the cutis. It is probable that some of the vertical strands become tonofibrils in the adult, which are in direct connexion with the cutis. Chromatophores of Mullus.* — E. Ballowitz has studied the changes in these pigment-cells, and finds reason to believe that the cytoplasm is traversed by very numerous, very delicate, radial canaliculi with thin contractile plasmic walls. The streaming of the pigment-granules is due to the contraction of the protoplasm forming the walls. The pigment may be concentrated in the central disk or spread out to the very periphery. When the granules do not reach the periphery they exhibit a remarkable " dance." Chromatophores of Gobies. f — E. Ballowitz continues his study of the chromatophores of Gobius minutvs and 67. pictus, and gives a finely illustrated account of combinations of pigment-cells that occur. There are melanophores (of two types), xanthophores, erythrophores (derived from xanthophores), and iridocytes. Their cytoplasm is " canalized," and the pigment-granules and guanin-crystals move about according to the contraction or relaxation of the plasmic walls of the canaliculi. The chromatophores are generally united in organ-like complexes- — black-red and stellate combinations, which are minutely described. " Mast "-cells of the Blood.J — Alexander Maximow distinguishes two kinds of " mast "-cells, those of the tissues and those of the blood. They agree in showing characteristic metachromatic basophilous granules in the cytoplasm, but they are quite distinct. Those of the blood show a certain specificity in different types. They represent a specialized kind of granulocyte, and are never to be regarded as degenerate elements. They arise from " mast "-myelocytes in the marrow, and they do not multiply in the blood. Pecten of Bird's Eye.§ — Ebba von Husen has made a careful study of the structure and development and function of the pecten. The tissue is a reticular syncytium of neuroglia. There is a superficial epithelium with the bases of the cells turned to the outer surface, and a network of anastomosing cells with fluid in the intercellular spaces. There are blood-vessels with an endothelium and a homogeneous en- velope. The pigment is inside the glia-cells and their processes. The fibres in the pecten are glia-fibres, not nerve-fibres. They are best developed at the bridge, and end on the surface of the pecten and on the vessels in knob-like thickenings, which are not sensory. The cells of the bridge have papilla-like elevations on their outer surface, from which fibrils of the vitreous humour take their origin. This explains * Arch. Mikr. Anat., lxxxiii. (1913) lte Abt., pp. 290-304 (2 pis.), t Zeitschr. wiss. Zool., cvi. (1913) pp. 527-93(5 pis. and 25 figs.). % Arch. Mikr. Anat., lxxxiii. (1913) lte Abt., pp. 247-89 (2 pis.). § Zool. Jahrb.,xxxvi. (1913) pp. 214-70 (4 pis.). D 2 36 SUMMARY OF CURRENT RESEARCHES RELATING TO the adherence of the vitreous humour to the pecten. The pecten is thus concerned in the production of the vitreous humour in the adult eye. In development the pecten starts, as Bernd has shown, from a mesodermic keel and an ectodermic primodium, which are intimately associated. Both form fibrils, which go to the making of the em- bryonic vitreous humour. The neuroglia of the pecten arises from proliferations of both layers of the secondary optic vesicle. The vas- cular supply of the pecten is very carefully described. The author's results go to show that the pecten helps to form the vitreous humour and is also nutritive. It probably assists in regulating pressure, and may have other functions. Eye of Toad.* — D. Tretjakoff gives an account of the minute structure of the front part of the eye of Bufo cinereus, with especial reference to the margin of the pupil and the associated structures. He connects some of the peculiarities with the toad's nocturnal habits, and takes a comparative survey. The development of the eye in general is briefly discussed. Nerve-endings in Crocodile. f — R. Hulanicka has studied the minute structure of nerve-endings in Crocodilus niloticus and Alligator lucius, and in so doing breaks almost new ground. She describes the free nerve-endings on the palate : the tactile cells of the tongue, jaws, and ventral surface ; the tactile papilla? of the scales ; the mucosa of the tongue and the palate ; the tactile corpuscles ; and the taste-buds, which contain special cells not previously detected. Nervous System of Ampiiioxus.J — H. L. Kutchin describes the structure and distribution of the peripheral nerves of the rostrum, the buccal region, the velum, the branchial region, and the area pos- terior to the atriopore. Attention is also directed to the so-called " spinal ganglia " of Dogiel, which are interpreted as artefacts, to the structure of the dorsal nerves, to their sensory endings, and to the ventral nerves. Very satisfactory figures are given. Degeneration of Nerve-cells in Embryonic Nerve-cord. § — A. Weber calls attention to the occurrence of cellular degeneration in the course of development. Some cells disappear, and others more useful or more favoured take their place. He refers particularly to germina- tive ceds which equip the internal wall of the medullary canal of the embryo skate. After having produced a number of neuroblasts, the elements in question mostly die and disappear. The degeneration goes on without seeming to impair the karyokinetic activity, and it is in trying to multiply still further that they die. What persists longest in the moribund element is the attraction sphere with its radiations. The import of this is discussed. * Zeitsehr. wiss. Zool.,cv. (19131 pp. 537-73 (1 pi. and 6 figs.), t Arch. Zool. Exper., liii. (1913) pp. 1-14 (3 pis.). t Proc. Auier. Acad., xlix. (1913) pp. 571-621 (8 pis.). § A"at. Anzeig., xliv. (1913) pp. 356-G4 (1 pi.). ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 37 » Membranes of Notochord in Cyclostomes and Fishes.* — 0. Schneider finds that the elastica interna is almost always present. It is usually a fenestrated membrane with predominantly longitudinal meshes, within which there is a reticulum of thinner and irregular fibres. In Cyclostomes it is not coherent or separable, but a membrane is hinted at in the occasional union of individual fibrils. The elastica interna reaches its highest differentiation in the inter- vertebral region of Selachians. In sturgeons it extends all along the vertebral column. In Teleostsit is usually confined to the intervertebral regions. In the fibrous sheath, in the vicinity both of the elastica interna and of the elastica externa, there are often elements of an elastic nature. These are short fibrils or spindle-shaped strands in Cyclostomes and Selachians and some Teleosts, but in most Teleosts and in Ganoids a network may be formed. There are cellular elements in the fibrous sheath of sturgeons. It is probable that both elastica interna and elastica externa arise directly from the notochord epithelium. Stroma of Suprarenal Cortex.t — P. Snessarew describes in the cortical region of the suprarenal bodies a very fine fibrillar connective- tissue reticulum, which appears to have at once a supporting and an isolating function. Double Innervation of Striped Muscle. J — J. Boeke finds that striped muscle is innervated by two independent hypolemmal nerve- endings — motor and sympathetic, the latter probably being a tonus- innervation. The sensory nerve-endings are always epilemmal ; the other two are hypolemmal. Mitochondria in Adult Nerve-cells.§ — J. J. Schirokogoroff refers to the fact that most investigators of nerve-cells doubt the presence of mitochondria in the cells of the central nervous system of adult warm- blooded animals. By using special methods he has convinced himself of the presence of mitochondria in all the ganglion cells of the rabbit's central nervous system. He has also seen mitochondria in the nerve- cells of the retina. Glans-penis of Felidge.|| — E. Retterer and H. Neuville have studied the minute structure of the glans-penis in lion, tiger, panther, leopard, serval, etc. In spite of its conical shape, the glans of Felidte is homo- logous with that of man, dog, and horse. It consists essentially of a prolongation of the corpora cavernosa which are at first erectile and adipose, but become eventually bony. In all the feline race, the " balanic " mucosa bears projecting papillae which have at the base of the glans a corneous covering and represent organs of sexual excitation. * Zool. Jahrb., xxxvi. (1913) pp. 171-214 (7 pis.). t Arch. Mikr. Anat., lxxxii. (1913) lte Abt., pp. 408-13 (3 figs.). j Anat. Anzeig., xliv. (1913) pp. 343-6 (10 figs.). § Anat. Anzeig., xliii. (1913) pp. 522-4 (1 pi.). || C.R. Soc. Biol. Paris, Ixxv. (1913) pp. 314-17. 38 SUMMARY OF CURRENT RESEARCHES RELATING TO Glans Penis in Rodents.* — E. Retterer and H. Neuville find that there is considerable diversity in the detailed structure of the glans penis in rodents. They describe that of squirrel, marmot, hamster, and jerboa. The os penis in the latter is very remarkable. Its anterior end is flattened, posteriorly it becomes triangular, and the edges of the triangle are elongated into branches. The surface of the glans in the jerboa is covered with papilla? which bear secondary papillae and towards the apex there are two horny " odontoid " points. The os penis of the hamster is trifurcate. The terminations of the penial nerves end on the odontoids and this doubtless secures multiplication of sensations. Penis of Bats.f — E. Retterer and H. Neuville have studied the structure of the penis in Vesperugo pipistrellus, Rhinolophus ferrum equinum, and Pteropus medius. They find that the glans is covered by a stratified pavement epithelium, without a stratum corneum ; it is surrounded by a prepuce externally covered with hairs. The penis is characterized by the strong development of erectile tissue both in the corpus cavernosum and in the glans. In the horseshoe bat and in the fox bat the os penis is confined to the glans ; in the pipistrelle it extends far back behind the base of the glans. c. General. Effect of Rbntgen Rays on Organs of Chicken.! — Hans Unzeitig finds that chickens can stand about two hours' exposure to a given intensity of Rontgen rays. For a few days following there is a marked reduction of body weight. Feathers often fall off. The bursa fabricii becomes smaller and lighter, and in one case almost disappeared. The lymphocytes of the cortical substance are destroyed in large numbers ; the number of follicles is reduced ; after the fifth day or so regenerative processes often set. in. The testes are Very susceptible : there is marked loss of weight and great destruction of sperm-cells. The interstitial cells do not seem to be affected. The spleen loses greatly in weight and there is a marked reduction of lymphocytes. " Lymphatic System " ;in Fishes.§— B. Mozejko finds that fishes have no lymphatic system in the strict sense. Certain veins take on lymphatic function and become more or less sinusoid. A true lym- phatic system occurs first in Amphibians. The so-called "lymphatic system " in fishes represents a stage in evolution, and may be called " veno-lymphatic." Remarkable Cyprinodont.|| — C. Tate Regan describes Phallostethus dunck&ri g. et sp. n., a remarkable new Cyprinodont from Johore. The largest male was 25 mm. in length, the largest female 29 mm. The male has a relatively large muscular appendage (the " priapium") attached between the expanded hypocoracoids and free distally, bearing the anus * C.R. Soc. Biol. Paris, lxxv. (1913) pp. 345-7. t C.R. Soc. Biol. Paris, lxxv. (1913) pp. 381-3. X Arch. Mikr. Anat., lxxxii. (1913) l*e Abt., pp. 380-407 (1 pi. and 2 figs.). § Anat. Anzeig., xlv. (1913) pp. 102-4. Ann. Nat. Hist., xii. (1913) pp. 548-55 (2 figs.). ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 39 on one side at about the middle of its length and the genital opening at its posterior end, just behind the articulation of an external movable t'orwardly directed serrated bone (the " ctenactinium "). Anteriorly the appendage ends in a long slender bone extending forwards to beneath the chin, curved towards the side on which the serrated bone lies and away from that on which the anus opens. For this bone the name '' toxactinium " is proposed. The priapium is an intromittent organ : it is unlike any other copulatory organ among Fishes. The vas deferens is coiled in a remarkable way to form a sort of epididymis. Another remarkable feature is the wide separation of the openings of the urinary and genital ducts. Statocysts of Marine Invertebrates.* — W. v. Buddenbrock has continued his study of these structures, with especial reference to Arenicola, Myxkola infundibulum, Branchiomma vesiculosum, and Solen vagina. He finds that Branchiomma can bore tail foremost vertically into the mud, and the same is probably true of Myxkola. The statocysts effect an increase of the tonus of the longitudinal muscles on the side that is undermost, and cause their contraction. There is also a musculo- sensory regulation which always tends to bring the tail parallel to the head. The two factors co-operate to bring about the vertical positively geotropic boring. If both statocysts are removed from Branchiomma, it loses the power of boring vertically from any initial position. The removal of one statocyst has no effect. The statocysts have nothing to do with the perception of oscillations in the water. INVERTEBRATA. Moilusca. a. Cephalopoda. Minute Structure of Argonaut's Food-canal. f — W. Gariaeff has studied the gullet and the csecurn of the female Argonaut. The former shows a thick-layered cuticula perforated by fine canals, then the epithelium with distal basal corpuscles, and then a fibrillar basal membrane in continuity with the connective-tissue, in which there are obliquely striped muscle-fibres. The lumen of the caecum is divided by a large number of septa covered with high cylindrical ciliated epithelium. There are also mucin cells and strongly developed glan- dular cells. Minute Structure of Cuttlefishes.! — F. R. Tippmar has made a study of various parts of numerous Cephalopods. He deals with the disposition of the muscle-fibres in the mantle, the structure of the skin and subcutaneous connective-tissue, the integumentary structures (in- cluding the luminous organs of Mastiyoteuthis), the innervation of the mantle, and the body musculature in general. He has also notes on the post-embryonic development of Calliteuthis reversa. * Zool. Jahrb., xxxiii. (1913) pp. 441-82 (13 figs.). t Anat. Anzeig., xiv. (1913) pp. 38-45 (2 pis.). t Zeitschr. wiss. Zool., cvii. (1913) pp. 509-73 (2 pis. and 39 figs.). 40 SUMMARY OF CURRENT RESEARCHES RELATING TO 8. Lamellibranchiata- Structure of Pearls.* — Fr. Alverdes has studied this in Margaritana, Unio, Mytilus, and Ostrea. He distinguishes between nucleated and non-nucleated pearls. A nucleus is a central body which is not composed of one of the shell-substances. The centre is often a peri- ostracum centre. The pearl-sac is always ectodermic, but its origin remains obscure. The nucleus of a pearl may be a parasite, an ovum, or a fragment of tissue, and some have reported a nucleus made from a quartz fragment or the like. In such cases the ectoderm cells are displaced, and a sort of cyst is formed in which a pearl develops. By introducing ectoderm cells into the mantle parenchyma the author was able to bring about the origin of pearl -sac-like cysts, in which concentric layers of nacre were laid down. Epithelium of Anodonta cellensis.f — AY. Siebert gives a detailed account of the minute structure of the epithelium on various parts of the mantle, on the foot, and on the labial palps. The various forms of ciliated, mucus, and sensory cells are dealt with, and the system of currents is mapped out. In an appendix the author discusses the occurrence of lime in the connective-tissue and the wandering cells. Arthropoda. a. Insecta. Histogenesis of Wing-musculature in Diptera.J— - S. Hansel finds that the whole of the wing-musculature in Pachygaster meromelas arises from indifferent cells lying at the basis of the appendage-disks of the inesothorax. These unite in two nucleated strands crossing one another. The anterior strand forms the longitudinal and the anterior vertical muscles ; the posterior forms the posterior-vertical elevators of the wings. Only unimportant parts of the larval longitudinal and dorso- ventral musculature are utilized. The larval muscle-nuclei probably pass through changes by which, in part at least, they become imaginal nuclei. They thus form a part, though an inconsiderable part, of the imaginal myoblast. The tendons are purely epidermic. The histolysis of the larval musculature occurs by autolysis without any assistance from phagocytes. It appears that the genera] statement may be made, that the wing-musculature in Diptera is always due to two embryonic or post- embryonic dorso-ventral primorclia, with a little help from certain larval muscles. Horse-fly of Philippines.§ — M. Bruin Mitzmain has made a study of Tabanus striatum Fabricius, which he finds may aid Stomoxys calcitrans in the transmission of surra {Trypanosoma evansi). The eggs (270-425) are chiefly laid on particles of wood ; the incubation period is 3-5 days; the larvae are essentially aquatic and very cannibalistic ; the larval period lasts for six weeks or more ; there are three distinct moults. * Zeitschr. wiss. Zool., cv. (1913) pp. 598-633 (2 pis.). t Zeitschr. wiss. Zool., cvi. (1913) pp. 449-526 (39 figs.). j Zool. Jahrb., xxxvi. (1913) pp. 465-512 (3 pis. and 18 figs.). § Philippine Journ. Sci., viii. (1913) Sect. B, pp. 197-221, 223-34 (7 pis.). ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 41 From the time the eggs are laid till the flies emerge is about 52 days. Both sexes have a lapping organ, in addition to which the females have a distinct piercing instrument. The " rain-trees " serve to harbour great numbers of resting horse-flies. Genitalia of Diptera.* — P. E. Keuchenius has studied Syrphidse in particular. He calls attention to the asymmetrical position of the testes. They are almost invariably invested by a Tunica externa and a T. interna or propria. These investments are continued on to the vasa deferentia. The accessory glands, seminal vesicle, and the ductus ejacnlatorius are minutely described. It is striking that nowhere, around the testes or vasa deferentia or accessory tubes, or beginning of the ductus ejaculatorius, are there muscle-fibres to be found. It is con- cluded that the contraction of the abdomen, caused by the abdominal muscles, together with the muscles of the sacculus ejaculatorius, play a part in propelling the sperm and the accompanying fluid. Vesicular Secretion of Malpighian Tubes.f — P. Shiwago describes the process by which vesicular plasmic structures appear on the free surface of the cells lining the Malpighian tubes, and lose their con- nexion with the cells, and fall into the lumen. The detailed structure of the cells after feeding and after starving is discussed, with special reference to the changes in the mitochondria. Changes of Peripheral Nerves during Metamorphosis.^ — Sorokina- Agafonowa has studied this in the meal-worm (Tenebrio molitor). The nerve-strand which is seen in the sac-like limb during the pupa-stage shows a definite number of collaterals which abut on the hypodermis and end in bipolar cells ; a single multinuclear cell divides into a group of bipolar cells. The young myoblasts seem to link themselves on by means of amoeboid prolongations to fine threads coming from the nerve- strand. Embryonic Malformation in Meal-worm.§ — Jar. Krizenecky de- scribes in Tenebrio molitor two cases of consertio segmenti, where seg- ments are connected in an oblique or almost dove-tailed fashion. It was previously recorded by Megusar in the same animal. It is perhaps of widespread occurrence among larva?. It arises during the period of embryonic development. Excretory System of Gryllidse.|| — L. Bordas describes the occur- rence of a collecting reservoir or urinary bladder into which the Mal- pighian tubules open and from which a ureter proceeds to the junction of mid-gut and hind-gut. The minute structure is discussed. The internal epithelium, of the tubules consists of large irregular cells, with large nuclei, and long cilia. The bladder shows a very delicate external * Zeitschr. wiss. Zool., cv. (1913) pp. 501-36 (3 pis.). t Anat. Anzeig., xliv. (1913) pp. 365-70. J. C.B, Soc. Biol. Paris, lxxv. (1913) pp. 369-71. § Anat. Anzeig., xlv. (1913) pp. 64-73 (8 figs.). Bull. Soc. Zool. France, xxxviii. (1913) pp. 212-17 (3 figs.). 42 SUMMARY OF CURRENT RESEARCHES RELATING TO membrane with some circular fibres, a basal membrane, and a layer of long cylindrical epithelial cells with short cilia. The ureter is sinuous with internal folds of epithelium. It is covered by a thick muscula- ture with a thin layer of external longitudinal fibres and a thick layer of circular muscles. Within this the wall shows" a basal membrane, a chitinogenous epithelium, and an internal intima of chitin with folds and minute denticulations. Crop of Mallophaga.*— Bruce F. Cummings finds that the crop presents three types of structure in Mallophaga. It is just an expan- sion of the lower part of the oesophagus in Amblycera ; it is a large diverticulum in most Ischnocera ; it is a long narrow-necked sac in Trickodectida?. In Amblycera the crop-teeth are characteristic in the different genera ; in Trichodectidse they are absent ; in other Ischnocera there is a characteristic patch in the anterior csecum of the crop. Plateau suggested that proventricular teeth in general are used for straining, not for mastication. In Amblycera it seems unlikelv that there can be any masticatory function, for the teeth are long, slender, and sharp, and their development is not correlated with powerful muscular folds. In the Ischnocera the short scattered teeth mav be of assistance in clearing out the food which collects in the anterior csecuni. Oogenesis in Podurids.f— L. de Winter has studied in Podura the development of the ovarian cells before the differentiation of the oocytes into ova and vitelline cells, and in the course of this differentiation. Finally the ovarian cavity is found to be occupied with full-sized ova and some masses of vitelline cells and some liquefied residue. The vitelline cells are nothing but abortive ova, which are unfavourably situated. In the first phase of the nutrition of the ova, there is an accumulation of fatty material ; in the second phase albuminoid material is secured. In the second phase the ova occupy the surface of the ovary; they absorb nutritive materials from the hgemoccel ; they utilize material from the ovarian cavity ; they engulf vitelline cells and absorb products of the disruption of vitelline' cells. The author compares the ovary of Podura with that of other insect types. $• Prototracheata. New Forms of Peripatus.^— C. T. Brues gives a preliminary account of Peripatus manni sp. n., which is closely related to P. sedgwichi Bou- vier from the Caribbean coast of South America, and P. dominkse Pollard subsp. haitiensis subsp. n. Both were collected in Haiti bv W. M. Mann. 5. Araehnida. Study of Trichotarsus osmise.§ — A. Popovici-Baznosanu has in- vestigated the life-history of this mite which occurs in the cells of Osmia, one of the solitary bees. He describes the ovum, the hexapod * Ann. Nat. Hist., xii. (1913) pp. 266-70 (3 figs.). t Arch. Biol. Soc, xxviii. (1913) p. 197-227 (4 pis. and 3 figs.). X Bull. Mus. Zool. Harvard, liv. (1913) pp. 519-21. § Arcb Zool. Exper., lii. (1913) Notes et Revue, No. 2, pp. 32-41 (12 figs.). ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 43 larva, the octopod nymph, the adults, the hypopus-sb&ge, and the en- cysted nymph. The last-named stage is a nymph ahout to be trans- formed into an adult, but arrested in its development. It can remain dry but alive for years. The hypopus -stage arises from a transformation of a nymph ; it is a stage adapted for dispersal, not for dormancy. i«- Crustacea. Eye of Ocypoda Ceratophthalma.* — J. Dembowski finds that the eye of this crab is not pseudoconic as Doflein reported, but euconic. The crystalline cells lie between tbe cone and the lens. The eye has a long horn, the cavity of which is filled with loose connective-tissne and groups of gland-cells. No ducts or openings were to be seen. There are also glands on the dorsal side of the eye itself — separated from the optic portion by a hypodermic membrane. Maxillary Glands of Squilla.f — W. N. F. Woodland describes the minnte structure of these interesting glands. To begin with, the gland is a pocket of the ectoderm. Later on, it consists of two wide sacs which communicate only by a narrow duct. There is the distal end-sac and the proximal kidney proper. Their lumina become invaded and almost obliterated by numerous invaginations. The entire exterior is invested by two layers of squamous epithelium, between which lies a division of the haimoccel. The inner layer only is closely applied to the surface of the entire gland, and becomes involved in all the invagina- tions just referred to. The mass of the gland shows (a) hgemoccelic spaces, morphologically outside the gland, lined by squamous epithelium which originally covered the surface, and (b) spaces bordered by the gland-cells and representing all that is left of the originally wide lumen. The author notes that each half of the " liver " has a single duct opening into the pyloric region, and that each duct opens independently. There are two large rectal glands. The nauplius eye persists in the adult. Abnormalities in Copepods.J — C. Dwight Marsh calls attention to the fact that abnormal or freak structures in the genera of Cyclops and Daphnia are remarkably rare. While there is great variability in the species of Cyclops, unusual structures seldom occur. In Dinptomus, which shows hardly any variability within species limits, freak organs are still more rare. The author puts on record a few abnormalities in Cyclops and Biaptomus which he has come across in the course of his systematic work on Copepods. Development of Cypris incongruens.§ — Kurt Muller-Cale gives an account of the early development. The centrosomes of the oocyte nucleus persist, but do not share in the directive division. They come into activity again in the first cleavage. The polar bodies are very vigorous and divide mitotically once or of tener. At the fourth cleavage * Zool. Jahrb., xxxvi. (1913) pp. 513-24 (1 pi.). | t Quart. Journ. Micr. Sci., lix. (1913) pp. 401-30 (1 pi. and 9 figs.). X Trans. Wisconsin Acad., xvii. (1911) pp. 195-6 (1 pi.). § Zool. Jahrb., xxxvi. (1913) pp. 113-70 (6 pis. and 25 figs.). 44 SUMMARY OF CURRENT RESEARCHES RELATING TO they usually sink into the blastoderm cavity, and degenerate when the endodermic immigration occurs. The cleavage is total, approximately equal, and radially symmetrical. A blastosphere of 128 cells is formed. The immigration of the primary endoderm is started by a polar proliferation and localized "primary delamiuation." The mid-gut appears as a gradually increasing vesicle among the primary endoderm nuclei, cell-boundaries having become indistinct. The remaining nuclei form the mesoderm nuclei. The author describes the formation of the apical plate, the oesophagus, the ventral nerve-cord, and so on, and compares the mode of development in Gypris incongruens with that in other Entomostraca. Five types of development are distinguished, depending chiefly on the amount of yolk and on the way in which it is utilized. Thersitina gasterostei Pagenstecher.* — Robert Clurney has some notes on this parasitic Copepod, the females of which occur in abundance under the opercula of the stickleback, especially Gasterosteus aculeatus. It is probable that, as in the nearly related Ergasilus, the female is fertilized once and for all during the free-swimming stage. No males were found below the operculum ; spermatophores have been seen attached to a free-swimming female ; there is a large receptaculum seminis : it is probable that spermatozoa remain alive within the female for about five months ; it is probable that a mature female lays two, or perhaps three, lots of eggs and then dies, giving place to a new genera- tion ; there may be five generations within the year, overlapping to some extent. The author describes the male for the first time. The life-history is also described. Annulata. British Fresh-water Leeches.j — Henry Whitehead gives an account, based on Harding's Revision (1911), of eleven species of Hirudinea found i n Britain, and adds^notes of his own observations. Nematohelrmnthes. New Nematodes from Soil.J — N. A. Cobb gives the characters of no fewer than twenty-six proposed new genera and of a type of each, found in soils (fresh and non-brackish). Most of them are injurious to vegeta- tion. Useful diagnostic tables are given, and attention must be called to the ingenious way in which the author has been able to condense a long paragraph of characters into a single line of formula with numbers and signs. Vulvar Annulus in Nematode^ — L. Gr. Seurat describes in Mau- pasiella weissi, a Nematode from the ctecum of Macroseelides, a peculiar brown or black chitinoid annulus, about a millimetre in width, which * Ann. Nat. Hist., xii. (1913) pp. 415-24 (4 pis.). t Essex Naturalist, xvii. (1913) pp. 61-85 (2 pis.). % Joum. Washington Acad. Sci., iii. (1913) p. 432-44 (1 fig.). § C.R. Soc. Biol. Paris, lxxv. (1913) pp. 326 30 (6 figs.). ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 45 surrounds the posterior end of the body in the mature female and hides the anus and the vulva, leaving only the tip of the tail free. It does not occur in the unfertilized female. Structure of Onchocera volvulus.* — L. Kiilz and F. W. Bach com- municate some notes on the structure of this Nematode ( = Filaria volvulus), which is known to cause fibrous tumours and abscesses in natives of Cameroon. Blood Filaria of Camel.t — Antonio Pricolo describes Filaria hsema- ticacameli sp. n. from the blood of the camel. He has found the adults as well as the larvas. The larvae are found usually, if not always, at night. The parasites were found chiefly in the vessels of the lungs and the testes, causing aneurism-like enlargements, apparently of little im- portance. Spermatogenesis and Oogenesis in Sclerostomum.J — K. Kiihtz has studied these processes in various species of Scleroatomum found in the horse. He calls attention to the strong development of the rhachis in the male ; it extends far into the maturation zone. In the female the rhachis is much less strong and disappears before the beginning of the maturation zone. There are eleven chromosomes in the nuclei of the spermatagonia, twelve in the nuclei of the oogonia. The spermato- cytes show five tetrads and a monosome. The first or second maturation division is unequal. Six equivalent tetrads are seen in the polar body formation. There is an expulsion of an achromatin residue of the germinal vesicle. In the ejaculatory phase the spermatozoon is elongated, but in the uterus this degenerates into a spherical form which effects fertilization. In isolated cases a segmention spindle is seen without there having been r any antecedent union of pronuclei. The eggs leave the body in a morula-stage. ' ^ , v Strongylus capillarisj— Antonio Pricolo describes under this title a new species, 5-7 mm. in length, 90-100 /x in maximum thickness, which occurs as a parasite in the small intestine of dromedaries, and ap- pears to be associated with haemorrhage, hypersemia, and catarrh of the intestinal mucosa. Structure of Male Reproductive Organs in Acanthocephala.|| Willy Bieler has studied the testes, vas deferens, cement glands, and other parts of the male reproductive system in seven species of Acantho- cephala from fishes, and finds that the structure of the cementing appar- atus shows considerable specificity and may be used for systematic purposes. No other part of the system is of use in classification. * Centralbl. Bakt. Parasitenk., lxx. (1913) pp. 321-6 (6 figs.). t Centralbl. Bakt. Parasitenk., lxxi. (1913) pp. 199-200. I Arch. Mikr. Anat., lxxxiii. (1913) 2te Abt., pp. 191-265 (3 pis. and 8 figs.). § Centralbl. Bakt. Parasitenk., lxxi. (1913) pp. 201-2. || Zool. Jahrb., xxxvi. (1913) pp. 525-78 (1 pi. and 15 figs.). 46 SUMMARY OF CURRENT RESEARCHES RELATING TO Human Parasites in Manila.* — B. C. Crowell and R. W. Hamniack report on the intestinal parasites observed in 500 consecutive autopsies on people of all ages in Manila. They found Ascaris lumbricoides in 41*2 p.c, Trichiuris trichiura in 34 "4:; hookworm in 16*6, Tsenia saginata and Gysticercus cellulosse in - 2, Oxyuris in 1, Glonorchis sinensis in - 4, Schistosomum japonicum in 0*2, malaria in 5, and amoebic colitis in 5 p.c. Platyhelmixithes. Peculiar New Trematode.f — Gr. A. MacCallum describes Thoraco- cotyle croceus g. et sp. n., found clinging to the gills of the Spanish mackerel (Scomberomorus maculatus) in the New York markets. The name refers to the peculiar barrel-like or thorax-like arrangement of the chitinous ribs forming the skeleton of the suckers. The body is elongated (4*5 mm. by 0*75-0 "9 mm.), with bilaterally placed ventral marginal clasping suckers extending along more than half the body- length. The testicular mass is single, dorsal, with elongated seminal vesicle and protrusible cirrus. The ovary is in a single coil ; the uterus is elongated, opening anteriorly with the cirrus through an unarmed genital pore. There seem to be only three or four relatively large elliptical ova (0' 18 mm. by - 06 mm.) with a tapering filament at each end about 27 mm. long. Loxogenes arcanum.^ — H. L. Osborn discusses some histological peculiarities in this rare Trematode which has been found in frogs in Minnesota and elsewhere. The mature worm was found within cysts in the vicinity of the pylorus, which seems an extraordinary fact. A description is given of alimentary, excretory, and reproductive systems. A remarkable fact is that there are spines on the outer ends of the genital passages and on the cavity of the ventral sucker. The sub- cuticular cells are discussed at some length. New Trematodes in Marine Fishes.§ — G. A. MacCallum describes AcanthocotyU bothi sp. n. from the gills of Bothus maculatus ; Distomum trachinoti sp. n. from the intestine of Trachinotus carolinus ; D. carangis sp. n. from the rectum of Caranx crysos, and Podocotyle morone from the gills of Morone americana. In Podocotyle at about one-quarter of the length from the caudal end there are given off six pedicelled suckers, 4 mm. in length by 0*15 mm. in width. Each pedicel is surmounted by a sucker which is strengthened by a peculiar chicinous formation. At or near the caudal end there are two small suckers, and there is an ordinary oval sucker on each side of the mouth. Histological Studies on Turbellarians.|| — Paul Lang has studied Planar ia poly chroa Schmidt in reference to the regenerating epithelium, the accessory eyes, and the structure of the pharynx. In the regenera- * Philippine Journ. Sci., viii. (1913) Sect. B, pp. 157-74. t Centralbl. Bakt. Parasitenk., lxviii. (1913) pp. 335-7 (4 figs.). t Zool. Jahrb., xxxvi. (1913) pp. 271-92 (1 pi. and 2 figs.). § Centralbl. Bakt. Parasitenk., lxx. (1913) pp. 407-16 (11 figs.). || Arch. Mikr. Anat., lxxxii. (1913) 1** Abt., pp. 339-64 (1 pi. and 2 figs.). ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 47 tion of the epithelium after a wound the adjacent ceils spread over the wound till they meet in the middle. A thin epithelium with few nuclei is formed and parenchyma cells wander into it, insinuating themselves among the elongated old cells. Both sets of cells multiply amitotically and a normal epithelium is retored. But its cells cannot multiply mito- tically. The structure and the regeneration of the pharynx are discussed. Besides the main eyes there are accessory eyes (one or two) in about ;">0 p.c. of cases. They lie in front of the main eyes, nearer the middle line. They are smaller than the main eyes, but may show the same structure, though with small pigment-cup and fewer visual cells. Not to be confused with accessory eyes are abnormal or supernumerary eyes of inconstant form, position, and structure. Echinoderma. Development of some Echinoderms.*— Th. Mortensen describes the bipinnaria of Asterias glacialis (in which two dorsal pores were present in about 50 p.c. of cases) ; the bipinnaria of Luidia ciliaris (the grown female has no fewer than 200 millions of eggs) ; the ophiopluteus of Ophiactis balli (in which recurrent rods are present in the skeleton so that two large meshes are formed in each half of the body) ; the larva of Ophiocoma nigra ; the echinopluteus of Spatangus purpureus, which is 3 ' 5 mm. in length with long processes — all except the pre-oral with a conspicuous red point ; and the larva of Holothuria nigra, which is a typical Auricularia with a star-shaped spicule at the posterior end. Ova of Echinaster sepositus.f — F. Rosen describes the ovum of this starfish, which is unusually rich in yolk. At the beginning of the ovum's growth there is one nucleolus ; it grows greatly and falls into hundreds of small nucleoli. Some of the nucleolar forms are deceptively like tetrads, but there are quite distinct chromosomes and tetrads. The chromosomes retain their continuity on to the maturation division, and are quite independent of the nucleolar apparatus. Development of Sea-urchins.:}: — L. v. Ubisch has studied Strongylo- centrotus lividus, Echinus microtuberculatus, and Arbacia pustidosa, and confirms in the main the accounts of the development given by MacBride and Theel. He describes the primordia of the chief organs and the differentiation of the water-vasculiir system, the epineural canals, the nervous system, the skeleton, Aristotle's lantern, the gut, the ccelom, and so on. Some abnormal duplex larva? are described. Ccelentera. Study of Eleutheria.§— Anna Drzewina and G. Bohn have studied the polyps and medusoids of Ehutheria dichotoma and E. claparedii. They fed them on minute supra-littoral Copepods, which are stung by the ends of the arms. A detached end may go on for several days * Journ. Marine Biol. Assoc, x. (1913) pp. 1-18 (15 figs.), t Anat. Anzeig., xliv. (1913) pp. 381-3 (4 figs.). X Zeitschr. wiss. Zool., c. (1913) pp. 409-48 (3 pis. and 20 figs.). § Arch. Zool. Exper., liii. (1913) pp. 15-60 (37 figs.). > 48 SUMMARY OF CURRENT RESEARCHES RELATING TO capturing and paralysing Copepods. Starving brings about reduction of size. The creatures showed great indifference to high temperatures (30° C.) and scarcity of oxygen. The number of arms varies from five to twelve, and a temporary absence of oxygen causes a developing bud to become an arm attached to the parent medusoid. Wounds are quickly healed, two portions can be united readily ; there is great regenerative capacity ; in short, there is extraordinary plasticity. Germ-cells of Leptomedusaj.* — I. Apstein has studied the history of the germ-cells and the development of the gonads in Octorchis gegen- lauri and other Leptoniedusse. In Octorchis the ova always differentiate in the ectoderm. The oocytes of the first order appear in association with the endoderm. The ova dispose themselves with their maximum surface on the supporting lamella, become attached to it, and are surrounded by it. The older ova lie topographically in the endoderm, but they are really in the supporting lamella. Those that get free from this come to nothing. The ova have always a membrane. Their food is fluid. They show no amoeboid movement, nor any formation of a syncytium. Environmental influences have a demonstrable effect on the history of the ova. There is no true migration. The germ-cells are moved by an extension of the germinal zone, not by their own movement. In some other cases, such as Euchilota maculata, Obelia, Phialidium, the ova differentiate in the endoderm. Whether the germ- cells differentiate in the ectoderm or the endoderm, their definitive position is in the supporting lamella. The male germ-cells always appear in the ectoderm, but become embedded in the supporting lamella. Nematocysts of Polykrikos and Campanella.f — E. Faure-Fremiet describes in the Dinoflagellate Polykrikos nematocyst-like structures, to which Biitschli has previously called attention. Besides trichocysts there are explosive nematocysts (ten to fifteen in number hi all indi- viduals) which pass through a trichocyst-like stage. In some specimens of the large Vorticellid Gampanella umbellaria there are somewhat similar structures which require further study. The author found only one instance. They differ from the nematocysts of Polykrikos not only in being inconstant, but in their minute structure. Porifera. Hexactinellid and Radiolarian Spicules.^ — A Schwan makes an interesting comparison between these, showing how much they have in common in architecture and disposition. They serve similar functions, giving the living substance support, cohesion, and elasticity. Protozoa. Inheritance of Size in ParamoBcium.§ — H. S. Jennings and K. S. Lashley find that, as a result of conjugation, the progeny of the two in- * Zool. Jahrb., xxxvi. (1913) pp. 579-616 (2 pis.). t G.R. Soc. Biol. Paris, lxxv. (1913) pp. 366-8. t Zool. Jahrb., xxxiii. (1913) pp. 603-16 (11 figs.). § Journ. Exper. Zool., xv. (1913) pp. 193-9. ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 49 dividuals that have conjugated become more alike in their average length, so that by-parental inheritance occurs in respect to body size (as well as in respect to rate of fission). The members of pairs in the culture examined showed, owing to assortative mating, a coefficient of correlation in body length of 0*3881 : this was increased as a result of conjugation to snch an extent that their progeny showed a coefficient of U'5744 — an increase of 48 p.c. Remarkable Protistan Parasite.* — H. M. Woodcock and G-. Lapage describe a new type, Solenomastix ruminantium (Certes), which occurs in the rumen of the goat in two forms, crescents and ovals. The crescents present a homogeneous non-granular appearance, with a defi- nite envelope, with a single large flagellum arising from the concavity of the crescent. They may move by the flagellum or by the body alone. There is no proper nucleus, the chromatin being present in the form of a peripheral layer of granules, or there may be one or two large masses projecting into the cytoplasm. Division is by equal binary fission transverse to the long axis. The ovals resemble the crescents in general, but have no flagellum, although capable of active movement. The chromatinic substance may be in a narrow peripheral layer with or without granules. In others there is a lighter central zone and a darker peripheral zone, perhaps chromatinic. Perhaps the second type of oval gives rise to the first, and perhaps the crescent may become an oval of the first type. The new type is not a Dinoflagellate, nor a Schizosaccharomycete, nor a Spirochete. It may be regarded as a Proflagellate. Urceolaria synaptse.f— N. L. Cosmovici has studied this Infusorian from the intestine of Synaptids. There is a crown of cilia in the interior of the urn (the " Kranz " cirri of others). The foot of the urn is lined with active vibratile cilia (the " batonoi'des " elements of Schneider). The micronucleus appears in the resting-stage like a homogeneous mass, lodged in an excavation of the aboral end of the macronucleus. The cilia of the peristomial ring are usually immobile, but they move when the animal is at rest. There is conjugation and fission. The marine habitat, the presence of cilia at the foot of the urn, and the simple triangular form of the vestibule (cytopharynx) lead the author to regard Urceolaria as a primitive member of the Urceolarinae. New Chytridiopsid.^ — G. Tregouboff describes Chytridioides schizo- phylli g. et sp. n. from the intestine of a millipede (Schizophyllum meiliterraneum) common at Banyuls-sur-mer. It presents a considerable resemblance to Clujtriopsis socius of Blaps. But in its mode of sporu- lation with transient partitioning of the contents of the cyst and in its amoeboid schizozoites it approaches the Chytridineas. * Quart. Journ. Micr. Sci., lix. (1913) pp. 431-57 (2 pis. and 2 figs.). t Bull. Soc. Zool. France, xxxviii. (1013) p. 233. X Arch. Zool. Exper., lii. (1013) Notes et Revue, No. 2, pp. 25-31 (2 figs.). Feb. 18th, 1914 E 50 SUMMARY OF CURRENT RESEARCHES RELATING TO Spirochsets of the Intestine in Birds.* — C. Lebailly finds abundant Spirochaets in the terminal portion of the intestine of fowls, partridges, crows, starlings, sanderlings, plovers, and other birds. He names and briefly describes a number of new species of Treponema. Schizotrypanum cruzi.t- -Kurt Nagler finds that mice, rats, guinea pigs, rabbits, dogs, and cats can be infected with this Trypanosoma He was not able to transfer.it to canaries, lizards, or pigs ; or to find that it was carried by insects. The stages which Chagas called male and female are really vegetative phases. Divisions occur in the peripheral blood-vessels and may be observed even two hours after death. Schizogony of Female Gametocytes of Laverania malari8e4 — N. H. Swellengrebel describes stages which appear to represent a schizo- gony of the young half -moon stages of the female gametocytes. Flagellates of Larval Tipula.§ — Doris L. MacKinnon notes that at least eight flagellates and two ameebse live as parasites or more probably symbionts in the rich bacterial flora of the intestine of the larval crane-fly. The largest and healthiest-looking grubs were generally found to have the richest intestinal fauna. The encystment of a beautiful little monoflagellate, Rhizomastix gracilis Alexeieff, is described. The cysts showed no trace of fusion of nuclei, nor any indication of a sexual process. They seem to be simply multiplication cysts. A description is given of Tetratrkhomastix parisii subg. et sp. n., a flagellate with a slender and rather poorly developed axostyle and with five free flagella, four anteriorly and one posteriorly directed. The nucleus is oval or round (1) compact, rich in chromatin blocks, or (2) feebly siderophilous, with a few scattered chromatin granules and a well-defined nuclear membrane. There is no visible cytostome. * C.R. Soc. Biol. Paris, lxxv. (1913) pp. 389-91. t Ceutralbl. Bakt. Parasitenk., lxxi. (1913) pp. 202-6(1 pi.). t Centralbl. Bakt. Parasitenk., lxx. (1913) pp. 179-81 (1 pi.). § Quart. Journ. Micr. Sci., lix. (1913) pp. 459-70 (2 pis.). ZOOLOGY AHD BOTANY, MICROSCOPY, ETC. 51 BOTANY. GENERAL, Including the Anatomy and Physiology of Seed Plants. Cytology, including' Cell-Contents. Chromosomes of Allium.* — D. M. Mottier and M. Nothnagel have studied the mitosis of the pollen-mother-cells of Allium csmuum. The results of the investigation differ in many points from those obtained with A . Gepa, and are as follows : — Prior to synapsis the nucleus consists of a network of linin and chromatin grannies, with one or more nucleoli but without knots, and there is a tendency to form a continuous spireme. During synapsis there is no union of two spiremes, but a real contraction of the nuclear network, and the spireme is a direct transformation of the latter. The hollow spireme is a thick chromatin cord, and where splits are present these always close before cross-segmentation. A rearrangement of the spireme takes place, resulting in an entanglement of loops and parallel parts twisted upon one another, and during this process transverse division occurs Each bivalent chromosome results from the approximation, usually side by side, of different lengths of the spireme, and may therefore be regarded as two somatic chromosomes that were previously arranged end to end. The prevalent form of bivalent chromosomes is that of a large ring. The daughter-segments split longitudinally' during metaphase. pre- paratory to the second or homotypic mitosis. In the daughter-nuclei the chromatin segments elongate, become waved, and form an inter- rupted spireme by the union of the free ends. This spireme forms a crown open at both the polar and antipolar sides, and there is no fusion of the ends into knots. Relation between the Nucleus and Crystal-formation.t — J. A. Samuels has studied the cytology of the nucleus in connexion with the development of crystals in the cells of the perianth of Anthurium. Polyhedral crystals are very numerous in the outer cells, less numerous in the more internal cells ; raphides occur less frequently, and are found in the central cells of the bracts of the perianth. At the time of crystal-formation the protoplasm accumulates in the cell, while the nucleus takes up a peripheral position where the cytoplasm is densest, and the whole mass becomes enveloped in a membrane. Later on. those cells in which polyhedral crystals are developing exhibit striations * Bull. Torrey Bot. Club, xl. (1913) pp. 555-65 (2 pis.). t Comptes Rendus, clvi. (1913) pp. 1275-7. E 2 52 SUMMARY OF CURRENT RESEARCHES RELATING TO diverging from the nucleus to the crystals. Immediately the crystals are formed both striations* and nucleus disappear. "When raphides are being formed, the wall of an adjacent and more internal cell disappears, while its nucleus and protoplasm fuse into a single mass ; several neighbouring cells behave in a similar way, until a single large cell is formed containing a large central nucleus, from which raphides diverge. As before, completion of the crystals is accompanied by disappearance of the nucleus. The author believes this to be the first instance described of such a fusion, and regards it as having great significance in proving the intimate relation of the nucleus and the physiological processes of the cell. Movements of Plasmodia.* — V. Vouk publishes the second part of a paper dealing with the rhythmic movements of Didymium nigripes and Chondrioderma difforme. The chief results are as follows : The stream- ing starts in the plasmodia and is of a slow amoeboid nature. The amplitude of the movement is the course traversed by a particle of the plasma, and it increases with the circumference of the plasmodium. The duration of the movement is proportional to the amplitude. The movement itself is very sensitive to light, the ultra-violet rays being specially harmful ; it is uninfluenced by gravity, and there is no evidence of geotaxis. Poisons cause degeneration of the plasmodia. The in- ternal osmotic pressure of a plasmodium appears to be about ^ of the atmosphere. The author disagrees with Klebsschen, who states that plasmodia never live for more than two or three weeks. Structure and Development. Vegetative. Cutinization of Roots.f — H. Mager has studied the cutinization of the root of Fmikia Sieboldiana, in order to discover the cause of this general phenomenon. In normal roots examined in July, the epiblem cells were distinctly outlined almost to the growing point and cutinization had already commenced. At a distance of 2 to 3 cm. behind the grow- ing point a single layer of semi-cutinized cells merged into short, usually non-cutinized cells, but whrrever the root had suffered any injury these short cells together with the adjacent parenchyma cells became more or less cutinized. Roots were then cultivated in tap-water and in various culture solutions ; in the former case there was little difference beyond a decrease in the number of root-hairs and later cutinization ; in a complete culture solution there was no important difference at all ; in solutions of higher osmotic pressure cutinization showed a proportional increase. Roots grown in dry earth and in a damp atmosphere in the absence of fluid water also exhibited increased cutinization. At the beginning of November, fresh roots were examined and found to be fully cutinized, but when placed in water or in a culture solution, the * Zeitschr. Bot., v. (1913) pp. 405-6. + Flora, n.s. vi. (1913) pp. 42-50 (4 figs.). ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 53 cutinized cells began to break down. This fact, interpreted in the light of the foregoing experiments, induces the author to regard Meyer as in- correct in stating that the cntinization of the root is a safeguard against loss of food materials ; on the contrary, it appears to be a protection against loss of water under conditions of physiological dryness of soil. Root-cap of the Leguminosae.* — E. Tiegs has studied the origin of the root-cap of Vicia villosa, Pisum sativum, and Trifolium repens, and finds that it arises through growth of the dermatogen and of the cells adjoining the suspensor. These " limiting cells," as they are termed by the author, divide so as to give rise to root-cap above and plerome and periblem below, and they are regarded by many authors as the transverse meristem characteristic of the majority of roots, but this view appears to be incorrect. The origin and mode of growth of the root-cap in the Leguminosag is extremely like that found in the Cruciferee, and in Pisum it resembles that of Helianthus. The central portion of the root-cap, i.e. the columella, arises from the daughter-cells of the " limiting cells," and its breadth depends upon their number. It is highly probable that the periblem and plerome arise from their own initial cells, for such cells can be found in the main root of Pisum sativum and Trifolium repens and in the lateral roots of Vicia villosa. Secondary Growth in Palms.f — J. C. Schoute publishes the results of his comprehensive investigations as to the growth in thickness of palms. The author's method consisted in a comparison of cross- sections, made at equal heights above the soil, of specimens of different ages. The first section of the paper deals with the presence of secondary thickening, and in the 96 species examined 31 showed an undoubted growth in thickness, in 27 it was absent, and doubtful in the remainder. The second section deals with the anatomical details of secondary growth : the results agree with those of Eichler and others. Secondary growth takes place in the outer part of the central cylinder, and the chief zone of growth is the sclerenchyma associated with the vascular bundles. This growth is due to division of the outer radially elongated selerenchyma-cells, while the inner cells thicken early and take no part in secondary growth. This explains the cessation of growth in thickness in older parts of growing stems. In a few cases, in which a protoxylem was present, there was secondary growth in the xylem parenchyma. The growth in the sclerenchymatous tissues causes changes in the other tissues. The epidermal and cortical cells become tangentially flattened, and soon afterwards the epidermis splits and cork and lenticels are formed. The medullary parenchyma has many schizogenous spaces, and the cells are much elongated. In many palms, e.g. Pinanga coronata, secondary growth only proceeds until that part of the stem is covered with leaves ; in other species it continues longer. The author terms secondary thickening like that of the palms, " diffuse " thickening, as opposed to the normal cambial thickening. * Jahrb. wiss. Bot., lii. (1913) pp. 622-47 (1 pi. and 14 figs.). t Zeitschr. Bot., v. (1913) pp. 392-4. See also Ann. Jard. Bot. Buitenzorg, xi. (1912) pp. 1-209. f>4 SUMMARY OF CURRENT RESEARCHES RELATING TO Reproductive. Embryology of Arissema.*— F. L. Pickett has studied the develop- ment of the embryo-sac of Arissema triphyllum, and although most of the results agree with those of previous investigators, the author has discovered a few variations which have not been described before. The origin of the mega«pore mother-cells from a single primary cell is doubtful, the first division of the tetrad having probably been mistaken for a division of a primary cell into embryo-sac initials. The tetrad is composed of potential megaspores, some of which will develop into the embrvo-sac or sacs. As in other Araceas, more than one embryo-sac may lie formed. It is doubtful whether the polar nuclei ever fuse, while the antipodal cells are rarely fully developed. Embryology of the Euphorbiacese.t — Gr. Donati has studied the embryology of eight species of Euphorbiacese, and finds that in seven of them the development is normal : in Poimettia pulcherrima, however, the two embryo-sacs have each sixteen cells and nuclei. This is the fourth instance of the kind in this family, and appears to indicate that further investigations will reveal further abnormalities. Embryology of the Dianthacese.:}: — R. Perotti has studied specimens of six different representatives of the Dianthaceae in order to determine (1) the origin of the embryo-sac ; (2) the number of embryo-sac mother- cells and of embryos in the nucellus ; (3) the origin and structure of the large suspensor-cells found in Stellaria media and other species. The author finds that in Stellaria media, Lychnis dioica, Silene Cucubalus, Tunica prolifera, and Gypsophila saxifraya, the archesporial cell does not develop directly into an embryo-sac, but undergoes a previous tangential division. In these species the mother-cell arises from the lower cell and in Cerastium glomeratum from the upper cell. In all six species there is usually a complete tetrad-division, and the lowest cell forms the embryo- sac. Silene Cucubalus frequently has a multicellular archesporium, several embryo-sac mother cells, and several embryo-sacs. In Cerastium glomeratum, Lychnis dioica, and Silene Cucubalus, the suspensor has a bladder-like ceil of a haustorial nature similar to that found in Stellaria media. In Tunica prolifera, Gypsophila saxifraya, and Sapouariu offici- nalis, the adjacent cell is also much enlarged, while the remaining sus- pensor cells are reduced both in size and number. Anatomy and Germination of Heteromorphous Seeds. § — H. Baar has studied the anatomy and the physiology of the germination of heteromorphous seeds of Chenopodium album and Atriplex nitens. The difference in appearance of the seed is accompanied by difference in structure ; this especially applies to the thickness of the seed-coat with which is closely connected the capacity of the seed for absorption of * Bull. Torrey Bot. Club, xl. (1913) pp. 229-35 (2 pis.). t Zeitschr. Bot., v. (1913)p. 792. See also Annul di Bot., xi. (1913) pp. 395-9 (1 pi.). \ Zeitschr. Bot., v. (1913) pp. 792-3. See also Annal. di Bot., xi. (1913) pp. 371-85 (3 pis.). § S.B. Akad. Wiss., exxii. (1913) pp. 21-40 (2 pis.). ZOOLOGY AND BOTANY, MICROSCOPY, ETC. ■>■> water and hence the time elapsing before germination. The experiments tended to show that it was not the diminished absorption of oxygen but the decrease of water which affected germination. Different seeds behaved differently under the influence of light. One experiment made with Atrvphx seemed to indicate that when the seeds are placed in water, there is an outward diffusion of some substance having the power of retarding germination. The present work shows that, although there may be differences in the stages of development, the adult plants obtained from the two kinds of seeds are equally strong, and show no material difference in structure. General. Organisms in Nectaries.* — I. V. Schuster and V. Ulehla publish a preliminary paper in connexion with their study of the organisms found in nectar-secreting structures. They have examined 32 different species of woody and herbaceous plants, and find that the presence of minute fungi and bacteria is of extremely common occurrence. In 23 of the plants examined the nectaries were infected with a yellow species of bac- teria, also even more frequently with a yeast fungus typically found in Lamium album. To a smaller extent red yeast fungi and torula species were also found. Under special conditions, e.g. where there is a stigmatic cavity, as in Viola tricolor or in the slimy buds of poplar, infection can only be brought about by a single species, which is always present. This circumstance, together with the fact that such common forms of mould fungi as Mucor, Penicillium, Aspergillus, etc. are never found in nectar, points to the conclusion that nectar is the habitat of various species of specially adapted bacteria and yeast fungi. That the latter are not parasitic or harmful is shown by the perfectly normal ripening of the fruit and seed of infected flowers. CRYPTOGAMS. Pteridophyta. (By A. Gbpp, M.A., P.L.S.) Phylogenetic Studies of Ferns. | — F. 0. Bower finds in Metaxya rostrata Presl. {Alsophila blechnoides Hook.), an interesting step in the phylogeny of the Ferns — a more primitive member of the Cyatheaceae, which provides evidence that the arborescent habit of the Cyatheacere is secondary and derived. Metaxya is distinct from Alsophila in the fol- lowing characters : — creeping habit, simple hairs (not scales), soleno- stelic structure of axis, undivided leaf-trace, flat receptacle, simultaneous origin of numerous sporangia, almost vertical annulus interrupted at insertion of sporangial stalk. It holds a similar independent position to that of Lophosoria. Bower discusses the value of the point of origin of the sorus as a constant systematic character, and divides the lepto- sporangiate ferns into two series according as the sori originate from the * Ber. Deutsch. Bot. GeselL, xxxi. (1913) pp. 129-39 (1 pi.), t Arm. of Bot., xxvii. (1913) pp. 443-77 (3 pis. and figs.). 56 SUMMARY OF CURRENT RESEARCHES RELATING TO margin or the surface of the frond. In DavalUa and Nephrotepis the aorus, marginal in origin, is carried by subsequent growth on to 'the lower surface. The position of the nascent sorus is, like the character of the sporangium, of prime importance, and takes precedence ol the anatomical characters of the axis. Bryophy ta. (By A. Gepp.) Riccia Frostii.* — C. A. Black gives a morphological account of Ricria Frostii — structure of thallus, reproductive organs, sporophyte, s] Hire-formation, etc. The air-chambers originate between adjacent up-growing filaments, and when mature are of various sizes and are separated by unilamellate plates of green tissue. The plants are dioicous ; and the reproductive organs are not definitely grouped. The spore- mother-cell nucleus diminishes gradually in size during the successive mitoses ; no centrosomes or centrospheres were observed. The spore contains a very small nucleus surrounded by food material, principally oil. It has two protective coats ; and later the endospore is formed. The exospore is marked with irregular ridges. In the spermogenous tissue the final division is diagonally placed : no cell-wall was found between the resulting triangular cells. The blepharoplast, originating in an angle of the cell, elongates and becomes applied to the transformed nucleus and terminates in a thickened end bearing two cilia. The number of chromosomes is eight for the gametophyte, and sixteen for the sporophyte. Tetraphidopsis.f — H. N. Dixon describes the male inflorescence of the rare New Zealand moss, Tetraphidopsis novae-seel andise, and shows that the plant is identical with the older species Meteorium pustltum Hook. f. & Wils. He also shows that Limpricht was in error in re- ducing Weisia WelwitscMi Schinrp. as a synonym of Campylostelium strictum Solms, the two species being distinct in habitat and in the structure of their leaves, capsule, and peristome. Ditrichum and Thuidium.J — H. N. Dixon discusses the history of Ditricli urn jlexifol ium (Hook.) Hampe, a South African moss, and finds that it is identical in structure with some eight other species, which he now reduces to synonymy. The distribution of the plant thus extends from South Africa to Asia, Australia, and South America. He also pub- lishes critical notes on some species of Thuidium from Australasia and Oceania, adding a description of T. orientate Mitt., a new species from Penang. Dicranoloma.§ — H. N. Dixon begins a series of studies in the bryology of Xew Zealand by publishing a monograph of the sixteen species of Dicranoloma found in New Zealand. He figures the structure * Ann. of Bot., xxvii. (1913) pp. 511-32 (2 pis.). t Journ. Bot., li. (1913) pp. 244-7. X Journ. Bot., li. (1913) pp. 324-30. § New Zealand Institute, Bui'. No. 3 (Wellington, 1913)29 pp. (4 pis.). ZOOLOGY AND BOTANY MICROSCOPY, ETC. 57 of each, and supplies diagnoses of five which had been issued with name only by C. Muller. Dixon calls attention to the exceeding difficulty attached to New Zealand bryology, owing to the creation of numerous new species by C. Muller, W. Colenso and R. Brown (of Christchurch), and the impossibility of obtaining authentic specimens. North American Sphagnum.* — A. Le R. Andrews treats of the section Acisphagnum, which shows a high development in its structure, It is divisible into Squarrosa, Cuspidata, Acutifolia. In Squarrosa he includes S. Angstromii Hartm., S. teres Angstr., S. squarrosum Crome ; and shows how, by their cell-structure and the shape of their leaves, they may be distinguished from one another and from other species. Thallophyta. Algae. (By Mrs. E. S. Gepp.) Oceanic Plankton. f — H. H. Gran contributes a chapter on the plankton collected on the ' Michael Sars ' expedition, to the report of that voyage lately published. He used a steam centrifuge capable of centrifuging 1200 c.cm.' of sea-water at a speed of 700-800 revolutions per minute, thereby discovering that the minute nannoplankton is far more abundant than the larger plankton. He found also that pelagic life is most abundant at depths of 10-20 metres, but becomes extremely scanty below 100 metres ; and he agrees with Natkaiisohn that marine plant life thrives best where ascending currents bring upward a supply of nitrogenous compounds derived from the decomposition of organic matter in the deep sea. Grau also finds that tropical collections of plankton show that the species are numerous and mostly rare, whereas in colder waters there are few species but great aggregations of indi- viduals. Diatoms in Sea-urchins. :j: — CI. Antonelli records fifty-three species of diatoms which he found in the digestive tract of sea-urchins collected at Irani on the Adriatic. The predominant species belonged to Limno- phora and Sgnedra. Gocconeis and Navkula were also abundant, as well as species of Pleurosigma, Hyalodiscus, Biddulphia, and Surirella. Among the rare genera were Goscino discus, Gerataulus, Actinoptychus, Amphora, and Grammatophora. Nuclear Division in Spirogyra.§ — M. L. Merrirnan writes on nuclear division in Spirogyra rrassa. He finds that : — 1. A spireme originates from material derived from both nucleolus and nuclear net- work. The materials constituting this spireme are aggregations varying in appearance, in number, and in staining capacities. 2 These aggre- gations are not the chromosomes. They greatly exceed in number that * Bryologist, xvi. (1913) pp. 59-62, 74-6. + Murray and Hjort, The Depths of the Ocean. London: Macmillan, 1912, Chap. vi. X Att. Pontif. Ace. Rom. Nuov. Line, lxvi. (1912-13) pp. 25-33. § Bot. Gaz., lvi. (1913) pp. 319-30 (2 pis.). 58 SUMMARY OF CURRENT RESEARCHES RELATING TO published for chromosomes in any species of Spirogyra, although a comparative study of plates of other investigators indicates that these are the bodies heretofore designated as chromosomes. 3. This spireme in the pachyneme-stage is composed of deeply-stained short filaments, intermixed with material of a granular nature. There is evidence that this granular material was derived from the nucleolus, the filamentous from the nuclear network. 4. These two materials amalgamate to form one of intensive staining capacity. The amalgamated material retains the spireme form. This spireme as a whole is spherical ; later it elongates, becoming cylindrical. Cross-sections of the loops reveal their tubular structure. 5. This spireme does not appear to split either tiansversely or longitudinally, but separates at various points as would a viscid mass if pulled in opposite directions. Fourteen or more tubular chromosomes for each daughter-nucleus result from the elonga- tion of the coils of the spireme. These are not to be considered "pseudo-chromosomes." 6. At this stage, and subsequently, chromidia are discharged into the cytoplasm. It is probable that these chromidia are concerned in the development of pyrenoids. 7. There is no evi- dence throughout the karyokinesis of an equational division of auto- nomous bodies. The advantage of this form of division over direct divisions appears to be in the opportunity for escape of the chromidia from the nucleus. 8. Spirogyra crassa does not, in the behaviour of its nucleus in karyokinesis, present a unique case, for the stages can be homologized with similar stages in Allium, as typical of the higher plants. Kaplosiphon filiformis.* — K. Yendo has made a thorough exam- ination of Ruprecht's type-material of this species, preserved at St. Petersburg, and finds it consists of four different species. Three of these are already known under other names. The fourth is here de- scribed as forming the type of a new genus, Ruprecktietta. The differ- ences between the characters of Ruprecht's plants are discussed, and the synonymy given of the species to which they belong. Melbourne Fresh-water Algae. f — A. I). Hardy writes a short account of some algae of the Zoological Cardens, Melbourne, collected from pools supplied from the Yan Yean reservoir and the watershed of the Maroondah. The pools are all shallow with no conspicious benthos. In March 1910 Botryococcus Braunii was visible at the surface ; and diffused in abundance were Scenedesmus quadricauda, Merismopedia glauca and Ankistrodesmus quater/ws, the latter hitherto recorded only from Burmah. These specimens are discussed, and theories put forward as to how they reached the Melbourne ponds. The author suggests the foreign birds from the Calcutta market as the possible carriers of the spores in dried mud on the legs. Twenty-three species in all are re- corded from the ponds. For convenience the author adds a note on Euglena spirogyra, here recorded for the first time from the southern hemisphere. Peculiarities in several of the species are figured. * Trav. Mus. Bot. Acad. Imp. Sci. St. Petersbourg, x. (1913) pp. 114-21. t Victorian Naturalist, xxx. (1913) pp. 89-95 (1 pi.). ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 59 Laminaria Zoospores.* — J. Lloyd Williams, replying to a paper by G. H. Drew,f in which the zoospores of Laminaria were described ae gametes on account of the fusions observed, shows that the colourless fusing organisms seen by Drew were Monads— not zoospores ofLariiin- aria. The genuine pear-shaped zoospores, with their prominent bent cliromoplasts, never fuse. When they settle down they become spherical, and are invested with a wall ; and the curved chromoplast divides at the bend. A long tube grows out at one side of the spherical spore- case ; and into this pass the two chloroplasts and most of the other contents. But the nucleus remains behind and divides ; the two daughter- nuclei then move into the tube. An enlargement is formed at the distal end, and, becoming separated off by a transverse wall, is found to contain the chloroplasts, one of the nuclei, and most of the other cell-contents. The second nucleus remains in the tube and degenerates. The new cell grows, and by cell-division may form a simple or branched protonema, which may rest for months or may give rise'to a germling in a fortnight. In the curious process of germination a cell of the protonema becomes pear-shaped, with a thick mucilaginous wall at the pointed end. At this end the cell contents are forced out enclosed in a thin pellicle. The escapedcell divides ; and the basal cell of the row puts out one or more rhizoids, which often grow along the outside of the empty cell — not inside as figured by Drew. "Williams ex- amined Laminaria, Alaria, and Chorda, and found the same process in each. There is no doubt that the swarming bodies are asexual. Life-history of Zanardinia. J — 8. Yainanouchi describes the life- history of Zanardinia. He begins with the mitosis in the negative cells of the gamete-bearing plants, the formation of the gametes, the fertili- zation and germination of the fertilized female gametes, and the apoga- mous germination of the unfertilized female gametes. Then there is described the mitosis in the vegetative cells of the zoospore-bearing plants ; the formation and germination of the zoospores ; and finally, there is a brief statement concerning an alternation of generations in the life-history of Zanardinia. The following is the summary of the results : — 1. The nucleus of the gamete-bearing plants contains tAventy- two chromosomes ; and the male and female gametes contain the same number. 2. In the union of the gametes the number is doubled ; and forty-four chromosomes appear in the fertilized sporeling, which de- velops into the Zanardinia plant containing forty-four chromosomes. 3. The nucleus of the zoospore-producing plants contains forty-four chromosomes ; and the number is reduced in zoospore formation, the zoospore containing twenty-two chromosomes. The zoospore with the reduced number of chromosomes germinates and develops into an in- dividual with twenty-two chromosomes. 4. It is evident that the gamete- bearing plants come from zoospores, and that the zoospore-bearing plants come from fertilized gametes, so that the two generations alternate in the life-history. 5. The female gametes of Zanardinia may germi- nate apogamously. There is no irregularity in the mitotic process, * Rep. Brit. Assoc, Dundee, 1912 (1913) pp. 685-6. t Ann. of Bot., xxiv. (1910) p. 177. X Bot. Gaz., lvi. (1913) pp. 1-35 (4 pis. and 24 figs.). 60 SUMMARY OF CURRENT RESEARCHES RELATING TO twenty-two chromosomes being invariably present. The individual pro- duced shows external morphological characters similar to those of the product of the fertilized gamete ; but the fate of the apogamous indi- vidual was not determined. Iridescent Floridese.* — F. C. von Faber writes on the organization and development of the iridescent bodies of Florideae. His investiga- tions were made on species of Nitophyllum and Taenioma, collected in the Malay Archipelago. He finds that they show in intensive light a peculiar steel-blue gleam which gradually disappears if the alga is exposed to a weaker light. This gleam, which has been observed in many other Floridese by other workers, is caused by iridescent bodies in the cells. They are able to move phototactically, are positively phototactic, and in intensive light they glide to the outer wall of the cell, where they act as a kind of curtain. The chromatophores, like the iridescent bodies, show amoeboid movements, and are negatively phototactic ; in intensive light they range themselves in profile. The iridescent bodies have a protein nature of a distinct structure ; under the influence of strong light small globular bodies arise in them which apparently represent a product of assimilation and are the true cause of the iridescence. In diffused light these globular bodies disappear and the stalk-like portions withdraw to the side walls of the cell. The stroma of the iridescent bodies is, there- fore, not destroyed, but has the power in intensive light of returning to the outer wall, where, under the influence of light, the globular bodies may be again formed. The iridescent bodies arise from the same original material as the chromatophores. Small spindle-shaped bodies are formed in the apical cells and even in the tetraspores, some of which develop into chromatophores, some into iridescent bodies. The latter act as light- reflectors probably to weaken off not only the chemical but also the thermal effect. This reflection is worked on a simple physical principle, that of the clouded media. The structure of the bodies which are in the act of protecting from light show that they disperse the short- waved rays- the blue. Thus the light reflected from these bodies has a bluish colour. Irish Marine Algae. f — A. D.Cotton publishes a list of 120 marine algre collected by Praeger at Saltees off the south coast of county Wexford. Previously only 63 species had been recorded for the region. Notes on several of the records add to the interest of this paper, which, taken in connexion with the Clare Island report by the same author, forms a valuable addition to British marine botany. The microscopic fungus Mycosphserplla Ascophylli Cotton, was present in the receptacles of Ascopliyllum. Marine Algse4 — Gr. B. de Toni publishes notes on three species of marine algrc, JEodes marginata Schmitz, Sebdoaia Monardiana Berth., and Neurocaulon reniforme Zan. He discusses their history, distribution, habit, reproductive organs where known, and the time of year when * Zeitschr. Bot., v. (1913) pp. 801-20 (1 pi.). t Irish Naturalist, xxii. (1913) pp. 195-8. X It. Coinitato Talassografico Italiano, Memoria xxx. (1918) 11 pp. ZOOLOGY AND BOTANY, MICROSCOPY, ETC. Ill those appear. He recommends that attention should be paid by collectors to this point : and also that individuals arising from sexual and asexual plants respectively should be raised under culture, for a comparison of their cytological characters. North American Marine Algae.* — B. M. Davis publishes a report on the algal vegetation of Woods Hole and its vicinity. The first section deals with the ecology of the flora, the coast, the sea bottom, tides and tidal currents, the effect of ice, depth of water, light, tempera- ture, and seasonal changes, and salinity of the water. Characteristic algal associations are described, numbering 57. This section is accom- panied by 47 descriptive charts. The second section is a catalogue of the marine flora, with notes concerning the distribution of the individual species. Australian Marine Algse.t— A. H. S. Lucas publishes the first instalment of his notes on Australian algse, and iucludes descriptions of three new species — Nitophyllum sinuosum (Botany Bay), Polysiphonia compacta (Port Jackson), and Ptilonia intermedia (Tasmania) : the second of these has a nine-siphon structure. In discussing Turhinaria he suggests that the evesiculose T. Murrayana may be a simple un- branched reef -form of T. decurrens. Spermatochnus Lejolisii, found at Port Stephens, is a European species. Some of the plants are figured. New Japanese Algse.} — K. Yendo describes three new species of Japanese alga? and a new form of Goilodesme bulligera Stromf . One of these novelties forms the type of a new genus, Benzaitenia, and is para- sitic on Chondria crassicaulis and Laureacia paniculata. It is fully described and figured. The vegetative organs are reduced to a mere aggregation of cells, which in the young plant are embedded in the parenchymatous host-tissue, and require staining to differentiate them. It belongs to the Dasyere. The antheridia, tetraspores, and cystocarps have all been found. Fungi. (By A. Lorrain Smith, F.L.S.) Morphological and Biological Study of Rhizopus Artocarpi.§ The fungus studied by A. Sartory and H. Sydow was sent to them from the Philippine Islands by C. F. Baker. It was originally found in Java. The mycelium is white at first, but becomes brown or even black. Upright tufts are formed, and some of the filaments bear sporangia. The spores are very variable in size, from 8 /* to 20 /x in diameter, and are globose or ovoid or often angular, clear brown in colour, and striate. The authors grew the mould on various media, and give the results of the experiments. * Bull. Bur. Fisheries, xxxi. (1911) pp. 443-544, 795-833 (chartsj. t Proc. Linn. Soc. N.S.W., xxxviii. (1913) pp. 49-60 (5 pis.). t Nyt Mag. Naturvid., li. (1913) pp. 275-88 (2 pis.). § Ann. Mycol., xi. (1913) pp. 421-4 (9 figs.). 62 SUMMARY OF CURRENT RESEARCHES RELATING TO Study of Sclerotinia.* — W. A. Matheny had remarked that the fungus Sclerotinia fructigena grows always on pome fruits in Europe, and that a form considered identical with it grows only on stone fruits in the United States. He has therefore experimented with artificial cultures on different fruits, and has decided that the European species is different from the American brown-rot : the former is of slower growth ; the conidial tufts differ in size, shape or colour, and the conidia of the European form are larger, while asci and ascospores apparently correspond in size, hut the spores of S. fructigena, the European fungus, are sharply pointed at each end and are free from guttulse. The American species he refers to S. cinerea. Study of Lembosia.f — T. Theiszen has written an account of the genera Lembosia and Morenoella, members of the family Hemihysteri- acea?. They grow on leaves and are found in warm climates, Ceylon, Brazil, etc ' The genera have frequently been confused with Asterina and Microthyrium. The characters of the different species (sixty in all) are described, and their history traced. Synopses of genera and species are added. Germination of Jlcidiospores.J — Otto Kunkel has made experi- ments on the ascidiospores of Gseoma nitens taken from leaves of Rubus frondosus. On germination they produced a promycelium in much the same way as the ascidiospores of Endophyllum Sempervivi. The pro- mycelium consists normally of five cells — a stalk cell without a nucleus, and four nucleated cells. From each of the latter a sterigma is pro- duced bearing a sporidium. The sporidia germinate immediately, either forming a secondary sporidium or a germ-tube. The author questions if the Gseoma nitens can have any connexion with Puccinia Peckiana, as these facts seem to prove a short life-cyle. The only other instance of ascidiospores known to function as rusts is that of Endophyllum. Study of Perennial Rusts.§ — E. W. Olive divides rusts as annual and occupying a limited area of the host tissue, or as perennial and un- limited, pervading practically the whole host-plant with the possible exception of the roots. Among these unlimited species are Puccinia Podophylli, P. obtegens, and Uromyces Glycyrrhizse, the forms that were examined. Olive found three states of mycelial distribution : an intermingled growth of binucleate sporophyte and uninucleate gametophyte in the same host, giving rise to spermogonia followed by ascidiospores and finally by teleutospores in P. Podophylli, or by confluent uredo- and teleutosori in P. obtegens and Uromyces Glycyrrhizse. There was also an unlimited growth of the perennial sporophytic mycelium alone in the two latter forms, producing secondary uredo- and teleutospores in confluent sori. * Bot. Gaz., lvi. (1913) pp. 418-32 (6 figs.). t Ann. Mycol., xi. (1913) pp. 425-67. % Bull. Torrey Bot. Club, xl. (1913) pp. 361-6 (1 fig.). § Ann. Mycol., xi. (1913) pp. 297-311 (1 pi.). ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 63 Lastly there was found a localized binucleate sporophyte mycelium in P. Podophylli, which gave rise to a sorus of teleutospores, and in the other two species to the " summer generation " or " repeating genera- tion," producing secondary uredo- and teleutospores. No fusion of nuclei was observed in any preparation. The ascidio- spores of P. Podophyllii, as well as the uredospores of the other two species, are regarded as secondary in origin and apogamously derived, arising solely from binucleate mycelium. The gametophytic or uninucleate mycelium produces only the pycnidia or so-called spermatia, and in instances where the two kinds of mycelium are intermingled, the uninucleate appears usually to predominate in young tissues over the binucleate. In older and more mature tissues the reverse is the case. Rusts of Nova Scotia.* — W. P. Fraser has published a paper which includes not only descriptive accounts of the species occurring in Nova Scotia, but also a general life history of the rust fungi ; the various forms that occur ; and an account of culture methods, specialization, etc. The cytology is also described so far as known. Under enemies of the rusts he describes Darlueafllum and Tuderculina, and the larva of a species of Cecidomyia. The economic aspect of rusts in Nova Scotia is also fully dealt with. All the genera recorded in North America have been found in the district, with the exception of two — Gallowaya and Hyalospora. Contribution to a Knowledge of Black Yeasts.j — These yeasts are the product of dark-coloured fungi and are generally known as Saccharomyces niger or Torula niger. W. Will bas made an extensive cultural study, and distinguishes three forms. 1. Yeast-cells elongate- ellipsoid. 2. Yeast-eells ovoid. 3. Y"east-cells globose. All of these forms are closely related morphologically and pbysiologicaliy, and are probably only varieties of one original species. No higher development of the organism was obtained, and Will considers that the old names must be dropped ; though until more definite results are obtained he does not feel able to give a more accurate designation. Culture of Polyporus squamosus.J — S. R. Price made cultures of the fungus from the spores on different pieces of wood. Growth was very slow, but finally various structures were formed — without, however, any appearance of a hymenium. At a later date a system of irregular pores appeared on one surface of a long spathulate stalk developed in brigbt light and supplied with a peptone solution. Special attention was paid to the wood-destroying characters of the mycelium. It takes two months to appear after spore-infection of the wood and after a few months more produces " oidia." The mycelial growth was generally stronger in darkness than in the light — but both extremes, darkness and a bright liglrt, were unfavourable to the forma- tion of fruiting structure. The wood -cells were deliguified from the lumen outwards, the middle lamella remaining intact. * Proc. and Trans. Nova Scotia Inst. Sci. Halifax, xii. pp. 313-445 (figs.). + Centralbl. Bakt., xxxix. (1913) pp. 1-2(5 (14 figs). X New Phvtologist, xii. (1913) pp. 269-81 (1 pi. and 4 figs.). 64 SUMMARY OF CURRENT RESEARCHES RELATING TO Mycological Notes.* — F. von Hohnel devotes almost the whole of his paper to the microscopic structure of Mycena, more especially to the cystidia that occur in the gills. He finds that their form is very con- stant, though occasionally more or less variable within the species. They may be slender, threadlike, or cylindrical, cone-shaped or globose, with intermediate forms. The swollen globose cystidia have frequently fungus-like or blunt thorn-like processes confined to the tip of the cystidium or covering the whole free portion. The tips are, however, mostly simple, though occasionally branched or forked. The sharply pointed are the most constant in form. These bodies are most easily examined when the fungus has just reached maturity ; at a. later stage they are apt to be overlooked. Von Hohnel gives a synopsis of the 60 to 70 species studied by him according to the occurrence and form of the cystidia. In each group a certain number bear cystidia only at the edge, others over the surface of the or 7 feet from the Microscope eye-piece, will be the most suitable. It is found that the structural changes which take place in the test-piece are of great importance, the information thus conveyed being not only very interesting but very valuable. Watson and Sons' Micrometer Microscope.* — The production of a Micrometer Microscope that will give readings of the accuracy that is invariably desired is fraught wibh complications and difficulty. Many instruments are made which are stated to give measurements to several thousandths of an inch, but they frequently fail to give even accurate readings in hundredths, not only on account of infinitesimal backlash and strain in the screw movements, but also because of the lack of exact co-ordination between the divided scales and the pitch of the screw, on the drum heads of which fractions of the scales have to be read. Messrs. W. Watson have produced an instrument (fig. 7) which they hope will satisfy the utmost demands in respect of accuracy. It will be noticed that the Microscope is made on the same principle as an ordinary instrument in the upper portion. It has coarse and fine adjustments to focus, the vital portion being the stage. The subject to be measured is placed between adjustable jaws A, and in order to save time, a quick- acting screw B is provided, by means of which a long subject can be moved rapidly across the field to the extreme point that is to be set. The horizontal movement is then effected by means of a standard micro- meter screw C, which may have a thread in millimetres or inches, reading to TT yVo m - or too mm - T ne sca l e D exactly corresponds with the screw. It is verified to be in correspondence with the screw thread, that is, if the screw thread is reputed to produce a movement of ? V mcu * W. Watson and Sons' Special Catalogue : Microscopes and Accessories for Metallurgy, pp. 19-20. ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 73 or " 5 mm. per turn, as the case may be, that amount will be recorded on the scale with unerring - accuracy, and thereby enable fractions to be read on the drum of the micrometer. To obviate backlash, the screw works against a spring which is coiled in a box, thereby abolishing the inaccuracies that creep in on account of strain and backlash. The range of screw movement with the micrometer is one inch. If a greater length is required than this, the stage is moved by means of the quick-acting screw for a further inch, and a pivot bar F, exactly one inch in length is interposed between the end of the micrometer and the Fig. 7. stage plate. This enables measurements up to 2 inches in length to be taken. The vertical movement is effected by means of a rack-and-pinion which again is maintained with a tension coiled spring shown at G. A divided scale of the same accuracy, reading by means of a vernier to ^ mm. or ^ in., whichever may be preferred, is fitted. The greater portion of the measurements are intended to be made in conjunction with the horizontal movement, hence the vertical movement is not pro- vided with the same conveniences for fine measurement. These could, however, be provided, if required. The eyepiece is fitted with a single line for setting and reading, the two ends of the subject to be measured 74 SUMMARY OF CURRENT RESEARCHES 1! ELATING TO being carried by means of the stage micrometer screw, so that the ex- treme edge is exactly on the eye-piece line. The eye-piece can be rotated for vertical measurements. For measuring screws a divided circle is fitted to the top of the body tube, so that by rotating the eyepiece, and reading on the divided circle in conjunction with the stage movements, the diameter, angle, and depth of cut can be exactly ascertained. Fig. 8. Leitz' Double Microscope.*— C. Metz describes this apparatus, which has an optical equipment essentially different from other forms of appar- * Zeitschr. wiss. Mikrosk., xxx. (1913) pp. 188-91 (2 figs.). ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 75 atus intended for observation with both eyes. It consists of two Micro- scopes combined on a single stand. Each of these Microscopes possesses a complete optical equipment : mirror, illuminating apparatus, objective, and ocular. The stage is unusually large so as to receive two preparations. The coarse adjustment, which is by rack-and-pinion, acts simultaneously on the two combined tubes. Two fine screws between the tube and objectives serve as fine-adjustment. For regulation of the ocular width an arrangement is adopted similar to that used in the Greenough Microscope, and, as in the same instrument, the images are directed up- wards by Porro prisms. The upper tube parts, containing the Porro prisms and the oculars, are both movable. The result is that the optical axes are moved • parallel to one another and thus impinge on the ob- server's ocular width ; both images therefore enter his eyes. The images overlap in accordance with that wonderful property of the eye, whereby an image received from the one eye is conveyed by means of a central nerve station to the other. But these images are usually not alike. If the objects can be so arranged that the resultant images group themselves separately in one field of view, both objects can be compared without any further precautions. If the objects do not lend themselves to this, as indeed is usually the case, the semicircular stops are applied to both oculars to stop out half of each field of view in such a manner that in the eye two semicircular fields form a complete circular field, in which both objects separated by a scarcely visible line of demarcation can be observed and compared. If it be desired to observe consecutively both complete images in quick succession, the stops can be opened and shut by a left and right movement. This property makes the double Microscope especially adapted for the comparison of healthy and un- healthy organs, or of adulterated and normal foodstuffs. It would be also possible to compare two objects under different conditions of magnification, of illumination, of bright and dark ground, of ordinary and polarized light. With the usual accessories the instrument could be used as a penological Microscope for the examination of minerals. Its application to colorimetric and spectroscopic tests readily suggests itself. It is, moreover, pre-eminently suitable for stereoscopic observa- tions. Fig. 8 shows this instrument externally. (3) Illuminating- and other Apparatus. Zeiss Pocket Refractometer for Mineralogists and Jewellers." F. Lowe describes this instrument, which has been constructed at the suggestion of the gem expert W. Ran, and which involves an adaptation of the Bertrand-Leiss refractometer. The principle of this refractometer depends on observing the angle of total reflection of rays incident on a face of the crystal, the rays having previously passed through a flint-glai-s hemisphere horizontally placed and rotatory about its vertical axis. Fig. 9 shows a portable form of the instrument. The mirror $p is adjustable and reversible, so that it can be used for downwards or * Zeitschr. f. Instrumeutenk., xxxiii. (191:!) pp. 108-11 (2 figs.). (b SUMMARY OF CURRENT RESEARCHES RELATING TO upwards light. The light can also reach the crystal K horizontally through a diaphragm : H is the hemisphere. After total reflection ;it the flint-glass-crystal surface the light rays pass into the reflection- prism P, and through the ocular-scale S&, in which lies the limit-line (Grenzlinie) and are observed through the ocular 0, which can be tilted about the hinge A, and is independent of the ocular scale. The ocular tube can be inclined by means of the position-screw St, and the hemisphere can be rotated by the screw-head G. It will be noted that the hemisphere partly functions as a telescope objective. The angle really measured is that between the normal to the crystal face and the limit- Fig. 9. rays yielding the limit-line, i.e. the limit-angle of total reflection. The pillar of the instrument is provided with a bayonet-clutch by which it can be secured to a cast-iron base for laboratory use. In the portable form the same clutch is attached to an arrangement on the floor of the case. A diaphragm cap fits on to the ring R, so that extraneous light can be excluded and the incident beam admitted through a little window. Ordinary daylight suffices for the illumination, and the accu- racy attainable is within one to two units of the third place of decimals. The readings are taken on the cylindrical-shaped ocular scale S# and range up to n = 1 -85. The axis of this cylinder is such that, on being tilted into the vertical position, it would, if the prism were removed, ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 77 pass through the centre of the hemisphere H. When the ocular is tilted about the hinge A, the limit-line can be brought into its axis, and therefore can be read off with all desirable sharpness. Watson-Conrady Condenser Vertical Illuminator.* — This instru- ment is shown in fig. 10, and is intended to obviate the difficulties experienced in working with a vertical illuminator. The objects attained by this piece of apparatus are : — 1. Bringing the illumination under a control as complete as that which is obtained with transparent objects and the best substage apparatus. 2. Obtaining the brightest possible illumination from small sources of light. 8. Simplifying and rendering certain the correct placing of the illuminant, whether it be supplied as a fixed portion of the apparatus or separately. 4. Rendering unnecessary the usual short mounting to objectives for metallurgy. Reference to the diagram will show that it is built on the plan of a condenser system in miniature complete with lenses and iris diaphragm. The reflector, which is mounted in a central box, is a large transparent plate. For general purposes a small 4-volt electric lamp may be fixed in a suitable position at the end of the condenser system, and, when work is to be Pig. 10. done, it is only necessary to switch on the current from the battery and everything will be found to be in good order. With this an illumina- tion can be obtained sufficient for visual or photographic purposes. A specially constructed 25 caudle-power lamp of small size is also supplied with fittings to attach to the illuminator, and this lamp can be connected to the ordinary current supply. If an independent illuminant is used, it should be set about 1^ in. from the outer end of the tube. Any small source of light can be used, such as the edge of an oil lamp flame, or, if a very brilliant illumination is required for projection, a small arc-lamp should be used, such as the makers' " Argus." The apparatus is used in the following manner : — The illuminator is attached to the nose-piece of the Microscope, the objective is screwed into it, and approximately focused on the polished metal objects. The light is turned on, and the illumination is then regulated by the inner iris diaphragm so as to cover the extent of the object actually under observation. This eliminates a large amount of stray light, and a con- sequent gain in contrast in the image is obtained. The iris dia- phragm nearest the illuminant is then used in precisely the same manner as that of the ordinary substage condenser, and by its means the cone * W. Watson and Sons' Special Catalogue : Microscopes and Accessories for Metallurgy, pp. 28-9. 78 SUMMARY OF CURRENT RESEARCHES RELATING TO of illumination is adjusted to give the best effect. The illuminator can be fitted with a permanently attached metallic filament lamp, which reduces to a minimum the trouble of setting-up and adjustment. Further, it enables metallurgical work to be done on an ordinary Microscope. Wychgram's New Low-current Microscopical Lamp.* — E. Wych- gram points out that a microscopist's lamp should satisfy the following requirements : — Stability and compactness, with light-control ; applica- bility both to optical bench and to work-table ; maximum light-produc- tion with minimum energy- consumption ; simplicity of construction and of eventual repairs ; absolute invariability of the position of the light-spot. The author points out that all these requirements are only satisfied by the use of right-angled carbons, the horizontal crater carbon lying in the optical axis. Even in such lamps of small dimensions the invariability of light-spot can be depended on. Automatic action com- bined with applicability either to optical bench or to work-table is not so easily attained, and, so far as the author knows, is only attained by a new form of Leitz lamp, which has, furthermore, the advantage of extreme compactness. This new Leitz lamp consists of a plane-sided rectangular box containing the rackwork for the carbon-holders. The positive carbon is moved forward parallel to the upper surface and lies horizontally in the optical axis : the negative carbon is vertical and parallel to the front surface. Behind the box and secured to it is a clock-work, which, although of equal thickness, is half as large as the lamp-box : it is worked with a pendulum with a hair-spring and simple escapement, and can be delicately regulated. The clockwork is controlled externally so that the approximation of the carbons equals the velocity of carbon consumption. The gearing is large and strong, and the risk of magnetic attraction of the steel parts appears to be insignificant. A small hand-wheel regulates the coarse adjustment, the combustion of the lamp, and the length of the arc, exactly as in the Zeiss-Wenle lamp. Some of the lamp data are :— Current intensity, 4-5 amp. ; length of positive and negative carbons, 15 cm.; thickness of positive carbon, 8 mm. ; ditto of negative, 6 mm. ; combustion duration, 2 hours ; perio- dicity of clockwork, 8-10 hours ; focal length of condenser lens, 75 mm. ; weight of lamp without foot, 1'36 kgm. ; thickness of pillar for rider, 10 "8 mm.; minimum distance at which the lens yields an image of crater, 80 cm. The lamp is easily equipped with a U-Y filter and can, therefore, be adapted to luminiscent investigations. New Safety Device for High-power Lenses and Cover-glasses. This instrument (fig. 11) was exhibited and described by C. E. Heath at the November Meeting last year.f A gives the plan and elevation ; B shows it in use on an ordinary stage ; C is a modified form as adapted to an open mechanical stage. In use the apparatus is placed over the objective threads and the lens screwed home. The tube is then racked up till the chain can be slipped over the milled head so as to * Zeitschr. wiss. Mikrosk.,xxx. (1913) pp. 203-5. t See this Journal, 1913, p. 644. ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 79 hang on its stem. When racked down and the focus found, the chain can be drawn taut by turning the adjusting screw at the bottom. The coarse adjustment is thus deprived of further extension downwards, while the fine adjustment is left quite uncontrolled. The protection given by the first form is the more reliable as the fine adjustment is limited also. For a somewhat similar device see this Journal 1904, p. 114, where a " Focusing Safeguard " devised by S. E. Dowdy is described and illustrated. 5TAC£ T 3 B Pig. 11. New Epidiascope.*— VV. Freiherr of Wieser has designed some im- provements in Zeis?' epidiascope for the purpose of producing episcopic projections of very large objects. His desire was to make the apparatus capable of showing the corpse of a fully grown person, and he has been quite successful in attaining his purpose. Simple Method for Obtaining Photomicrographs.!— K. Hulds- schinsky describes a simple and inexpensive method of obtaining photo- micrographs when a projection apparatus is not at hand. He uses for this purpose Leitz' drawing apparatus (fig. 12), which consists of a small mirror obliquely placed over the tube of the Microscope ; fchemosl convenient light-source being Leitz' hand-regulated arc lamp, and the picture to be drawn being projected on to a sheet of paper near the Microscope. For the paper, however, the author substitutes a photo- graphic plate. He screens off the whole light-field between mirror and plate with black paper, and, furthermore, confines the light within a piece of black cardboard inserted so as to enclose object, objective and Abbe condenser. The screen-paper might be replaced by a cardboard box. * Anat. Anzeig., xlv. (1913) pp. 21-31 (4 figs.). t Zeitschr. wiss. Mikrosk., xxx. (1913) pp. 206-7 (1 fig.). 80 SUMMARY OF CURRENT RESEARCHES RELATING TO with blackened inner surfaces, the mirror being set obliquely in one of its sides. The box has a lid for the adjustment of the image, and later- ally a catch for the insertion of the plate. The plate must be laid on a frame of corresponding size whose under surface can be raised or lowered to the height required for the image. In arranging the adjustment a piece of white paper the size of the plate is first laid in the frame. The insertion of the actual plate must naturally be performed in complete Fig. 12. darkness. The light-exposure depends on the light-strength and magni- fication, and varies from fractions of a second up to two seconds. The author finds that with this apparatus very useful photomicrographs can be taken. (5) Microscopical Optics land Manipulation. Exercises in Scientific Microscopy.*— Part 2 of this series has now been published, and has been compiled by H. Ambronn and H. Sieden- topf . It is exclusively devoted to Abbe's theory of the Microscopic image. All the usual grating experiments with their effects on pleuro- sigma angulation are collected and described in such a form that they may be easily followed by the student. The experiments are copiously and clearly illustrated. Ainslie, M. A. — Microscopical Measurement of Magnifying Power: Measurement of Numerical Aperture. [Two very practical and interesting letters on the above subjects.] English Mechanic, xcviii. (1913) pp. 60 and 111. Orueta, Domingo de — La luz ultra-violeta y sus aplicaciones en microscopia con un resumen de los trabajos hechos en el laboratcrio del autor durante el ano 1911 y primer semestre de 1912. [The author gives a very complete account of ultra-microscopical methods and of the results obtained.] Reprinted from the Bevista de la real Academia de ciencias exactas, fisicas y naturales de Madrid (1913) 92 pp. (14 pis.). * Ubung. zur Wiss. Mikrosk. Leipzig : S. Hirzel, Heft 2, 28 pp. (39 figs.) ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 81 (6) Miscellaneous. Quekett Microscopical Club.* — The 493rd Ordinary Meeting of the Club was held on November 25, 1913, the President, Professor A. Dendy, F.R.S., in the chair. The President described a " Red Water Phenomenon due to Euglena.' n J. Burton (Hon. Sec.) read a note " On the Disk-like termination of the Flagellum of some Euglense." Earliest reference to this was Science Gossip, 1879. Saville Kent, "Manual of Infusoria," p. 382, refers to the same phenomenon. After careful in- vestigation the writer had to come to the conclusion that there is no disk, no bull), or sucker, or anything of the sort or the end of the flagellum. The appearance is due to the " kinking " of the protoplasm of the flagellum, a quite common occurrence, and the " disk-like " ap- pearance is observed when the distal end has happened, in coiling or kinking, to touch a part of the flagellum just behind the end, and has, in fact, overlapped and adhered to it. J. Burton also read a note on " A Method of Marking a given Object for Reference on a Mounted Slide." When the object is large enough to be recognized with a hand-lens, place a dot of water-colour over it large enough to be seen with the naked eye. When dry turn a small ring of dark cement round it on a turn-table. When the cement is hard, remove the water-colour with a damp brush. For objects too small to be recognized without a higher power — find and centre the object with a suitable power. For the objective first employed substitute a water-immersion say, a ^ ; put on the front lens as small a drop of water as can be used, carefully focus, and centre. Then rather sharply raise the Microscope tube, and a tiny circular spot of water will be left on the cover-glass over the desired place. Colour this drop with water-colour, dry and ring as before. Any close-working objective may be used for this purpose if a water-immer- sion is not available. E. M. Nelson, F.R.M.S., " On the Measurement of the Initial Magnifying Powers of Objectives." The 494th Ordinary Meeting was held on December 23, 1913. B. M. Draper exhibited and described "A Live Box for the Observation of Insects and similar Objects." He also recommended the use of the ordinary concave Microscope mirror, employed with lamp and bullseye, for the illumination of any large opaque object under the lowest powers. The mirror should be made removable, and can then be fixed, when re- quired, to the upper side of the stage on the end of a jointed arm giving universal movement. B. M. Draper, " Dark-ground Illumination with the Greenough Binocular Microscope." The best form of patch-stop was found to be two small circular patches placed side by side and opposite the two front lenses of the twin objectives. E. M. Nelson, F.R.M.S., " A Peculiar Form of Diatom." E. M. Nelson, F.R.M.S., " On Amphi- pleura lindheimeri." A coarser form of this well-known test has been found having 67,000 striae per inch instead of about 77,000 in the older form. The new Lindheimeri may be recognized by its very long terminal nodules, each nodule being one-third of the whole length of the valve. Feb. 18th, 1914 G 82 SUMM ARY OF CURRENT RESEARCHES RELATING TO In the old form the ratio was one-fifth. The length-breadth ratio in the new form is 7 : 5, in the old 8 : 5. Wright, F. E.— (1) Graphical Methods in Microscopical Petrography. (2) Graphical Plot for Use in the Microscopical Determination of the Plagioclad Feldspars. Amer. Joum. Sci., xxxvi. (1913) pp. 509-42 (10 pis.). B. Technique.* ^"(DiiCollectiiig' Objects, including- Culture Processes. Cultivation of Cladothrix dichotoma.f — The material for culti- vation was obtained from a ditch in the neighbourhood of a sewer. The water was turbid and contained organic impurities. In the month of July a strong growth of green plants was found at the edge of the ditch. Some leaves were taken, examined for the presence of cladothrix, and placed in a • 5 per 1000 meat extract fluid in glass cylinders pro- vided with close-fitting lids. These cylinders were kept, some in day- light, some in the dark. Vorticellae and such types died out within twenty-four hours. After two or three days filaments of cladothrix were seen attached to the leaves. These were freed from the leaves and transferred to fresh fluid. After several such transferences to remove as far as possible extraneous organisms, the filaments were transferred to agar plates containing 0*05 p.c. meat extract. The cladothrix filaments on this medium soon outgrew the other organisms. A pure culture thus obtained was sealed up and kept under anaerobic conditions. It was found alive after two months. P. Linde further describes the characters of the culture. It con- tained threads of varying dimensions, and it was thought possible that more than one species was present. Single-filament cultures were examined by means of the Indian ink method, and it was found that the same variations in size were to be observed. Egg-broth. :]: — A. Besrekda and F. Jupille have found that many organisms grow well on a medium containing four parts of white of egg (10 p.c. solution) in distilled water, one part of yolk (10 p.c. solu- tion), and five parts of peptone broth. Such organisms as pneumococci, meningococci, gonococci, B. melitensis, and B. pertussis of Bordet and Geno-ou grew luxuriantly, and retained their vitality for several months. On a modified medium, containing 100 c.cm. of broth without peptone, 20 c.cm. of white (10 p.c), and 5-20 c.cm. of yolk of egg (10 p.c.) tubercle grew with remarkable luxuriance and rapidity. A tuberculin * This subdivision contains (1) Collecting Objects, including Culture Pro cesses ; (2) Preparing Objects ; (3) Cutting, including Embedding and Microtomes ; (4) Staining and Injecting ; (5) Mounting, including slides, preservation fluids, etc. ; (6) Miscellaneous. t Centralbl. Bakt., 2te Abt., xxxix. (1913) pp. 372-5. % Ann. Inst. Pasteur, xxvii. (1913) pp. 1009-17. ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 83 prepared from such a growth was found capable, when combined with serum from a tuberculous patient, of binding complement. Cultivation of Spirochaeta recurrens.* — S. Hata gives an account of his work undertaken in order to confirm that of Noguchi upon the cultivation of S. recurrens. Xoguchi used fresh ascitic fluid in which a small piece of rabbit-kidney was immersed. This is inoculated with a small quantity of blood containing S. recurrens, and the organism multi- plies when incubated at 37° C. for two to three days. The maximum growth is reached on the eighth day. Spirochetes thus cultivated show a tendency to rapid degeneration. Hata found it quite unnecessary to cover the ascitic fluid with paraffin oil as Noguchi had recommended. He found also that serum could be substituted for ascitic fluid. Blood was drawn from the veins of a horse into a tall cylinder, and set aside for the serum to separate. Serum is then put into tubes and mixed with normal saline : > - - pq - - o o d 00 a> > to a 3 ^3 CO co tS p t; "- 1 CD r^HO-*00)OtM c/Jt-COOntf-H/liOlO rH rH M CNa)t-OCllOCN ^ 03 lO i— I -* iO CM K3HHH rH rn A eg c6 a -* »■< d 3 ® o EH to CD Pj c5 Pj no 1—1 CD d * ™ CO a O -aPn^ o *>.3 u d f=h £ n J to" ® CD ^ ^ ™ & o I i *4 1 Sh -~ rrt CO d coco&oP pq t3 d SO =*} r. 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The Society had been wonderfully active and vital in the past, and a great future still seemed to be assured to it. Mr. Watson Baker, in moving the adoption of the Report, said that it had been a great pleasure to hear so satisfactory a statement of affairs. It had not been quite possible to grasp all the figures of the Financial Statement which had just been read, but full opportunity for doing so would be offered on the publication of the Report in their Journal. He considered that it was perhaps only very few who realized to the full ex- tent what the activities of the Secretaries, Treasurer and Council had been during the last few years. The way in which economies in expen- diture had been effected in the production of their Journal, without im- pairing its high level, and in fact the splendid way in which all the affairs of the Society generally had been conducted, reflected very great credit on their Officers. He had extreme pleasure in proposing that the Report of the Council and the Statement of Accounts should be adopted. Mr. Tierney, seconded the proposal, which was carried unanimously Mr. Rousselet then said a few words in description of the Leeuwen- hoek Microscope presented by Sir Frank Crisp to the Society, and which was handed round for examination by Members. Mr. Rousselet said that this apparatus was a copy of the simple Microscope invented and made by Leeuwenhoek before 1678, with which this " father of Microscopists " made his numerous and remarkable discoveries, which were nearly all published by the Royal Society of Loudon between 1673 and 1722. Leeuwenhoek made his Microscopes, lenses and all, with his own hands, but gave no details of their construction to anyone, a secret which he jealously kept to himself all through his long life. Beyond the fact that his observations were made with " simple Microscopes " nothing was known about them by his contemporaries. At his death in 1723, at the age of 91, he bequeathed to the Royal Society a cabinet con- taining 26 of these Microscopes which unfortunately are now lost. In 1S86 Professor Hiibrecht of Utrecht University brought to London one of Leeuwenhoek's Microscopes belonging to the Zoological Laboratory of his University, and from this original Sir Frank Crisp, then Secretary of this Society, had an exact copy made for his own collection. Last year, at the time of the International Congress of Medicine held in London, the Medical Society obtained the loan of this copy for their museum, and afterwards they joined the Royal Microscopical Society in a request for permission to have copies made of this interesting old Microscope, whereupon Sir Frank Crisp very kindly offered to supply a copy of it to each of these Societies. This has now been done, and the Society's best thanks are due to the donor for this generous gift, w T hich, although only a copy, fills a great gap in the Society's collection, and is correspondingly appreciated. The Microscope consists of a single biconvex lens of about \ in. focus, mounted in concavities between two thin plates of copper about :i in. high by about 1 in. wide, riveted together in three places, and with a very small hole on each side ; a very simple and primitive 106 PROCEEDINGS OF THE SOCIETY. arrangement of screws for holding and focusing the object in front of the lens completes the apparatus. For figures and further particulars see this Journal, 188(5, p. 1047 ; also -John Mayall, jun., Cantor Lectures before the Society of Arts. 1885, published in that Society's Journal for 1886 ; and for an account of tin- wonderful work done by Leeuwenhoek with these primitive means see Dr. Plimmer's Presidential Address in this Journal, 1913 pp. 121-135. The President announced that the Scrutineers having handed in their report as to the result of the Ballot, the following Fellows pro- posed by the Council had been duly elected as the Officers and Council for the ensuing year : — President Prof. G. Sims Woodhead, M. A. M.D. LL.D. F.R.S.E., etc. Vice-Presidents— J.E.Barnard ; Wynne E.Baxter, J.P. D.L. F.G.S. ; E. Heron-Allen, F.L.S. F.G.S. F.Z.S., etc. ; David J. Scourfield, F.Z.S. Treasurer — Cyril F. Hill. Secretaries— J . W. H. Eyre, M.D. F.R.S.E. ; F. Shillington Scales, ALA. M.D. B.C. (Cantab.). Ordinary Members of Council — F. W. Watson Baker ; Frederic J. Cheshire ; A. N. Disney, M.A. B.Sc. ; Arthur Earland ; R. G. Hebb, M.A. M.D. F.R.C.P. ; John Hopkinson, F.L.S. F.G.S. F.Z.S. ; J. W. Ogilvy ; Percy E. Radley ; Julius Rheinbers: ; Charles F. Rousselet ; A. W. Sheppard ; E. J. Spitta, L.R.C.P. (Lond.) M.R.C.S. (Eng.). Librarian — Percy E. Radley. ( 'urator of Instruments, etc. — Charles F. Rousselet. Curator of Slides — Edward J. Sheppard. The President then delivered his annual address, entitled " The Microscope and Medicine." Mr. Michael said he wished to propose the usual Resolution, that of returning thanks to their President for his Address, and to ask for his con- sent to print it in the Journal. It was not usually easy to find anything distinctive to say on the subject of a President's address, but of late years they had listened to a series of addresses from men who specialized in their own subjects and who had enabled the proposer to ask all present to join in the vote of thanks with genuine accord. The address thev had heard that evening had not fallen behind the high level of its predecessors : it had brought to their notice the use of the Microscope as a working tool in one very important branch of science, and shown how improvement in the instrument brought in its train increase of the quality of the work done to the far-reaching benefit of races profiting by such improvement, and to the perfection and advance of science in general A most important and interesting subject had been dealt with by their P esident in a clear ai d attractive way, and his address would form a record of the progress of the Microscope in that particular branch PROCEEDINGS OF THE SOCIETY. 107 of which he had treated. He asked the Meeting to return their best thanks to their President for his very interesting address, and to beg his permission to print that address in the Journal. Mr. A. W. Sheppard seconded the proposal, which was carried with acclamation by all present. The President thanked Mr. Michael very heartily for his kind words, and accorded his consent for his address to be published in the Journal. Mr. Disney proposed that a hearty vote of thanks be accorded to the Honorary Officers — President, Secretaries, Treasurer and Council — of the Society. It was only necessary to ask those present to remember the successful meetings held during the past year, culminating in the satisfactory Report and Balance Sheet, to recognize the unceasing labours of their Officers. With these recollections in their minds he thought they would find no difficulty in supporting the motion he proposed. Mr. Wilson seconded the vote to the Honorary Officers, which, having been put to the Meeting, was carried with acclamation. Mr. Hill, the Honorary Treasurer, said it was always a pleasant duty to reply to the vote of thanks on behalf of the Honorary Officers, and he thanked all present for the vote accorded. There was a good deal of work to be done in connexion with the Society, and a fair amount of time was given to it, and it was gratifying to know that their labour was appreciated, and he hoped that they would still continue to merit that appreciation. The Conversazione was an innovation which had given a certain amount of extra work, but on behalf of the Officers he felt that he could say that they would only be too delighted to con- tinue to give their services in promoting the welfare and success of the Society. One more thing he would like to say, and that was on the subject mentioned by Dr. Shillington Scales at the last meeting. It was a very easy thing for the Council to get out of touch with the Fellows of the Society, and they would always welcome very heartily any suggestion from Fellows, particularly as to nominations to the Council. Mr. Waldron Griffiths proposed that a hearty vote of thanks should be passed to the Auditors and Scrutineers of the Ballot for their work in connexion with the Society. The work of the Auditors could not be said to be very onerous, but it was none the less useful, and though the work of the Honorary Treasurer was excellently done, yet it was not likely to be less well done by having the sharp glance of the Auditors behind it. Mr. E. J. Sheppard seconded the vote, which, having been put to the Meeting, was carried unanimously. The President called attention of Fellows to the Roll, and any pre- sent who had not signed were asked tit do so. 108 PROCEEDINGS OF THE SOCIETY. The President announced that the next Ordinary Meeting would take place on Wednesday, February 18th. The next Meeting of the Brass and Glass Section would be held on the 28th inst., at 7.30. The Biological Section would meet in the Society's Rooms on the 4th February. The President announced that a letter had been received from the Quekett Microscopical Club, cordially inviting the Fellows of the Royal Microscopical Society to be present at a Conversazione to be held on the 10 th February next, by the kind permission of the authorities of King's College, Strand, W.C., in the Great Hall of that building. The meeting was timed to commence at 7 . 30 p.m., and Microscopes would be in position soon after 7 o'clock. Tickets were to be obtained from the Hon. Secretary, James Burton, Esq., 8 St. Hilary Road, West Hampstead, N.W. Morning Dress. New Fellows : — The following were elected Ordinary Fellows of the Society : — Ernest Hermann Anthes, Major William Cooke Daniels. Theodore Crawford, Albert McCalla, M.A., Ph.D. JOURNAL OF THE ROYAL MICROSCOPICAL SOCIETY. APRIL, 1914. TRANSACTIONS OF THE SOCIETY. V. — The President's Address. By G. Sims Woodhead. (Bead January 21, 1914.) Through your kindness, gentlemen, it falls to my lot to occupy a position of which I feel I may justly be proud, but I recognize that, the latest, I am probably one of the least worthy of the series of men honoured by your choice. Former Presidents have, in return for the honour you have done them, conferred great distinction on our Society : many of them have contributed lavishly to the improvement of the Microscope, and much to the development of the science of Microscopy ; and I cannot but be impressed by my inability to maintain the high standard set by my predecessors, and to prove myself worthy of the great traditions of this corporation. Only since I became a member of this Society have I realized how dependent upon others I have been for the apparatus with which to carry on investiga- tions in the one department of study (Pathology, or the science of disease) to which I have devoted my professional life. As I have come to realize this, and as one branch of that study depends so largely for its successful prosecution on the use of all that pertains to the Microscope, I have decided, with your permission, to give some account of what Medicine, and therefore Humanity, owes to the Microscope. My colleague, Sir Clifford Allbutt,* defending the thesis that medicine and surgery are but internal and external medicine, and that external medicine advanced by leaps and bounds at * The Historical Relations of Medicine and Surgery to the End of the Sixteenth Century. London, 1905. April 15th, 19J4 I 110 Transactions of the Society. periods when internal medicine was lethargic and even stationary, attributes this to the fact that to the surgeon the application of scientific methods (observation together with close, repeated, and careful reasoning from ascertained facts as recommended by Hippocrates) was not only more necessary than to the Pnysician, but more readily achieved. The lesions he had to treat were patent to all, and the cause of them was so often known and so frequently of traumatic origin, that rational and effective treatment was more easy of application, and satisfactory results more readily obtained. Moreover, what was evident to the surgeon was also laid bare to the eye of the passer-by : it was not easy to hush up failures and hide mistakes. In internal medicine, on the other hand, excuse might be made by the physician that he could not expose the lesiuns with which he had to grapple, and that, in many cases, it was not possible to trace the causes or even the course of the disease. Hippocrates, indeed, insisted upon the need of careful observation and classifica- tion of symptoms, and the tracing and following out of the action of remedies ; and from time to time there have been those who have come back to his first principles in carrying on the study of such diseases as are relegated to the domain of internal medicine ; but for long — indeed, until the era of the Microscope — the physician remained the slave of convention, bound by the crude and ill- founded hypotheses of men, who, instead of studying nature, relied on the " authority " of those as ill-informed as themselves. They treated disease as an entity in itself and something apart from the patient. Custom, popular superstitions, religious susceptibilities, were, through the middle ages, all against the handling or dissection of the dead body, and although Vesalius and Eustachius and others, now and again, made careful dissections and thorough examination of the bodies of patients, no sustained and systematic account was kept of the condition of the organs and tissues of patients who had succumbed to disease, conditions that could be correlated with the symptoms manifested during life. Then a first step was taken, and post-mortem examinations were made on a considerable scale by Antonio Benivieni, who died in 1502, and whose work " De abditis causis morborum" was published posthumously in 1507. Allbutt says of him : " Before Vesalius, before Eustachius, he opened the bodies of the dead as deliberately and clear-sightedly as any patho- logist in the spacious times of Baillie, Bright, and Addison." It was not, however, until Giovanni Bittista Morg.igni (1682-1771), as Professor in Padua, published his great work " De sedibus et causis morborum " (1761) that the way was opened up for the microscopist. There have been many great morbid anatomists since — Rukitansky, Lancereaux, Virchow, Wilks, Hamilton, Hebb, Shattock, and others — but morbid anatomy was but the basis of pathology, and not until the Microscope was called to the aid of the later of these workers and others in the field of pathology was it possible to reach our The President's Address. By G. S. Woodhead. Ill present advanced and advancing position. When such marked and extraordinary changes were found to have taken place in the organs of the body, physicians asked : " How can a patient with organs so diseased possibly remain alive ? " and they came to be amongst the most pessimistic of men. On the post-mortem table they saw but the final lesions or products of disease, and whenever a physician was called to treat a patient suffering from one of the diseases the morbid anatomy of which had been studied, he recog- nized that he had seen the lesions on the post-mortem table, and assumed that the disease must necessarily follow the course of those of his previous cases that had proved mortal. Morbid anatomy could carry him no further ; and it was only as it came to be realized that, with the aid of the Microscope, changes invisible to the uneducated and unaided eye could be demonstrated, that men gradually learned that lesions or damage to organs and tissues must have small beginnings which might easily be righted ; but that, once begun, unless checked by treatment, natural or artificial, they must, after passing through various stages and phases, become like the lesions seen on the post-mortem table, the patient then being able to withstand their ravages no longer. The Microscope, then, came as a harbinger of hope to the physician. Normal histology is still a growing science, and much remains to be done in this field of investigation ; but with each step made, pathological histology has advanced — always a step behind, it may be, but seldom more than that step. The medical student of to-day knows more of the histology of the kidney, for example, normal and pathological, than did Malpighi, Henle or Bowman ; and has a knowledge of other organs and tissues that was hidden from the teacher of thirty years ago. As a result of all this, internal medi- cine has gradually come to be studied on the same plan and plane as external medicine, and is, indeed, now making more rapid strides than surgery, which, however, it often calls upon to complete its work. Our late distinguished President, Dr. Plimmer, in his interesting and illuminating address on the Dutch erstwhile linendraper's apprentice and Bedellus,* told us how his hero Leeuwenhoek, a non- medical man, opened up the way along which physicians and sur- geons were in after years to toil so arduously, but in the long run, under the leadership of another brilliant layman, so successfully. In these days of biological chemistry and of theories of immunity, men are apt to forget or to lose sight of the path by which we have arrived at our present heights, though they realize clearly enough that no great advances have been made in our knowledge of the functions of the human body until accurate information has been gained as to their structure, first with the aid of the scalpel, and then * See this Journal, 1913, p. 121. i 2 112 Transactions of the Society. of the Microscope ; and that as these have gone hand-in -hand in the past, so in the future they can never be dissevered. William Carruthers, in his Presidential address delivered in 1902,* notes that Cornelius Drebbel is said to have brought the first compound Microscope to England from Holland in 1619, and that the first application of the Microscope to the examination of the minute structure of plants was made by Eobert Hooke, Secretary of the Koyal Society in 1677, who constructed simple Microscopes and yreatly improved the compound Microscope. Hooke's work is specially interesting to Cambridge men in that much of his histo- logical work preceded that carried out by Nathaniel Grew, who acknowledges his indebtedness to Hooke, and who in all probability worked with the same Microscope. Grew's work was of extreme interest to all botanists, but especially to his fellow-alumni in Cam- bridge, and were it not that Carruthers has given such an admirable account of his training, life and work, I should be tempted to enlarge somewhat fully on Grew's contribution to histology. Even though I refrain from this, 1 cannot help drawing attention to the fact that Grew puts into very concise and convincing form a corrobora- tion of Sir Win. Eoberts's contention referred to elsewhere. Grew was led to his studies by what he noted of the observations of others ; for he says in the preface to his "Anatomy of Plants" (1682), " The first occasion of directing my thought this way was in the year 1664, upon reading some of the many and curious inventions of learned men, in the bodies of animals. For, considering that both of them (plants and animals) came at first out of the same Hand, and were, tberefore, the contrivance of the same Wisdom, I thence fully assured myself that it could not be a vain design to seek it in both. And being then newly furnished with a good stock of seeds, in order to make a nursery of plants, I resolved, besides what I first aimed at, to make the utmost use of them for that purpose, that so I might put somewhat upon that side the leaf which the best botanies had left bare and empty." We read Mr. Carruther's defence of Grew and his work with keen interest, especially as he attributes much to Grew without belittling Malpighi, on whose behalf Schleiden makes claims as against Grew's independence, which certainly cannot be upheld. He grants that Italy may well be proud of her son, but that England has no less reason for her pride in Grew. Out of this controversy comes the comforting assurance that in all these controversies men's work is fitted into the great mosaic of scientific achievement, each receiving his meed of credit, if not in his own, in a subsequent, generation. To Hooke undoubtedly belongs the discovery of the vegetable cell, a discovery not at first recognized by Grew, but gradually accepted by him. Grew appears * See this Journal, 1902, p. 129. The President's Address. By G. S. Woodkead. 113 to have been Secretary of the Royal Society in 1677, when Hooke was also in office.- A great Dutch contemporary of van Leeuwenhoek, Jan Swam- merdani (1637-1680), was the first, apparently, to give a descrip- tion of red blood corpuscles (1658) ; whilst he laid all histologists under a great debt by introducing warm wax injections, by means of which a much more intimate knowledge of the relations of the blood-vessels to one another and to the surrounding tissues was obtained. Leeuwenhoek, who is described as an inheritor of well-to-do brewers, is said to have " led an easy-going life " ; it is allowed, however, that during that " easy-going life " he contributed no fewer than 375 scientific papers to the Royal Society of London, and 27 to the French Academy, which "contain, in addition to a vast amount of work on animalcule? and plant histology, many dis- coveries of capital importance to medicine," amongst these the histological characters of voluntary muscle, from which has arisen all our present knowledge of the mechanism of muscular con- traction. They also contain an account of the structure of the crystalline lens, which has provided the modern physiologist and pathologist with a basis on which to build up the pathology of cataract. I would refer those who wish to know something about the Microscope with which Leeuwenhoek did his work to Mr. Nelson's paper,* and it is interesting to note that he made out the transverse diameter of the red corpuscles in human blood to be T340 tn °^ an inch, a measurement that differs very considerably from that obtained by use of our present lenses, 33^0^ °f an mcn - Histology has ever been a bone for which the anatomist on the one hand, and the physiologist on the other, have contended Were we to consider merely the earlier microscopic researches on the structure of the tissues, we should undoubtedly have to cede this branch of research to the anatomist, as it is to Marcello Malpighi (1628-1694), to whom reference has already been made, that we owe much of the most fruitful and accurate of the early work on this subject. After professing anatomy in three Italian Universities, Malpighi died whilst acting as physician to Pope Innocent XII. Human anatomy was but a small part of the field tilled and cultivated by this indefatigable genius. As pointed out by Dr. Plimmer, the final demonstration of Harvey's almost- demonstrated theory of the circulation of the blood was given by Malpighi, who, with his Microscope, traced it in its course through the capillaries of the lungs from one chamber of the heart to the other, demonstrating not only the presence of these capillaries, but their structure. Insects, animals, plants, histology, embryology, * See this Journal, 1910, p. 42, "What did our forefathers see in a Micro- scope ?" 114 Transactions of the Society. and physiology, all came within his ken, and to him, as modern nomenclature indicates, we owe much of our early knowledge of the structure of the skin, of the structure and functions of the organs of taste, of the lungs, liver, spleen, and kidney, whilst on his observations is founded our present knowledge of the developing ovum. So pregnant were his researches on the structure and re- lations of the capillary vessels, and on the lymphatic glands and spleen, that of the first it has been said that " Harvey made their existence a logical necessity ; Malpighi made it a histological cer- tainty."* Whilst in connexion with the second — observations of special interest to the pathologist — he described the enlarged lym- phatic glands and the curious suet-like nodules in the spleen which were afterwards more fully described by two great English physicians of the nineteenth century, Hodgkin in 1832,t and later Samuel Wilks, who, attaching to this disease the name of the earlier observer, termed it Hodgkin's disease, lymphadenoma, or pseudo-leukaemia. By his indefatigable researches, Malpighi staked a claim for the anatomist in the field of histology, a claim that they cannot be asked to resign unless good cause can be adduced why they should do so. That cause now exists. For some time after the birth of physiology the Micro- scope could play but little part in the elucidation of the problems' with which the physiologist had to deal ; but, as the Microscope was improved and histology was advanced almost to the dignity of a separate branch of science, it soon became manifest that altered function is invariably associated with altered structure, and that it is possible to determine by careful histological examination of secretory cells whether they were resting, or whether they were functionally active at the time that their structures were "fixed." Moreover, it may be determined whether such cells as those of the brain were resting when fixed, were active after a period of rest, or whether they were fixed at the end of a long or strenuous period of activity. Accepting and verifying the observations of the normal histologist and physiologist, the pathologist has, by means of the Microscope, been able to trace the various stages of stimula- tion by morbid irritants of the cells of tissues and organs, to follow the processes by which these cells and tissues have become more or less permanently modified, and to observe the changes during their reversion to their original and normal condition ; or, as they have gradually wasted or degenerated, until they reached a stage at which not only are they useless to the individual but are by their presence an actual menace. Living, they had a useful function to perform ; dead, they are foreign bodies, which not only cumber the ground, but may harbour enemies to the organism that otherwise could find no foothold or coign of vantage from which to attack it. * Fraser Harris, Nature, London, 1911, p. 584. t Med. Chi. Trans. London, 1832, xvii, p. 68. The President's Address. Bij (I . S. Woodhead. 115 It is sometimes cast up as a reproach against the surgeon and physician that with all their microscopic examination of tumours they have, as yet, been unable to find the cause or to explain the origin of tumours. It must be remembered, however, that specific etiology is, after all, but of recent growth, and although the demonstration of the specific causes of a few diseases is still awanting, we have still been able, even in those in which we have failed to do this, to give guidance to the surgeon or physician as regards the prognosis of his case, to help him in carrying out treatment, and in many cases to relieve the suffering, both physical and mental, of the patient. Before the days of the Microscope the surgeon had little to guide him as to the probable course of the various tumours that he met with. He knew that they could be divided into benign and malignant, but he had few data on which to determine to which class a particular tumour might belong. With the advent of the Microscope all this was change* 1. Certain tumours, although growing independently, were found when examined histologically to depart little from the structure charac- terizing normal tissues, and did not give rise to any secondary growths ; these proved to be benign, and, except mechanically, interfered little with the health of the patient. Other tumours were found to depart somewhat widely from normal adult tissues in arrangement, in their structure, rate of growth, and degree of development. These often gave rise to secondary growths at a distance, and so invaded and interfered with the tissues of the vital organs of the body that they came to be looked upon as malignant, in that the patient succumbed, sometimes very rapidly, in consequence of this invasion. A microscopic examina- tion of all tumours is now carried on as a matter of routine by most surgeons at the time of operation, and the morbid histologist, by gradual improvement of methods, has succeeded in showing how these tumours spread, and even in marking the points to which the tumour has advanced. He has enabled the surgeon to become gradually more and more confident in effecting the com- plete removal of these tumours, and so prolonging, sometimes to the full span, the life of his patient. Again, dealing with a benign tumour, a microscopical examination enables him to assure his patient that it will not return, whilst, even in the case of malignant tumours, he is able to give some indication as to whether he has removed the whole of the ramifications of the tumour mass. Thus, though the microscopist has not been able to demonstrate the causes of tumour growth, his work has not been entirely in vain. As one whose main interest in scientific work must necessarily have a bias in the direction of pathology, I might descant for hours on this aspect of the value of the Microscope in medicine, but I realize that, except generally, it can have but little attrac- 116 Transactions of the Society. tion for those whose interest in the use of the Microscope is not so circumscribed. I wish to insist that were it not for the con- tributions made by the histologist, whether dealing with animal or vegetable tissues, modern biochemistry could have had no existence, and to indicate that those who are engaged in the stud) 7 of chemical problems which now occupy some of the greatest minds might do worse than treat with greater sympathy the methods and work of the men who laid the foundation on which is built up one of the greatest branches of modern science, Biological Chemistry. The late Sir William Roberts often gave expression to a fondly cherished idea of his that art, philosophy, and even literature might ebb and flow in tides, and that these might be brought to perfection by individuals, or groups of individuals, but that each individual must attain great heights for himself, often unaided by either his predecessors or his fellows, no body of knowledge or experience of past generations serving as a high ground from which new generations might rise still higher. With science, and where man turns to nature for his knowledge, how different are the conditions. " Natural " knowledge once gained and recorded is available for all time, and although but few may have the insight to interpret, and may pass by blindly and ignore pointers and land- marks which should guide their footsteps, these pointers and land- marks abide for ever and for the use of those who can read them aright. Roberts believed that the great nations of the past, with their philosophy, their literature, and their art, have degenerated as they have become conventional, and even with their high traditions have come to be of but little account, whilst those who have based their success on natural and physical science, and have trained their active workers in the school of observation, and only then in reasoning and argument, have taken a path that can but lead them to higher things and broader knowledge. That this holds good we have ample evidence in the history of the Microscope and micro- sec py. Each step forward has made further advance possible ; the simple lens was succeeded by the compound Microscope, lenses have been corrected, the mirror, the parabolic reflector, the con- denser, and all of that marvellous series of accessory illuminating- apparatus, the increased magnification and definition, the opening up of the angle of aperture, and the wonderful apparatus for demonstrating structure and the use of monochromatic light, have placed in the hands, even of the tyro, powers of investigation far beyond those possessed by the most able and skilful workers of half a century ago, witli the result that neither the anatomist nor the physiologist with his ever-widening field of observation and work can have time or energy to devote to the many histological problems that call for solution by the microscopist. Embryology, bacteriology, protozoology, each calls for its own devotees, but to each, skill in the use of the Microscope and the interpretation of The President's Address. By G. S. Woodhead. 117 microscopic observation is the foundation on which all new knowledge must be built up. The common feature of this as of all other results obtained by honest work in any field of science truly recorded, is that it always remains a coign of vantage from which fresh fields may be surveyed and explored new regions full of beauty and wealth and from these again still greater lands and more beautiful. Although van Leeuwenhoek, through his close association with the Koyal Society of London and the French Academy of Sciences, is, very rightly, most closely associated with the development of microscopy in relation to medicine, we have to go back to Athanasius Kircher of Fulda, a Jesuit priest, scholar and microscopist, for the first* of that long series of investigations into the microscopic causes of disease that shed such lustre on the seventeenth century. This work lay dormant for a period and bore little fruit, but it was again brought to light in the latter part of the eighteenth century with results as far reaching and important to men as were those obtained by Galileo (1609), whose "telescope had given a glimpse of the intimate vast in astronomy. "t Although Kircher' s " worms," which he found in decaying matter, were certainly not met with in the blood from plague patients which he examined, it is possible, as Loeffier % points out, that he actually saw some of the larger bacteria met with in decaying matter, working as he did with a magnification of some 32 diameters. However this may be, such magnification and definition as he could obtain were not sufficient to enable him to discriminate between the pus cells or leucocytes and rouleaux of red blood corpuscles and these minute organisms. These observations, however, trained Kircher's mind on the subject of the causation of disease. He was convinced that disease was produced by something that could multiply, something that had the attributes of a living organism, and he stated very definitely his belief in a contagium animatum as to the cause of infective disease. It is interesting to find, as pointed out by Garrison, that the great Veronese virtuoso Girolamo Fracastoro (Fracastorius), who " shares with Leonardo de Vinci the honour of being the first geologist to see fossil remains in their true light (1530)," and "was also the first scientist to refer to the magnetic poles of the earth (1543) " in a treatise " De contagione" (1546), "states with wonderful clair- voyance the modern theory of infection by a micro-organism (seminaria contagionum)," thus anticipating Kircher by about 112 years. Garrison, in a footnote, adds : " It is to be remembered, however, that Fracastorius nowhere refers to the latter as living * Ars magna lucis et umbrae, Romse, 1646 ; Scrutinium . . . pestis, Romae, 1658. t An Introduction to the History of Medicine, by Fielding H. Garrison, A.B., M.D., 1913. X Vorlesungen die Geschichtlicbe Entwickelung der Lehre von den Bacterien. Leipzig, 1887, p. 2. 118 Transactions of the Society. organisms (contagia animata), but describes them (as if in terms of physical chemistry) as something very like our modern ' colloidal systems,' although he regards them as capable of reproduction in appropriate media. As between Fracastorius and Athanasius Kircher, the decision of priority in regard to the germ theory will depend upon whether the arbiter is a materialist or a vitalist." * When Kircher, Swammerdam, Hooke, Leeuwenhoek demon- strated the presence of minute organisms in decomposing matter, in material taken from carious teeth and in the excreta of patients suffering from diarrhoea, they laid the foundation of our present knowledge of specific infective diseases, and, imperfect as that knowledge is, it has enabled those working at the cure and pre- vention of disease to initiate and carry out a plan of campaign that has reduced mortality aDd diminished suffering to an extent that could not have been anticipated even later than half a century ago. At the time they were obtained the findings of these observers were accepted as curious and interesting, no doubt, but as being of so little practical importance that few workers deemed it necessary to continue them or to make any special deductions from them. Later, however, Donne, finding vibrios in pus as well as in the secretions and excretions of the human subject, made a real attempt to connect the presence of microscopic organisms with the occurrence of an infective disease. In all probability Donne's observations were incorrect, or rather his deductions therefrom, for in 1837 he appears to have convinced himself that the presence of these organisms was purely accidental. His observations, however, suggested a new meaning and importance for the study of vibrios and monad-like organisms, and micros- copists of all degrees of eminence took up their study, and there followed a time of preparation for the great advance that was made forty or fifty years later by Pasteur, Koch, and Lister. There had, of course, been preliminary tilling of the ground, but in 1837 Theodor Schwann,! a German anatomist and physiologist, and Cagniard Latour,| a French chemist, working independently, demonstrated that Leeuwenhoek's yeast globules present in fer- menting beer and wine were really living organisms, probably plants, of a low order, which, multiplying by budding and by fission, might be regarded as setting up fermentation by their vital activities. With this observation in their minds, and study- ing the course of certain infective processes, they came to the conclusion that both fermentation and disease might be the result of the vital activity of similar, if not identical, organisms. Bohm, with his Microscope, looked for and found yeasts in the intestinal * An Introduction to the History of Medicine, by Fielding H. Garrison, A.B., M.D., 1913. t Mittb. a. d. Verbandl d. Gesellscb. Naturf., Berlin, Bd. ii. s. 9. X Ann. d. Cbim. et Pbys., Paris, 1838, t. lxviii. p. 206. The President's Address. By G. S. Woodhead. 119 contents of patients suffering from cholera, but, as he found them only when the patient had taken beer, and being a wise and observant man, he wrote them down as having no special significance in relation to the disease Then came the work of Bassi(1837),* who made a real advance for us by his careful study of silk-worm disease (muscardine), with which he found associated a vegetable organism or fungus, whose spores appeared to be exceedingly infective even for healthy caterpillars These spores were transferred by direct contact or by currents of air from the affected to the healthy larvse, germinat- ing on the skin, making their way inwards, and so producing the specific disease. Bassi thus was able to demonstrate that the lower plants are capable of living parasitically on animals as well as on plants. Others, also, seem to have been greatly occupied at this period with the question of parasitism, for we find that just about the same time the itch mite, Acarus scabei — which had been described by the Cordovan physician, Avenzoa (died 1164), and then forgotten until Bernard de Gordon, a Scottish physician who taught in Montpellier at the end of the thirteenth and beginning of the fourteenth century, re-discovered it, though it was again lost sight of for centuries — was again " re-discovered " and brought into prominence as the cause of itch. All these important observations made in the thirties of the nineteenth century drew attention to the question of the exist- ence of a living contagious agent, the contagium animation, and Jacob Henle (1840), histologist and microscopist, summing up the evidence at his disposal,! concluded that the contagia of diseases carried by air currents, as well as of those resulting from direct contact with patients suffering from contagious disease, must be living organisms, capable of continued, and probably independent, existence, for some time at least, having the power of multiplying and able to produce special substances, poisons or ferments, that act upon animal tissues, altering their functions or bringing about their disintegration. He realized that it might not be the animal or vegetable organisms themselves, but their eggs or spores that constituted the infective agent. He pointed out, however, that the mere presence in the excretions or degenerated tissues of patients suffering from disease of either the organisms or their spores did not afford adequate proof that these organisms or spores were the infective factors in the " contairia " as he called them. How wide and, at the same time, intensive was his outlook is evident when we realize that he foreshadowed the postulates deemed necessary by Koch for the proof of the connexion between a possible con- tagium and a definite disease. He insists that the demon- stration of the presence of an organism in the lesions or tissues * Del mal del segno, calcinaccio o rnoscardino. Sec. ed. Milano, 1837. t Pathologische Untersuchungen, Berlin, 1840. 120 Transactions of the Society. of a diseased patient is essential, and that such organism must be so isolated from its surroundings, that its action may be tested by experiment, and must produce the same or similar results when allowed to act upon a healthy plant or animal. He could not complete the chain, as at that time no methods of growing these organisms in pure culture outside the body had been devised, and animal tests were impossible ; but Koch, who succeeded in making these animal tests, insisted that it was necessary, for complete proof, to isolate the same organism from the experimental case. Many of the earlier achievements in the history of bacteriology we owe to the great botanist (John, of Breslau, and for long the stimulus that he cave to tbose who were working under him or were inspired by his example was chiefly instrumental in advancing the study of this subject. From the time of Pasteur and Koch onwards, however, this work has been taken over almost entirely, not by the surgeon only, but by the physician also, who often, with little training in botanical methods, but confronted by practical problems of great significance to their art and to their patients, have built up a new study which has revolutionized medicine, has raised internal medicine from the position of a conventional art to that of a great and living science, and has removed the reproach that whilst surgery was scientific and progressive the physician remained empirical and unenterprising. It is unnecessary to give an account of the numerous observa- tions that were made, and controversies that were carried on during this period — a period of great activity in the physiological and pathological world. A few investigators were working away steadily and quietly at the minute structure of tissues, and at fungi and yeasts, and a still larger number were making sugges- tions, forming hypotheses, elaborating theories and analysing the work of this period, a vast mass of careful observation character- izing the years between 1849 and 1859, when Pasteur took up his famous work. The anthrax bacillus, the largest of the pathogenic bacteria, was observed by Pollender in anthrax blood in 1849, and again by Davaine and Payer in 1850, and in the new search for the causes of disease this bacillus played a very prominent part, the study of its life-history helping men to crystallize their ideas as to the relation of micro-organisms to disease. Davaine held that the virulence of an attack of anthrax varied according to the number of the bacteria present in the blood and although he was unable to furnish all the proof that Koch later demanded, there can be little doubt that he was satisfied that the anthrax bacillus was the primary cause of splenic fever in animals. Edwin Klebs, a worker of great ingenuity and industry — who has recently passed from amongst us, full of years and held in honour by his fellows — devised a very striking The President's Address. By G. S. Woodhead. 121 experiment.* Taking fluid, diluted blood, in which the presence of the anthrax bacillus could be demonstrated by means of the Microscope and by experiments upon animals, he filtered it through earthenware, and found that, although the part kept back by the filter contained the bacilli, and was still capable of pro- ducing the disease, the filtrate, in which no bacilli could be found, was absolutely innocuous. It was left to Koch, however, to lay down the lines of research in connexion with the demon- stration of the etiology of most of the infective diseases now recognized. By means of admirable technique he succeeded in studying the anthrax bacillus in great microscopical detail.f After demonstrating its presence in the blood' of animals dying from anthrax, he succeeded, by the use of solidifying media — which had first been used by Klebs, whose work Koch seems to have studied with keen appreciation — in isolating and cultivating colonies arising from individual bacteria, colonies that could be watched under the Microscope as they grew,' and their various phases of development noted. From these individual colonies pure cultures were obtained, and by transferring the organism from one lot of medium to another all possibility of anything but the growing organisms remaining was removed. With the organisms so separated and purified, organisms that had the same micro- scopical character as had those found in the blood of the original diseased animal, he produced definite anthrax by inoculating them into various animals ; from these animals he isolated the original organism, with which he succeeded in repeating the whole series of experiments. Further, he showed that when the organism was allowed to grow outside the body under special conditions — con- ditions apparently unfavourable to the continuance of the species — it had the power of forming spores, bodies that he had never met with in the organism as it occurred in the fresh blood of animals dying from the disease, but which were afterwards found in old shed blood, i.e. when the bacillus came into contact with the air. He noted the resistance of these spores, and recognized their importance in maintaining the continuity of the species outside the animal body. He and his pupils now put to the test many of the observations that had been made by his brilliant predecessors, Henle and Edwin Klebs, observations on miasmata and contagia and on wound-infection that constituted epoch- making contributions to our knowledge of these conditions. He applied his methods to the bacteria of no fewer than six "infections," and showed that each bred true, each produced a definite form of disease, and that five at least could be again isolated and cultivated from the inoculated experimental animals. Such revolutionary methods and observations were naturally * Cor.-Bl. f. Schweiz. Aerzte, Bern, i. (1871) p. 279. t Die Aetiologie der Milzbrand Kraukheit, 1876. 122 Transactions of the Society. distrusted alike by philosopher and pedant ; but Pasteur — whose work on silk-worm diseases, flaeherie and pebrine, and whose studies in fermenting wine and beer even now had become classical, — stimulated by Lister's praise and Koch's work on the anthrax bacillus, took up the tale and fully confirmed Koch's results. He cultivated the anthrax bacillus through a hundred generations, and with the final culture series produced typical anthrax. Once started, this brilliant and pertinacious layman (non-medical) stormed position after position. He isolated and differentiated pathogenetic anaerobic micro-organisms ; determined the effects of temperature upon bacteria ; noted the fact that chicken -cholera virus gradually loses its virulence when left growing in an arti- ficial medium over a long period ; that this modification may persist for many successive culture generations ; and that the modified culture serves as a protective vaccine against acute chicken-cholera virus much as Edward Jenner's vaccinia protects against smallpox. In the test-tube or in the flask he succeeded in producing vaccines against chicken-cholera, against anthrax, and against certain diseases of swine, and then gradually brought out the fact that a modification of a virus into a vaccine could also be obtained by passing these viruses through a succession of different animals — modification by passage —a method that later served him so well in his experiments on the production of a protective virus against hydrophobia. At every stage of his work, except in that dealing with rabies or hydrophobia, he checked his results by careful microscopical observation, and the confidence thus gained in his earlier studies enabled him to anticipate the results that he would obtain in his hydrophobia investigations, although he was not able to confirm them microscopically. It is sometimes said that the Microscope can no longer be called to our aid in the elucidation of the life-history of the minute ultra-microscopic organisms that are supposed to produce disease ; but it may be adduced with- justice that it has already provided so many analogies that men walk with great assurance in paths that they know must lead to the goal aimed at. Moreover, the Microscope in its perfected form now gives shadow-pictures which, like those imagined by Plato, indicate the presence of things unseen. Medicine, then, has advanced just as fast and as far as the Microscoi e, and other instruments of precision have helped and allowed. All Ehrlich's earlier work in tissue-staining, and the affinity of certain colours for special structures, was based on ob- servations made with the Microscope. Weigert carried on similar studies on the histo chemical reactions obtained in the staining of micro-organisms and of the central nervous system, and laid the foundation for Koch's special stain for the tubercle bacillus, without which, and the aid of powerful and well-corrected lenses, we should still be carrying on a blindly ineffective campaign against tuber- The President's Address. By G. S. Woodhead. 123 culosis, but with the aicUof which the white plague is gradually being driven back. Without the Microscope we should still be making but feeble ineffective and ineffectual attempts to stem the death-rate from typhoid fever, cholera, diphtheria, pneumonia, the plague, pneumonic and bubonic, and many other disease of animals, plants, and man. Some of these have been scotched and others killed, and recent discoveries have led us to believe that others may, ere long, follow in their wake. It is not many years since Kitasato, Yersin, Lowson and others tracked down the Bacillus pestis, and in it the cause of plague. Our knowledge of the life-history of this organism has been acquired with great labour, slowly and intermittently, and at each stage the Microscope has been called in to provide the last scrap of evidence, to forge the last link in the chain. The disease was known to be either contagious or infective. There must then be an infective agent. This was soon demon- strated in the buboes and blood of patients affected with the bubonic plague, and when the same organism was found in the lungs and blood of the patient affected with the pneumonic plague, a far more mortal disease than the bubonic form, evidence of the etiological identity of the two conditions was complete. How is the disease carried from patient to patient ? What relation has the increased mortality of rats, before and during the first stages of an outbreak, to the outbreak itself ? The plague bacillus was found in many dead rats. Then it was found that healthy rats might safely be placed near plague- stricken rats if an interchange of fleas could be prevented, but that if an interchange of fleas was allowed the healthy rats became plague-stricken. How the conveyance of the bacillus was effected by the flea still remained doubtful until C. J. Martin demonstrated under the Microscope the blocking of the alimentary canal of a proportion of the fleas that had been fed on mice infected with the Bacillus pestis* In the beautiful specimens exhibited by him at our last conversazione could be seen viscid masses of plague bacilli, which were evidently the result of rapid multiplication of a number that had been ingested by the flea when it took its meal of blood from the infected mouse. This mass, blocking up the alimentary canal, renders the flea a more dangerous foe than an irritated cobra. Ingested blood can no longer pass through the canal, but after being mixed with a number of germs detached from the front portion of the bacillary bolus, it is regurgitated and driven into the next puncture made by the practically starving and irritated flea, operating whether on mouse or man. First and last, the Microscope, and the Microscope only, could provide the special and most im- portant evidence required to make good the case against the plague * See full account in Journ. Hygiene, xiii. (1914). Plague Suppl. iii., p. 423. 124 Transactions of the Society. bacillus. With his knowledge thus acquired the plague officer goes forth to war against the disease with a confidence of success in his struggle that he has never known before, and in areas in which cleanliness and freedom from rats, mice and fleas can be ensured, we reed never fear the ravages of a plague, which, in the epidemic described in Boccaccio's " Decameron " (1348), is said to have destroyed one quarter of the population of the whole world, whilst it is calculated that near home, in East Anglia, at least half the population succumbed to this disease. Without the Microscope Pfeiffer's phenomenon, the solution of bacteria in the fluids of living immunized animals, could never have been observed, and our acquisition of knowledge concerning protection against disease would have been sadly cramped. Without the Microscope there could have been no Durham-Bordet or Widal reaction, and diagnosis in cases of typhoid fever could never have gained its present accuracy. Without the Microscope we could not have put our finger on the typhoid carrier — probably the cause of all endemic typhoid and of many epidemic outbreaks — and without its aid Wright could have devised no opsonic index, no knowledge of phagocytosis could have been acquired, and we should lack all that these mean in the study and treatment of microbic disease. It would take me too long to give a history of the twentieth cen- tury development of protozoology, now the most important branch of microscopic parasitology ; but as this subject is one that must occupy a great place in the history of medicine, it may be well again to insist that it could not have come into existence without the aid of the modern Microscope, and the Eoyal Microscopical Society has cause to congratulate itself that its members have continued to work and to improve the Microscope even beyond what appeared to be necessary to meet the immediate requirements of the botanist and the zoologist. Malaria, which has probably accounted for more illnesses and deaths than the bubonic plague and pneumonia together, is gradually being driven from its fastnesses. Time fails me to recount the stages by which a knowledge of the life-history of the infective agents in the different types of malarial disease has been acquired. Minute blood parasites were first found in the human blood, in the red blood corpuscle and in the plasma ; then their development in shed blood was careiully studied. For long no solution of the problems: How do these parasites pass from man to man ? anil why is malaria specially associated with low-lying swampy ground ? was obtained. Then similar parasites were found in birds, and Manson urged Boss to study the mosquito, infesting the regions inhabited by these birds, and to see whether he could find any stage of the bird parasite in the stomach or glands of the mosquito, and Boss did succeed in tracing certain phases of develop- ment of these parasites in the stomach wall of this mosquito. The The President's Address. By G. S. Woodland. 125 Italians, following up these observations, demonstrated a similar series of stages of the malarial parasite in the stomach wall of certain of the Anopheline mosquitoes, and gradually the complete life-history of the parasite was obtained ; and now, given proper facilities, malaria has been or can be driven out of fever-stricken areas that once were regarded as uninhabitable bv the white man. Yellow fever has given way to the researches of the Americans, who, though not finding the causal parasite, have found its mosquito host Stegomyia faseiata, and whole areas and islands once spoken of as " white men's graves " have been rendered comparatively healthy by raids on the mosquito host of the hypothetical parasite. Trypanosomes have also been traced from host to host, human, animal, and insect, and anyone who has seen the beautiful preparations and exquisite microscopical technique and management of monochromatic light utilized by Professor Minchin in his work cannot be surprised at the great progress that has been made in the study and description of the various phases of existence of the protozoal parasite and of the development of these parasites in their different hosts. We are told that Schaudinn was one of the most expert microscopists of his time, and that his discovery of the spirochetes or spironema of syphilis, against which Ehrlich has waged such successful war with his chemiotherapy, was due in no small measure to his incom- parable skill in technique and staining methods. Once he had made the demonstration of this almost invisible parasite, however, the Microscope manufacturers soon provided optical combinations by means of which Schaudinn's and Metchnikoff's observations were readily confirmed by investigators all over the world. It is generally recognized, even outside Great Britain, that some sixty years ago (old Pepys notes this at an earlier date) and onwards, the best Microscopes of a certain type were constructed in this country, and that nowhere have the results of the study of the mathematics of optics been applied with greater skill and intelligence ; and we all look forward with keen interest to the appearance of Mr. Eousselet's and Mr. Cheshire's catalogue of Microscopes, the property of our Society. When we examine the dates of the various English Microscopes, note their special features, and compare them with the list of contemporary foreign Micro- scopes, when we make a survey of the work done by them at home and abroad, I think it will be found that we, at any rate, have been well supplied with instruments with which to pursue those branches of Medical Science involving the use of the Microscope. Individuals have used their great opportunities, but it must be admitted that until comparatively recently our Continental brethren, making use of their fewer opportunities more quickly and com- pletely, forged ahead so rapidly and with such vigour that in this work we have not always held our own. Whilst it has always been the boast of English Medicine that it has been intensely April 15th, 191U K 126 Transactions of the Society. practical, it seems at times almost to have lost sight of the value of practical microscopy, and to have ignored the necessity of co- operating with those engaged in developing the Microscope and in perfecting the means of studying pathogenetic germs and the minute structure of tissues and organs — matters of prime import- ance to those who have charge of patients and of the public health. British skill and brains in plenty have been worked into our Microscopes ; the Royal Microscopical Society has contributed more to the evolution of the modern Microscope than any other single body of men.; but how many who should be users of the Microscope have lagged behind ! Is it possible to remedy this ? Is there not at present far too little attention paid, especially in our Medical Schools, to the technical instruction of the histologist, normal and morbid, plant and animal, in the construction of the Microscope ? I well remember the sensation that was created by Hughes Bennett and by Rutherford when they introduced the less compli- cated Continental Microscope of Oberhauser and Hartnack into their histology classes in Edinburgh and London ; and by Hamilton, when he opened classes of pathological histology similar to those that he had entered under Strieker in Vienna, Virchow in Berlin, and Cornil and Ranvier in Paris. As a medical student I had but little idea of the importance of a knowledge of the funda- mental principles involved in the construction and use of objectives, oculars, condensers, mirrors, and the like. We were told to examine a specimen with a "high power" or a "low power" combination, by reflected light focused through a bullseye con- denser, or by transmitted light reflected from a sub-stage mirror, with the stage diaphragm wide open or with it contracted. We were taught to stain specimens with the object of bringing out special cellular or nuclear structure, but beyond this nothing was expected of us. The thing that was most firmly impressed on my mind in those days, when we had practically no acces- sory apparatus, was that in screwing the objective into the removable tube of the old Hartnack Microscope, with which we were supplied, one -must be careful "not to allow the eye-piece to fall out." Some of those ancient uncomplicated Hartnack Microscopes are still in use in the same laboratory after a lapse of thirty-eight or forty years. In spite of all this, the work done by some 300 students a year has played a great part in this one School in the development of modern methods of study and research in medicine ; and one cannot but realize how much more might have been done even by a small fraction of these men had they been carefully instructed in matters then of common knowledge to the members of the Royal Microscopical Society. Indeed, since I have been privileged to take part in the proceed- ings of this Societv, it has been borne in on me that if we could The President's Address. By G. S. Woodhead. 127 only turn some twenty or thirty of our members into the various Medical Schools of the kingdom, there to instruct first our junior students, and then those engaged in research, in the finer working and wonderful possibilities of the modern Microscope, the rate of advance of medical knowledge would be enormously speeded up. Pondering this matter, it has struck me that in Cambridge we have mercies for which we are not sufficiently thankful, and opportunities that we have failed to seize. Why, I put it to myself, should not our distinguished Secretary, with his knowledge of technique, be called upon to help us in providing for the men who are studying histology, normal and pathological, and bac- teriology, sound teaching on the optical and mechanical principles on which are based the construction and use of the Microscope, in order that they may utilize to the full this wonderful instrument. My desire — and hope — is that ere long our best students, at any rate, may have some opportunity of acquiring facility in the use of the various types of sub-stage condenser, dark-ground illumina- tion, monochromatic lighting, methods of measurement, ultra- microscopic work, micro-spectroscopy, polarization, and the like. Much of the rough work has been done with the simpler apparatus of the past, the blocking and hewing, in the domain of histology and cytology, bacteriology and protozoology. For further and finer work, every available adventitious aid, most of them corning to us through improvements in the structure and use of the Micro- scope, must be called upon. How much has been done in recent years only those can realize who have followed, in our Journal, the reports of what has been done in the great working centres of the microscopical world. Only they, too, can form any idea of the tremendous additional powers of investigation that might be placed in the hands of thousands of workers, were the facilities for microscopical work increased. I am afraid that we Britons are endowed with a natural repugnance to either giving or receiving State grants for furthering the development and utilization of brains. It may be that this repugnance is not so marked as it was, but it is still so great that one cannot hope that this Society, for example, may ever receive a grant for the encouragement of research, for the improvement of the optical and mechanical parts of the Microscope, or in aid of the diffusion of the knowledge acquired as the result of the encouragement of technical work. In the meantime, the researches of the brilliant and persevering investigators who have placed our Society in the honourable position it now holds in the scientific world, have helped to confer benefits on sick and sound alike such as could not have been realized fifty years ago, and the source of which is even now inadequately, very inadequately, recognized. K 2 128 Transactions of the Society. VI. — British Enchytrseids. By The Eev. Hilderic Friend, F.R.M.S. (Bead February 18, 1914.) Figs. 15 to 19. VI. New Species and Revised List. During the past year my researches into this interesting group of microscopic Annelids have been diligently continued by the aid of a Government grant, and with the valued co-operation of Mr. H. Hillman, of Nottingham, who has, both in that county and in Jersey, discovered many interesting species, two of which I propose to name after him in recognition of his invaluable aid. In the last paper which I had the honour to submit to this Society (1)* I gave a brief outline of Enchytrseid characters, and it will suffice if the reader turns to page 255 (Vol. for 1913) for such details as he may require to enable him to follow the present descriptions. The progress made in this study renders it necessary to bring our knowledge of the group to a focus, and it is proposed in the present paper to deal in the first place with such new species as have been added to the family, or whose definition requires criticism, and then to tabulate results and give a revised catalogue of species known to Britain. Since, however, the red-blooded Enchytraeids (Marionina and Lumbricillus) still await careful revision, and the family is now so extensive, it will be necessary for the present to con tine attention entirely to the genera with colourless blood. It must not, how- ever, be thought that the colour of the blood is taken as a generic character, since we occasionally find red, pink, and yellow blood outside the range of the two genera {Marionina and Lumbricillus) in which red is the normal colour. Several of the genera possessing white blood have yielded good results during the year. I have personally explored some new localities as well as many old ones, and during my brief vacation spent some time in Germany and Belgium ; but these countries did not yield much of special interest which was not already known to me at home. The truth is that Great Britain is peculiarly rich in Enchytraeids, and though Bretscher, Issel, and others have found a goodly number in Switzerland and * The figures in brackets refer to the Bibliography at the end of the paper. British Enchytrmids. By Rev. H. Friend. 129 Italy, England seems to be at present considerably ahead of other countries in the number of known species. Owing to the uncertainty which still prevails in reference to the genus Enchytrs&us, it has been thought desirable to omit con- sideration of that group also for the present. This leaves us with eight genera for our present study, viz. Achseta, Fridericia, Buch- holzia, Henlea, Bryodrilus, Mescnchytrseus, Grania, and Chamsedrilus. Stercutus, Hydrenchytrmus, Michaelseni, Distichopus, Hepatog 'aster, and Chirodrihis are at present unknown in Great Britain. I.— SPECIES NEW TO SCIENCE. a. The Genus Buchholzia.. In the year 1900, when Michaelsen published his Oligochseta (4), two species only of Buchholzia were known to science, and these differed from each other so widely that one could hardly see how they could both be members of the same genus. The inter- vening years have brought other species to light which must for the present be spoken of as members of the genus Buchholzia ; but they still further illustrate the difficulty of finding true generic characters. One of the new species about to be described is evidently a connecting link between this and other genera, and might well have been named intermedia, but that when a further revision is required such a name would be robbed of much of its significance. 1. Buchholzia focale sp. n. Length, 8-10 mm. Segments number about 45. While the chloragogen cells often give it a dark appearance, it is white and transparent. Setae 2-3 in posterior region of body, 3 dorsal and 4 ventral as a rule in anterior bundles ; not arranged as the setse of Fridericia are, with the shortest in the middle of the bundle, but sigmoid and fallax- like, i.e. the shortest near the middle line. Setae persisting on the girdle segment to a late period. Chlora- gogen cells very large, almost black under the lens, commencing in segment f>. Ccelomic corpuscles varying in size and shape, from round to oval or discoid, pointed, brownish, nucleated. Three pairs of septal glands normal in shape and position. Blood sometimes yellowish in colour. Body frequently glandular, and segments annulated. Nerve chord enlarged in front. Brain about 1^ X 1, concave before and behind, Henlean in type. The origin of the dorsal vessel also in 12/13 is Henlean. Three specimens carefully examined all agreed in this peculiarity as in every other. Girdle normal on the 12th segment, extending over 12 and half 13, with fairly large cells. Sperm funnel about 2x1, with long 130 Transactions of the Society. slender duct arranged frequently like coils of vermicelli. Sperma- thecee as usual, one pair opening in 4/5 with or without glands ; duct about equal in length to ampulla, short, stout, gourd-like in outline (see fig. 15). The most striking peculiarity, however, is the presence of a pair of glands (possibly aborted salivaries) apparently issuing from the posterior of the pharynx, and looking like the two ends of a clergyman's bands or cravat. Hence the specific name focale. The nephridia were not studied. It will be observed that the position of the girdle and sperm- funnel, the point of origin of the dorsal vessel, and the peculiar glands, differentiate it from B. appendiculata and B.fallax, while the spermatheca? show it to be unlike B. parva — a species not yet found in Britain. The brain, salivaries, spermathecae, and origin Pig. 15. — Buchholzia focale sp. n. 1. Cravat-like appendages. 2. Brain. 3. Spermatheca. of the dorsal vessel also serve to make its dissimilarity from the next clear. Habitat. — Alexandra Park, Hastings. Collected December 21, 1911 ; described from living material March 7, 1912 ; but the details now published for the first time, for reasons given under the next. 2. Buchholzia tenuissima sp. n. Very slender. Length 8-10 mm. Segments 35-50. Setae gradually decreasing in number posteriorly, from five in anterior to two in posterior segments ; slightly sigmoid, wanting on segment 8. The most arresting external character is the girdle, which ex- British Enchytrseids. By 'Rev. H. Friend. 131 tends in the fully adult worm from the setae of segment 7 to those of segment 9, and includes the whole of the 8th segment. Here the blind sac is situated internally from which the dorsal vessel takes its rise. The oesophagus suddenly emerges in this segment into the enlarged intestine. The brain is about as long as broad, varying somewhat under tension ; slightly convex in front ; straight, or slightly convex when strained ; not incised, but nearly straight behind. Sperm-funnels rather large, about 2x1, somewhat mobile and variable, with fairly stout ducts, opening into a moderately large atrial gland-pore on segment 8. Large nephridia-like salivary glands in segment 4. Nephridia seen in 8/9 and later as in Chamsedrilus, but not observed in the anterior seg- ments. Duct a continuation of the postseptal. Coelomic corpuscles of two kinds, larger and smaller. Very characteristic sperma- Fig. 16. — Buchholzia tenuissima sp. n. 1. Brain. 2. Spermatheca. thecse (fig. 16), with bulbous ampulla attached to oesophagus, and stout duct tapering to 4/5 opening without glands. Five specimens were examined, of which three were adult and agreed in all particulars. The details respecting their length and number of segments may not be without interest. 1. Immature 2. 3. Mature 4. „ 5. Length Segments 6 mm. 35 8 „ 35 10 „ 50 8 „ 45 6 „ 36 There is thus a difference of fourteen segments and 4 mm. even in the adults. The length usually agrees with the number of segments. 132 Transactions of the Society. The position of the girdle and other organs allies this species with B. appendiculata, from which it differs in the shape of the brain, diverticulum, sperrnathecse, sperm-funnel, and other particulars. While B. appendiculata is stout, the new species is attenuated, whence its trivial name. Habitat. — Under moss in the Alexandra Park, Hastings. Col- lected at the end of June 1912 ; described February 13, 1913, but the details now published for the first time. When B. focale was examined, I was daily expecting to be called to Hastings again on domestic business, and hoped to be able then to obtain new material. It was not till six months after my former visit, how- ever, that I was able to examine the spot, and the results are note- worthy. In December I found B. focale, in June B. tenuissima. Such striking facts are continually coming under one's observation, and are of exceeding interest in the study of Enchytrseid bionomics. We now have four British species of Buchholzia on record, which may be distinguished thus : — 1. Girdle on segment 12. (i) Dorsal diverticulum present, from which dorsal vessel arises . . B. fallax (ii) Dorsal diverticulum absent ; dorsal vessel arising in segment 12/13 . B. focale 2. Girdle on segment 8. (iii) Spermathecse with pear-shaped am- pulla, and two large glands . B. appendiculata (iv) Spermathecse with bulbous ampulla, destitute of glands . . . B. tenuissima The members of this genus are not, so far as our present know- ledge goes, common in this country, and deserve a little further study. I first reported B. fallax Mich, as British in the Irish Naturalist for 1898, as having been taken on the shores of Lough Neagh in June 1896, and, about the same time, at Lodore and Lowther in Cumberland. My later records are Ledbury Church- yard, April 17, 1911 ; Eel-traps on Sutton Broad, August 19, 1911 ; Cauldwell, near Burton-on-Trent, June 11, 1912 ; Dundrum Boad, Dublin, March 7, 1913; Blenheim Park, Oxon, April 14, 1913. The species seems liable to a good deal of variation. B. appendicu- lata, however, seems more fluid still, and presents many problems which I have not yet been able to solve. I first found and figured it April 21, 1892. It was first recorded as British, however, by Southern (6) in 1909. The type and varieties have been found British Enchytrseids. By Rev. H. Friend. 133 by me at several places in Derbyshire between February 1911 and July 1912; at Hastings, June 1912; and Sedlescombe, Sussex, August 16, 1913. /3. The Genus Acileta. This interesting genus is characterized bv the absence of setae. In some instances setae sacs still remain in the form of ccelomic processes slightly attached to the body-wall, while in others these vestiges have entirely disappeared. Michaelsen (4-) has three species only, known to science in 1900, all of which are British. Bretscher (8) in 1902 added a fourth, which has not yet been found in these Islands. Southern (-5) has described an Irish species, and to these I am now able to add two others. 1. Achasta spermatophora Friend. Length about 8 mm. Segments from 35-40. Setre sacs pre- sent dorsally. Brain large, nearly oval, convex before and behind, about 1^—2 X 1. Characterized by a pair of bodies resembling spermatophores, whence the specific name. First described in Irish Naturalist for September 1912, p. 174. 2. Achseta incisa Friend. Length at rest about 5 mm., extending to 7 or 8 mm. when stretching eagerly, when it is very slender. Segments 35-40. Destitute of setse, but possessing dorsal setse sacs. Owing to the presence of large opaque coelomic corpuscles and chloragogen cells, it resembles Enchytr&us nigrinus under the Microscope. Sperm- funnels 2 or 2^ times as long as broad, with long sperm duct, medium atrium and pores. Three pairs of septal glands, but no salivary glands observed. Dorsal vessel arises in segment 7 and pulsates in front, especially in segment 6. Nephridia in 6/7, 7/8 with very large postseptal. Behind the girdle the nephridia show the postseptal narrowing into a duct. Spermathecae bottle-shaped, with neck opening into the oesophagus ; not like those of A. bohemica. Brain about 2-3 times as long as broad, sometimes incised behind, suggesting the specific name. The brain (fig. 17) was found, after this specific name had been given, to be variable, but the name is retained as the other characters are sufficiently definite to ensure recognition. Habitat. — Sandy soil, Mansfield, Notts, May 8, 1912. See Trans. Notts Nat. Soc, 1911-12, pp. 58-9. No figures were 134 Transactions of the Society. supplied, as it was intended at an early date to publish the diagnosis in one of the scientific journals. Pig. 17. — Achseta incisa sp. n. 1. Brain incised, typical. 2. Brain convex behind. 3. Nephridium. 4. Spermatheca. The British species of Achseta now number six, and may be distinguished by the following characters : — g 1. Seta? sacs absent . 2. Seta? sacs present ( Sacs present ventrally and dorsal ly ' (Sacs present dorsally only . J Brain concave behind ( Brain convex or oval : a. Spermatheca? with pear-shaped ampulla A. bohemica (3. Spermatheca? like spermatophores . A. spermatophora y. Spermatheca? simple ducts . .A. minima • • A. cameranoi . 3 • • A. eiseni • • 1 • • A. incisa British Encliytr&ids. By Rev. H. Friend. 135 7. The Genus Henlea. On more than one occasion in the past this important genus has received attention in these pages. It is therefore unnecessary here to do more than describe those species which have been recently added to our indigenous Annelid fauna. 1. Henlea glandulosa Friend. Resembles, in some respects, H. marina. First described in Irish Naturalise, January 1913, pp. 9-10 ; at the time when my paper on Henleas was in the hands of the Sec, R.M.S. (See Zoologist, March 1913). 2. Henlea bisetosa sp. n. A very small transparent worm. Length 3-4 mm. Segments about 30. Setse 2 throughout. Often a young one may be found growing beside the regular pair, but never three fully formed. Bulbous enlargement of intestine in segment 8, with dorsal vessel originating in 7/8. No oesophageal glands ; but it might be pos- sible to regard the bulb as an unpaired gland. Coelomic corpuscles large, clear, not granular. Special glands (salivaries probably) between the second and third pair of se} .als (similar to H. inusitata). Septals of rather unusual form, three pairs in normal position. Intestine yellowish, chloragogen cells rare. Nephridia begin in 6/7, with long slender duct originating behind the septum. Though not adult, this species is readily distinguished from all other British forms by the number of setse and the shape of the septals. The position of the salivary glands is unusual, and allies it with H. inusitata. Habitat. — Canal side, Dublin. Found by myself March 11, 1913, and recorded in Irish Naturalist, September 1913, p. 172; but now described for the first time. Also recorded for Nottingham, April 1913 (£) 3. Henlea hillmani sp. n. Length 5-6 mm. Segments 30-36. Yellowish-white, rather a squatty form. Ventral setse 2-4, usually two dorsally, largest m posterior end. When four are present the innermost pair is shortest. Three pairs of septals, the hind pair with globular pro- cesses behind ; otherwise normal in position and shape. Dorsal vessel arising about thirteenth or fourteenth segment; in one traced to 12/13, in another to 14/15, pulsating forward to seg- ment 5. Brain incised behind, somewhat longer than broad, of 136 Transactions of the Society. Henlean type. Coelomic corpuscles not horny, of two kinds, the larger granulated. No oesophageal glands or bulb ; the oesophagus going gradually into the intestine. Strong gizzard extending from segment 2 to 4. Eather long, narrow salivaries, with tips slightly budding, or branching freely. First nephridia in 7/8 ; duct not always issuing from the same part of the postseptal. In the hindermost segments the duct tends to spring from the posterior portion. Habitat.— Collected at Scarrington, Notts, June 10, 1913, by Mr. H. Hillman, after whom it is named in recognition of the splendid service he has rendered by his intelligent and indefatigable collecting. 4. Henlea insulse Friend. Collected in June 1913 by Mr. Hillman in Jersey, and first described in Zoologist, December 1913, p. 460. 5. Henlea inusitata Friend. First regarded as a variety of H. dicksoni, but found to be a true species. Length variable (unless again two species are in- cluded) ; 5-15 mm. Segments 25-45. Setae Fridericia-like ; i.e. shortest in the middle of the bundle, three to six in posterior bundles, five to eight in front, rarely in the most adult reaching nine in a set. Brain typical, incised, concave or sometimes straight or convex behind, according to tension. Nephridia begin in 5/6 or 6/7, duct as long as postseptal, from the middle of which it usually springs. Sperinatheca usually a simple duct, occasionally with glands at the 4/5 opening. Bulb in segment 8, and dorsal vessel in 8/9. Salivary glands between the second and third pair of septals. First described in Zoologist, March 1913, p. 85. Habitat. — Frequently found, and formerly recorded as H. dicksoni in part. Definite records for the new species are Eolleston Junction, Notts, March 26, 1912 ; Cauldwell near Burton-on- Trent, June 11, 1912, and again on April 7, 1913 ; Dundrum Eoad, Dublin, March 7, 1913 ; Oxford Botanic Garden, April 15, 1913. 6. Henlea minima Friend. Length 5-6 mm. Segments 25. Brain slightly concave behind, converging forwards, of the usual Henlean type. Spermathecaa like an Indian club or champagne bottle, without ampulla or British Enchytr&ids. By Rev. H. Friend. 137 glands. Septals three pairs, small (in front), medium, and large. No oesophageal glands. Girdle 12 to half 13. Ccelomic corpuscles large, clear, oval to round. Setae about six in front, shortest in the middle of each bundle, as in Fridericia, 4-5 behind, larger and nearly equal. (Esophagus merges suddenly into intestine in 7/8, dorsal vessel arises in 10/11. Four pairs of large nephridia in pre- clitellar segments (6/7-9/10). Duct of nephridia equalling post- septal in length, and usually arising from the middle portion. Sperm-duct in girdle segment very fine, coiled. Related to H. dicksoni, but much smaller, and possessed of specific characters, such as origin of dorsal vessel, shape of sperma- thecae, and size of brain. Habitat. — Stream at Netherseal, near Ashby-de-la-Zouch, 1911. First described as a new species in Zoologist, March 1913, p 84. 7. Henlea multispinosa Friend. Length 23 mm., fairly stout. Segments 40-50, transparent. Spermathecae consisting of narrow ducts, sometimes varying in diameter, with small glands (apparently 2 to 4) at the 4/5 opening. Salivary glands present, slender, forked or branched (resembling those of certain species of Fridericia) ; three pairs of septals, normal in shape, size and position. First nephridia in 4/5 large ; duct emerging from behind the septum, and exceeding post- septal in length. Bulb in 7, dorsal vessel arising in 8th segment. Setae very numerous ; 4-6 in posterior region, 8 in the middle, rising to 10-12 in front. Very few known Enchytrseids ever exceed 10 setae per set. H dicksoni, which the new species re- sembles, may possess 8 setae, and H. puteana may have 8-10. Habitat. — Under moss, overflow from Canal, Nottingham City, December 16, 1912. Formerly regarded as a variety (multi- spinus) of H. dicksoni. See Trans. Notts Nat. Soc, 1911-12, p 55. Described for the first time as a distinct species in Zoologist, March 1913, p. 83. 8. Henlea quadrupla Friend. Length 10-12 mm. Segments 45-50. Four pairs of septal glands, whence the specific name. One pair of oesophageal glands in segment 8, with dorsal vessel in 8/9. Large sac-like salivaries in front of first pair of septals. Setae somewhat variable, 3-4 dor- sally, 4-5 ventrally, but sometimes as few as two per set. Ccelomic corpuscles not of the horny type. Brain not much longer than broad ; not rigidly outlined, but varying with tension. Postseptal about three times as large as anterior portion of nephridium ; duct arising near posterior end, or as a continuation thereof, short. 138 Transactions of the Society. Sperraathecse in the perfect adult with short duct, large ampulla and 4/5 glands, as shown in illustration (Fig. 18). B to a •l"H % o3 w u ■ rl e3 u O m &'* c3 - > <£ •H O & & > a 2 ® (6 <" N N •r-t bo c8 M PI 1 .a 00 c3 British Enchytr&ids. By Bev. H. Friend. 139 Habitats. — Overseal, November 1911 ; Netherhall, November 22, 1912; Midway, January 30, 1913. These localities are all between Burton-on-Trent and Ashby-de-la-Zouck. First described in Zoologist, March 1913, p. 85. 9. Henlea trisetosa Friend. Length 5-6 mm. Segments 35-40. Setae sigmoid, three in each set throughout. Like the last, it has four pairs of septal glands, but no cesophageals, nor any salivaries. The dorsal vessel arises in 9/10. First described in Zoologist, March 1913, p. 86. 10. Henlea tubula sp. n. Length 10-12 mm. Segments up to 45. The most striking feature is the bulb, which seems to be made up of tubes (whence the trivial name), and is capped with very dark cells. No oeso- phageal glands, three pairs of septals of normal type ; setae unequal in length, as if some had fallen out from one side of the Fridericia- like bundles. Usually 3-4 dorsal and 4-5 ventral ; seldom, if ever, exceeding five. Bulb in segment 7 with dorsal vessel in inter- segment 6/7 in front of the black cap and tubules. Sperm-funnel 1^ X 1, the long coiled duct ending in an atrial gland half as large as the funnel. Coelomic corpuscles not horny or clear, but granulated, in healthy worms embedded in a thick coelomic fluid. Brain incised behind, rather longer than broad, Henlean in charac- ter. Large sac-like salivaries in front of first pair of septals. Sperinathecse with distinct duct and ampulla, with or without 4/5 glands. Posterior of nephridia merging in short duct. Large interspaces between the girdle cells. Habitat. — Several localities in and around Dublin : Canal Side, Dundrum Eoad, Balls Bridge, and St. Doulough's, March 1913 ; now first described." See Irish Naturalist, September 1913, p. 172, for the first record. 10. Henlea mariona Friend. Length 10 mm., stout. Segments about 50. Setse up to eight in front and behind ; those in anterior bundles Fridericia-like, i.e. shortest in the middle of each set. Only two pairs of septals ; front pair very large, second pair smaller, with spermathecse be- tween them. No oesophageal glands. Sperm-funnel small, l£-2 x 1, with fine irregularly coiled duct ; large atrial glands and pores on segment 12. Bulb-like enlargement in 9 or 10, with the dorsal vessel arising in 10/11, pulsating forward. Girdle extending from seta- of segment 11 to setae of 13. First pair of 140 Transactions of the Society. nepliriclia in 4/5 ; postseptal large, duct not proceeding from pos- terior extremity. Brain incised behind, length about 1^ width. Spermathecre very unusual, appearing to combine dorsally so as to form an unpaired ampulla. Ccelomic corpuscles oval, not horny. . The characters are intermediate between those of Marionina and Henlca, on which account the specific name has been chosen. 1912, Friend, in Trans. Notts Nat. Soc, pp. 59-60. Found be- tween Burton Joyce and Lowdham, December 16, 1912. Owing to the large number of species of Henlea now found in Great Britain, 1 have found it desirable (9) to divide them into two groups, reserving the name Henlea for those which possess oesophageal glands, and calling the others, which are destitute of such glands, Hcyileanella. 8. The Genus Fridericia. The members of this genus are very numerous, and in most instances can be readily distinguished from other genera by their setse and spermathecse. When the setse number four or more per set, the innermost are the shortest. In many cases the sperma- thecse are possessed of diverticula, and the brain is almost invariably convex behind. To differentiate the species, however, is by no means an easy task, since their number is now rapidly approaching a hundred. In Great Britain alone we have now some forty known species, and every year the number grows. I have already in this Journal (1) shown how they may be conveniently tabulated. Fridericia arborea sp. n. Length 6-8 mm. Segments 35-40. Front setse two, rarely three dorsally,3-4ventrally, small ; three stronger ones in the middle and two in the final segments. Brain of the typical shape, but in some cases tending to concave behind, with underlap. Salivary glands extending to 5/6 with long forked ends. First pair of nephridia in 6/7. Dorsal vessel arising about the 15th segment. Ccelomic corpuscles of two kinds, the larger oval. Three pairs of septal glands. Girdle on 12 to balf 13. Spermathecse with duct roughly covered with small cellular outgrowths. I found two forms. The first has the brain slightly concave behind, and the duct of the anterior nephridia short; while the second has the brain convex before and behind, and long ducts to the nephridia, opening by large glandular pores. The species belongs to the bulbosa group. The members of this section are numerous and not easy to distinguish on paper, though presenting very clear charac- teristics under the Microscope when alive. The first was found in a decaying tree trunk at Zouch Mills, Notts, April 2 ; the second form at Mapperley, May 14, 1913. British Enchytrmds. By Rev. H. Friend. 141 Fridericia bretseheri Southern. When Southern created this species he assumed that it was already known as F. parva Bret. ; and as the name parva had already been appropriated, he changed the name. But F. parva Bret, is quite distinct from F. bretseheri Southern, and both are British. 1 draw attention to the point here, and will refer to Southern's own works (5, 6) for his definition. Bretscher's species will be discussed later. Fredericia bulbifera sp. n. Length 5-1 mm ; slender. Segments 35-40. Setae four un- equal in segments 2-16 or thereabouts, and two equal thence to end. Brain egg-shaped, largest behind. Spermathecae with duct about twice as long as bulbous ampulla and the posterior attach- ment ; glands at 4/5 present or absent. Salivaries long, often ex- tending back to 5/6 unbranched. Nephridia in anterior segments, with bulbous anteseptal and distinct duct ; those behind with pointed anteseptal and postseptal merging into a duct. Girdle 12 to half 13, with large gland-cells. Sperm-funnels small. Dorsal vessel arising in or near segment 16. Three pairs of septals, the posterior pair sometimes having forward processes, so that at first sight there appear to be four pairs of glands. Another member of the bulhosa group. First taken at Portobello, Dublin, March 10, 1913. Oxford Botanic Garden and Blenheim Palace in April, and frequently in Notts in May to July 1913. Fridericia coronata sp. n. Length 15, stretching to 20 mm. Segments 50, opaque, yellowish, and resembling Heulea dicksoni in appearance. A stout worm, difficult to study alive. Setae never exceed four in front ; in the middle and posterior usually one dorsal, and one, two, or three ventral setae present. The larger setae strongly curved within, and tending to a central bulb or bulging. Brain convex before and behind, with under! ap. Salivary glands much branched behind. Spermathecae very characteristic ; with long, somewhat slender duct, and a coronet of small glands around the ampulla (fig. 19). Girdle in normal position, with large male pores. Funnel about 4x1, rather long and narrow, with long irregularly-coiled duct. Dorsal vessel arising in or behind segment 16. Charac- teristic nephridia, with medium anteseptal, large postseptal with a lobe or indentation behind, and duct much exceeding postseptal in April 15th, 1914 L 142 Transactions of the Society. length. Duct springs from just behind the septum. Coelomic corpuscles of two kinds, the larger oval, nucleated and granular. Large dorsal pores and conspicuous guard cells. Altogether a well- defined species. The crown of glands on the spermathecre recalls hegemon and microcara, but the differences are well marked. Fig. 19. — Fridericia coronata sp. n. Spermatheca. Habitat. — Blenheim Park, April 14, 1913. Examined in June, after keeping the material nearly three months ; worms were then fully adult. Fridericia parva Bret. Some of Bretscher's descriptions are very imperfect, but of this he distinctly says that it has two seta? in each bundle ; hence it cannot be the same as F. bretsclieri Southern. The F. parva of Moore has been referred to F. bulbosa Eosa. I am not so sure that they are one and the same, but my record in Naturalist, August 1898, was made before we dreamed that the genus was so extensive, and later research has not cleared the matter up. Fridericia hillmani Friend. Described in Zoologist, December 1913, p. 462. Fridericia rotunda sp. n. Length 15-20 mm. Segments 55-60. Dense, opaque ; dirty white or yellowish in colour. Set?e usually 4-6 dorsal, and up to eight ventral in anterior bundles, and, as a rule, four or three behind, very stout. Brain almost spherical, whence the name. Sperma- thecse with short stout duct, two glands at 4/5 opening, and five or perhaps six sessile diverticula. The whole organ quite the stoutest I have seen in the genus. Girdle thick, including half 11 to half 13, or perhaps the whole of the latter segment when perfectly British Enchytr&ids. By H. Friend. 143 developed ; gland cells small. Three pairs of very large septals. Slender sperm-ducts, with large atrial glands and male pores. Ampullae 3-4 X 1, with collar absent or small. Dorsal vessel about the 19th segment. Though seven distinct specimens were examined, no nephridia could be seen. Salivary glands branched. The brain and spermathecse serve to separate this from every other known British species. • Habitat. — Rough place by the wall of Woodboro' Hall Gardens, Notts, December 18, 1912. I have notes of other species which it is impossible at present to determine. II.— A REVISED LIST. So great has been the increase in the number of Enchytrseids known to Britain since the Government aided me in my researches, that the time has come when a complete list should be prepared for the guidance of zoologists. The present contribution to that revised list contains the names of all known British genera and species, except Enehytrseus and the red-blooded group which consists of the two genera Lumbricillus and Marionina. These will form the subject of a later communication. For facility of reference, the genera and species will be alpha- betically arranged, and the references will, as far as possible, relate to the original memoirs or principal monographs. Wherever possible the first British record will be cited, and any additional information given which may be deemed necessary for purposes of identification or further research. The Oligochseta volume (Das Tierreich) of Michaelsen is indispensable. Ach^eta Vejd. Setae wanting ; setee sacs sometimes wanting. Salivary glands unpaired, dorsal. Spermathecse free, not attached to the oesoph- agus. 1. A. bohemica Vejd. 1879, Anachseta bohemica, Vejdovsky, in Zool. Anzeig., ii. p. 183. Michaelsen, Das Tierreich, p. 103. August 28, 1911, Kew Gardens; See Bulletin of Mis. Inf., xii. p. 374. November 7, 1911 and March 2, 1912, Nottingham, Trans. Notts Nat. Soc, 1910-11, p. 38. March 11, 1913, Dublin, Irish Nat., 1913, p. 171. 2. A. cameranoi Cognetti. 1889, Anachseta camerani Cogn. in Boll. Mus. Torino, xiv. No. 354, p. 2 ; Michaelsen, Das Tierreich, p. 103 ; July 2, 1911, Acresford near Ashby-de-le-Zouch ; Eriend, in The Naturalist, December 1911, p. 413. " 3. A. eiseni Vejd. 1877, Achseta eisenii Vejdovsky, in SB. L 2 144 Transactions of the Society. . Bohm. Ges., p. 300 ; Michaelsen, Das Tierreich, p. 103. 1909, Southern, in Proc. Koy. Ir. Acad., xxvii. p. 165. Limerick, Ireland. 4. A. incisa Friend. 1912, Friend, in Trans. Notts Nat. Soc, p. 58 ; Mansfield, Notts, May 8, 1912. Vide supra, p. 133. 5. A. minima Southern. 1907, Southern, in Irish Naturalist, xvi. p. 77. Lambay, Ireland. 6. A. spermatophora Friend. 1912, Friend, in Irish Naturalist, xxi. p. 174. Poyntzpass, Armagh, Ireland. Bryodrilus Ude. Setae, present, sigmoid. Blind sacs on oesophagus in segment 6. Spermathecae simple, destitute of diverticula, communicating with oesophagus. 7. Bryodrilus ehlersi Ude. 1892, Ude, in Zool. Anzeig., xv. p. 344; Michaelsen, Das Tierreich, p. 71. 1909, Southern, in Proc. Koy. Ir. Acad., xxvii. p. 147. B. ehlersi Ude. var. ? Powerscourt, Wicklow, Ireland. 1911, Netherhall, near Burton- on-Trent, Derbyshire. Buchholzia Michaelsen. Setae present, sigmoid [oesophagus widens suddenly in seg- ment 7. Dorsal vessel arises in diverticulum]. Spermathecae communicating with oesophagus. 8. B. appendiculata Buch. 1863, Enehytrasus appendiculatu* Buchholz, in Schr. Ges. Konisb., iii. Abh. p. 96 ; Michaelsen, Das Tierreich, p. 72. 1892, April 21, Suburbs of Bradford, Yorkshire. 1909, Southern, in Proc. Eoy. Ir. Acad, xxvii. p. 148. Co. Dublin, Ireland. 1911, February 10, Woodville. July 11, Cauldwell, Derbyshire. 1912, Hastings and Sedlescombe, Sussex. 9. B. fallax Mchln. 1887, Michaelsen, in Arch. Mikr. Anat., xxx. p. 374. 1896, June 4> Antrim, Ireland ; Friend, in Irish Naturalist, vii. 1898. 1911. April 17, Ledbury, Herefordshire ; Sutton Broad, Norfolk. 1913. Dublin, Ireland, Irish Naturalist, xxii. p. 171 ; Blenheim Park, Oxfordshire, April 14. 10. B. focale sp. n. Supra, p. 129. Hastings, Sussex, December, 1911. 11. B. tenuissima sp. n. Supra, p. 130. Hastings, Sussex, June, 1912. Cham^edrilus Friend. Setae present, sigmoid. No preclitellian nephridia or salivary glands ; girdle on segment 9. Spermathecae with large 4/5 gland but without diverticula, not free in coelom. Origin of dorsal vessel postclitellian. British Enchytraeids. By H. Friend. 145 12. 0. chlorophilus Friend. 1913, Friend in J.R.M.S., p. 257 et seq. 1912, November 23, Netherhall, Derbyshire ; December 3, Hastings, Sussex; Smisby, Newhall, Hathern, Oxford and else- where. Jersey, June. Zoologist, December, 1913, p. 457. Chikodkilus Verril. Not yet known as British. Distichopus Leidy. Not yet known as British. Hepatog aster Cejka. Not yet known as British. Enchytpleus Henle. Reserved for later treatment. Fridericia Michaelsen. Setse present, not sigmoid, innermost shortest. Dorsal pores present, also salivary glands. Spermathecse frequently with diverticula and glands. (N. B. The order is alphabetical.) 13. F.agricola Moore. 1895, Moore, in Proc. Ac. Phil., p. 342. Michaelsen, Das Tierreich, p. 97. Carlisle, -January 1898, and fre- quently since. My large accumulation of notes and specimens sug- gests the need of revision and clear definition. 1899, Friend in Zoologist, p. 264. Gardeners' Chronicle, June 1899. 14. F. alba Moore. 1895, Moore, in Proc. Ac. Phil., p. 344. 1898, Friend in The Naturalist, p. 20. Carlisle, January 1898. A record which needs confirmation, owing to the great advances in our knowledge of the genus. 15. F. anglica Friend. 1912, Friend in J.R.M.S., p. 24. Near Ashby-de-la-Zouch in March, and Swadlincote, Derbyshire, April 1911. 16. F. arborea sp. n. Supra, p. 140. Notts, April and May, 1913. A similar Annelid from St. Doulough's, Dublin, March 12, and near Blenheim Palace (Kiddington, Oxon), April, 1913. 17. F. aurita Issel. 1905, Issel, in Zool. Jahrb., xxii. p. 468-70. 1907, Southern, in Irish Naturalist, xvi. p. 74. Bray Head, Wick- low, and Lambay, Dublin. New records are Dublin Canal side, collected by myself March 11; Stretton-en-le-field, May 12; Isle of May, collected by Mr. Evans, June 6, 1913. In most instances they varied somewhat from Issel's description, but could be referred to no other species. 146 Transactions of the Society. 18. F. beddardi Bret. 1900, Bretscher, in Eev. Suisse Zool., viii. p. 29; 1904, ibid., xii. p. 265; 1909, Southern, Proc. Eoy. Ir. Acad., xxvii. p. 164. Newton Moss, near Penrith, Cumberland ; collected March, kept alive and examined August 11, 1911. See F. ratzeli infra. 19. F. bisetosa Lev. 1884, Levinsen, in Vid. Meddel. 1883, Michaelsen, Das Tierreich, pp. 96-7. I have a large collection of bisetose material which shows that. the group must be carefully revised. Bretscher (1900, Bev. Suisse Zool., viii. p. 27) errone- ously places here a form with four setse. I simply record the species as British, and await an opportunity to sift and edit. 19a. F. bretscheri Southern. 1907, Southern, in Irish Naturalist, xvi. p. 73. 1909, Proc. Boy. Ir. Acad., xxvii. p. 160. Not to be confused with F. parva Bret, or F. parva Moore. Dublin, Edin- burgh, frequent in Notts and elsewhere, 1913. 20. F. bulbifera sp. n. Supra, p. 141. To be compared with bulbosa, glandifera, and others. 21. F. bulbosa Bosa. 1887, Neoenchytrseus bulbosus Bosa, in Boll. Mus. Torino, ii. No. 29, p. 2. Michaelsen, Das Tierreich, p. 96, places F. parva Moore here. One of the most widely distributed of British species. Already I have divided my mate- rial and made two or three new species, but more remains to be done. Friend, in J.K.MS., 1912, pp. 14-15. Trans. Notts Nat. Soc, 1910-11, p. 40. 22. F. callosa Eisen. 1878, Neoenchytrmus callosus Eisen in Ofv. Ah. Forh., xxxv. No. 3, p. 76. Michaelsen, Das Tierreich, p. 99; Friend, in J.B.M.S., 1912, p. 19. In April 1913 I found in the gardens at Blenheim Palace, along with specimens of F. michaelseni and F. leydigi, a worm which approaches this species most nearly, though there are differences between my own notes and Eisen's description. Trans. Notts Nat. Soc, 1911-12, p. 62. 23. F. clara Friend. 1913, Friend, in J.R.M.S., p. 267. I have nothing to add to the description and record there given. 24. F. connata Bret. 1902, Bretscher, in Bev. Suisse Zool., x. p. 20. 1907, Southern, in Irish Nat, xvi. p. 75. 1909, Proc. Boy. Ir. Acad., xxvii. p. 161. 1912, Friend, in J.B.M.S., p. 17. Belongs to the bisetose group, and often needs careful study to distinguish it from diach/eta, bisetosa, and related forms. More accurate diagnosis is needed in this large and interesting section, in the light of my recent gleanings. Trans. Notts Nat. Soc, 1910-11, pp. 34, 40'; ib., 1911-12, p. 56. 25. F. coronata sp. n. Supra, p. 141. A clearly-defined species. 1913, Blenheim Palace. 26. F. densa Friend. 1912, Friend, in Trans. Notts Nat. Soc, p. 61. Collected in Notts December 16, 1912, and stated in a footnote to be possibly a variety only of F. michaelseni. But British Enchytrseids. By Rev. H. Friend '. 147 Mr. Hillman collected a form at Rolleston, Notts, on May 14, 1913, which leads to the suspicion that densa may be a true species. It has not yet been carefully described. 27. F. diachseta Bret. 1900, Bretscher, in Eev. Suisse Zool., viii. p. 451. 1902, ib., x. pp. 23-4. See No. 24 above. First British record in Trans. Notts Nat. Soc, 1910-11, p. 41. Fre- quently found in Notts since. 1913, Pocklington, Yorkshire, December 1. 28. F. galba Hoffm. 1843, Hoffmeister, in Arch. Natur., xci. p. 194; Michaelsen, Das Tierreich, p. 101; Friend, in J.R.M.S. 1912, pp. 12-13. Recently found in Notts and elsewhere. See Southern, Proc. Roy. Irish Acad., xxvii. p. 163. 29. F. glandifera Friend. 1913, Friend, in J.R.M.S., pp. 263-5. Separated from bullosa and bulbifera ; characters permanent. Trans. Notts Nat. Soc, 1910-11, p. 40. 30. F. glandtdosa Southern. 1907, Southern, in Irish Nat., xvi. p. 76. 1909, Proc. Roy. Ir. Acad., xxvii. p. 162 ; Dublin and Edinburgh. 1911, Friend, in Trans. Notts Nat. Soc, 1910-11, p. 41. 31. F. hegemon Vejd. 1887, Enchytrseus hegemon Vejdovsky, in SB. Bohm. Ges., p. 303 ; Michaelsen, Das Tierreich, p. 101. The earliest British record is doubtful. See Friend, in J.R.M.S. (1912) p. 15. 1909, Southern, in Proc. Roy. Irish Acad., xxvii. pp. 164-5. 32. F. helvetica Bret. 1896, Bretscher, in Rev. Suisse Zool., iii. p. 516. 1899. ib., vi. p. 407 ; Michaelsen, Das Tierreich, p. 98. 1911, Friend, in Naturalist, p. 291. Frequent records during the past three years awaiting revision. 32a. F. hillrnani Friend. 1913, Zoologist, December, p. 462. Jersey. 33. F. humilis Friend. 1911, Friend, in Naturalist, August, p. 291. 1912, J.R.M.S., pp. 20-1. Smisby, near Ashby-de-la- Zouch, January 31, 1913. 34. F. leydigi Vejd. 1877, Enchytrseus leydigii, Vejdovsky, in SB. Bohm. Ges., p. 303 ; Michaelsen, Das Tierrejch, p. 97. 1912, Friend, in J.R.M.S., comp. 1907, Southern, in Proc. Roy. Ir. Acad., xxvii. pp. 161-2. Several gleanings from various parts of England and Jersey show the need of further revision here. 35. F. lolifera Vejd. 1879, Enchytrseus lolifer Vejdovsky, Enchytraidse, p. 57. Michaelsen, Das Tierreich, p. 98. 1907, Southern, in Proc. Roy. Ir. Acad., xxvii. p. 163. 1911, Friend, in Trans. Notts Nat. Soc, p. 41. 1912, J.R.M.S., p. 12 ; ib., 1913, p. 268, for var. minor. So fluid are some of the forms that it seems at times absolutely impossible to fix the species. 36. F. maculata Issel. 1905, Issel, in Zool. Jahrb., xxii. pp. 466-8. Fields between Swadlincote and Overseal, Derbyshire, April 12, 1912. 148 Transactions of the Society. 37. F. magna Friend. 1889, Friend, in Zoologist, ser. 4, in* p. 262 ; Michaelsen, Das Tierreich, p. 97. 1907, Southern, in. Proc. Roy. Ir. Acad., xxvii. p. 165, footnote; Friend, in J.R.M.S., 1912, pp. 15-16. After losing sight of the species for nearly a quarter of a century, I rediscovered it, May 13, 1913, in a shrubbery at Stretton-en-le-Field. 38. F. micluelseni Bret. 1899, Bretscher, in Rev. Suisse Zool., vi. p. 410; Michaelsen, Das Tierreich, p. 100. 1909, Southern, in Proc. Roy. Ir. Acad., xxvii. p. 163. 1912, Friend, in J.R.M.S., p. 18. Quite distinct from F. galba. Widespread and very vari- able. Here again my large collection of material needs careful revision. 39. F. microcara Friend. 1912, Friend, in J.R.M.S., p. 23. Sutton Broad, August 22, 1911. I brought away from the Broads a quantity of the Enchytrseid soil, and, in June 1912, re-examined the material. This species was again present, and my diagnosis was confirmed. 40. F. minuta Bret. 1900, Bretscher, in Rev. Suisse Zool., vii. p. 33. 1907, Southern, in Proc. Roy. Ir. Acad., xxvii. p. 162. 1912, Friend, in J.R.M.S., p. 17. 41. F. nigrina Friend. 1913, Friend, in J.R.M.S., p. 266. Hastings, Sussex ; and Stretton-en-le-Field, near Ashby-de-la- Zouch. 42. F. obtusa Friend. 1913, Friend, in J.R.M.S., p. 267 ; Trans. Notts Nat. Soc, 1911-12, p. 61. 43. F. oligosetosa Nusb. 1895, Nusbaum. in Biol. Centrabl, xv. p. 27 ; Michaelsen, Das Tierreich, p. 99. Collected Hastings, June 1912. 44. F. paroniana Issel. 1904, Issel, in Atti Soc. Lig,xv. p. 3. 1905, Zool. Jahrb., xxii. p. 416. 1907, Southern, in Proc. Roy. Ir. Acad, xxvii. p. 161. 1912, Friend, in J.R.M.S., p. 18. Dublin, in Ireland; Acresford,near Ashby-de-la-Zouch, July 1911. Natur- alist, December 1911, p. 413. 45. F. parva Bret, and F. parva Moore are named here because they have been recorded in earlier days as British. The growth of our knowledge, however, makes those records doubtful, and the material must be re-examined. 46. F. perrieri Vejd. 1877, Enchytrivus perrieri Vejdovsky in SB. Bohm. Ges., p. 302 ; Michaelsen, Das Tierreich, p. 98. 1898, Friend, in Irish Nat., p. 196. 1912, Friend, in J.R.M.S, p. 15. Earliest record somewhat doubtful; frequently found of late years, resulting in large masses of notes and material awaiting careful analysis. 47. F. peruviana Friend. 1911, Friend, in J.R.M.S., xxviii. p. 734. Kew Gardens, May 12, 1911. 48. F. polychseta Bret. 1900, Bretscher, in Rev. Suisse Zool., viii. p. 450. 1907, Southern, in Irish Nat, xvi. p. 75. 1912, British Bnchytr/eids. By Rev. H. Friend. 149 Friend, in J.R.M.S., p. 17. Kerry, Dublin, and Donegal in Ireland ; Derbyshire, Notts, Jersey, and elsewhere. 49. F. pulchra Friend. 1912, Friend, in J.E.M.S., pp. 21-2. Kew Gardens, 1911. Naturalist, December 1911, p. 415. 50. F. ratzeli Eisen. 1872, Enchytrmvs ratzeli Eisen, in Ofv. Ak. Forh. xxx. No. 1, p. 123 ; Michaelsen, Das Tierreich, p. 100. 1897, Friend, injrish Nat., vi. p. 206. 1907, Southern, in Proc. Roy. Ir. Acad., xxvii. p. 164. 1912, Friend, in J.R.M.S., p. 14. A difficult species, concerning which I have much material for future study. 51. F. reversa Friend. 1911, Friend, in Trans. Notts Nat. Soc, p. 41. 1913, J.RM.S., p. 265. Since found in several new localities. 51. F. rotunda Friend. 1912, Friend, in Trans. Notts Nat. Soc, p. 62. Supra, p. 142. Found at Woodboro' Hall, Notts, December 17, 1912. In looking over my notes I find that this species has been taken by me elsewhere, but entered under other names. An accurate account of its distribution as at present known can only be written when the genus has been carefully brought up to date. 52. F. striata Lev. 1884, Enchytrzms striatus Levinsen, in Yid. Meddel., 1883, p. 236 ; Michaelsen, Das Tierreich, p. 96. 1898, Friend, in Zoologist, p. 121. 1907, Southern, in Irish Nat., xvi. p. 73. 1909, Proc. Roy. Ir. Acad., xxvii. pp. 159-60. 1912, Friend, in J.RM.S., p. 13. A well defined species, widely distri- buted in England. 53. F. ulmicola Friend. 1898, Friend, in Irish Nat., p. 195. 1912, J.R.M.S., p. 13. Ireland, Malvern, Jersey. Cf. Zoologist, December 1913, p. 460. 54. F. variata Bret. 1902, Bretscher, in Rev. Sui3se Zool., x. pp. 19-20. 1907, Southern, in Irish Nat., xvi. p. 73. 1912, Friend, in J.RM.S., p. 22. Very nearly related to F. bulbosa, as are also F. bulbifera, F. glandifera, etc. Sometimes, however, they appear to be quite distinct. Here again much remains to be done. It will be clear from the foregoing notes that even yet our knowledge of this genus is far from satisfactory. In spite of careful study, accurate diagnoses and diagrams, and constant reference to authorities and types, I find it frequently impossible to satisfy myself. The number of seta?, shape of the spermathecse, presence of glands, and arrangement of diverticula, the point of origin of dorsal vessel and duct of nephridia, to mention no more of the specific characters, are often very variable and uucertain. Only by the examination in detail of large numbers of specimens, and most careful diagnosis and description, can we hope eventually to place the subject on a satisfactory and scientific basis. Towards that end I am devoting almost all my leisure time. 150 Transactions of the Society. Geania Southern. Set* present, straight and thick, but absent from anterior region; habitat marine. 1913, Southern, in Proc. Roy. Ir. Acad., xxxi. No. 48, pp. 8-12. 55. G. maricola Southern. 1913, Southern, as above. Clew Bay, Blacksod Bay, and Dingle Bay, Ireland. Regarded by the author as related to Enchj/tiwus monochwtus Mich. Henlea Michaelsen, em. Friend. Setae straight or sigmoid. No dorsal pores. (Esophagus fre- quently enters the intestine by a bulbous enlargement in segments 7, 8, or 9. Spermathecpe simple, devoid of diverticula. N.B. — The discovery of many new species which do not agree with the old generic definition makes revision necessary. As a first step towards this the genus is divided for the present into two sections. §1. Henlea, possessing oesophageal glands. §2. Henlea- nella, destitute of such glands. It would be advisable to make a third group for those species which show a gradual emergence of the oesophagus into the bulbous enlargement. These will in due course probably constitute a new genus. Many details will be found in my previous contributions to this Journal, as well as to the pages of the Zoologist and other scientific magazines or the records of various Natural History Societies. § 1. Henlea Mich. (Esophageal glands present. 56. H. attenuata Friend. 1912, Friend, in J.E.M.S., p. 592; Southwell, Notts, March 26; Overseal, Derbyshire, April 12, 1913. Friend, in Trans. Notts Nat. Soc, 1910-11, p. 39. 57. H. fragilis Friend. 1912, Friend, in J.R.M.S., pp. 588-9. Hastings, Sussex, December 21, 1911. 58. H. fridericioides Friend. 1912, Friend, in J.R.M.S.,p. 587. Hastings with the foregoing, December 21, 1911. 59. H. heterotropa Friend. 1912, Friend, in J.R.M.S., p. 589. Hastings, as before. 60. H. hibernica Southern. 1907, Southern, in Irish Nat., xvi. p. 70. 1909, Proc. Roy. Ir. Acad., xxvii. p. 146. Lambay, Ireland. Also counties Kerry and Meath. 1913, Notts (first English record, April 25, received from Mr. H. Hillman, who also collected it for me in Jersey) ; Sedlescombe, Sussex, August 16, 1913. British Enchytrxids. By Rev. H. Friend. 151 61. H. nasuta Eisen (= H. leptodera). 1878, Archienchytrseus nasutus Eisen, in Of v. Ak. Forh., xxxv. No. 3, p. 72. Miobaelsen, Das Tierreich, p. 69. Schand 'India henlcse Nusbaum, in Zool. Anzeig., ix. pp. 46, 57. 1896, Friend, in Naturalist, p. 298. 1909, Southern, in Proc. Roy. Ir. Acad., xxvii. p. 146. Yorkshire, Co. Dublin, and elsewhere. Friend, in Naturalist, Sept 1, 1911, p. 319. J.R.M.S., 1912, p. 580. 62. H. pusilla Friend. 1913, Friend, in J.R.M.S., p. 270. Notts, September 1912. A similar worm found in Derbyshire, November 22. 63. H. quadrupla Friend. 1913, Friend, in Zoologist, No. 861, p. 85. Separated from H. tenella: see ib. 1911, p. 468. Acres- ford, near Ashby-de-la-Zouch, November 28, 1911, and later at Netherhall, Bretby, and Overseal, Derbyshire. Supra, p. 137. 64. H. triloba Friend. 1912, Friend, in J.R.M.S., p. 596. Hastings, December 21, 1911. 65. H. ventriculosa Udek. ? 1837. Enchytrseus albidus (part). See for synonymy Michaelsen, Das Tierreich 69. 1896, Friend, in Naturalist, p. 298. 1907, Southern, in Irish Nat. xvi., p, 70. 1909, Southern, in Proc. Roy. Ir. Anad. xxvii., p. 147. 1911, Friend, in Zoologist, December, p. 464. The first record (Essex Naturalist, 1896, p. 298) is open to doubt. In those early days it was not suspected that so many new species awaited discovery. § 2. Henleanella Friend. (Esophageal glands absent. 66. H. alba Friend. 1913, Friend, in Zoologist, March 15, No. 861, p. 83. Netherhall, Derbyshire, November 22, 1912. 67. H. arenicola Friend. 1912, Friend, in J.R M.S., p. 586. Hastings, December 21, 1911. 68. H. bisetosa Friend. 1913, Friend, in Irish Nat., xxii. p. 172. Supra, p. 135. Dublin, March 11, 1913, and Nottingham the following month. 69. If. curiosa Friend. 1912, Friend, in J.R.M.S., p. 588. Hastings, December 21, 1911. 70. ff. dicksoni Eisen. 1878, Archienchytrseus dicksonii Eisen in Ofv. Ak. Forh., xxxv. p. 70. Michaelsen, Das Tierreich, p. 68. 1907, Southern, in Irish Nat., xvi. p. 70; Proc. Roy. Ir. Acad., xxvii. p. 146. 1912, Friend, in J.R.M.S., p. 581. Ireland, Hastings, Nottingham. 71. H. glandulosa Friend. 1913, Friend, in Irish Nat., xxii. p. 9; J.R.M.S., July 1913, p. 270. Poyntzpass, Ireland, May 1912. Cauldwell, Derbyshire, June 1913. 72. H. hillmani sp. n. 1913, supra p. 135. Collected by Mr. Hillman, June 10, 1913, in Notts. Trans. Notts Nat. Soc. 1912-13. 152 Transactions of the Society, 73. H. insuliv sp. n. 1913, supra p. 136. Collected by Mr. Hillman, June 1913, in Jersey. Friend, in Zoologist, December 1913. 74. H.inusitata Friend. 1913, Friend, in Zoologist, March 15, No. 861, p. 83-4; see supra, p. 136. Eolleston Junction, Notts, March 26, and Cauldwell, Derbyshire, June 11, 1912. .75. H. lampas Eisen, enlarged by Friend. 1911, Friend, in Zoologist, December 15, p. 465; J.E.M.S. 1912, p. 584. St.Anne's- on-Sea, 1898. The species as enlarged has since been found at Hastings, Dublin, Notts, and elsewhere. 76. H. marina Friend. 1912, Friend, in J.E.M.S., pp. 589 seq, Hastings, Sussex, December 21, 1911. 77. IT. mariona Friend. 1912, Friend, in Trans. Notts Nat. Soc. 1911-12, p. 59-60 ; supra, p. 139. Between Burton Joyce and Lowdham. Notts, December 16, 1912. 78. H. minima Friend. 1913, Friend, in Zoologist, No. 861, p. 84. See supra, p. 136. With H. alba at Netherhall, near Burton-on-Trent, autumn, 1911. 79. H. minuta Friend. 1913, Friend, in J.E.M.S., p. 268. Sutton Broad, by the landing stage, August 25, 1911. 80. H. multispinosa Friend. 1913, Friend, in Zoologist, No. 861, p. 80. See supra, p. 137. Canal, Notts, December 16, 1912. Beported as H. dicksoni var multispinus, in Trans. Notts Nat. Soc, 1911-12, p. 55 (cp. p. 59). 81. H.perpusilla Friend. 1911, Friend in Zoologist, pp. 466-7 ; also Naturalist, pp. 320- 21 ; Cauldwell, Derbyshire, July 9, 1911 ; Worcester, October 23, 1912 ; St. Doulough's, Dublin, March 12, 1913, Irish Nat., xxii. p. 172. Careful revision of my material and notes leads to the conclusion that H. jiarva Friend may be identi- cal with, or only a variety of H. pcrpusilla. But cf. Zoologist, December 1913, p. 461. 82. H. puteana Vejd. 1887, Enchytrseus puteanus Vejdovsky, in SB. Bohm. Ges., p, 301. Michaelsen, Das Tierreich, p. 68. 1911, Friend, in Zoologist, p v 465. 1912, J.E.M.S., p. 583; Ledbury Churchyard, April 17, 1911. 83. H. rhzetica Bret. 1903, Bretscher, in Eev. Suisse Zool., xi. p 115. 1912, Friend, in J.E.M.S., pp. 593-5 ; Trans. Notts Nat. Soc, 1911-12, p. 59: Hastings, December 21, 1911; Notts, April 15, 1912; Dublin, March 1913; Irish Nat., xxii. p. 172. Widely distributed and very variable. For the present I include H. variata Friend (J.E.M S., 1912, p. 592), but the material is not very homogeneous, and needs further revision. 84. H. rosai Bret. 1899, Bretscher, in Eev. Suisse Zool., vi. p. 412 ; Michaelsen, Das Tierreich, pp. 68-9. 1911, Friend, in Zoologist, pp. 465-6 ; Naturalist, p. 320. 1912, J.E.M.S., p. 583-4. Buxton, May 27, 1911 ; Eel-traps on Sutton Broad, August 19, 1911 ; Cauldwell, Derbyshire. June 11, 1912. British Fnchytrseids. By Rev. H. Friend. 153 85. R. tenella Eisen. 1878, Archienchytrseus tenellus Eisen in Ofv. Ak. Forh., xxxv. No. 3, p. 70 ; Michaelsen, Das Tierreich, p. 70. 1911, Friend, in Zoologist, pp. 467-8. 1912, J.R.M.S., pp. 585-6. Acresibrd, near Ashby-de-la-Zouch, November 28, 1911. 1913, Irish Nat., xxii. p. 172, a form found in Dublin at present referred to this species provisionally. 86. H. trisetosa Friend. 1913, Friend, in Zoologist, No. 861, p. 86. See supra, p. 139. In tree-stump with H. quadruplet Friend at Midway, between Ashby and Burton, January 30, 1913. 87. H. tubula Friend. 1913, Friend, in Irish Nat., xxii. p. 172. First described supra, p. 139. Balls Bridge, Canal Side, Dundrum Road, Dublin, and St. Doulough's, March 6 to 12, 1913. It will be seen that the British Annelid fauna is peculiarly rich in Henleas and Fridericias. There are doubtless many more species yet to be discovered. Mesenchytioeus Eisen. Setae present, sigmoid, fewer in lateral than in ventral bundles. No salivary glands, no dorsal pores. Nephridia with small ante- septal. 88 M. beumeri Mich. 1896, Pachydrilus (M.) beumeri, Michaelsen. See Das Tierreich, p. 86. 1909, Southern, in Proc. Roy. Ir. Acad., xxvii. p. 155. County Kerry, Ireland. 89. M. celticus Southern. 1909, Southern, in Proc. Roy. Ir. Acad., xxvii. pp. 155-6 ; Montpelier, Dublin, December 1907 ; Edinburgh, February 1908. 90. M. fenestratus Eisen. 1878, Neoenchytrsnus fenestratus, Eisen, in Ofv. Ak. Forh. xxxv. No. 3, p. 74; Michaelsen, Das Tierreich, 85 ; see Ditlevsen, in Zeit. wiss. Zool., Bd. 77, 1904, p. 439. 1897, Friend, in Irish Nat., as having probably been found by Dr. Trumbull at Powerscourt, Wicklow. In poor condi- tion ; record not confirmed. 91. M. flavidus Mich. 1887, Michaelsen, in Arch. Mikr. Anat. xxx., p. 372. Das Tierreich, p. 35. Found June 11, 1912, at Swain's Park, Swadlincote, Derbyshire, and now recorded for the first time as British. Varies a little from Michaelsen's type. 92. M. oligosctosus Friend. 1913, Friend, in Zoologist, December, p. 462. Jersey, Collected by Mr. Hill man. 93. M. setosus Mich. 1888, Michaelsen, in Arch. Mikr. Anat. xxxi., p. 494 ; Das Tierreich, p. 85. 1907, Southern, in Irish Nat. xvi., p. 71. 1909, Proc. Roy. Ir. Acad, xxvii., p. 155. Cauldwell, Derbyshire, June 11, 1912. On August 8, 1913, I found it with other Etich) trseids between Oberlieber and Brauns- berg, Neuwied-am-Rhein. 154 Transactions of the Society. Michaelseni Ude. Not known in Great Britain. Stekcutus Mich. Not reported as British hitherto. BlBLIOGEAPHY. 1. Friend— J.R.M.S., 1912-13. 2. „ Trans. Notts Nat. Soc, 1911-13. 3. „ Irish Nat., xxi. (1912) ; xxii. (1913). 4. Michaelsen — Das Tierreich, 1900. 5. Southern— Irish Nat., xvi. (1907) pp. 68-82. 6. „ Proc. Roy. Ir. Acad., xxvii. (1909) pp. 119-82. 7. „ Proc. Roy. Ir. Acad., xxxi. (1913) pt. 48. 8. Bretscher— Rev. Suisse Zool., x. (1902) p. 27. 9. Friend — Zoologist, 1913. SUMMARY OF CURRENT RESEARCHES RELATING TO ZOOLOGY AND BOTANY (principally invertebrata and cryptogahia), MICROSCOPY, Etc.* ZOOLOGY. VERTEBRATA. a. Embryology. t Development of Rabbit's Embryo in Vitro. J — A. Brachet has been able to secure for 24-48 hours the development of " explanted " blastodermic vesicles of the rabbit (from the sixth or seventh day) in plasmic media, formed from the rabbit's blood. They not only remained in life : they exhibited progressive development. The noteworthy result is that in the artificial plasmic medium the development was not appreciably altered. Thus the placenta, whose formation might have been supposed to require the direct action of the uterine mucosa, not only made its appearance but had its foundations laid just as if the blastodermic vesicle had remained in the mother. A blastodermic vesicle with a didermic embryonic disk, but otherwise undifferentiated, is explanted into a blood clot and submitted, therefore, to uniform influences all over its surface, yet its development for the short term of its survival is quite normal ; it forms an embryo, an ectoplacenta, and a papuliferous zone. There are only slight differences in detail. It follows from this important conclusion that the influence of the im- mediate normal environment within the mother is not so rigorously indispensable as some have supposed. Plasma formed from the blood of the male rabbit is just as suitable as that from the blood of the female. The general conclusion is that the internal causes of organo- genesis are of paramount importance. Artificial Parthenogenesis in Amphibians.§— E. Bataillon dis- tinguishes between the activation of the egg and its karyocatalysis (an * The Society are not intended to be denoted by the editorial " we," and they do not hold themselves responsible for the views of the authors of the papers noted, nor for any claim to novelty or otherwise made by them. The object of this part of the Journal is to present a summary of the papers as actually pub- lished, and to describe and illustrate Instruments, Apparatus, etc., which are either new or have not been previously described in this country. t This section includes not only papers relating to Embryology properly so called, but also those dealing with Evolution, Development, Reproduction, and allied subjects. J Arch. Biol., xxviii. (1913) pp. 449-503 (2 pis.). § Ann. Sci. Nat. (Zool.) xvi. (1912) pp. 257-307. 156 SUMMARY OF CURRENT RESEARCHES RELATING TO acceleration induced by the introduction of a foreign nuclear element). After electric shocks the eggs become non-fertilizable, but they will develop abnormally and form larva? if they are inoculated with a cata- lysing nucleus. Mere pricking them is not efficacious. The efficacy of the second faction (the introduction of a foreign nuclear element) seems to be limited to the first hour after activation. The change of state produced by activation is independent of the afflux of water. Internal movements may be seen going on in the ova in a moist chamber just as in those in immersed ova. Eggs of Rana fusca, exposed to vapour of chloroform in a moist chamber for three minutes, are activated as others are by electricity. They are non-fertilizable. They give off their second polar body and divide. If they are moistened with blood and then pricked they develop into larva?. The same result may be obtained by using vapour of ether, benzol, and toluol. After the activation there has to be an introduction of some organic apparently nuclear matter, which Bataillon regards as having a catalytic influence. Various physical and chemical excitations (electric discharges, changes of osmotic pressure, exposure to vapours, etc.) affect the ovum, and are followed by a reaction which opposes a barrier to fertilizing elements. The addition of a catalysing nucleus to the ovum in its new state of equilibrium is followed by embryogenesis. Artificial Parthenogenesis in Frog.* — Fritz Levy has reared not only tadpoles, but three young frogs from artifically stimulated eggs. His method was to prick the eggs with a platinum needle, which was sometimes first dipped in salt or in the blood of the mother. He finds that the nuclei of the results of this aspermic development are smaller than the normal, and he believes that they are haploid, i.e. with half the normal number of chromosomes. Artificial Parthenogenesis in Frog and Toad. f — Giinther Hertwig finds that eggs of Rana esculenta and Bufo vulgaris fertilized by sperms of Rana fusca segment normally, but die before gastrulation. But if the sperm of R. fusca be first exposed to intense radium rays, and then used for fertilization, the eggs go through gastrulation and become larva?, which survive for several weeks. The explanation suggested of this paradox is that the sperm of R. fusca contains some chromatin element which is not in harmony with the idioplasm of the ova of R. esculenta or Bufo vulgaris ; therefore the developing ova soon die. But if this element be destroyed by the radium, the sperm may act simply as a stimulus to development — which is really parthenogenetic. In various organs, it is noticed, the surface or the volume of the nuclei is half the normal. Hermaphroditism in Toad.J — 0. Fuhrmann describes a number of cases of hermaphroditism in Bufo vulgaris — several of rudimentary hermaphroditism affecting the gonads and their ducts, two of potential * Arch. Mikr. Anat., lxxxii. (1913) 2te Abt. , pp. 65-77 (8 figs.). t Arch. Mikr. Anat., lxxxi. (1913) 2te Abt., pp. 87-127 (2 pis. and 6 figs.). J Rev. Suisse Zool., xxi. (1913) pp. 331-45 (6 figs.). ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 157 hermaphroditism with testes and ovaries (with unpigmented ova), and oviducts well formed, and two of effective hermaphroditism, able to produce both eggs and sperms. There does not seem to be any direct correlation between the state of the ovary and the degree of development of the oviduct. Bidder's organ has doubtless come to have a secondary physiological significance, but it is morphologically a rudimentary ovary. Eggs of Skates.* — A, Chas. Williamson has done a useful piece of work in preparing drawings of the egg-cases or mermaid's purses of seven species of skate, showing that these have in some cases a marked specificity. Spermatozoon of Guillemot-! — E. Ballowitz describes the mature spermatozoon of Uria lomvia, which shows (a) an elongated cylindrical curved head with an apical piece ; (b) a middle piece with a spiral filament coiled around the axis ; and (c) the tail ending in a short fine terminal portion. t Larval Phases of Nemichthydas.J — Louis Roule finds evidence that the forms described as Tilurella are larval stages of Nemichthys, the principal genus in the family Nernichthydas. In this family, there- fore, as in other Apoda, the occurrence of Leptocephalid or Lepto- cephalid-like larvae is characteristic. b. Histolog-y. Active Movements of Epithelial Cells.§ — A. Oppel describes the active movements of the epithelial cells at the wound-surface of a tail excised from a tadpole. Apart from a passive shifting of cells as the result of pressure, there is independent movement. This is to be seen also when half of an excised cornea has the epithelium stripped off it. The epithelial cells on the uninjured half elongate, and some of them move on to the stripped half. Miiller's Epithelium. || — S. E. Wichmann maintains the homology of the Mullerian duct in mammals, reptiles and amphibians, and describes its origin from a flat stretch of blastema, which is phylo- genetically derivable from the nephrostomial epithelium of the pro- nephros. He gives the name " Miiller's epithelium " to the various components of this blastema and to the epithelium of structures which arise from it, such as Miiller's duct and the fimbria ovarica. Muscle-bands in Middle Coat of Arteries. f — A. H. MacCordick finds that when the course of an artery is straight, and it is not sub- jected to bending, the muscle-fibres of its media are circularly disposed. * Sci. Invest. Fisheries Scotland, 1912 (published 1913) No. 1, pp. 1-6 (5 pis.), t Anat. Anzeig., xliv. (1913) pp. 305-9 (9 figs.). X Comptes Rendus, clviii. (1914) pp. 352-4. § Anat. Anzeig., xlv. (1913) pp. 173-85 (7 figs.). || Verh. Anat. Ges., 1913, in Anat. Anzeig., xliv. (1913) Erganzung., pp. 139-54 (19 figs.). U Anat. Anzeig., xliv. (1913) pp. 225-61 (3 figs.). April 15th, 191 If. M 158 SUMMAKY OF CURRENT RESEARCHES RELATING TO When the course of an artery is not straight, and when it is subjected to bending of various grades, the circularly disposed fibres of its media are reinforced by oblique or longitudinal bundles, the oblique fibres occurring much more frequently than the longitudinal. These oblique and longitudinal fibres are to be found in the middle coat in all periods of life. It does not appear that these occur in any particular site of development within the media. Spongiosa of Cetacean Pelvis.* — Willy Augustin took Rontgen photographs of several specimens of rudimentary pelvic bones. They showed the characteristic trajectories in the spongiosa. This is inter- esting, since these rudimentary bones are connected only with muscles (the tail-muscle, the genital muscles, and trunk muscles). Structure of Preen Gland. | — Hugo Granvik describes the structure of the glandula uropy^ii in a number of types. He shows, for instance, the presence of Herbst's corpuscles (modifications of Paccinian corpuscles) in the fowl and some other birds, the secondary canals of the efferent duct in the flamingo, the septum in Passer montanus, which is absent in the house-sparrow, the very well-developed state of the gland in the snow-bunting, and many other points. Structure of Preen Grland.J — P. Paris gives a detailed account of the state of the preen gland in different orders of birds, and discusses its vascularization, innervation, development, and use. He describes the gland, which is present in most birds, and probably in all their embryos, as a subcutaneous mass of variable but clearly-defined form, made up of two equal lobes entirely or partly separate, but united at the apex in an excretory nipple projecting on the integument, by which it is closely invested. Each of the constituent lobes is autonomous — that is, each has its own vascularization and innervation, and can secrete independently of the other. Each lobe is surrounded by a capsule of connective-tissue without smooth muscular fibres. It contains a great many glandular tubules, separated from each other by thin partitions, of the same nature as the enveloping capsule, which enclose the glandular epithelium. The glandular tubes form a mass, sometimes single, sometimes sub-divided into glandules within each lobe. The tubes are of varying length, and they unite to form secondary ducts, which in their turn form the primary ducts. These ducts may be wholly or partly absent, in which case the secretion is collected in a cavity at the apex of each lobe and is discharged to the exterior by an excretory canal through the nipple. Each lobe has thus at least one excretory canal, except in a few cases {Gaprimulgus europseus, Upupa epops), which have only a single duct for the whole gland. The glandular epithelium is formed by several — at least three — layers of secretory cells, which increase progressively in size from the periphery to the axis of the tube. Primitively triangular, they become polyhedral, then globular in form. These secretory cells are very similar * Zool. Jahrb., xxxv. (1913) pp. 533-80 (2 pis.;. t Arkiv Zool., viii. (1913) No. 4, pp. 1-19 (2 pis. and 10 figs.). j Arch. Zool. Exp6r., liii. (1913) pp. 139-274 (4 pis.). ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 159 throughout the whole length of the tube, except in Rhyncotus rufescens, and perhaps in other Tinarniformes where the tubes are divided into two zones of cells of quite different aspect. The excretory nipple, in- vested by the fine integument, encloses the excretory canals of the lobes with the terminal portions of their enveloping capsules. Its extremity may be naked or furnished with plumules or exceptionally with feathers. Within it, as whhin the capsules, there are often very large capsules of Herbst and abundant adipose tissue. There may be bundles of smooth muscular fibres forming two constricting groups, one at the apex, the other at the base of the nipple, the two connected by sparse longitudinal fibres. The arteries which supply the gland arise from two trunks issuing from the caudal artery. After a variable course, at some point of which they anastomose with vessels from the next interapophysary spaces, these arterial trunks break up into two or three branches, which are distributed throughout the gland. The two coccygeal veins arise directly from anastomosis of the hypogastric veins, or from a trunk rapidly dichotomized. They follow the same course as the arteries. The nerves arise from branches, issuing between the first and second caudal vertebras, which after dividing anastomose with sympathetic nerves. The investigator gives a detailed account of the development of the gland (in Anas boscas), as well as of the chemical composition of its secretion, and of physiological experiments undertaken to prove its function. The general result of these experiments is that the gland is of no use for increasing the impermeability of the feathers, has no toxic action — at least in this country — and that its removal or hypertrophy has no effect whatever on the health of the bird. In origin, develop- ment, anatomy, etc., the uropygium of birds presents marked analogies with the odoriferous glands of other Amniota, especially with those of reptiles, and it must therefore be regarded as an odoriferous gland. The paper includes a synoptic table of the state of the gland in different groups. Plastosomes of Visual Cells.*— G. Leplat has studied the differen- tiation of the plastosomes in the rods and cones of the bird's eye. Definite plastosomes seen in the embryonic cells and in the visual cells undergo chemical change and differentiation in the primordia of the rods and cones. Some granulations persist in the internal segment ; others, in the external segment, form a homogeneous sheath on the , centrosomic filament. Minute Structure of Amnion of Chick. f — Tiberius Peterfi has studied the epithelial cells of the chick's amnion. The young cells become vacuolated. The fibrils appear as a haptogen-membranous boundary between the vacuoles. Lainellse become reduced to a reti- culum of fibrils which extend continuously over the whole amnion, without it being possible to define beginnings or ends. The stronger lines become cell-boundaries, the finer form intracellular fibrils. * Anat. Anzeig., xlv. (1213) pp. 215-21 (5 figs.). f Anat. Anzeig., xlv. (1913) pp. 161-73 (8 figs.). M 2 160 SUMMAKY OF CURRENT RESEARCHES RELATING TO Phenomena of surface-tension and absorption play an important part in the differentiation. Histological Peculiarities of Turtle.* — K. Ogushi describes the vascularization in the villi of the buccal, pharyngeal, and oesophageal epithelium in Trionyx japonicas, which have a respiratory function. As Agassiz pointed out, there is also a very abundant ramification of blood-vessels on the skin of the lower surface, and this is also of respiratory significance. The author also describes a nerve-ending beneath a papilla on the lip, and the peculiar structure of the epithelium of the epididymis. Development of Cartilage of Notochord in Lizards. f — J. Pusanow goes back to the stage when the notochord consists of a vacuolated syncytium without even a chorda-epithelium. There is active amitotic division of the nuclei ; no penetration of ectochordal cells was seen ; there is a chondro-mucoid metaplasis of the " chorda-membranes " which are formed between the vacuoles ; a differentiation of a ground- substance or exoplasma and an active endoplasma occurs ; the nuclei increase in size as the ground-substance increases, and thereafter they get smaller again ; a hyaline cartilage is formed which very soon undergoes degeneration till only a vestige remains. The spot where the chorda cartilage appears is the spot where the vertebra afterwards breaks across in autotomy. Leucocytes of Amblystoma.J — Hal Downey finds that the poly- morphonuclear leucocytes of this Amphibian contain granules with the general character and staining reactions of azurophil granules. They are quite variable in size, number, and distribution. In this respect they resemble the azurophil granules of the mammalian lymphoid cells, but their radial grouping around the centrosphere, their constant appearance in the polymorphonuclears, and their great number in any one cell, place them nearer the " special " granules of the higher animals. The lymphocytes of most Amphibia (frog, Cryptobranchus, etc.) lose their azurophil granules when they differentiate into polymorpho- nuclears, and their cytoplasm becomes oxyphilic. In Amblystoma the cytoplasm of the polymorphonuclears remains " lymphoid " in character, while the azurophil granules remain and their number is increased. This may be regarded as an attempt towards the differentiation of a " special " granulation. In Amblystoma all possible intermediate stages between larger lymphocytes and polymorphonuclears are found in the circulating blood. The " parachromatin canals " of Werzberg are optical appearances due to deep furrows on the surface of the nuclei. The erythrocyte nuclei of Amblystoma are more pyknotic and more degenerative in character than those of the erythrocytes of the garter snake, and Minot's distinc- tion of ichthyoid and sauroid types of erythrocytes will not hold in this case. * Anat. Anzeig., xlv. (1913) pp. 193-215 (1 pi. and 5 figs.), t Anat. Anzeig., xliv. (1913) pp. 262-9 (2 figs.). % Anat. Anzeig., xliv. (1913) pp. 339-22 (8 figs.). ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 161 c General. Relation between Diameter of Nerve-fibres and their Rapidity of Action.* — L. Lapique and R. Legendre find that the nerves of the greatest functional rapidity, innervating the most rapidly contracting muscles, have fibres with the largest diameter. The rapidity of trans- mission is in proportion to the diameter of the fibres. Thus the nerve- fibres to the white muscles of the rabbit, which contract quickly, have a diameter of 13 fx., while those to the red muscles, which contract slowly, have a diameter of 8 /x. Pigmentation of Skin in Primates.!— K. Toldt, jun. has found that in thick-haired Primates there is considerable marking of the skin hidden by the hair. It is due to pigmentation in the epidermis and corium. There seems to be no constant relation in position or intensity between pigmentation in the hair, in the epidermis, and in the corium. There is often a marked symmetry in the integumentary pigmentation, and it appears to be characteristic for genera at least. Numerous points of interest are discussed, such as the occurrence of blue birth-marks in man, which are due to a vestigial pigmentation of the corium. Ontogeny and Phylogeny of Pancreas.! — Ivar Broman calls atten- tion to cases where there are accessory pancreatic glands, to the frequent development of the pancreas from three primordia, to Oppel's observa- tion that the pancreas of Proteus anguimus has nineteen to forty-four ducts, and to other facts, which lead him to the view that in the primi- tive condition of the vertebrate gut there were numerous small pan- creatic glands in the vicinity of the opening of the bile-duct. Ciliary Mechanisms in Amphioxus, Ascidians, and Solenomya.§ J. H. Orton has made a study of the function of cilia in connexion with feeding. He finds that feeding in Amphioxus is effected in three main ways. (1) By the maintenance of a stream of water through the pharynx by rows of lateral cilia on the gill-bars ; (2) the throwing out of mucus from the endostyle on to the gill-bars to serve for entrapping food-particles ; (3 ) the collection of food-particles by rows of cilia on the pharyngeal surface of the gill-bars ; these cilia work up the food- particles with mucus into cylindrical masses, and transport these dorsally into the dorsal groove, which carries the collected masses backwards into the digestive tract. Thus the ciliary mechanisms on a gill-bar of Amphioxus are exactly the same as those on the gill-filaments of some Lamellibranchs, as Pecten, and some Gastropods, as Grepidula. The ciliated tract known as the wheel-organ also effects food-collection, and Hatschek's pit supplies mucus for entrapping food-particles. The gill of Amphioxus functions mainly as a feeding-organ and a water-pump, and probably not at all as an organ for aerating the blood. The mode of feeding in Ascidians is almost exactly the same as in Amphioxus, but * Comptes Rendus, clvii. (1913) pp. 1163-6 (2 figs.), t Zool Jahrb., xxxv. (1913) pp. 271-350 (4 pis. and 3 figs.), t Verh. Anat. Ges., 1913, in Anat. Anzeig., xliv. (1913) Erganzung., pp. 14-20 (3 figs.). § Journ. Mar. Biol. Assoc, x. (1913) pp. 19-49 (11 figs.). 162 SUMMARY OF CURRENT RESEARCHES RELATING TO food-collecting- is effected by cilia on the papilla? and on the gills, and is helped in some forms by transverse waving of the longitudinal bars. The investigator's observations lend support to the view that the neural gland in Ascidians is an organ for secreting mucus, which aids in the collection of food-particles, and that the dorsal tubercle of Ascidians is an organ for passing mucus on to the pharynx. The ciliation of the gill-bars of Balanoglossus is essentially the same as that of Ampkioxus. Hence the current of water through the body is doubtless produced by the lateral cilia, and food-collecting is effected by the frontal cilia. The ciliation of the gill of Sohnomya closely resembles that of Nucula ; the lateral cilia produce the main current ; the latero-frontal and the frontal cilia collect food-particles, which the frontal cilia carry to the ventral surface of the gill, whence they are conveyed to the mouth by special transporting cilia. Numerous small ciliated knobs occur on the ab-frontal face of the gill-lamellae, and serve to interlock with their fellows on opposite leaflets. These ciliated knobs correspond to the ciliated disks of the gill-filaments of other Lamellibranchs, such as the mussel. Interlocking cilia occur on the edges of the upper and lower leaflets of the gill, and serve to lock the gill to the inner wall of the mantle, and thus to partition the mantle-cavity. The function of the Lamellibranch gill is probably mainly that of a food-collecting organ and water-pump, and except in Protobranchs it is probably not an organ in which aeration of blood occurs. Tunicata. Protostigmata in Ascidians.* — A. G. Huntsman describes the development of the primitive stigmata or gill-slits, which are elongated dorso-ventrally and occur in a longitudinal series on each side of the pharynx. The stigmata of the adult differ from these in being usually very numerous, indefinite in number, and elongated antero-posteriorly. In Ciona there are to begin with two protostigmata of the first order, arising from a division of the stigmatic primordium. The two primaries produce four secondaries by division, and the first pair divide into four tertiaries. The protostigmata are formed either by simple sub-division or by modified sub-division, resulting in the intercalation of new stigmata. Or there may be an intermediate method of sub- division. In various ways, which are described, the protostigmata are converted into the rows of definitive stigmata of the adult. The genesis of the stigmata affords a proper basis for an understanding of the adult pharynx and a serviceable aid in classification. Localization of Plastosomes in Ascidian Ovum.t— J. Duesberg describes the unequal distribution of the fundamental substance, the yolk-granules, and the plastosomes in the egg of Ciona intestinalis, and regards the plastosomes in particular as the organ-forming substances. He gives good figures and refers to other intances of localization described by Conklin and others. * Proc. Roy. Soc, Series B, lxxxvi. (1913) pp. 440-53 (2 figs.), t Verh. Anat. Ges., 1913, in Anat. Anzeig., xliv. (1913) Erganzung., pp. 3-13 (12 figs.). ZOOLOGY AND BOTANY, MICEOSCOPY, ETC. 163 Origin of Ascidian Mouth.*— A. Gr. Huntsman has studied this in Chwelina, Dendrodoa (Siyelopsis), and Gsesira (Molgnla), and has reached the unexpected result that a large part of the epithelium of the wall of the oral cavity is derived from the primitive neural tube of the embryo. New Type of Compound Ascidian. f — A. Oka describes a remark- able compound Ascidian from Japan, Gyathocormus mirabilis sp. n., for which a new family will be required. The colony is fixed and stalked ; the portion composed of zooids is like a beautiful open cup. The mouth of the cup is the common cloacal opening, the cavity of the cup the common cloaca. The wall of the cup consists of a single layer of zooids, with their anterior ends external and their posterior ends internal. The body of each is divided into a thorax and an abdomen, the latter with a long vascular appendage. The peribronchial wall is imperfectly developed ; the stigmata of the branchial sac open directly into the central common cloaca. The test is soft, gelatinous, and transparent ; there are no calcareous spicules ; the bladder-cells are very numerous. There are four rows of stigmata on the well-developed branchial sac. No internal longitudinal vessels are present. The stigmata are very long and narrow. The tentacles are simple. The dorsal lamina is represented by a series of languets. The gut forms a simple loop posteriorly to the branchial sac The gonads are not conspicuous. An incubatory pouch is present. There is a tailed larva. Oka considers this interesting form as representative of a new family, somewhere in the neighbourhood of Distomidas, e.g. near Golella, but leading in the direction of Pyrosoniidae. In many ways it agrees with Pyrosoma and serves to link that type nearer to other Ascidise cornpositae. INVERTEBRATA. Mollusca. 5. Lamellibranchiata. Development of Anadonta cellensis.J — Karl Herbers has reared the young stages artificially to a length of 3 '13 mm. ; from 5" 7 mm. in length onwards the stages were found in natural conditions. The primary mesoblasts form two bilaterally symmetrical mesoderm-bands, which can be traced into the glochidium, and do not break up into loose mesenchyme. The young shell of Anodonta differs in shape and colour from that of the adult ; it has a typical wavy sculpture, and carries the glochidial shell for a considerable time. The labial palps arise from two epithelial folds ; the gills from rows of papillae. A saccular invagination, homologous with a byssus cavity, arises from the pedal epithelium and moves inwards to near the pedal ganglion. Besides the paired statocysts, there are the osphradia and the adoral * Proc. Roy. Soc, Series B, lxxxvi. (1913) pp. 454-9 (2 figs.). t Journ. Coll. Sci. Univ. Tokyo, xxxii. (1913) Art. 12, pp. 1-30 (3 pis.). t Zeitschr, wiss. Zool., cviii. (1913) pp. 1-174 (104 figs.). 164 SUMMARY OF CURRENT RESEARCHES RELATING TO integumentary sense-organs, the lateral and oral sensory ridges, and a lateral sensory organ between the openings of ureter and gonoduct. The kidneys, heart, pericardium, and gonads arise from paired primordia, associated with the mesoderm-bands. The gonads appear to arise as paired invaginations from the anterior pericardium. The development of the remarkable relation between the heart and the gut is described. Vascular System of Anodonta cellensis.*— G. Schwanecke gives a detailed and effectively illustrated account of the arterial and venous systems. He deals with the heart, the valves, the circulation in the gills, the kidneys, the mantle, the foot, and so on. The main circulation is from heart to body, from body to gills, from gills to heart. A minor stream is from heart to mantle, and back to the heart. Another stream passes from the body through the kidney to the heart, and an accessory stream through the parenchymatous tissue of the branchial septum instead of through the gills themselves. Arthropoda. «• Insecta. Structure of Ovary in Insects.f — Paul Govaerts distinguishes, like previous investigators, between panoistic ovaries that have no nutritive cells, but only ova and follicular cells, and meroistic ovaries that have nutritive cells either connected with each ovum or located in the terminal chamber of the ovarian tube (and with or without uniting filaments). He is chiefly concerned with the history of the follicle cells and the ovocytes, as seen particularly in Trichiosoma, Carabus, and GicindMa. In Carabus (and probably in Trichiosoma) the nutritive cell and the ovum has a quite similar nucleus and a similar stage of synapsis. Both have a mitochondrial apparatus, but that of the ovum is a regular crescent ; that of the nutritive cells is diffuse. The nucleus of the nutritive cells becomes much larger than the germinal vesicle. Both show an elimination of nucleolar matter into the cytoplasm, but the details differ. The nutritive cell degenerates, the ovocyte proceeds to vitellogenesis. In short, they have much in common, but they have quite distinct histories, and the nutritive cells cannot be called abortive ova. Chromatoid Body in Spermatogenesis of Pentatoma.l — Edmund B. Wilson discusses a chromatoid body simulating an accessory chromo- some in Pentatoma (Rkyiodolomia) senilis Sav. It is of large size, invariably present, and almost always single. A study of the entire spermatogenesis shows that it is neither an accessory nor any other kind of chromosome. It is in fact of protoplasmic origin, first appearing early in the growth period outside the nucleus, whence it may be followed uninterruptedly through all the succeeding stages until it is finally cast out of the spermatozoon. Its nature is problematical, but it is important to note its deceptive resemblance to an accessory chromo- * Zeitschr. wiss. ZooL, ovii. (1913) pp. 1-77 (39 figs.), t Arch. Biol., xxviii. (1913) pp. 347-445 (3 pis.). I Biol. Bulletin, xxiv. (1913) pp. 392-410 (3 pis.). ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 165 some. Decisive evidence as to sex-chrotnosomes can only be obtained by tracing their individual history and by accurate correlation of the chromosome-numbers in the spermatogonial and spermatocyte divisions. Comparison of Nervous Systems of Insects.* — K. F. Kiihnle gives an account of the brain, cerebral nerves, and head-glands of the common earwig (Forficula auricularia) and compares these with what he finds in a bug {Tomocerus flavescens), a termite (Eutermes peruana.*), and a walking-stick insect (Dixippus morosus). He gives a careful analysis of the proto-, deutero-, and trito-cerebrum, and the nerves arising from these parts. New Order of Insects. | — F. Silvestri describes three species of an interesting new genus, Zorotypus, from the Gold Coast, Ceylon, and Java, and proposes a new order Zoraptera for their reception. The insects are minute, terrestrial, wingless, and agile ; they live among rotting vegetable debris, and seem to catch mites and the like. The mandibles are strong biting organs ; the antennas are short and monili- form ; there are conical single-jointed cerci ; the thorax is relatively long ; the abdomen has 10 segments, 8 stigmata, and 2 ganglia. Tracheal Capillaries among Fibres of Wing-muscles. % — J- Athanasiu and J. Dragoiu describe the tracheoles or fine capillary branches of the tracheae among the fibres of the wing -muscles in Hydro- philus. Penetrating below the sarcolemma the branches divide into a large number of capillaries which lie between the columns, some longitudinally, some transversely. In a longitudinal section it is seen that the space between two muscle columns is occupied by a tracheal capillary with an approximate diameter of 0*001 mm. The transverse capillaries are seen as minute dark circles. The ramification is extra- ordinarily rich, and it is a very interesting point that it is not seen at all in the muscles of the legs. Skin and Glands of Dytiscus marginalis.§— Alois Casper describes the cuticle, hypodermis (single-layered), and the basal membrane. The cuticle is formed in part by secretion, in part by a direct change of the cell-plasma of the hypodermic cells. The cuticle is made up of many lamellae and beams, and has a complex structure. The insertion of muscles is effected by an epithelial tendon (modified cells of the hypo- dermis). There are varnishing unicellular glands, modified epidermic cells. Packets of such cells occur which have a specialized function, e.g. at the genital apparatus. Or a more compact packet is formed, and the chitinous tubules open on a common cribellum. This occurs on the jaws. A third type of packet occurs, with looser vesicular cells. Invagination and the differentiation of a canal lead on to more complicated glands — offensive, pseudoacinous, and pygidial. These are * Jen. Zeitschr. Naturw., 1. (1913) pp. 147-276 (5 pis. and 39 figs.). t Boll. Lab. Zool. Scuola Agricoltura Portici, vii. (1913) pp. 193-209 (13 figs ) t Comptes Rendus, clvii. (1913) pp. 1168-71 (2 figs.). § Zeitschr. wiss. Zbol., cvii. (1913) pp. 387-508 (44 figs.). 166 SUMMARY OF CURRENT RESEARCHES RELATING TO described in detail. The offensive glands repel larger enemies. The secretion of the other two types serves to close up the air-chambers under the elytra and between pro- and mesotliorax. The imago shows a distinctly segmental arrangement of its larger glands. The glandular cells have a vesicular nucleus, a reticulate plasma, an internal vesicle, and a chitinous tubule. Secretion is preceded by an increase of chromatin by the nucleolus ; the secreted product appears in the plasma, collects around the vesicle, passes along fine plasmic threads through the membrane of the internal vesicle, and thence osmoticaliy through the wall of the chitinous tubule. During each secretory period the chromatin of the nucleus is temporarily exhausted. Odoriferous Organs of Female Lepidoptera.* — Ernst Urbahn has made a detailed study of these organs, which may occur in the vicinity of the external genitalia or elsewhere. Illig and Freiling have dis- tinguished (a) protrusible scent-areas {Phalera, Pygsera) • (b) evaginated scent-rings (Pterostoma, Cucullia, Golocasia) ; (c) the dorsal scent-fold of Lymantriidas ; (d) intersegmental scent-sacs {Hi/pocrita, Callimorpha, Saturnia, Aglia, Argynnis) ; (e) the glandula? odoriferse of species of A rgynnis ; and (/) the ventral tufts of Agrotis fimbria. All scent-organs that are restricted to the females are abdominal. They always lie at the end of the abdomen and are either tufts or intersegmental folds, sacs, and the like. The folds and sacs arise from an intersegmental fold, usually between 8 and 9, which has become glandular. There are large glandular cells with large nuclei, and a plasma with numerous secretion- vacuoles. Trophi of Leaf-Miners. f — Ivar Tragardh describes the larvaa of a series of Lepidopterous leaf-miners. He has been able to follow the whole of the interesting transformation from the so-called " flattened type" to the cylindrical type. A pronounced dimorphism in the mouth-parts of the younger and the later instars occurs in those forms where there are two well-defined, and in some respects entirely different periods in the life-history of the larva. The difference depends on the two methods of feeding and mining. The one method is to cut a thin horizontal slice in the parenchyma and suck the sap ; the other method is to eat mouthful after mouthful of the parenchyma, excavating a mine without wounding the epidermis. The relation of the mouth-parts to the sap-feeding and tissue-feeding is illustrated in detail. Larva of Egle spreta.J — Ivar Tragardh describes the eggs and larvae of Egle (Anthomyia) spreta, which he found on Epichloe typhina, a fungus attacking grasses (Phleum pratense and DactyUs glomerata). Three instars which, differ greatly, are described. When they hatch the larvae use the egg-shell as a cover, but soon form a thin oblong-oval tube of faecal or fungoid matter. From this cover the larva makes ex- cursions into the fungus, devouring it, and "leaving broad winding streets." As it grows it adds to its tube, which becomes as broad as the * Jen. Zeitschr. Naturw., 1. (1913) pp. 277-358 (2 pis. and 26 figs.), t Arkiv Zool., viii. (1913) No. 9, pp. 1-48 (67 figs.). X Arkiv Zool., viii. (1913) No. 5, pp. 1-16 (1 pi.). ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 167 grass blade. At the same time the greater part of the fungus disappears. At last the larva attacks the grass itself. Development of Wings in a Caddis-fly.* — W. S. Marshall has studied the development of the wings in Platyphylax designates Walk. The wing-rudiments of Platyphylax appear in the larva soon after hatch- ing, probably in the second instar, and are noticed as small disk-like thickenings of the hypodermis, lying each under a small dark marking of the cuticular layer. Each disk invaginates, and, insinking below the surface, forms a peripodial cavity which communicates with the outside by a peripodial pore. The disk is at first circular, but soon elongates and then lies obliquely to the longitudinal axis of the body of the larva. The cuticular layer just over the rudiment differs from the surrounding part in being darker, and free from small setse. The cuticular layer is secreted at all stages by the cells of the rudiment. The disk evaginates and soon grows so large that a folding of the rudiment within the peri- podial cavity is necessary. The peripodial pore becomes a long narrow slit, through which the wing rudiment leaves the peripodial cavity and becomes external. While still within the peripodial cavity dark markings appear on each rudiment ; these form alternating light and dark areas upon the wing; ; the former become the wing veins, and the latter the areas between them. Trachea? do not enter the developing wings until they have become external, and the wing veins have been formed. The wings become external soon after the larva has closed its case for pupa- tion. Each wing rudiment is situated under the dorsal plate a little above its lateral margin. Eyes of Termites.f — Kurt von Eosen finds that in the youngest larvas of Termites the primordia of the eyes are all alike. This changes as the larvse differentiate into big-headed and small-headed forms— apparently in response to different nurture. In the big-headed forms the development of the eye soon stops. In the lowest Termites, the workers and soldiers have complex eyes, and this is probably primitive. Many degrees of rudimentariness occur. In the sexual forms the eyes and the optic ganglia soon degenerate. The various conditions of the eyes in different types and in different castes are discussed. Spermatophores of Gryllidae and Locustidae.J — Ulrich Gerhard t describes the various kinds of spermatophores — simple and compound — which are formed in Locustidse and Gryllidse. The spermatophore is always fastened by a longer or shorter hollow stalk in the vulva of the female, and the spermatozoa pass from the reservoir or reservoirs of the spermatophore into the receptaculum seminis of the female. In all Locustidas, but not in GryllicUe, the reservoir portion is surrounded by a large envelope formed from the accessory glands. This is almost always eaten by the female after the pairing is accomplished. The most primitive spermatophores and mode of pairing may be found probably in the Locustid family Stenopelinatidre. * Zeitschr. wiss. "Zool., cv. (1913) pp. 574-97 (3 pis. and 6 figs.). t Zool. Jahrb., xxxv. (1913) pp. 625-64 (3 pis. and 10 figs.). t Zool. Jahrb., xxxv. (1913) pp. 415-532 (2 pis. and 22 figs.). 168 SUMMARY OF CURRENT RESEARCHES RELATING TO Study of Lomechusa and Atemeles.* — Karl Jordan has studied these and some related myrmecophilous beetles. The secretions which the ants lick come from numerous unicellular glands situated on the sides of the abdomen and opening among the setae. Wasmann's so-called exsudation tissue is simply fatty tissue. The beetles have numerous offensive glands and a large dorsal reservoir which opens between the third and fourth abdominal segments. These glands occur in all members of the sub-family Aleocharinaj. They are used by the myrmecophilous beetles against strange ants, or against their hosts when these go too far. The secretion has a stupefying effect on ants. Its odour is like amyl-acetate or methyl-heptenon, which have a similar effect on ants. The symphilous state depends on adaptations on the part of the guests. The offensive glands give the beetles a standing, but they are much older than the partnership. A new adaptation, however, is tht acquisition of the myrmecophilous glands. The males of Lomechusa are much excited at the breeding season ; the sexual act is several times repeated : only a few eggs are laid in the recesses of the nest. 7- Prototracheata. Integument of Peripatus.f — D. II. Webster, who has specialized on the detection of chitin, finds secure evidence of its presence in Peripatus as a thin covering of the skin. This shows, he says, that Peripatus is nearer to Arthropods than to Annelids. In Aphrodite, Lepidonotus, Lumbricus, Echiurus, Hirudo, etc., he found no trace of chitin. New Peripatus from India. :j: — Stanley Kemp gives a preliminary account of Typhloperipatus williamsoni g. et sp. n. from the Abor country. No external trace of eyes could be seen ; the ocular lobe is well developed, but has a rudimentary nerve. A non- cellular structure in the lobe may be remains of the rods and cones. The male has nineteen legs, the female twenty. The legs have four spinous pads a