‘ i Ay “4 7. «7 3 "|S ® a oh : 4 He 4 4 | ; rncapanast fast Kanetee Ck WS em a cee as Dan te Dae Epo La ates Sa aaa aks Te pacwe Mente oat ena Mine te eee ae le SR Sas se te i ste WR = . 7 P 2 ; pn « 7 4 he 7 : : “ « ‘- ‘ “ : CS anne Y * . . : “- axes 72 o~ a ° b o Cae oy % FT ae ‘ : . ‘ ; ahs afus . ‘ 3 ' 7 or te, fe ee EL Se wes Paar a ‘ ‘ $ ®, are : . ; oe te , rie : we f twas we Be s Py . Bo pak? : © = ca . 7 what - ® ‘> : See Sh F Dale iia ae ‘. * “ote ~ N ~s ‘ 5 Pos Le ae 4 . . BT hae Fe ap oe i Ny re ee ee pred. Se snieiten ee lia OS tee ee NS mah Web 8! 05 deus Same ae De is A ane ptm . bs ‘oan lav aiatdnes wae eels 6 SPORT rear AT TSE TT ee ee ee wae - ~ ~ a wa > a g( iaate ns BE owR eide otis ole SMa cee a ae Sl He lol 3a stone Or thes AUG hit alte" 7 ar ’ . - . ) > -~ @ f +, *! . P) ; oe » 3 « Bs F an ‘ ! . 7 F , 3 © \ F o : 4 . of r ¥ a ‘ . “ ay L ay : Gps 2S : a), Pe Ws TENG RRO SOENTIAD TI REEL ‘: A eek G Bry: Pei P= e eke “4 any! ciate, i a 145) i : JOURNAL OF THE ROYAL MICROSCOPICAL SOCIETY: CONTAINING ITS TRANSACTIONS AND PROCEEDINGS, AND A SUMMARY OF CURRENT RESEARCHES RELATING TO MeO MOG, ALIN DS 2 OE Asin (principally Invertebrata and Cryptogamia), MICROSCOPYWZ, Sc. Ledited by FRANK CRISP, LLB. B.A, One of the Secretaries of the Society and a Vice-President and Treasurer of the Linnean Society of London ; WITH THE ASSISTANCE OF THE PUBLICATION COMMITTEE AND A. W. BENNETT, M.A., BSc., F.LS., F, JEFFREY BELL, M.A., F.ZS., Lecturer on Botany at St. Thomas's Hospital, Professor of Comparative Anatomy in King’s College, JOHN MAYALL, Jon., F.Z58., FRANK E. BEDDARD, M.A., F.ZS., B. B. WOODWARD, F.G.S., R. G. HEBB, M.A., M.D. (Cantad,), Librarian, British Museum (Natural History), AND J. ARTHUR THOMSON, M.A., FELLOWS OF THE SOCIETY. Ser. II—VOL. V. PART 2. PUBLISHED FOR THE SOCIETY BY WILLIAMS & NORGATE, LONDON AND EDINBURGH. 1885. The Journal is issued on the second Wednesday of February, April, June, August, October, and December. ie Y, C5) | Jin Ser. IT. To Non-Fellows, “& | Wol ¥. Part 4. ¢ @UGUST, 1886. {price bs. | JOURNAL OF THE ROYAL MICROSCOPICAL SOCIETY; CONTAINING ITS TRANSACTIONS AND PROCEEDINGS, AND A SUMMARY OF CURRENT RESEARCHES RELATING TO ZRooLtoGey AND BOTAN DT (principally Invertebrata and Cryptogamia), MICROSCOPY, ac. Edited by FRANK CRISP, LL.B., B.A,, One of the Secretaries of the Society and a Vice-President and Treasurer of the Linnean Society of London ; WITH THE ASSISTANCE OF THE PUBLICATION COMMITTEE AND A. W. BENNETT, M.A., B.Sc., F.LS., | F, JEFFREY BELL, M.A., F-.Z.8., Lecturer on Botany at St. Thomas's Hospital, Professor of Comparative Anatomy in King’s College, JOHN MAYALL, Jom, F.Z.8., FRANK E. BEDDARD, M.A., F.Z8., AND B. B. WOODWARD, F.G:S., . Librarian, British Museum (Natural History), FELLOWS OF THE SOCIETY. BR 24” 2 a oP WILLIAMS & NORGATE, | oN (A bet LONDON AND EDINBURGH, a4 PRINTED BY WM. CLOWES AND SONS, LIMITED,] [STAMFORD STREET AND CHARING CROSS» f he, CONTENTS. ——— TRANSACTIONS OF THE SocrmTy— XI.—Tue Patnogento History anp History UNDER CULTIVATION PAGE or A New Baomuvs (B. atvet), rox Cause or A Dismasn — oF THE Hive Ber HITHERTO KNOWN AS Foun Broop. By Frank R. Cheshire, F.R.M.S., F.L.8., and W. Watson Cheyne, M.B., F.R.C.S. (Plates X. & XI. & Fig. 134) .. XII.— Experiments on Fuxpive some Insucts with THE CuRVED — or “Comma ” BAcILivs, AND ALSO WITH ANOTHER BAcILLUS (B. susriiis?). By R. L. Maddox, M.D., Hon. P.R.MS.. . , XIIT.—On Four New Specizs oF THE GENus FLOscuLARTA, AND. Frve oraer New Species or Rotirera. By C. 'T. Hudson, Li.Di; WBMES. (Plate KIL) eine ise PAs aio et SUMMARY OF CURRENT RESEARCHES. ZOOLOGY. A. GENERAL, including Embryology and Histology — of the Vertebrata. LAvLAWe—Unity of the Process of Spermatogenesis in Mammalia ... 1. .+ ve Dovat, M.—Formation of the Blastoderm in the Bird’s Hgg .. -. ue oo DaxestE, C.—Physiological Purpose of Turning the Incubating Hen’s Eggs .. . LascuenserG, O.—Colours of Birds’ Hogs .. 9.1 ts ww es Sarasin, P. B. & C, F.—Development of Epicrium .. ° ee oe oe Ryper, J. A——Translocation forwards of the Rudiments of the Pelvic Fins an the Embryos of Physoclist Fishes... aeatiehte Loew, 0., & T. Boxorny—Silver-reducing Animal Organs Coreman, J. J., & M‘Kenpricx—Hfects of Very Low Temperat Organisms Bett, F. JerrRey—Bell’s “ Comparative Anatomy and. Physiology ; i B. INVERTEBRATA. Ricnarp—Action of Cocain on Invertebrates... ss 0 ace MaoMonn, C, A.—Enterochlorophyll and Allied Pigments... Mollusca. ViatteTon, L.—Buecal Membrane of Cephalopoda...) .. .. Gurritus, A. B— Pancreatic Function of the Cephalopod Liver Patten, W.—Artificial Fecundation of Mollusca... .. .. 2... Brocg, J.—Development of Generative Organs of Pulmonata » .. Fou, H.—Microscopic Anatomy of Dentalium Bouran, L.—Nervous System of Fissurella °.. SE EG ON a Porter, J.—Anatomy and Systematic Position of Halia priamus Risso .. 5 Vayssiire, A.—Tectibranchiata of the Gulf of Marseilles .. Nevumayr, M.—Classification of the Lamellibranchs Ziecurr, H. E.—Development of Cycles Coniige 062i Lyte Sara : chs Menu in which Lamellibranchs attach themselves ets. a, Macponatp, J. D.—General Characters of Cymbulia i Molluscoida. a. Tunicata. | Srpiicer, O.—Development of Social Ascidians .. ., .. ra Niel BarRnois, J.— Genetic Cycle and Germination of Anchinia.. 2. vs Rovuz, L.—New Species of Simple Ascidians ures on Living — ae or Co eo ee ee we A ce ee ee eo eo oo 581 602 608 eee | 8, Polyzoa. Harmer, 8. F.—Structure and Development of Loxosomaé ..° .. MacGiniryray, P. H.—Australian Bryozoa.: .. ee es y. Brachiopoda. Joustn—Anatomy of Crania 2. 9 se ee ne eee we Arthropoda. « Insecta. Hickson, S. J.—Eye and Optic Tract of Insects... Zeiier, R.—Tracks of Insects resembling the Impression of Plants” Water, A.— Morphology of the Lepidoptera Packarn, A. S.—Number of Abdominal Segments : in Lepidopier ous Larvae Lex, A. B.—Structure of the Halteres of Diptera... s Rowsovzs, J. E.—Movement of Flies on Smooth Surfaces Ss Crevrzpure, N.—Circulation in Ephemera Larve —-. SomMMER, ‘A.——Maecrotoma plumbea .. 9.2 oe eS B. Mysiopoda- Larzet’s Myriopods of Austria .... e 8. peene ak é a E. Rayv—New Hypothesis as to the Relepiepety ae the Prt Ri, a Scorpio to the Gill-book of Limulus... ay PELsENEER, P.—Coxal Glands of Mygale 6s nee ee ae ee .- Daut, F.—Anatomy of Spiders... SS ea stig ; ‘MacCoox— Hibernation and Winter Habits of Spiders e. Crustacea, “ SPENCER, W. Bitowin Urinary Organs of Amphipoda a ~-Brano, H.—Development of the Egg and auser of the Primitive Layers v Cuma Rathkit.. .. ES DR SEIS Bp _URBANOVICS, F.— Development ‘of Cyclops EA opeSnectea Hoek, P. P. Again} of the pias wat BNA dce: aly Ha tn fei soe abl N.—Embryology of Balanus.. 966 +e ue eee ie beer ! Vornes. “ -Vorer, W. —Oogenesis and § ey. in Branchiobdella .. .. _ Lespy, J.—New Parasitic Leech .. BED be AS ier By ENS ~ Micnartsen, W.—Archenchytreus Movit’ <.. Wes Wen, si _ Provot, G.—Nervous System of Polychxtous Meds Bab Gaiedh ook 4 J. W.—Larval forms of Spirorbis borealis ., Scuanrr, R.—Skin and Nervous System Bs fi Lies and. t Halioryptas - Jour, L.— Development of Spherularia bomb 2205) _ Ferument, L.—New Nematoid from Matasoin Ligh Me RODOEL sant eins ~ Nremmmo, J.—Nervous System of Bothriocephalide 9.0 4.3. a ‘Zsouoxke, F.—Parasites of Fresh-water Wishes 2... 6. uns /-MameaY-WaicuT, R.—Free-swimming Sporocyst.. 6s 6s aes ASLAWZEW, Mile. 8.—Development of Turbellaria .. «. . - Smum1ax, W. A.—Fresh-water Turbellaria of North America .,.. Gesu W.—Later Stages in the Development of Balanoglossus a cf eh iad Echinodermata. Ps Spat gs bate ee of Echinoderms’ ..° .. ts ee - ~ Dunoan, P, Marti. Suapen—Arbaciade - ees ens - Hamann, 0. —Histology of Asterida Canvey, P. Henspar—Stallced Orinoids of the ‘ Challenger’ Expedition = ie Fatt of Comatula.. 2s sey ay ae as ' -. Geelenterata. » Bais Ww. ‘M.— Australian Hydroid Zoophytes - Or ete -_. Lexvenrevp, R. voy—Cwlenterates of the ‘Southern Boas pare | Maem, C. A.--Chromatology Of ADAMS phe a's S845 as eh Porifera. . _ pars F. ‘BE Raahonship o nges to Choano-flagellata .. ie - Canrer, H. J.—New Variely of J asd Gostins Ward bin oh ad: di ile E.—New Fresh-water Sponge ve ANSEN, G, A. Bl i a) the Nore North Sea "Expedition 4 > AM , poh Sets ~ ee, Protozoa. PAGE Grusee, A.—Further Experiments on the Arti, ‘ficial Division of Infusoria eee ROSE Sroxes, A. C.— ee with two Contractile Vesicles .. Peer REA. NS: i Jew Fresh-water Infusoria . Be Gt tp OOD Kr NT, W. eee: Taptartal Parasites of the Tasmanian White Ante 662 Buck, E.—Unstalked Variety of Pedepinds as eine ; wee ee ey | 662 Lock ywoon, Be ~ Peeudo- cyclosis as Se Me EAT MT ME es oe NE DreEcKke, 'T.—New Protozoon .. PORES es ED Gas i eT a ee RRUSCHHAUPT, e. —Development of Monocystid Gregarines Be ye Ee ae ee BOTANY. eg A. GENERAL, including the Anatomy and Physiclogs ues of the Phanerogamia. ee ithe a. Anatomy. : ft : ‘Vries, H. pe—Cireulation and Rotation of. Restopiaem as a means of oa of ‘i Food-matertal..° . ; BR Tassie GuienarD, L.—Divison of the Cell-nucleus 4 an > Planis and Animals - .. 666. Frommann, C.—Changes in the ona # POE Call and in the ¢ Hairs of aks Pelargonium zonale . : Co, 668, ba Carnoy’s (J. B.) Biology of the Cell aid (ight spas aca a OBOE Nae RBINEE, J. nape oie of Solutions ‘of Citoraphuit a Light 669 Waescnemer, R.—Spectra of the Pigments of Green Leaves and their Derivatives CEO. 3 Wortmann, J.—Red Pigment in Flowering Plants .. OO (0 Anryaup—identity of the Orange-red Colouring Matter of Leaves with Car otine eae Ose eis Cuzont, G.— Formation of Starch in the Leaves of the Vine’ «. -. ae nd ee OT0 Fiscuer, A.—Starch in Vessels os Bi nar lanes E PI ce ae acc Obes vias 5 3 Mavument, E. J.—Presence of Mangariese in Plants. AOE LE ciny GIRARD, A.—Nutritive Pr operties of the various portions of the Gr aim in of. Wheat Pag ool Benen Prizm, E —Assimilating Cavities in the interior of Tubers of Bolbophyllum.. ... 671 Herxercurr, E.—Idioblasts containing Albuminotds in some Cruciferae .. Pe Tineuem, P. yan—Annular and Spiral Cells of Cactace® ..0 064 0 ee ee ae g HECKEL, "E.—Formation of Secondary Corte: 05 as. an 90 Vans Saag ine Moror, L.—Pericycle of the Root, Stem, and Leaves 62 vs ScuENCK, H.— Changes of Structure in Land-Plants when growing vibmare CosTaNtin, J.—Epidermis of the Leaves of Aquatic rea telat Fis p kan eens Maris, P.—Structure of Ranuneulacer ... cp Heal at ck en cia ee eae Russy, H. H.— Opening of the Anthers in Bricacez 3. ss aalhy ae tle aaa Vesqur, J.—Anetomy of the Leaf in Vismiew 6. se ne ae ee oe ws Heinnicuer, E.—Reduced Organ in Campanula .. Po wd sc akg OWE Oar Savastano, L.—Hypertrophy of the Bud-cones of the Oarob 3 TOWNSEND, F.— Homology of the Floral Envelopes mn ie aan and C) Cyperacee Chua Ducwartee, P.—Bulbils of Begonia socotrana .. —.. peeenee Masters, M. T.—Petalody of Ovules .. Mal Pence ntnetia dies ieee Haperianpr’s Physiological Anatomy of Plants .. ei atch phe eee ee ae Buunens’s Tent-book of General Botany... ce 1. eee Bei bara eer tis, B. Physiology. ; i By HorrmMann, H iP rodutian of Male and Female Planta os ee ae JOnsson, B.—Fertilization of Naias and Callitriche .. 0. ek ee cat peaks Boysuan—Injluence of direct Sunlight on Vegetation .. — .. ; 5 Deneray, P. P., &L. Maquenne—Absorption of Oxygen and Evolution v Carton ee dioxide in Leaves kept in Darkness .. des Bonnier, G., & L. Mancin— Variation of: Respiration 1th i Development a Wonraass, J. ~—Thermotropism of Roote.. 6 Kae) io Se ae Sonert, M.—Air in Water-conducting Wood .. ss ee ce ae ac tk Lapornav, A.—Ammoniacal Ferment .. .. RELL Dierzent, B. E.—Source of the Nitrogen of the Tegan’ Nahticaptat Heine tees Anwarer, ae O.— Absorption of Atmospheric Ni itrogen by Plants... oe fe: ? B. CRYPTOGAMIA, | : Cryptogamia Vaerularia, ne ZritwER, R.— Affinities of Laccopteris .. °° .. tj a DievLarait—Composition of the Ash of E wiattane Formation of Coal. ‘ Ae A ee ep ee and ts Bearing a ts 681 TO6prrer, A. —Pransitional Equisetum SARS ONS. MRO PR TN I i Owe ABB ap é ee oo ee & abet Se =o Tee x! (93) Muscinee, PAGE Haservannpr, G.—Conduction of Water in the Stem of Mosses .. .. 681 ScuLrepHackr, K.— Pottia Giissfeldti, a new Mos’ 52. ++ te ae oe we ne 682 Santon, LecLerc pu—Elaters of Hepatice 1. 2. 0s ee te te ees 682 Alges. Hicr, T.—Protoplasmie Continuity in the Fucacee «sss eae we 682 Bertuoup, G.—Fertilization of Cryptonemiaces .. 02s we tenet ee 683 WILLE, N.— Sicbe-hypha in Algo be se pane a an Se oe ee ee OBE Hanseine, A—Algz of Bohemia %. os ee) oe ne a oe ee ee ee oe OSE ~ Soa, R. "F.—Peiagic Alia 2 53 see be NOE See (abn ee Bike Toad dice ti nese "OO Rasenuorst’s Cryptogamic Flora of Germany (Marine Algz) Sie Taytor, H., & F. Kirron.—Diatoms and Bladderwort’ ..0 01 se an veo 689 MULLER, O. Structure of the Cell-wall of Diatoms (Fig. 135) .. 0s. +) +s ve 689 Van Havrox’s Synopsis of the Diatoms of Belgium... +. ae ee ee te 686 Lichenes. ZuKAL, H.—Structure of Lichens svi ee ee re ne a ae ae ae 687 seat pa J. M.—Algo-Lichen Hypothesis =... +1 > ee te te nee 688 oes Fungi. Scur6rer, J.—Classification of Fungi 1.010 ee he te ee oe ee ge ae 689 Fiscu, 0.—Development of Ascomyces .. iP Sirs eS ik ea ale NCR fe Kuen, L.—Nocturnal Spore-formation in Botrytis cinerea... Pee ere 8) Winter, G.—Rabenhorst’s sb ok sine Flora os Sone (Fungi). Se oidas. 7 ONO ZOPE’S ig a it see Regine Mee My ee ona Protophyta. ~ att Biinscuis, ni — Distribution of Chromatophores and Nuelet in the itilnak penn’ +» 691 - Bruer, A.— Formation of the Spores ws CGS? WeoisG i; Ae ie aes 1 ~ Bonet, E., & C. Franautt—Aulosira . 25 ee ee ae eevee hea ae se) 692 “} Ricarer, P.— Microcystis .. HA Sor th 9 Ss) SE Wi gate goles cee A hose aL Wier nu Oa _ . Boneener, H. —Degeneration of Yi east. 693 Centres, A., & D. Cooutn—Effect of High Pressures on the Vitality of Pecans, and 215% On Fermentation. en pes Seaees 693 - Bécaamp, A.—Organisms Productive of Zymosis .. aS Wale Peta esto! tak ees ently Oee " WoLLyy, E.— Microbes in the Soil PA Ee aioe che as. Boe \ Free, D., & Resourcron—Microbe of Vuln Fever, Ne 694 LP Lorrier—Micro-organisms as a cause of Diphtheria in aig Pigeons, and Calves. 694 . _ ' Briecer, L.— Bacteria wey ov Thee oe se o- * oe ** o* 695 ; 696 _ Bruret, A.— Bacterium urex .. * * Moors, Srencer Le M.—Ideitity of Raden Sale (Thin) with Soil Cocct ... 696 Koon, Garrxy, & Lorrter— Artificial Attenuation ay fags anthracts... s+. +696 _ Bieetow, H. R.—Cholera Bacillus... ... CRN satiate ar ae ey atte Cad, y Henscourr, J.—Curved Bacilli in Air and SL RANE GHG See eA RI RS Ea RE 7 6 yeaa oa la ait ted EEA nay, ea gine Sala. pee OS MICROSCOPY. ait: Vee iY, he _ Instruments, Accessories, &e.. - Bavownsa Stage Microscope (Fig. 136)" EEN acy PM Gel MLN Se: a OP OR Porrarie Microscopes (Figs. 137-140) .. FRY aan ay DOTY ye Pe or aR ay TOMO cr A - Prave’s Microgoniometer (Figs, 141 and 149) PAREN AURA Bean Thue undt sere. aks nate ea OM 2 Doonte-Deum Mion (Fig. 143) ‘ SAF She Nast @ Oe ry | Bares" * Universal (Achromatic) . Pocket itieroseupa » Fig. 144). PS ie artes rhe 0: 3 .. Touman, H. L.—Lye-piece Micrometers .. - 704 _ Bovcwer’s Holder bie Pitan Prism and Goniometer igs. | 145 ond ii re a | Goypracu, E.—* An rovement in Objectives” uM ee Wee, Wee Care and the of Objectives... i ies Fe Eh cg arcs al a ores. be Bie OE Guerewrn’s Mechanical ome Objective (Rig. 147) ep aH eg ke MAGI veh Reet OR {Se nites G.—Right-angled Prism “hggece! of @ Plane Mirror ss) .6 ie) ae od bey, (709 _ Gegrmayen's Abbe Condenser (Fig. 148) Bee byl BA ew Suetiee eo) hE _ Torvan's batt spied Migec, Y4RAAS LY se eee Ladd Pees PTA (82) Bavscn & Lome Optical Company's “ Hiidseraed a ge 4 ae 152 ane ee a Se Nexson, E. M.—Jilumination (Figs. 154-170). aes Hawnins’s Observatory Trough... a gS ae eg Prinesnemm’s Gas Chambers (ies, 171 and 172) Le, ic er tialy, bttainte vores CNet alate Deny, J.— Test for the Hand-Lens ..' .. per dedi fone ead cloeld Mere, 4 wlengilem ay APERTURE Puzzle Pigs. V7IBV15) ise) oe ee ae fee ae ne ee Noes bal Seas ee ee Govi—Discovery of Pseudoscopy Le Baa Wp i ao artis AO 796 nee Carpanter, W. B.—Focal Depth with the Binocular Seth ie ir sles Meee in male ale 78° ScuooLroom, Microscope in «1 +» wt Shieh ee oes a ae B. Collecting, Mounting and Examining Objects, &e. Lowe, L. a en Embryos elon che ei care ces ale eee 739 Brass, A.—Methods of Investigating g Animal Cells. ne betea ard Cee) oP te Lapowsky—Demonstrating the Nuclet in Blood-corpuscles .. et Prag ra Tizzont— Demonstration of Karyokinesis in Epithelial Tissues 6+ ve ee ABO ‘ Scm1ine, J.—Investigating the Structure of the Central. Nervous Organs .. 730 ees | Sanu, H.—Application of Bovaz-methylen-blue am the Examination of the Central : eee Nervous System. 7 1 a Gotat, C.—Preserving Sections of the Nervous System treated ‘with Bichromate of Se Hae Potash and, Nitrate of Silver’... .. Vere he eas ee enemas Zawanyuin, Tu.—Study of Fat-absorption OM 2 the Small Intestine... solo Me ean 53 : List, J. H.—Preparing the Oloacal Epithelium of Scyllium Caniclla .. 4. 2. 7B i MAvRICE, C., & A. Scxunein—Preparing Embryos of Amarzcium proliferum ~ .. 731 Gino, R —Mounting Insects without Pressure .. Se ce NOE dit Sune, H.—Mounting the Proboscis of the Blow-fly im Biniodide of Mercury thee 0733 i Emnny, C -—Preparing Luciola italica,... we) 133 Kuynet, J. v.—Preparing Embryo of Peripatus Bdwardsié and P. torquetus.. cane Ao Courroux, E. 8.—Preparing Diatoms from the Stomachs of Mollusca and Crustacea BOTS Sanaa Baysrrry Tallow jor Imbedding ... .. a, Monte 2) ales Vide ate _ Biscumr, P, M.—Imbedding and Examining Trematodes te ah oe ge Harrin.y’s Rotary Section-cutter (Figs. ee and 177).. es ee ae et Marx, E. L.—Notes on Section- eutting . aoe aroha eat SE oa Gite, oc gy gues Bia SPEE, ¥ -—Sections in Series .. Se ae re eee Cae Oa te Hamann, O,—New Carmine Solution hatte vee Hicxson, 8. J.—Method of Preparing Hematonylon Statning Fig Ou ae aon BuzzozEro, G., & Torres—Staining for the Study of Red, Blood- -conpuscles sabbath ete Sanu, H. “New Double Stain for the Nervous System.. ; NE Apamnrewicz, A —New Method of Staining the Spinal Cord Rr yoru Kurrrur, C.—Staining the Axis-cylinder of Medullated Nerve- fibres. say tine Turner, W. B.—Staining Desmids.. 2. 40 sn oe . isle) So'aye vial ~ Wire, A. P.—Boro-glyceride for Mounting. rip ries Rrareeinee ays Dovenas, J. O.—Litharge and Glycerin ds a “Cement. Hei Wa CU ea Ops aah ere Hamum’s Ideal Slide (Wigs. 178 and. 179)... eee ee seh beet iw Hays, J, E.—Finish for Slides... .. jan ‘ Hansun, HE. C.—Counting of Microscopic Objects for. Botanieal Purposes. ; Avgert, A. B., & J. Desy.—Styrax and Baleam peace cat am al ee Boureav’ of Scientific Infortnation Vea ebGirietet- Dowty a tii ag A New Departure ay lee Gi laa dese het Raat heen ta Rex, G: A.— Collecting and Preservin Myxomycetes op iri Aiea Seah one aa ee VOLVOX GLOBATOR, Keeping Alive ng MOUNTING cr sic ea teed swash lew ates Wevpiwe, H.— Examination of Malleable Iron .. eo ee ee PRoogEpines oF THE SOCIETY) 6425. ye ROYAL MICROSCOPICAL SOCIETY. COUNCIL. ELECTED Mth FEBRUARY, 1885. Hee PRESIDENT. Rey. W. H. Dauuncrr, LL.D., FBS. VICE-PRESIDENTS. Joun Antaony, Esq., M.D., F.R.C.P.L. G. F. Dowprswen, Esq., M.A. Pror, P. Marts Duncan, M.B., F-R.S. Aupert D. MicuArn, Esq., F.LS8. : ~ TREASURER. Lions §, Bratz, Esq., M-B., F.R.O.P., PRS. SECRETARIES. -*Franx Crisp, Esq., LL.B., B.A. V-P. & Treas. LS. Prov. F. Jurrkex Bex, M.A., F.ZS. Twelve other MEMBERS of COUNCIL. Josep Becx, Esq., F.R.A.S. _ A, W. Bewyzrt, Esq., M.A, BSc., F.LS. 33 ~/ *Ropsert Brarrawarre, Esq., M.D., M:B.CS., F.LS. James Graisuer, Esq., F.RS., F.BAS. -*J. Witt1am Groves, Esq. _ Joun Marrnews, Esq., M.D. - Joun Mayauu, Esq., Jun. *Jonn Minzar, Esq., L-B.C-P., F.LS, --. Unean Prironanp, Esq., M.D. | 2 Sruart O. Rivrey, Esq., M.A., F.LS. - - *Pror. Cuartes Stewart, M.R.OS., E.LS. ~Wiu1am Tuomas Surrotx, Esq. pee we “LIBRARIAN and ASSISTANT SECRETARY. Mr. James West. 5 * Members of the Publication Committee. » js - re oT an a $$$ : i ? eg ERT Sp EEN Ea aa Sige MEETINGS FOR 1885, at 8 p.m. Wednesday, January .. .. 14 Wednesday, May .. .. .. 138 ; -. Fepevanry .. 4. 11 pe SUNM, 5 ie he Lee AO ee 9” gt “i xe, (Annual Meeting for Election of 3 Ocroppr .. 3. 7 eh heat % ssicmia etd 4 Novempre .. .. 11 Drie aati CRARBOR Fico pic, dao’ a 4 “ neo é —Aprin Je a. ja 8 ” DrcEMBER *. ee 9 ADVERTISEMENTS FOR THE JOURNAL. ae Me ‘CHARLES BLENCOWE, of 9, Baince Srreer, Westminster, 8.W., is the a3 authorized Agent and Collector for Advertising Accounts on behalf of the Society. i Numerical Aperture Table. ese) _ The “ Arerturs” of an optical instrument indicates its greater or less capacity for receiving rays from the object and transmitting them to the image, and the aperture ¢fa Microscope objective is therefore determined by the ratio between its focal length and the diameter of the emergent pencil at the plane of its emergence—that is, the utilized diameter of a single-lens objective or of the back lens of acompound objective. - This ratio is expressed for all media and in all-cases by 7 sin wu, n being the refractive index o f the medium and u the Semi-angle of aperture. The value of n sin wu for any particular case is the “numerical aperture” of the objective, Their actual apertures are, however, as numerical apertures. : Diameters ofthe — Angle of Aperture (=2 w). Theoretical Pp Back Lenses of various 7 Tilumi- Resolving S20 Dry and Immersion | Numerical Water. |Homogeneous-| nating | Power, in | T4ng Objectives of the same Aperture. Dry Immersion| Immersion | Power. | Linestoan lich.| POW: Power (4 in.) Ce SEE ete) Objectives. Objectives.| Objectives. | (a2.) |_ (A=0°5269 « (-) from 0°50 to 1°52 NA. (@=1) | =1-33,)) (n= 1°52.) =line EK.) a 1°52 : on 180° 0! | 2°310| 146,528 *658 . 1:50 2 161° 237. | 2-250 144,600 “667 1:48 153° 39’: | 2-190 142,672 | ‘676 1:46... 147° 42’ | 2°132| 140, 744.1 685 f 1°44 142° 40’ |2°074). 138,816 “694 1/42 138° °12’ | 2:016) 136,888 704 1:40 134°. 10’ |:1:960 134,960 |) = 714° rt 1°38 130° 26’ |1:904| . 183,032 *725 1:36 126° 57’ 41°850} 131,104 *735 1-34 ~128° 40’ | 1°796 | 129,176 “746 1:33 422° 6’ | 1°770). 128,212 752 1°32 120°: 33.) 1°742|- 127,248. *758 ; 1°30 117° 34’ 41:690} 125,320 — “769 ; 1:28 114°. 44" |1°638} 1255392 "781 d 1:26 111° 59’ | 17588) 121,464 — “794 < ; 124 109° 20’ | 1°538 |) 119,536 *806 3 ~ 122 106° 45' | 1°488}... 117,608 *820 1:20 104° 15’ | 1440) 115,680 | *833 1:18 101° 50’ | 1:392) 118,752 °°} *847 en 1-16 - 99° 29’ | 1°3464 111,824. *862 Soe : 1-14 97° 11’ | 1°300) 109,896 ‘877 ‘ 1:12 94° 56’ | 1°254| 107,968 | ~°893 : 1:10 92° 43’ | 1-210}. 106,040: |. “909° ay 1:08 90° 33’ /1°166| 104,112 "926°, 2 : 1-06 88° 26' |-1°124} 102,184 943. feet - 1°04 86°.21' | 1°082 100,256 962. Why 1:02 84° 18’ | 1°040 98,828 }. +980 pagan ON 1:00 © 82° 17" |1:000|,. 96,400 | 1-000 tees es f 0:98 — 80° 17’ | -960 94,472 © | 1-020 ayaa - mae 0:96 78° 201} °9221° 92 5448-11-42 i ey EN 0:94 76° 24' | +884 90,616 | 1:064 Seas i ONG oh . 74°. 30’ | +846 88,688 | 1:087° oe pa 0:90 72°. 36' | 810 86,760 | 17111 aohes t+ 0-88 70° 44" |. 774 84,832 | 1-136 Layee: NTS Y 0:86 » 68° 54’ | +740 $2,904 | 1-163) Boe cea TTA Oe 67° 6" | +706} . 80,976 | 17190 oh 0782 65° 18’ |. °672).- 795048) 5 |. 1220 { ~.0°80 63° 31’ | 640: 77,120" 1 T260™ ke / 0:78. 61° 45’ | -608 75,192). = 15.282- : 0°76. 60° 0! |. -578| 78,264. | 1+316" BEA GAR a SAS ee “58° 16" | +548} 71,886 | 1+851- ae att (On¢e 56° 32’ | +518 69,408 | 1°389 70 0°70 — 54° 50’ | 7490} 67,480 | 17429. oy de O68: 93° 9! | +462 65,502.) | 1-471 ARE Pets: 0" 6G 51° 28). | +436 63,624 | 1°515. en ne Bent) Cates ‘OS Ba: 49° 48’ | -410 61,696 | 1*562 ~ a Ere Soe Or Ge. 48°. 9% |" #384 59,768 1°613> eo, 1 Kh 0760. : - 46° 30’ | -360) 57,840 . | 1°667 © Ne Sl @268 44° 51’ |, +336 55,912. | 1°724 a 0°56. 43° 14’ | +314 53,984 | 15786 ; 0:54 41° 37° ,°292 52,056. }T* 852° ~ 0:52 40° 0! ) 270). 50,128. |. 1-925". +90 *0°50.* 38° 24’ | -250| - 48,200 | 2-000 EXAMPLe.—The apertures of four objectives, two of which are dry, one water-immersion, and one oil-immersion, would be compared on the angular aperture view as aka har? (air), aay (air), ie (water), : ee , or'their © aay eale showing he relation of Millimetres, | c., to Inches. . s PEE eet ee bee EEL PELL ER EL —— a A Te Ce Pe: TTTITITTILIL LLU LEE Te —— ee ee PLLLLELICLELIELELELLEL ELE LL biti Se EE eS ES er So P TILUTITOT TT II. ay Bt COMO RODHT Ces) Conversion of British and Metric Measures. Micromillimetres, §c., into Inches, §c. ins, “000039 - (000079 -000118 *000157 - 000197 -000236 -000276 -000315 | 000354 | 000394 | “000433 | “000472 | “000512 | “000551 “000591 - 000630 000669 “000709 -000748 *000787 *000827 ~000866 *000906 "000945 . *000984 *001024 *001063 -001102 *001142 *001181 *001220 *001260 *001299 *001339 “001378 *001417 *001457 +001496 *001535 *001575 001614 001654 “001693 -001732 -+001772 “001811 - *001850 ~ +001890 --001929 001969 002362 *002756 ~003150 003543 003937 1007874 011811 “015748. “019685 023622 “027559 +031496 035433 | mm, (1.) LINEAL. ins, } ins. 2 078741 | “52 2°047262 | 1 8 -J18111| 538 2-086633 pa ote 4 157482 |. 54 2-126003 | 2°2°° 5 196852 55 2°165374 | 25902 6 -236223| 56 2-204744 salad ig -975593 | 57 2244115 ms 8 -314963 | 58 2°283485 eee 9 -354334| 59 2°320855 | 7? 10 (lem.) -393704| 60 (6cem.) 27362226] oA” 11 -4330751 61 2°401596 | zdsn 12 -472445 | 62 2°4409671 soo 13 *511816| 63 2°480337 | soso 14 551186 64 2-519708 ro000 15 “590556 | 65 2°559078 ; 16 629927 | 66 2°598449 | oo 17 -669297 | 67 2:637819 | #00 18 *708668| 68 2°677189 | Too 19 -748038| 69 2°716560.| 307 20 (20m.) °787409| 7O(7em.) 2°755930] ton 21 “826779 |. '71 2°795301} 3° 22 *866150| ‘72 9-934671!. £95 23 -905520| 73 2°874042 | 23° 24 944890 | 74 2913412 |. 59° 25 *984961| 75 2952782 ote 26 1023631 |. 76 2-9921538| | 7? 27 | 1:063002| '7'7 3°031523| 73° 28 --1°102372| 78 8070894 by 29 -1:141748| 79 3-110264| % 80 (8 em.) 1-181113| 80 (8em.) 3-149635| 3° 81 1°220483 | 81. - 8°189005 To 82 1:°259854 | 82 3°228875 is 383 1-299224| §3 8+267746 Te 84 1:338595 | 84 3°307116| 15 85 1:377965| 85 8°346487 ry 86 1°417336 | 86 3:885857 87 1°456706 | 87 3°425228 te 88 1:496076} 88 8°464598 5 89 - ¥-535447 |. 89 8-503968 4 40 (40m.)1:574817 |, 90:9 em.) 3-543339] 6 41. 1:614188| 91 3°582709 8 42 1°658558| 92 3622080 ee 43 1°692929 | 93 8-661450 1 44 ——-1-732299| 94 3°700820| a. 45. 1°771669| 95 3°740191 i HS 46 1°811040| 96 3+779561 Fiat 47 -- 1°850410| 97 3°818932 ry 48 - 1°889781| 98 8+858802 1s 49 1:929151} 99 + -—«-8-897678} _ 50 ( om.) 1°968522 | 100 (10 cm.=1 decim.)] 35 seh Rhag -— decim, ins. z ry 8°937048 3 2 7° 874086 4 3 11°811130 5 4 15°748173 6 5 19*685216 7 6 23+ 622259 8 vf 27:559302 9 8 ** 81°496346 10 9 _ 851438389 11 10 (1 metre) 39°370432 1 ft = 8+280869 ft. : = 1°093623 yds. lyd.= Inches, &e., tnto Micromillimetres, §e. be °015991 *269989 *693318 539977 $22197 174972 628539 233295 *079954 849943 466591 *699886 *399772 mm. * 028222 “031750 *036285 *042333 *050800 *056444 *063499 “072571 *084666 *101599 *126999 “169332 *253998 *507995 *015991 * 269989 “587486 *693318 7116648 *539977 7174972 4+233295 4°762457 5° 079954 6+349943 7937429 9°524915 cm. 1°111240 1°269989 1‘428737 1°587486 1°746234 1-904983 2° 063732 2*222480 2°381229 2°5389977 5: 079954 7°619932 decim. 1°015991 1°269989 1°523986 1777984 2°031982 2°285979 2°539977 2'793975 3:047978 metres. "914392 OINmoOnUPrPWONNH ee toe O92 DD DO et et et Rt OF SCIENTIFIC INSTRUMENTS. ee PARTNER WITH Rid. BECK. PATHOLOGICAL AND PHYSIOLOGICAL PREPARATIONS. _ Microscopes — 2 ; z for : ao | Students and a STAINING FLUIDS. \ hate. AND: ALL ACCESSORIES £4 _ FOR STUDENTS’ . Seo ye CATALOGUE, — -100,NEW BOND STREET, NB. SPECTACLES! 3 OGULISTS’ PRESCRIPTIONS RECEIVE PERSONAL ATTENTIO ' ; Y ; : ao RES _ AGENT For W. H. BULLOCH, CHICAGO, ILLS., U.S.A, R. H. SPENCER & CO., N.Y., U.S.A. _ JAMES L, PEASE, MASS., U.S.A. (oth M. PRAZMOWSKI, PARIS. | rpc a Mink AK : ~~ M.A-NACHET PARIS. ~ ihe be JOURN.R.MICR.SOC. SER IL VOLV PLX LES WEIR Se) Peart Venn Hag oh Poneman Bacillus alvei, “ATT OD WEUCMA NT 'FS 8M ; ‘ : ; “7ysu pe’ [ep eatyseyD yy yaeay DESEISS7 S45 [| os=: Sp :. re EE Sse rrRerag ii aaa ee) osex pT Bry IX Id ATOATI SUS 00S SHOIN & NaANor JAN @U LIVo JOUBRNAE: > OF THE ROYAL MICROSCOPICAL SOCIETY. AUGUST 1885. TRANSACTIONS OF THE SOCIETY. XI.—The Pathogenie History and History under Cultivation of a new Bacillus (B. alvez), the Cause of a Disease of the Hive Bee hitherto known as Foul Brood. By Franx R. Quusuirz, F.R.MS., F.L.S8., and W. Watson Curynz, M.B, F.R.CS. (Read 11th March, 1885.) Puates X. & XI. Part 1—Pathogenic History. (By Mr. Cuesutre.) Some indistinct references made by ancient writers as early as the Christian era to a devastating disease existing then amongst domesticated bees, render it not unlikely that the malady known as “foul brood” is far from a novelty; but be this as it may, it is EXPLANATION OF PLATES X. anp XI. Fig. 1.—Residue of larva three days dead of Bacillus alvei. 6, bacilli. Spores and degenerated trachez cover the field. Fig. 2.—Healthy juices of larva. Fig. 3.—Juices of larva (living) with disease in acute stage. a a, leptothrix forms. Fig. 4.—Bee-comb from a diseased stock. a a, cells containing healthy pups». bb, cells in which pupz have died; the covers are sunken and often torn or punctured, Fig. 5.—Cultivation in sterilized agar-agar showing the colony-form. Fig. 6.—Same cultivation twenty-four hours later. Fig. 7.—Passage of spore in bacillus condition. Fig. 8.—Passage of bacillus in spore condition, Fig. 9.—Bacillus alvei grown in blood-serum. a a, spores. Fig. 10.— Spores in line from agar-agar cultivation. Fig. 11.—Bacilli budding ? from a cultivation. Fig. 12.—Cualtivation in thin layer of peptonized gelutin, showing colony- form and bursting-off of lines of bacilli. Fig. 13.—Drawing from another flat cultivation. Fig. 14.—Flat cultivation more enlarged ; the bacilli by liquefying the gelatin form tracks along which they freely swim backwards and forwards. a, bacillus swimming along track. 4, bacilli in mass. c, bacilli breaking from concentric rings of growth previously formed, Ser. 2.—Vo1. V. 2 Q 582 Transactions of the Society. certain that not until very recent times have its ravages become so wide-spread as to make it the terror of bee-keepers. Since the investigation to which I now invite attention conclusively shows that a bacillus is the mischief-worker, it will be at once understood why modern methods of management have been the occasion of spreading far and wide that which formerly existed, though confined to narrow limits. In ancient days bees rarely changed hands except at the death of the owner, and in our country, at least, the selling of a hive was even half a century back dis- countenanced as “unlucky”; but now bee-dealing is an established industry not only here but on the continents of Hurope and America, and the stock of the bee farmer having once become infected, is inevitably the means of distributing the fatal germs into the private apiaries which he supplies. Man not alone then suffers from diseases propagated by modern civilisation, but the animals which he has associated with himself necessarily suffer with him. Let us now consider this matter under three heads :— Firstly, the nature of this germ disease; secondly, the means of its propagation ; and thirdly, the method of its cure. Ist. The nature of foul brood as a germ disease.—If a comb be removed from near the centre of a healthy hive during the summer months, its cells will normally be filled with eggs, larve, and pups in every stage of development. The eggs as left by the ovipositor of the queen or mother adhere commonly by the end to the base of the cells they occupy, and favoured by the high temperature constantly maintained within the hive, the germinal vesicle at about the end of three days matures into a larva ready for hatching. ‘These eggs I have shown are liable to the disease even before they leave the body of the mother, but most careful microscopic examination is needful to make this apparent (and of which I shall speak presently more particularly). On the contrary, the larve, which are constantly fed by the workers, so change in appearance soon after infection, that a practised eye at once detects the presence of the disease. Whilst healthy their bodies are of a beautiful pearly whiteness, lying, at first floating, in the abundant pabulum the nurses are ever at hand to supply. As they grow they curl themselves at the bottom of the cells until these become too strait for their occupants, which now advance the head to be in readiness for the cocoon-spinning which follows upon the close of the eating stage. When the disease strikes the larve they move uneasily in their cells, and often then present the dorsal surface to. its mouth, as I have indicated in the illustration of diseased comb, fig. 134, so that mere posture is no insufficient evidence of an unhealthy condition. The colour changes to yellow, passing on by degrees towards a pale brown, whilst the skin becomes flaccid and opaque; death soon occurs, when the body, now Bacillus alvei. By Messrs. F. Cheshire & Watson Cheyne. 583 shrunken by evaporation, lies on the lower side of the cell, increasing in depth of tone, until in a few days nothing more than a nearly black scale remains. Should the larve, however, escape contamina- tion until near the period of pupahood, they are sealed over in the normal way by a cover made of pollen-grains and wax, plate X. Fie. 134. fig. 4 a, and which is pervious to air. ‘he cover furnishes a screen, on which part of the cocoon is soon after spread, but the inhabitant of the cell is marked out for death, and before very long the capping or sealing sinks and becomes concave, and in it punctures of an irregular character appear, fig. 4 > and fig. 134, and this is a nearly conclusive sign of the diseased condition of the colony. The sense of smell is also appealed to, as a peculiar very offensive and extremely characteristic odour now escapes from the diseased combs. The bees in addition lose energy, but become unusually active in ventilating their hive by standing at the door, heads towards home, and flapping their wings persistently so that a strong out-current, and as a necessary consequence, a corresponding indraught, are set up. Should any attempt be made at removing a dead larva which has assumed a deep brown tint, its body tenaciously adhering to the cell-wall will stretch out into long and thin strings like half dried glue. he microscopist can easily explain this. The thin chitinous aerating sacs and trachesw do not undergo decomposition at all easily, and these remaining, occasion the peculiarity referred to. These trachee are well shown in fig. 1. ‘The disease is terribly infectious, and once started, soon spreads from cell to cell and not unfrequently from stock to stock. Should a speck of this tenacious coffee-coloured matter be examined by a 1/4 in., it would be found to contain Shan 2Q 584 Transactions of the Society. swarms of very minute bodies which appear under a 1/12 in. as seen in fig. 1, and which dance in the field with a pronounced Brownian movement. ‘hese have been supposed to be micrococci, im consequence of some reported experiments made in Germany about ten years since by Dr. Schonfeld, of whose account of the same it is desirable here to give only a very short summary. He states that having procured some foul-broody matter (1. e. the brown scales mentioned previously), he by a simple contrivance aspirated air which he passed over the “foul-broody” mass through cotton wool, which then he found full of micrococci. But since he made presumably no attempt at staining, this state- ment, I submit, can only be received with great reserve. He adds that this cotton wool spread over the cells of a comb in which larve were advancing, the latter took the disease and died, with their bodies filled with micrococci. That lastly, having infected the larva of Musca vomitoria, it not only died crammed with micro- cocci, but that these micrococci communicated foul brood to pre- viously healthy larvee in the bee-hive. These experiments were ~ accepted as so conclusive and satisfactory that for ten years they were quoted as authoritative, but many observations which could not be reconciled with commonly received ideas respecting this malady induced me in June last to attempt to repeat Schonfeld’s experiments, with such additions or modifications as might seem most suitable to my purpose. This attempt has left me in intense bewilderment so far as any possible explanation of the causes of the errors into which Schonfeld undoubtedly fell. My results showed that in foul-broody matter no micrococci necessarily existed ; the disease could not be at all easily communicated to Musca vomitoria ; but that every dead larva of this fly contained micrococci in- numerable, and that when larve of Apis mellifica were artificially infected with “ foul-broody matter” the bacillus nature of the disease was incontestable, while no micrococci, and not even the bacillus spore which Schonfeld had taken for a micrococcus, could be discovered. The confidence with which I, at the outset, left the old ideas which Schonfeld had promulgated was increased by the helpful interest which Mr. G. F. Dowdeswell took in my in- vestigation, and for whose suggestions I now have the pleasure of returning my thanks. Taking a small quantity of the juices of a healthy larva and examining under a cover-glass, one is presented with the appearance of fig. 2. Fat-globules are numerous, whilst here and there we note the large white blood-disks, and scattered throughout may be seen minute globular particles with lively Brownian movements. But if a speck of coffee-coloured “ foul- broody matter,” as previously hinted, be similarly treated, we find neither fat-globules, blood-cells, nor molecular base, but observe amidst the remains of broken-down trachez the field crowded with Bacillus alvei. By Messrs. F. Cheshire & Watson Cheyne. 9585 small ovoid bodies, as I have shown at fig. 1. These are the micrococci of Schonfeld; but if this substance be stained according to the plan of Weigert and Koch, and then carefully examined even with a good 1/4, we shall in all probability discover a very few un- doubted bacilli, fig. 1b. Whilst operating thus, the absence of dumb- bell forms and the distinctly oval shape of what I presently found to be spores of the associated bacilli, arrested at once my atten- tion. Now possessing myself. of an infected stock, so that the course of the disease could be traced, I submitted first the body of a grub dead, but in a fresher state, to the Microscope ; and here the bacilli were numerous, although still few in relation to the number of the spores. ‘hen selecting larve still feeding, but of suspicious colour, and examining their juices with a power of 600, I was delighted by seeing hundreds of bacilli actively swimming backwards and forwards and worming their way amongst the blood- cells and fat-globules, as presented at fig. 3, whilst the leptothrix form was not uncommon. The examination of a larger number of larva, not only from the stock referred to, but from combs coming from various parts of Great Britain and Ireland, showed most conclusively that each in- dividual at the beginning of the attack contained many bacilli of an average diameter of 0°5 jy, and length 4 y, mostly swimming with a corkscrew-like movement, and that if an end view were obtained of any one of them the termination of the rod constantly described a small circle; that when the disease was in rapid progress, lepto- thrix forms were common, some of these even reaching 250 mw in total length; that as the fluids of the grub failed by loss of fats and albumenoids, the bacilli began to swell centrally, drawing the mycoprotein from their extremities, as seen in fig. 8, and thus gradually becoming spores, fig. 8; that after the death of the grub and during the assumption of the viscid, putrid condition, this constant alteration of bacilli into spores continues ; that after removal from the hive it goes on so rapidly that in a day or two scarcely a bacillus as such is discoverable, whilst the spores are innumerable, and, in addition, that a very cautious preparation of some broken down viscus showed that the bacilli and spores arranged themselves in that most singular line fashion (fig. 10) which Mr. Watson Cheyne found subsequently to be characteristic in his agar-agar jelly cultivations of the same micro-organism. Since the force of conviction obliged me to deny the accuracy of Schonfeld’s conclusions, I felt it incumbent upon me to repeat his experiments, for if the disease be really due to « bacillus, how could the communication of it to Musca vomitoria produce, as he says, micrococci in that insect? I experimented on sixty indi- viduals: twenty were not brought near foul-broody matter, twenty I attempted to infect with bacilli in their active condition, and 586 “Transactions of the Society. twenty by spores, but only three of the latter and none of the former contracted the disease. The general appearance of the tissues of the dead fly larvae much resembled that of bees similarly affected. Striving to prove irrefragably the accuracy of the etiology I have given, I took a number of well-developed drone larvee from a healthy stock, and expressed their juices into two test-tubes 3 in. long and 1/2 in. wide. No.1 now received a very minute quantity of coffee-coloured matter containing spores, whilst No. 2 was in- fected with a trace of a bacillus-containing fluid from a larva just dead or dying. These tubes were each supported by a simple ar- rangement between the combs of a stock of bees, so that the tempe- rature for germination should be kept up. In twenty-two hours, examining No. 1, I found no spores, but that bacilli, mostly in threads, existed in considerable numbers, whilst the bacilli added to No. 2 were increasing by division, proving again that the spores produce bacilli so soon as they pass into condition for germination, the reverse process obtaining when these conditions cease. The somewhat extensive literature of this disease had always gone on the assumption that it affected larve, but larve only. This position did not appear to me to agree with many facts I had observed; e.g. we may take away two or three combs containing 5000 larvee each from a stock, and it will continue to progress pretty much as though it had lost nothing, while if foul brood attacks it and kills say 1000 of its grubs, it as a rule very per- ceptibly diminishes in strength. The only theory that appeared to me as satisfactory was that the adults of the hive die with the disease, but that according to a necessary instinct they leave the hive and finish their course alone. Going to the diseased stock then in my possession, I noticed on the ground and close to its entrance one bee nearly dead on its back, another hopping in abortive flights of 3 or 4 inches, and presently found a third and fourth worn out and too far gone to enter the hive again. The first bee presented nothing remarkable, but the second was almost an empty shell, the air-sacs occupying nearly the whole of the abdomen. ‘The stomach and colon were exceedingly small, and the amount of fluid I could obtain truly microscopic; but this was full of active bacilli of the ' game size and character I had previously discovered in the larve. The third and fourth bees were in similar condition. The consequences flowing from this discovery have more to do with practical apiculture than with general science, and so here I content myself with saying that bee-dealers who had in ignorance of the facts always proclaimed that swarms were incapable of being affected by it, and that queens constantly passing from one owner to another could never communicate it, were now to be told that this error had in all probability been the reason why foul brood had grown to be a veritable pest, and that large apiaries were in Bacillus alvet. By Messrs. F. Cheshire & Watson Cheyne. 587 some instances actually dying out in spite of every effort to save them, and that in America alone the losses through it had risen to very many thousands annually. Continuing the investigation, I found that a large proportion of imago workers and drones die of this disease if they are raised in infected stocks, and that this explained the marked dwindling in numbers in a colony from the very incidence of an attack. But further, if workers and drones are liable, why may not queens be so also? and if this be possible, may we not get a solution of certain peculiarities with which bee-keepers of experience are familiar, e.g. some months earlier I had imported some queens from Italy, one of which was inserted into a stock which quickly after developed foul brood, while the queen lived on six or seven weeks only. In addition, if the queen may be infected, why not the egg? In the case of pébrine this had already been proved to be the case. The bee’s egg is to the size of the bacillus enormous; its diameter of 0:36 mm. and its length of 1-8 mm. would enable it to accommo- date 100,000,000 spores of this organism, which stands to the egg itself as a single drop to 1500 gallons. Following this line, and knowing that foul brood had in some cases appeared to be more particularly destructive amongst the smaller larve, I not unnaturally judged that in these cases possibly the egg contained the germs of the disease at the time of deposition. I communicated my suspicions to several owners of large numbers of colonies, and explained what would be the probable peculiarities of genetic foul brood if such a form really existed. Mr. Hart, of Stockbridge, soon after sent me a queen from a hive which presented the indicated symptoms, viz. the early death of the larvae in most cases; the earnestness of the bees in attempting to raise a new queen, although their numbers were so small that swarming* was out of the question, this earnestness seeming to indicate that they were conscious of some unfitness about the mother, which they desired to remedy by dis- placing her, and lastly a continuance of their hospitality to drones at a period of the season when other stocks have destroyed theirs. The queen was fortunately alive at her arrival, and I forthwith commenced a careful dissection. Having removed the left air-sac (which lies within the first and second abdominal rings), which was very much above the average size, a constant indication as I have found it of the presence of bacilli, I came upon the ovary, of which I had upon previous occasions removed many dozens. This one was abnormally yellow and very soft, so that it was difficult to detach it from the larger external trachesw without tearing. I separated an ovarian tube and placed it under a second Micro- scope using 250 diameters, and at once saw four or five bacilli * Healthy stocks only raise new queens in the prospect of swarming, or when the mother is fading through age. 588 Transactions of the Society. swimming along with a lazy sort of progression. Detaching now a half-developed egg, and exercising great care to eliminate every possible source of accidental contamination, I placed the egg with a trace of water upon a glass slip and crushed it out flat with a thin cover, and in a few minutes I had counted no less than nine bacilli. The right ovary was nearly free from disease. During a prolonged search I traced three bacilli only, which may not im- possibly have floated on to it during the dissection. Many other subjects I have since had the opportunity of dissecting, some of whose ovaries contained bacilli in countless profusion. In one re- markable case the receptaculum seminis contained no spermatozoa, although the queen was young and had mated since she had produced worker bees, but was filled with a dirty fluid through which were scattered innumerable minute and irregular granules, amongst which swam large numbers of bacilli. Here then was a distinct point of incidence for an attack, which left the ovaries still in perfect health. A question of some difficulty here to my mind presents itself. The disease seems always acute in the case of the larvee, embracing all parts of their organization. This may possibly result from the thinness of their membranes, the freedom of their viscera, the frequency of invagination, and the rapidity of interstitial - changes in their case. In the imago, on the contrary, the disease assumes a chronic condition, and confined to a portion of the frame at least temporarily, may be several weeks, and possibly in queens even months, in running its course. The name foul brood, given in ignorance of the nature and scope of the malady, is manifestly utterly inappropriate. To say that a queen igs sufferimg from foul brood would be as illogical and ridiculous as talking of toothache in the liver. I therefore have proposed the name Bacillus alvec, which has been at once accepted and adopted amongst intelligent apiarians both in England and America. The necessity of a specific name has recently become more apparent, since during these investigations I have found that bees are not only liable to suffer from attacks of the organism now engaging our attention, but from many others producing certain characteristic symptoms, and of which I hope to speak in particular in a future communication. The old notion that the adult bee had perfect immunity from diseases, and which no doubt was based upon the constancy of its external appearance ag the outcome of an external skeleton, turns out to be the opposite of the truth, and the Microscope has supplied me at once with the means of explaining observed singularities in special stocks by revealing in each case disease organisms of some destructive type. These industrious creatures live in numerous colonies, of which the members are always in the closest contact; their usual system of communication Bacillus alver. By Messrs. F. Cheshire & Watson Cheyne. 589 is by actual touch ; they habitually pass their food from one stomach to another; all food has been carried either within or upon the bodies of their fellows; their very home is formed of one of their secretions; and their beds, cradles, and larders are all interchange- able. These are the conditions indeed in which disease organisms have the highest opportunity of running riot, and which makes the discovery of many pathogenic bacteria in their colonies to me the reverse of surprising. It is needful before passing to the second head to anticipate one or two points to which Mr. Watson Cheyne will especially refer. After very many cultivations conducted in series by that gentleman, a small quantity of sterilized milk was inoculated from the last tube. It behaved characteristically, as Mr. Cheyne will describe, the flask emitting upon the drawing of the plug the unmistakable odour so distinctive of the disease in the hive. Some of this milk I diffused through water, and sprayed from an atomizer over a healthy comb of larve, part of which was protected by a cardboard sheet into which four lozenge shapes had been cut. The larvee protected matured in health; those exposed to the spray in many cases were removed by the bees, while the rest died, their bodies filled with Bacillus alvei. This last experiment seems to complete the chain of evidence in favour of ‘foul brood” not being accidentally associated with this bacillus, but actually its result. 2ndly. The means of the propagation of the disease. Popular apiculture has greatly suffered because its supposed leaders have only very rarely been equal to any scientific analysis, and so crude guesses have frequently been as unhesitatingly accepted as though they had been theories supported by an exhaustive examination of facts. It isso here; the larvee alone were supposed to suffer from the disease under discussion, and so it was confidently asserted that it was propagated by bees from healthy colonies getting into con- tact with these larvee by taking advantage of the weakened dispirited condition of infected stocks by invading them and stealing from them their honey, which honey was said to abound with micro- cocci, but I have searched most carefully in honey in contiguity with cells holding dead larve, have examined samples from stocks dying out with rottenness, inspected extracted honey* from terribly diseased colonies, and yet in no instance have | found a living bacillus, and never have been able to be sure of discovering one in the spore condition, although it must be admitted that the problem has its microscopic difficulties, because the stains used to make the bacilli apparent attach themselves very strongly to all pollen- grains and parts thereof, and somewhat interfere with examination. * Honey thrown out from the comb by a centrifugal machine called an extractor. 590 Transactions of the Society. All attempts at propagating bacilli in honey I have found utterly futile. The presence of bacilli in honey as an accidental con- tamination would, it may be remarked, in no way render it in- jurious, for many pathogenic bacteria may be swallowed without risk if there be no internal rupture of the mucous membrane, and placing this bacillus in a skin wound has in my own case produced no disagreeable results. My belief is that the grubs are most usually infected by the antennz of the nurses. These travelling in the darkness of the hive become aware of the condition and needs of the occupants of the brood-cells by constantly inserting their antenne, which must continually where disease reigns be brought into contact with bacilli, and also into contact with those sticky masses into which the larva change about two days after death. The removal then of spores is highly probable, and these transferred to the next grub fed will there start the disease. These sticky masses will be found too to extend to the very front of the cells, and as the bees perambulate their combs the pulvillus will be in danger of re- moving spores and depositing them upon other cell edges to infect other grubs at the critical time of cocoon spinning. It is also extremely likely that the tramp of the bees frequently detaches numbers of spores, which fly about in the air and settle here and there, often where they take effect, many of them being carried into healthy stocks with the indraught set up by the fanners.* A large number of observations has shown that the disease in the larva at least is not one of the digestive tube, but of the blood, and through it of every viscus. If honey were the means of com- municating it, certainly traces of it should be found in the alimentary sac; but here I find only very occasionally bacilli. In the adult bee, however, although the disease fills the blood, it is still very prominent indeed in the chyle stomach. Microscopists will have no difficulty in accepting the idea of these organisms being carried about in air currents when it is remembered that a single cubic inch of material would form a quadruple line of these bacilli from London to New York. Ordinary dust motes are to such organisms as hens’ eggs to sand grains. Nor is their multitude less remarkable than their minuteness. I have examined many larvee which must at least have contained 1,000,000,000; so that the means by which they are disseminated must be altogether too varied. In the royal jelly—so called—of a queen pupa dead of bacillus I could discover no bacilli, nor have I succeeded better with the food provided to the workers, notwithstanding that I examined several hundreds of the cells containing feeding larvee where disease was rife; so that, although I would not dogmatize, my strong opinion is that commonly neither honey nor pollen carry the disease, but that the feet and * See supra, p. 583, line 18 et seq. Bacillus alvei. By Messrs. F. Cheshire & Watson Cheyne. 591 antennze of the bees usually do. I also think it probable that occasionally at least, nurse bees infected bring the disease-germs to the mouth in feeding the larve, and then, turning foragers, leave a germ or germs on the nectary of a flower, which, visited by another bee, becomes the means of infection to it. The malady is thus carried into other, and perhaps somewhat distant, apiaries. Balancing all the probabilities, it would appear that most gene- rally the adult bee takes the disease, and then carries it directly or indirectly to the brood. In a somewhat different malady, Empusa musci of the housefly, the germs are known to take effect by settling on the spiracles or between the abdominal rings, and the spiracle of the bee in all its stages may be the especially vulnerable oint. 4 3rdly. The method of the cure of Bacillus alvei. Upon this question the scientific is perhaps less than the practical interest, and so I shall content myself with a bare outline. Salicylic acid has been used in attempting to combat this disease with fluctuating and partial success, but phenol I have found perfectly specific. The difficulty of administration I overcame as follows: phenol was mingled with ordinary sugar syrup of a density most suitable for feeding purposes in the proportion of 1 to 500 by weight of the syrup, and this was then poured into the comb in which brood was being raised. The nurse bees immediately accepted the medicated food, and as a result the malady in the very worst cases disappeared, the exceptions being those in which the queen herself was badly diseased. ‘This would rather seem to indicate that the drug acts as a prophylactic, but upon this most vital point time has not at present enabled me to settle the ground for an opinion. The problem is beset by difficulties, but during the advancing summer experiments will be made in the hope of gaining evidence respecting it. Even apart from the solution of this question, this investigation promises to have a very important bearing upon the future of apiculture by exposing the errors of the past and supplying a satis- factory method of treating a disease which had promised to so increase as to thoroughly imperil the very existence of apiculture as an industry. Parr Il.— History under Cultivation. (By Mr. Curyne.) On August 11th, 1884, Mr. Cheshire brought to me a piece of comb containing larve affected with foul brood, with which I per- formed the following experiments:—Selecting cells which were closed, but which Mr. Cheshire thought contained diseased larvee, I brushed them over with a watery solution of bichloride of mercury (1 : 1000) to destroy the organisms on the outside. With several forceps that had been heated and allowed to cool, the covering of 592 Trans ictions of the Society. the cell was picked off so as to display the diseased larvee. These larvee were dead, of a yellowish colour, and almost liquid; and on examination afterwards their juices were found to contain numerous moving bacilli. By means of a heated platinum wire, tubes of meat infusion rendered solid by gelatin (10 per cent.), or by Japanese isinglass, were inoculated from several of these larvee and kept at a suitable temperature. Development of bacilli, microscopically similar to those seen in the juices of the larvee, occurred: the cha- racteristics of this development will be presently described. Further, in the tubes, kept at the body temperature, there was not only a development of bacilli, but also of spores. These bacilli, as seen in the larval juices, measure about 1/7000 in. in length, and 1/20,500 in. in breadth. ‘They are rounded or slightly tapering at their ends, and often have a clear space near one end. In the juices of the larva during life they apparently do not produce spores, although after death spores abound. In the cultivation in the peptonized meat infusion, rendered solid by agar-agar, the bacilli vary considerably in size, their average length being 1/7260 in., some being as small as 1/10,000 in. and others as large as 1/5000 in. When they have attained the latter size, division of the rod seems to begin. They are always some- what pointed at their ends. Their average breadth is 1/30,000 in., varying from 1/35,000 to 1/25,000. The spores are largish oval bodies, averaging in length 1/12,000 in. (varying from 1/13,100 to 1/10,200 in.), and in breadth 1/23,700 in. (varying from 1/24,000 to 1/25,000 in.). In the agar-agar material the spores are generally arranged side by side in long rows, and in old cultivations only a few bacilli can be seen, some forming spores, some without any indication of spores (figs. 10 and 11). That these small bacilli can produce such large spores seems at the first glance at a microscopical specimen almost inconceivable, but I have been able to trace on the one hand the development of the spores in the rods, and on the other the sprouting of the spores into adult bacilli. This can be done in the following very simple manner :— Take a number of glass slides, each having a moderate-sized cell hollowed out in its middle; clean it, and pass through a Bunsen flame several times to destroy any bacteria on its surface. With a brush apply a very little vaseline around the depression, and then place the slide under a glass shade to keep it from the dust. Clean a number of cover-glasses, purify them in the flame, and place them on a pure glass plate beneath another shade. With a fine pure pipette put a small drop of sterilized cultivating fluid (meat infusion with peptone) on the centre of each of these cover- glasses; then with a fine platinum wire inoculate each of the drops with the spores, or with non-spore-bearing bacilli; rapidly invert Bacillus alvei. By Messrs. F. Cheshire & Watson Cheyne. 593 them over the cell, press down the cover-glass so as to diffuse the vaseline around its edge, and place the slides in an incubator kept at the temperature of the body. These slides are removed at different intervals of time, and as soon as each is taken out the cover-glass is turned over and the drop of fluid rapidly dried. The specimen can then be stained, mounted in Canada balsam, and studied at leisure. This method seems to me to be much more satisfactory than the observation of the organisms swimming about in the drop of fluid, while the specimens can be kept permanently and compared with one another. In order to study the growth of the spores I used a cultivation on the agar-agar cultivating material which had been kept at the temperature of the body for fourteen days, and which consisted almost entirely of spores, though a few bacilli were present. As the result of several experiments, I have got a series of preparations which have been taken at various times (15 min., 30 min., 40 min., 1 hour, 13 hour, 1 hour 50 min., 2 hours, 2 hours 20 min., 2 hours 50 min., 2 hours 55 min., 3 hours 20 min., 4 hours 20 min., 5 hours, 5 hours 385 min., 5 hours 40 min., and 7 hours 50 min.), and the course of events is shown in plate X. The bacilli stain with various anilin dyes—best, I think, with methyl-violet; but the spores resemble the spores of other bacteria in not taking on the stain. The cover-glasses cn which the organisms are dried are passed three times through the gas flame and floated on. the sur- face of a fairly strong watery solution of methyl-violet for one to two hours. ‘They are then washed in water, and afterwards laid in weak acetic acid (1 per cent.) till no more stain comes out. ‘They are again washed in water, allowed to dry at the ordinary tem- perature, and mounted in Canada balsam. A spore-bearing culti- vation shows the bacilli stained violet, and the spores unstained, with the exception of their outline, which is of a faint violet colour. In most cases no trace of the rod in which the spore was formed can be seen (see fig. 7). The first change which is observed on cultivation is that in many cases the outline of the rod in which the spore was formed becomes faintly visible (see fig. 7). This can be seen in fifteen minutes, and is, I think, simply due to swelling by the fluid, as it is also evident to some extent in the case of spores soaked in water for the same length of time. In from half an hour to an hour it is evident that the bacilli which were present in the original material are beginning to multiply, and a considerable number of rods are now seen containing spores. It is evident that these spores are newly formed, as extremel few bacilli containing spores were seen in the original natant whereas in the preparations taken from in half an hour to an hour a considerable number are present. That some of the rods, instead of growing by fission, at once proceed to form spores 594 Transactions of the Society. is probably to be explained in this way. When the cultivation was removed from the incubator, some bacilli were growing by fission, some were forming spores, and some had passed into a state ready to form spores. The first go on growing by fission, the last complete their spore-formation, which was arrested by removal from the warm temperature. ‘That actively growing rods would not have formed spores so early is evidenced by the facts observed in the second series of observations on the formation of spores. The next thing that is observed is that several of the spores take on the stain, and are as intensely violet as the adult bacilli (see fig. 7). The number of the spores which take on the stain in this way goes on increasing as time passes, till in about four hours almost all the spores stain violet. In three hours the first indica- cation of sprouting of these spores becomes evident. The stained part of the spore loses its oval shape, becomes elongated, and is soon seen to burst through the spore-capsule at one part (see fig. 7). It then presents the appearance of a short rod, with a pale envelope embracing one end. ‘This rod gradually leaves the spore-capsule and then goes on multiplying as a full-grown bacillus. In specimens taken from four to five hours all stages of growth can be seen, and the remains of the ruptured spore-capsules are evident (see fig. 7). The bacilli appear to grow mainly by fission, but I have seen appearances which seem to me only explicable on the supposition that they also grow by sending out buds from one end (see fiz. 11). A bacillus may be seen with a small somewhai conical stained point attached to one end, though separated by a marked division. This is certainly not the common mode of growth by fission, for there the rod seems to divide into two pretty equal halves, while here we but have a minute piece attached to one end. The mode of formation of spores may be traced in a similar manner to that described above in the case of the sprouting of the spores. It is, however, as a rule necessary to leave the organisms to grow for a much longer time than in the former instance. I have not found development of spores as a rule before twenty-three hours, but this depends very much apparently on the amount of fluid that was present and the number of bacilli introduced at the time of inoculation. The first thing noticeable is that the rod begins to swell and becomes spindle-shaped (see fig. 8). This swell- ing, which generally affects the middle of the rod, but may in some cases be most marked toward one end, increases in size, and the centre of the swelling gradually ceases to take on the stain (fig. 8). The capsule of the spore apparently is also formed within the rod, and is not merely the outer part of the rod. In three or four hours the rod is seen to have almost or completely disappeared, leaving the spore lying free or within the faint outline of the original bacillus Bacillus alvei. By Messrs. F. Cheshire & Watson Cheyne. 595 (figs. 7 and 8). It seems to me that the view that spore-formation occurs when the food is getting exhausted is correct, for the time at which this appearance is found depends greatly on the size of the drop placed on the cover-glasses, and I have found in one experiment that in one specimen after twenty-three hours most of the rods were forming spores, while in another specimen where the drop was much larger there was no trace of spore-formation after twenty- eight hours. I have here described the results of my earlier and rougher attempts to study the formation of spores. I have, how- ever, now improved the method in the followmg way. As I have just now shown, the period at which spores are first seen seems to depend mainly on the amount of fluid used and the number of of bacilli introduced, and as in the above method both these factors vary in each case, one cannot get a regular series of preparations showing the different stages at different times. In studying the sprouting of spores the amount of fiuid and the number of spores does not matter, for if sufficient nutriment is present and a proper temperature maintained the spores must sprout, and probably they always take about the same length of time. The difficulty of obtaining a series of specimens illustrating spore-formation is easily obviated in the following manner. Take a pure flask containing a small quantity of sterilized infusion, and inoculate it from a cultivation containing only bacilli. Place it in the incubator for two or three hours, so that the bacilli may increase somewhat in number and diffuse themselves through the liquid. Thus the cultivating mate- rial contains bacilli pretty equally diffused through it, and if after shaking the flask drops of equal size are taken, each will probably contain about the same number of bacilli. ‘The minutest quantity of fluid can easily be obtained by means of a syringe having a fine screw on its piston and a large nut revolving on this screw. The circumference of the nut being equally divided into a number of small segments, the same quantity of fluid can always be expelled from the syringe. By proceeding in this way equal sized drops containing an equal number of bacilli can be used and a regular series of specimens obtained. I have found that using 2/5 of a minim containing one bacillus and keeping the specimen at 36° C., en earliest appearance of spore-formation was evident in forty-one ours. Leaving these matters, which are of great interest not only in regard to the Bacillus alvei, but to all spore-bearing bacteria, and which I have therefore dwelt on at reife we must pass on to the further consideration of this particular organism. The first point to be determined in investigating its relation to foul brood was whether this was a new bacillus, unknown except in connection with this disease of bees, or whether it was a more or less well- known form. ‘To ascertain this point with regard to muicro- 596 Transactions of the Society. organisms the Microscope is of little use; recourse must be had to the study of their life-history, more especially of their peculiarities of growth on different soils. Of all the materials employed as cultivating media, Koch’s gelatinized meat infusion is the most useful for purposes of diagnosis. This is composed of an infusion of meat containing 1 to 3 per cent. of pepton, 10 per cent. gelatin made neutral by carbonate of soda, and thoroughly sterilized. This material was first introduced with the view of having a highly nutritive solid and at the same time transparent medium, on which to carry on pure cultivations, but it was soon found that owing to the remarkably diverse ways in which different micro-organisms grew in it, it could be used as a means of diagnosis of the kind of organism, a means more certain than any other which we at present possess. For purposes of diagnosis as well as with the view of carrying on pure cultivations this material is used in three ways. While the material is still fluid a small portion is poured into a number of pure tubes plugged with cotton wool, sterilized, and allowed to solidify. A fine platinum wire, heated in a flame and allowed to cool, is dipped into the material containing the bacterium in question, and then, after the removal of the cotton- wool plug, is rapidly plunged down through the gelatin to the bottom of the tube and then withdrawn. The plug is reinserted and the tube kept at a temperature suitable for the development of most forms of bacteria, but not high enough to melt the gelatin. If growth takes place at this temperature it occurs either on the surface around the point of entrance of the needle or along the needle track, or in both places, and the appearance of the growth varies remarkably, according to the different species of micro- organisms studied. ‘The second way is to liquefy and pour out a little of the gelatinized material on microscopic slides or on larger plates of glass which have been sterilized by heat. These plates are placed in giass vessels containing moist blotting-paper to prevent drying of the gelatin and to protect them from the dust. After the gelatin has solidified the purified platinum needle charged with the bacteria is drawn rapidly over the surface of the gelatin. Bacteria are sown along the track, grow there, and the whole can be placed under a Microscope and the characteristics of the growth studied with a low power. In the third mode a tube of the gelatin mixture is inoculated with a very minute quantity of the bacteria. The tube is then placed in water at the body temperature to melt the gelatin. When the material has melted it is thoroughly shaken up to diffuse the bacteria through it, and while still liquid is poured out on sterilized glass plates kept in a moist chamber, as in the former case. Solidification very soon occurs, and the bacteria being caught at various parts of the gelatin grow there in the form of groups or colonies, which can be observed under a low power of Bacillus alvei. By Messrs. F. Cheshire & Watson Cheyne. 597 the Microscope. I shall now describe the characteristics of the Baciilus alvet when cultivated in these three modes. a. Test-tube cultivations.—If an infected needle be plunged into a tube of gelatinized meat infusion, in the manner described above, growth occurs both on the surface and along the needle-track. On the surface the bacilli shoot out in all directions from the point of entrance of the needle, forming a delicate ramifying growth on the top of the gelatin; the characteristics of this growth will be presently described under b. Along the track whitish irregular- shaped masses appear, which slowly increase in size and run together. In a few days processes are seen to shoot out from these masses, which may extend through the gelatin for long distances from the track, being thickened at various parts and clubbed at the ends. These processes do not appear to join one another at their ends (see figs. 5and 6), A very beautiful and characteristic appearance is got where very few bacilli are introduced with the needle and where therefore at various parts of the track, more especially at the lower part, individual bacilli or groups of bacilli are planted at a consider- able distance from each other. In a few days minute round whitish specks become visible to the naked eye. These increase in size till in about ten days shoots begin to appear. These radiate from the central mass in all directions and become nodular at various parts as described above. When such a cultivation is old the white branches disappear, and only little whitish collections of bacilli are seen at various parts. On examining such a tube with a pocket lens, however, numerous watery-looking tracks are seen running through the gelatin from the central mass to the whitish collec- tions. The gelatin at the upper part of the track generally evaporates, to some extent giving rise to the air-bubble appearance so characteristic of the cholera bacillus (see fig. 6). ‘Lhese are the appearances seen where the material contains gelatin in the proportion of 10 per cent. Where less gelatin is present the naked eye appearances, while possessing the same characteristics, are somewhat different. The shoots are much more numerous and appear much more rapidly, giving rise to a haziness around the needle track which with the pocket lens is seen to consist of numerous delicate branches clubbed at the ends ax in the former case. I think the amount of peptone present also makes a difference in the appearance, though of this point I am not yet absolutely certain. The most characteristic growth is, however, obtained when the material contains 3 per cent. peptone as well as 10 per cent, gelatin, the shoots being then Jess numerous and much coarser. And I can easily understand that this would be the case, for the bacilli would have a large supply of nutriment in their immediate vicinity without the necessity of having, so to speak, to spread out through the gelatin in search of food, as may be the Ser. 2.—Vou, V. 2k 598 Transactions of the Society. case where no peptone, or only a small amount, is present. This appearance is quite characteristic of this bacillus, and is not seen in the cultivation of any other organism that I know of. The bacilli of anthrax and of mouse septicemia also spread out from the needle track, but the appearance of their cultivation is quite different. In anthrax delicate threads, not clubbed, shoot out from the track, soon anastomosing with other threads and forming a delicate network throughout the gelatin. In mouse septicaemia the appearance is that of a delicate cloudiness spreading through the gelatin. ‘These foul brood bacilli, growing in this material, render it liquid after a time, the liquefaction beginning at the surface and only spreading slowly downwards, but ultimately the whole tube becomes liquid. After two or three weeks’ growth the appearance presented by the tube is that of a layer of liquid at the upper part, and the growth along the needle track with the other appearances described at the lower part. The liquid portion is clear except at the bottom of the liquid, where there 1s a loose white flocculent deposit of bacilli, and on the surface there may be a very thin scum. The liquid becomes yellowish in colour after a time, and gives off an odour of stale, but not ammoniacal urine, or what may be better described as a shrimpy smell. This yellowish colour and the peculiar odour have been found by Mr. Cheshire to be distinctive of the diseased larvee. b. If gelatin be poured out on a plate, allowed to solidify, and then stroked with an infected needle, we learn the explanation of the appearances seen in the test-tube cultivations. The bacilli at first grow along the needle track, but very soon they are seen to be collecting at parts forming pointed processes. From the processes the bacilli grow out into the gelatin, often a single series of rods, in Indian file, or two or three rods side by side. These processes are not quite straight, but tend to curve, and at a little distance from the track they grow round so as to form a circle (see figs. 13 and 14c). From this circle, which may be formed of single bacilli, the process continues forming a fresh circle further on. The bacilli in the circle increase in number till ultimately it becomes completely filled up, and we have a nodule consisting of bacilli in the course of the shoot. These shoots may also join one another, forming a curved anastomosis, and the gelatin in the immediate vicinity of the bacilli becoming liquid, a series of channels are formed in the gelatin containing fluid in which the bacilli swim backwards and forwards. later on, parts of these channels become apparently deserted by the bacilli, so that the circles look to the naked eye as if they were detached from the main track, but with a low power of the Microscope the empty channels can be traced. (See figs. 13 and 14.) It is impossible to give a proper idea of the appearances of the Bacillus alvei. By Messrs. F. Cheshire & Watson Cheyne. 599 growth. The forms assumed are the most beautiful shapes I have ever seen, but they are very numerous, always however retaining the tendency to form curves and circles; thus we have the explanation of the appearances previously described in the test-tube cultivations. c. The appearances of the colonies on plates on which the mixture of bacilli and gelatinized infusion has been poured out is also very characteristic. The earliest appearance of colonies is a small oval or round group of bacilli. This group is not homogeneous in appearance under a low power of the Microscope, but lines indicating the bacilli are seen in it. It very soon becomes pear-shaped, and from the sharp end of the pear processes begin to pass out into the gelatin, as before described. (See fig. 12.) These bacilli do not grow below 16° C. The best growth in gelatin is obtained at a temperature of about 20°C. They grow most rapidly in cultivating materials kept at the body temperature. Very few spores are formed at the lower temperatures, but they appear rapidly and in large numbers at the body temperature. I have several times observed bacilli containing spores swimming about freely. The reaction of the medium is not of any very great importance, but a neutral medium is apparently the best. The bacilli swim freely in fluids with a slow oscillating movement. They grow readily at the body temperature in meat infusion with peptone and rendered solid by agar-agar, but the appearance of their growth is not nearly so characteristic as in gelatin. This, indeed, is the case with most bacteria, so that agar-agar preparations, though very useful for carrying on pure cultivations at the tem- perature of the body, are of little value for diagnostic purposes. They grow most rapidly on the surface of the agar-agar, forming a whitish layer, but the shoots described above in the case of gelatin do not occur, or only very imperfectly, in agar-agar. Here the bacilli arrange themselves apparently side by side, and, producing spores in this position, we have as a result, after a few days’ cultivation, long rows of spores lying side by side with here and there an adult bacillus. (See figs. 10 and 11.) On potatoes they grow slowly, forming a dryish yellow layer on the surface. They grow very slowly indeed at the lower tem- perature. In order to get good growth it is necessary to keep the potato at the body temperature. In milk they grow well at the body temperature, and in a few days cause coagulation of the milk, which also assumes a yellowish palbtic and gives off the odour previously described. ‘The coagulum is not firm, like that caused by the Bacteriwm lactis, but is like a tremulous jelly, and may remain for a considerable time without the separation of any fluid, but ultimately it becomes liquid, and after some months assumes the appearance of a dirty, brownish- yellow, glairy fluid. It is very slightly, if indeed at oi es ©) R € 600 Transactions of the Society. They grow extremely slowly in coagulated blood serum, though kept at the body temperature, and there form very long filaments (see fig. 9) with comparatively few spores. In meat infusion kept at the temperature of the body they grow readily, causing muddiness, and after a few days a slight but not tenacious scum. ‘The same peculiar odour is also developed here, more especially if the infusion contains a considerable amount of peptone. I do not think that there is any change in the reaction of the fluid; I generally make the infusions faintly alkaline, and after the growth of this organism in it it is faintly alkaline. These characteristics show that this is a new bacillus, and one which, so far as my knowledge and experience goes, is only found in foul brood. ‘The constant preseuce in large numbers of a cha- racteristic organism in a disease and its absence elsewhere must, according to our accumulating experience, afford a strong pre- sumption that the organism is the cause of the disease. In the case of foul brood this matter has been completely proved by the following experiments, the details of which will be found in Mr. Cheshire’s part of this paper. With a cultivation in milk he sprayed a comb containing a healthy brood, allowing the spray to act only on a particular part of the comb. ‘This part and no other became affected with foul brood. He has also succeeded in infecting adult bees by feeding them with material containing these cultivated bacilli. I have also had the opportunity of watching the effect of feeding flies with material containing spores and bacilli I was one day testing some milk in which these bacilli were growing; a large bluebottle fly settled on it and commenced to eat. I at once put a large glass funnel over the insect, leaving plenty of air. When I came to the laboratory twenty-two hours later the fly was in the sitting posture on the table and was dead. Its juices were full of these bacilli, as shown by microscopical examination and by cultivation. _ Other animals which I have tested are more or less refractory to this bacillus. I have kept cockroaches for days in a box in which was milk containing these bacilli mixed up with sugar. I have also kept them in a box containing a piece of paper which had been thoroughly smeared with the spores. None of them died, but I cannot be certain that in either case they ate any of the material, for I never saw them even near it. I inoculated two mice and one rabbit with a spore-bearing cultivation without effect. I injected half a syringeful of a spore-bearing cultivation into the dorsal subcutaneous tissue of each of two mice. One of these died in twenty-three hours, the other seemed unaffected, but in the second case I doubt whether the full quantity was introduced. In the case of the mouse which died the seat of injection and the neigh- Bacillus alvet. By Messrs. F. Cheshire & Watson Cheyne. 601 bouring cellular tissue was found to be very cedematous, but no macroscopic changes were apparent in the internal organs. Numerous bacilli were found in the cedematous fluid, as also a number of spores which had not yet sprouted, and there were also a few bacilli in the blood taken from the heart. This was proved, of course, by cultivation as well as by microscopical examination. On examining sections of the various organs no morbid changes were found, and only very few bacilli were seen in the blood- vessels. At the same time that I injected the mice I injected a syringeful of the same cultivation subcutaneously into a guinea-pig. This animal died six days later with extensive necrosis of the muscular tissue and skin, and cheesy looking patches distributed through it. There was no true pus. On making sections of the necrosed tissue, numerous bacilli, apparently Bacillus alvei, were seen, but there were other bacteria and also micrococci, as of course would be the case on account of the death of the skin. No micro-organisms were seen in the internal organs. It thus remains questionable whether the necrosis was due to the Bacillus alvei or not, more especially as I have since injected three guinea-pigs subcutaneously with spore-bearing cultivations, but without effect. I must reserve the action of these bacilli on the higher animals for further investiga- tion, as well as several other points of interest in regard to this organism to which I have not here alluded. I venture to think that when all the evidence brought forward by Mr. Cheshire and myself is carefully weighed no doubt can be entertained that this bacillus is new to science, and is the cause of foul brood. Many questions of course still remain open, requiring further investigation into the life-history of the disease. 602 Transactions of the Society. XII —Eaperiments on Feeding some Insects with the Curved or “Comma” Bacillus, and also with another Bacillus (B. subtilis ?). By R. L. Mappox, M.D., Hon. F.R.MS. (Read 13th May, 1885.) Tue record of a few experiments on feeding insects with the “comma” bacillus, and also with a straight bacillus (B. subtzlis ?) may be of some interest, as I am not aware that a similar attempt has been previously made and published. Although these expert- ments are too few to speak positively as to results, they are brought before the Fellows of the Society in the hope that others may be induced to extend them. They are of interest as bearing on the question of a possible mode of contagion, and are deserving of a more methodical inquiry, which as the season advances, I may perhaps be able to follow out. On the morning of the 23rd of April a bee and two blowflies were captured and put under a clean tumbler resting in a saucer, a small square of clean glass being also placed in the saucer. Hach was then fed off a bit of lump sugar well saturated with a liquefied impure gelatin culture of the “comma ” bacillus abound- ing in living specimens of this organism, but contaminated with micrococci. One of the flies appeared to have been somewhat injured in the capture. A few minutes afterwards a large wasp and another blowfly were captured, and placed together under the same conditions in another tumbler, and fed in the same way. Hach insect was seen to feed freely off the saturated sugar. Provision was duly made for ventilation by supporting the tumblers on strips of card placed in the saucers. On the 24th, 9 a.m., the bee seemed very dull, and one of the flies, the injured one, scarcely able to stand. The bee was now fed with a drop of fresh milk from the breakfast table, of which it partook freely, and about three minutes after it had a violent dejection on the square piece of glass, and then appeared very lively, but for more than twenty minutes it seemed unable to clean itself of the excreta or make itself presentable. Part of the dejection was at once placed on some clean thin covers and allowed to dry without heat; also examined wet; some of the curved bacilli were in motion. The wasp was also fed with the milk, and the blowflies partook of the same, but without any similar result. The small lump of sugar in each saucer was again moistened with the culture fluid. Later in the forenoon another hive bee was caught and put under the tumbler with the first one. All were now seen to again feed off the sugar, and the wasp in the interim had had a Feeding Insects with Bacilli. By Dr. R. L. Maddox. 603 copious dejection on the side of the tumbler, consisting of solid and fluid matter. The tumbler was removed and a fresh one sub- stituted. Part of the excreta was taken up by a flattened clean needle and spread on some clean cover-glasses and allowed to dry ; also examined wet; the bacilli were not in motion ; one of each of the covers was then stained with rose-anilin acetate in glycerin, the others with a watery solution of methyl-violet. Among the débris of the excreta of the wasp, which contained some fatty substance, were many of the “comma” bacilli, some micrococci, and some short straight bacilli. In the dejection from the bee, the “comma ” bacilli were very abundant, as likewise the micrococci, mingled with some pollen-grains. On the 25th they were all again fed with the liquefied culture, but on the 26th the sugar was moistened with distilled water only. On the 27th they were all fed as on the 25th. On the 28th the injured blowfly was found dead ; it was not examined. The others were fed with the curved bacilli culture. Another bee was caught and put into the tumbler with the two bees—there was an instant recognition and welcome by . the second bee—they were each seen to partake of the moistened sugar. On the same day a very large humble bee was captured, placed in captivity under similar conditions, and fed in the same way with the liquefied gelatin culture, of which it partook freely. On the 29th all were again fed in the same way, save the bee which had been the first caught. It was found lying on its back and soon died. It was easily recognised as the first one, by being smaller than the other two. It was at once examined. A section was made at each side of the abdomen and the abdominal plates lifted, the viscera were removed to a clean slide with some distilled water freshly boiled, then placed on a cover with some rose- anilin in glycerin and spread out. Some of the water the viscera had been placed in was put on thin covers, allowed to dry, then stained and examined, whilst another portion was examined wet and without staining, when several curved bacilli were seen in each field, many of them in active motion and among them numerous micrococci. The stained covers showed also the ‘“‘ comma ”’ bacilli and micrococci. ‘This examination took some time, hence the viscera were much oyverstained; no soaking unfortunately detached the stain sufficiently for the slide to be of use for further investigation. The 30th the rest were fed as before, save the blowfly in company with the wasp, which had succumbed ; the legs and wings had been bitten off and part of the thorax destroyed by the wasp. Part of the contents of the abdominal cavity, the perivisceral fluid, was spread out on a thin cover and showed a few curved bacilli and short rods, also some micrococci, but none abundant; some of the curved bacilli had a very slight motion. 604 Transactions of the Society. May 1st.—A culture medium made with gelatin, Carragheen moss, and Liebig’s extract of meat, and rendered rather too alkaline, which had not been used in any way from the time of making, nearly a month before, was found broken down, very much liquefied, and contaminated with a straight bacillus, which had formed cloud- like dense folds, exceedingly tender, and near to the surface. The two bees and blowfly, also the humble bee and wasp, were each fed with some of this culture on sugar. They all fed eagerly of the same. A medium-sized blackbeetle which had been caught on the 27th and treated to the culture of the “comma” bacillus on bread- crumb, was likewise fed with the same straight bacillus. The excreta of the beetle abounded in bacteria and bacilli, and amongst them the comma bacillus in motion. This food was repeated on the next day with all the insects, and on the 3rd they were found to be, so far as could be judged, unaffected. The two bees, humble-bee, and blowfly were allowed their liberty in the garden; the bees immediately went to some flowers, but the humble bee circled round until as high as the house, when it immediately flew off in one direction. On the 4th and 5th the wasp and beetle were fed with the straight bacillus, and on the 6th another blowfly was put with the wasp. All were again fed with the same culture up to the 9th, when, about 9 a.m., the fly was found on its back, and died very soon alter; the abdomen appeared tense and swollen. Within a few minutes a cut was made along one side of the abdomen, when the perivisceral fluid gushed out from this dropsical fly. Several covers were smeared with this clear but very sticky fluid, which would not dry well, but remained tacky and bright like albumen. Upon staining, a few short straight rods were found on all the covers, also some diplococci. ‘The fluid was miscible with water, remaining clear. Whether this effusion into the perivisceral cavity was due to the food, or to some by-play on the part of the wasp, I cannot say, but I suspect the latter as the cause of the intense effusion. Unfortunately engagements prevented the examination of the viscera. The wasp was dull and sleepy, and would not feed freely of the culture and sugar. The culture medium had now a rather more unpleasant smell, and when examined was found, though abounding in resting and motile rods, to be largely contaminated with Bacterium termo, the reaction being still markedly alkaline. 10¢h.—The wasp had much recovered, and was again fed in the same way. 11th.—While changing the saucers and squares of glass the wasp had a very fluid dejection, containing only a small lump of solid matter. The mixed dejection was at once placed on some thin covers, dried without heat, and when examined with the Microscope found to be swarming with short rods and the débris Feeding Insects with Bacili. By Dr. R. L. Maddox. 605 of the bacilli. There were also a few diplococci and Bacterium termo. ‘The wasp seemed very sleepy the greater part of the day, and at one time | thought it was dead. 12th—It was as lively as before. The sugar was now only moistened with distilled water. The beetle remained dull during the daytime since its captivity, and I could never see it actually partaking of the gelatin culture, though I could see the bread had been on many occasions partially eaten, and the curved bacilli had been found in the excreta. The question will naturally arise as to the value of these experiments. I think we may conclude that the “comma” bacillus is not pathogenic to the insects upon which the experiments were instituted. The two bees by being fed with a culture medium rich in this organism, one for seven days, had ample time for the effect of the organism, if pathogenic, to have been established, as also the wasp and the humble bee. In reference to the blowflies that died, I think they must be withdrawn from the list, and the one that was loosed from captivity had also sufficient time for any ill effects to be noted. ‘The wasp has been in captivity twenty-one days, and has withstood the variety of feeding with the comma bacillus and the straight bacillus, as also has the blackbeetle; but it is possible these organisms may have had some pernicious effect, as a diet contrary to the natural one, and may have caused in the three observed instances the increased dejections. They moreover show that the “curved” bacillus can be passed through their in- testines and ejected as a living organism, so that were this organism truly pathogenic to man and animals, the chances of contagion might be enhanced. Since commencing these experiments I see recorded in the ‘British Medical Journal’ for the 9th inst. that Mr. Watson Cheyne, who had already, I believe, proved the Bacillus alvei of the bee to be pathogenic to the blowfly, has also met with a curved bacillus in a diseased bee. These experiments I regard as simply preliminary; though not coupled with control experiments, they appear to me worth recording. Some experiments were also commenced by growing seeds on a damp clean medium, as embroidery canvas and coarse flannel. When the radicles had passed through the meshes, the whole was placed on some diluted “comma” bacillus culture for forty-eight hours, and afterwards transferred to distilled water for twenty-four hours, when the whole was again transferred to a weak watery solution of methyl-violet for forty-eight hours, and then again placed on distilled water for a day or more before examining them by the Microscope. In the case of the fine side radicles of the common Sinapis or mustard-seed, I thought I could in several 606 Transactions of the Society. instances, when mounted in water on a slide, detect the “ comma ” bacillus amongst the plasm of the cells, but I could not speak positively on this rather difficult pomt. The experiments require repetition. Still, if it be a fact that the rootlets can take up these organisms, it may point to another source for the conveyance of such into the intestines of man and animals, especially of birds and rodents. It may be an error, but I believe these experiments with these particular bacilli to be the first recorded. In reference to the straight bacillus, I cannot positively say it is Bacillus subtilis, but I expect it is. My friend Mr. Dowdeswell, who is more acquainted with these organisms than I am, has had some for examination, and I am now able to add his opinion, which is that they closely re- semble Bacillus subtilis, if not it. Experiments in these directions open a large field of inquiry, and I am not aware they are trammelled by any Act of Parliament. P.S. 19ti.—The abdominal sac of the bee that had been overstained and left covered on the slide in weak acetate of potash, was laid open in a little freshly boiled distilled water on the slide. A considerable number of bacteria were seen, some as narrow rods cf various lengths, another kind with slight motion, and some curved bacilli. A very few amongst these had slight though perceptible motion. ‘There were also straight rod-spores in full development. The dejections of the wasp after feeding on lump-sugar moistened with distilled water for five days, yielded scarcely a rod and the micrococci were much less numerous. The dejections had a very small portion of solid matter. 21st—A long red-bodied fly I had put with the wasp was soon killed; the head, legs, and wings were nipped off and the contents of the thorax speedily devoured. 22nd.—Fed with the sugar and water, and a blow-fly (Musca vomitoria) put with it in the same tumbler. 237rd.—Both were seen to feed freely off a lump of sugar moistened with old dried blood of mouse, dead of anthrax, mixed with distilled water. In the mixture only a few rods were noticed when examined microscopically. 24th.—Fed in the same way, and both watched feeding. 25th.—The two insects were separated, and just as the vessels, &c., had been changed, and before feeding them with the same blood-mixture, the wasp had a clear fluid dejection, which was im- mediately examined. Only six rods were counted in many fields. Within a quarter of an hour after feeding the wasp had three other dejections on the fresh square of glass, one with a tiny lump of . solid matter. Within ten minutes another clear fluid dejection was passed. This had some peculiar bodies which I regarded as intestinal parasites, ranging in size from the sixth to the half Feeding Insects with Bacilli. By Dr. R. L. Maddox. 607 diameter of the human blood-corpuscle. Seen on one surface they appeared circular and bright, with a central dot; seen on the reverse side, the largest had a pale centre, then a darkish ring, then a pale ring surrounded by a dark outline. The window-frame could be, with a little care, focused on this surface, but not on the opposite side. Seen in side view they were concavo-convex, the protoplasm forming a dark body like a comma lying closely against the inner edge of the outer convexity. Most of them had a gentle rolling, tumbling kind of motion, often springing up sud- denly and being for the moment lost to view, but directly after found in the same spot. This springing occurred only when seen with the ringed side upwards. It seemed as if the little organism had got twisted upon flagella which suddenly untwisted, throwing the object immediately out of focus, though I could not with cer- tainty detect any flagella. The organism was quite new to me. In the other three dejections nothing of moment was noticed, save a very few of the same organisms and a few rods in the solid por- tion, the longest being beaded. ‘The wasp was exceedingly restless all the forenoon. The blow-fly some little time after feeding on the sugar with the blood-mixture had a dejection, which was directly examined, and found to contain a few beaded rods amongst a considerable amount of débris. The rods in each resembled the anthrax rods. 26th and 27th—Again fed on the sugar moistened with dis- tilled water, and a humble bee (Bombus lapidarius) which had been captured on the 27th, was fed in the same way. A dejection from it that had been passed on to the square of glass was ex- amined and furnished amongst the débris a few very thick short non-motile rods with rather pointed ends. On the 28th, after changing the vessels and feeding with sugar, the three insects were unfortunately placed on the outside window- ledge in full sunshine, the window being slightly open. All were found dead at 3 p.m., supposed to be due to the powerful heat of the sun and a very free current of air. In the perivisceral cavities of the wasp and Bombus nothing of moment was noticed. The fly was not examined. The beetle (Blaps mortisaga) had not been fed on the blood-mixture, but on a variety of ordinary food-articles, and is still living. That specimen of anthrax blood, it seems, was not pathogenic to the fly or wasp. The death of the three insects appeared to be solely due to the high temperature (136° F.) under confinement (heat asphyxia ?), as all were lively enough when the vessels were changed. 608 Transactions of the Society. XIII.—On Four New Species of the Genus Floscularia, and Five other New Species of Rotifera. By C. T. Hupson, LL.D., F.R.M.S. (Read 18th May, 1885.) Puate XII. WueEn in 1883 I described in the pages of this Journal four new species of Floscules, I did not anticipate that, in two years’ time, I should have as many more to add to the genus; and yet such is the case. Scotland sends us two; one (discovered by Mr. J. Hood, of Dundee) with only two lobes, and one (discovered by Mr. W. Dingwall, of Dundee) without any lobes at all; so that there is now a regular series of Floscules with 7, 5, 3, 2 and O lobes. England, however, caps these additions to our rotiferous fauna, with two of the strangest species that have yet been found in the genus Floscularia. The one has setze which appear to be always in motion, each slowly extending and contracting in amoeboid fashion, but always in the direction of its length. ‘The other, to the horror of every classifier, is a swimming Floscule; and, as if that were not absurdity enough, it carries its eyes nearly at the summit of its dorsal lobe. The former of these was discovered by Mr. W. G. Cocks, of the Quekett Club, and the latter by Mr. T. Bolton, of Birmingham. Mr. Bolton has also added to his swimming Floscule a solitary swimming Conochilus, with an extraordinary pair of antenne; a large new Notommata with four spiky antennee; and a new species in each of Mr. Gosse’s rare genera Taphrocampa and Pompholyz ; while Mr. J. Hood has found yet another species of the rapidly extending genus Stephanops. Indeed, the record of the last three or four years shows how many pleasant surprises Nature has yet in store for us, if there were only reapers for the harvest. If the Scotch lakes and the English ponds have contributed so many new and strange forms, when EXPLANATION OF PLATE XII. Fig. 1.—Floscularia mutabilis (at rest). 2 Es Ss (swimming). 7 7 5 male. » +£—Conochilus dossuarius. » 0.—Notommata spicata. », 6.—Stephanops armatus. » 1.—Pompholyx sulcata (side view). >» &— rs » (front view). » %—Taphrocampa Saundersie. JOURN. R. MICR. SOC. SER. I. VOLN_ Pl. XT. ut, ty, = Sy, iy, INE 2 = \ Y 64 7 } : % Lj i ; i ere ets New Species of Floscularia, &c. By Dr. C. T. Hudson. 609 skilfully fished by Mr. Bolton and Mr. Hood, why should not the Welsh and Irish lakes, marsh ponds, and moorland pools yield forms equally curious and beautiful under similar treatment ? Let any one reflect that during the hundred years from 1766 to 1866 there were only three known species of Floscules, and that in the next twenty years no less than eleven very remarkable species have been added to the older three, mainly through the persistent researches of Mr. Bolton in England and Mr. Hood in Scotland, and he will at once admit that it is rather the lack of skilled observers, than the poverty of Nature, which we have to complain of. Floscularia mira n. sp. mihi. This is perhaps the most remarkable of all the strange creatures that belong to the genus. It was discovered by Mr. W. G. Cocks. It is a small Rotiferon; at least the only specimen that I have seen was but 1/100 in from the tops of the knobbed lobes to the extremity of the foot. It closely resembles F. ornata except in two points, viz. its tube and its setae. The tube is much more like the case of a Stephanoceros than that of a Floscule: but no great stress should be laid on this, as the cases of the tube-maker often differ a good deal from one another, even in the same species ; and of this species, as I have already said, I have seen but one specimen. The setae, however, are absolutely unique; no other Rotiferon that I am acquainted with has anything resembling them. When seen by transmitted light there is nothing remarkable about them, except their great length and abundance ; but, with dark-field illumination, they are at once seen to be all lengthening and contracting like the fine processes of an Actinophrys, only at a more rapid rate. The setee move quite independently of each other, not at all in groups; so that any score of them in view at once are in every phase of extension and contraction: and tiny particles may be seen to move along inside them as if carried by some current. When a contracted seta begins to extend in length, its tip is often driven forward with a curious flourish, such as the end of an empty elastic tube might give if a stream of water were suddenly driven along it. Floscularia mutabilis n. sp. Bolton. Plate XII. figs. 1, 2, and 3. This swimming tube-maker was discovered by Mr. Bolton in September 1884, and named, figured, and described by him in one of his fly-leayes sent out with each specimen. It is about 1/65 in. long; and, when quiet in its tube (fig. 1), looks as if it 610 Transactions of the Society. were some two-lobed Floscule that had dropped off its perch. The setze surrounding the trochal cup are somewhat scanty and short, but do not seem to differ from those of an ordinary species. After a few moments’ rest, however, the Floscule pulls down its two lobes, and so alters the aperture of its disk (fig. 2) that it now resembles: that of an Cicistes. At the same time the sete lash the water as cilia do, and the creature sails away, case, eggs, and all, stern foremost. Mr. Bolton thinks that the sete are held stiffly out (as usual) when the Floscule swims, and that the motion is effected by a row of small cilia running round the trochal cup, just under the bases of the setae. In favour of this supposition is the fact, that some species of Floscules have such a row of cilia, and that just such an arrange- ment appears to exist in the male (fig. 38): but I confess that my own opinion is adverse to this suggestion. I spent much time watching the disk of F’. mutabilis as it swam, and it appeared to me that it was the row of sete themselves which set up the apparent ciliary action. It was very striking how each individual seta became instantly visible as the action ceased, though quite invisible before. I saw two forms of young, one of which (fig. 3) I have little doubt is the male. I did not, however, succeed in catching it, and in viewing its internal organs. Floscularia calva n. sp. mihi. This is a rare Rotiferon, and was found last year by Mr. J. Hood in the lochs and marsh-pools of Fife and Forfar, on Myriophyllum and Sphagnum. It is a very bad traveller, for it appears to withdraw its foot from the plant it is on, and to fix it in the tube itself. In con- sequence of this the tube and the Rotiferon are easily knocked off the ‘stem they were originally on ; and every specimen, that came to me alive, was lying at the bottom of the tube mixed up with débris of all kinds. Under these cireumstances it was difficult to observe it well; still 1 made out distinctly that it had only two lobes, a dorsal and a ventral one, and that the setsze were remarkably short. The dorsal lobe, as usual, was the larger, and was a little swollen at its highest point, so as to give it rather a knobbed look when seen sideways. The body too was unusually slender for its length, so that the whole outline from the junction of the foot to the top of the trochal cup was almost cylindrical. It resembles F’. mutabilis in having only two lobes, but differs from it in its cylindrical shape, in the position of the eyes (which ig normal), and in the inability to alter its disk and swim. It is the first two-lobed Floscule that has ever been found. New Species of Floscularia, &e. By Dr. C. T. Hudson. 611 Floscularia edentata (?) Collins. In this species the lobes of the trochal disk have vanished altogether. There is a wrinkled edge to the trochal cup, and a few short setz rise from it, chiefly towards the dorsal and ventral sides ; but its roughly circular outline has no elevations or hollows, and lies in a plane transverse to the long axis of the body. This animal was discovered by Mr. W. Dingwall, of Dundee, in July 1884, near Blair Athol. I have only seen two specimens, but they were exactly alike. It is a very stout Floscule with a broad body and short foot, and the internal organs in each case were obscured by the gorged stomach. In each case too there were eggs, both within the body, and attached to the foot. The lobeless trochal cup in no way resembled the delicate contrivance with which Apsilus lentiformis fishes for its prey: it was a stout inverted cone, just such a one as might be produced by trimming off the lobes of an ordinary Floscule. I have considerable doubt as to whether this is a new species, or whether it is Floscularia edentata, which was discovered by Dr. F. Collins near Sandhurst about 1866, and described and figured by him in ‘Science-Gossip ’ for 1872, p. 9. The figure and the description tally with Mr. Dingwall’s Rotifer in many respects; but Dr. Collins says that his animal had neither maxillary apparatus nor tube. The apparent absence of tube is of little consequence, as this structure has been repeatedly overlooked in Floscules that are well known to have it. The absence of maxil- lary apparatus in a female rotifer is, however, a much greater diffi- culty ; yet Dr. Collins says that his specimen had no teeth, and that its food passed directly through the throat into a very capacious stomach. He also adds, that each of his specimens laid an egg while under observation, thus showing that they were females. The length of his specimens was 1/80 in., and that of those sent to me by Mr. Dingwall was 1/55. I am inclined to think that these Rotifera are the same, and so I have retained Dr. Collins’ name edentata; although it unluckily asserts as a specific distinction a doubtful fact: probably the teeth, which are at best small and inconspicuous, were lost to view in the gorged intestine. Conochilus dossuarius n. sp. Bolton. Plate XII. fig. 4. This is another swimming tube-maker, and is also one of Mr. Bolton’s prizes. The specimens sent to me were all solitary, and all swimming about in their cases; but Mr. Bolton noticed that the larger individuals have generally one or two younger specimens adhering to them. 612 Transactions of the Society. The most remarkable features, in the new Conochilus, are the position and form of the antenne. These are long, and grow together for nearly two-thirds of their height ; and, as they stand perched on the ventral surface, remind one a little of a rifle-sight. They are too, for a Conochilus, in an unusual position; for in C. volvox they are close to the mouth, and within the inner circlet of cilia. In C. dossuarius they are far away from the mouth, and entirely outside the trochal disk. The young of C. volvow are in the habit of clustering together, with their feet all tending to a common centre ; and, after swimming for some time in this odd fashion round about one another, they secrete tubes that fill up the spaces between the individual animals, and clasp them all together into one sphere. ~ But, from Mr. Bolton’s observation, this does not seem to be the case with C. dosswarius. Here young animals of different ages are attached by their tubes to the much larger tube of their common parent, forming clusters irregular in shape, and varying in size. However, I will not pursue the subject, as I hope that this summeny/resh specimens will enable us to see whether this Cono- chilus ever forms clusters, like the beautiful spheres of C. volvow. Notommata spicata n. sp. mihi, Plate XII. fig. 5. Mr. Bolton sent me this very large and remarkable Notommata in May 1884. It is 1/25 in. m length, and is surrounded with a transparent gelatinous covering, out of which peep the ends of its four dart-like antenne. It is something like N. centrura, but this latter has only one anterior antenna on the median dorsal line; and its two posterior dorsal antenne are not nearly as long as those of N. spicata, and are quite buried under the creature’s gelatinous coat. They both have the same funnel-like ciliated mouth, with its edges hanging down from under the ventral sur- face, but their general contour is unlike; N. centrwra, when viewed dorsally, is wider across the posterior end in proportion to its length: N. spicata tapers much more gradually. However, the four antenne are enough, I believe, to distinguish it from all other species.* It has a very long tapering stomach, much sacculated at its anterior end, and four gastric glands close beneath the mastax. The ovary, in the specimens I saw, was a long thick rope, with the germs lying in it singly one above another. I had the good fortune to see the adorning of a lasting-egg with * WN. spicata has a superficial resemblance to W. copeus; but the latter has a dorsal antenna on the median line (which the former lacks), as well as two stout, flexible, cylindrical auricles, which it moves into various positions, and each of which bears a circle of cilia on its free extremity. If WN. spicata has ciliated auricles, I have not seen them exhibited: I only know N, copeus from Ehrenberg’s drawings and description. New Species of Floscularia, &e. By Dr. C. T. Hudson. 613 its bristles. The large egg shown in fig. 5 was, when I first saw it, quite smooth ; and was separated by a clear space from its outer- most covering. After a little while the outline of the egg grew wavy, owing to small protuberances which projected into the clear space, and which by focusing I could see extended all over its surface. The growth of these protuberances was quite perceptible at the end of every ten minutes or so, and in two hours’ time they had grown long enough to stretch almost across the clear space that separated the two coverings of the egg. They were stouter than mere hairs, but cannot be effectively rendered on the small scale of fig. 5. Stephanops avmatus n. sp. mihi. Plate XII. fig. 6. This three-spined Stephanops was first found by Mr. J. Hood in Roscobbie Loch, in August 1884. I have not seen it; and the figure I have given is copied from a drawing of Mr. Hood’s. Its specific distinction lies in the presence of two posterior lateral spines, along with one long dorsal one. As this genus has received several additions lately, I here subjoin an analysis of its species. * No dorsal spine. Without posterior spines .. Stephanops muticus Ehrenberg. With two ,, » +. 8. ctrratus Miller. With three _,, » ++ SS. lamellaris Miller. ** With a dorsal spine. two toes .. S. longispinatus Tatem. three toes S. wniseta Collins. With one posterior spine... .. .. S&S. befureus Bolton. With two posterior spines.. .. .. S. armatus Hudson. Besides these there are S. ovalis Schmarda and S. tridentatus Fresenius; but I have not seen the descriptions of these. Possibly the latter of the two may be the same as S. armatus. Mr. J. EK. Lord’s three-toed Stephanopst is I think probably Dr. Collins’s S. uniscta. Without posterior spines \ Pompholyx suleata n. sp. Bolton. Plate XII. figs. 7 and 8. This new species differs from Mr. Gosse’s P. complanata in the shape of the lorica. In this latter the lorica is greatly compressed dorsally and ventrally, so as actually to be concave at the median line on both surfaces. But in P. sulcata the dorsal and ventral + Microscopical News, iy. (1884) p. 146, fig. 24. Ser, 2.—Vo. V. 238 614 Transactions of the Society. surfaces are both sharply convex, and there are convex lateral surfaces as well; in fig. 8 a transverse section of the lorica is given, showing its four-lobed form. This may be easily obtained from the live animal, as it has a habit of swimming head downwards with its trochal disk close to the glass. Mr. Bolton found this pretty little rotifer last summer in the same water with Conochilus dossuarius. Taphrocampa Saundersiz n. sp. Gosse. Pl. XII. fig. 9. Mr. Bolton sent me several specimens of a new Taphrocampa in July 1884. It is somewhat like Mr. Gosse’s T. annulosa, but differs from it in having a square curved hood projecting downwards over the head, and looking like a hook in profile; also in having two colourless spots like eyes on the head; as well as a stout short truncate tail, just above the forked foot. I did not notice the slightest trace of ciliary action about the head, neither has Mr. Gosse observed any, either in this species orin 7. annulosa; and yet it is possible that both animals possess ciliated auricles, for Mr. E. B. Brayley, the Hon. Secretary of our Bristol Microscopical Society, has given me a rough sketch of an animal which is probably T. annulosa, and which on several occasions he observed to put out little tufted auricles from the sides of its head and swim with “a slight vermiform movement.” He thinks also that “a row of very short cilia extend right across the forehead.” Mr. Gosse has named this new animal 7. Saundersiz, after Miss Saunders, of Cheltenham, who has sent both to Mr. Gosse and myself several specimens of rare Rotifera. I have been compelled by lack of leisure to give very brief notices of the above new species, and but few figures; but they will be dealt with in a more satisfactory manner in the Monograph on the Rotifera by Mr. Gosse and myself, which is now being prepared for publication. (276155 SUMMARY OF OURRENT RESEAROHES RELATING TO 2.0 GY AND. BOUT AUN Y, (principally Invertebrata and Cryptogamia), MICROSCOPY, &c., INCLUDING ORIGINAL COMMUNICATIONS FROM FELLOWS AND OTHERS.* ZOOLOGY. A. GENERAL, including Embryology and Histology of the Vertebrata. Unity of the Process of Spermatogensis in Mammalia.f—M. Laulainé recognizes two periods in the process of spermatogenesis ; the first is one of proliferation (formation of spermatoblasts), the second of differentiation (evolution of spermatoblasts); the former has been observed to take place either endo- or exo-genetically. In the horse and the pig spermatogenesis is similar to that in the rat, but the author does not agree with Balbiani in regarding the pheno- menon as exogenetic in character; indeed, the term exogenetic can only be used if we ceased to ascribe to it the meaning of there being proliferation by budding, and limit it to the intervention of the ramified cells first described by Sertoli. In mammals with an exogenetic method of spermatogenesis, the spermatoblasts are collected by the cells of Sertoli, and go through all the phases of their development on the surface of these cells; the last are only permanent elements of sup- port. In all mammals proliferation takes place by division. Formation of the Blastoderm in the Bird’s Egg.t—M. M. Duval denies that there is any absolute line of demarcation beyond the germ proper and the white yolk; indeed, we cannot even say that the * vitellus de formation ” only takes part in the process of segmentation, and that the ‘ vitellus de nutrition” has no share in it, for after the formation of the blastoderm a secondary segmentation goes on in the re- mainder of the yolk; and it is impossible to say exactly where this secondary segmentation ends. Segmentation, as Kélliker has pointed out, is excentric, or commences at a point which does not correspond * 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, or for any claim to novelty or otherwise made by them. ‘The object of this part of the Journal is to presenta summary of the papers as actually published, and to describe and illustrate Instruments, Apparatus, &c., which are either new or have not been previously described in this country. + Comptes Rendus, c. (1885) pp. 1407-9. ¢ Ann. Sci. Nat.—Zool., xvili. (1884) 208 pp. and 5 pls. a te 8 616 SUMMARY OF CURRENT RESEARCHES RELATING TO to the centre of the future blastoderm, and goes on most actively in this region ; to this the author adds the rider that the point where the most active segmentation commences corresponds to the future posterior region of the blastoderm, and we can, therefore, early distin- guish the front from the hind end. Like those of lower vertebrates the ova of birds have a true segmentation cavity, which has the form of a slit, is often difficult to recognize, and marks the point where the ectodermal are separated from the subjacent elements; as segmen- tation extends more deeply it affects the yolk-layers which ought to be considered as belonging to the white yolk; but at a certain depth this segmentation seems to stop; it does not really do so, there is only a modification of its rhythm ; the cavity formed by the furrows is the subgerminal cavity which is produced from behind forwards, and is the homologue of the primitive enteron of Batrachians, or in other words, represents the gastrula-invagination of lower verte- brates. : After the formation of this subgerminal cavity a number of free nuclei are to be found in the yolk which forms its floor; these arise from nuclei which, during the formation of the cavity, had divided into two ; of the halves one remained in one of the deeper spheres of the blastoderm, and the other in the floor of the segmentation cavity. A secondary segmentation appeared around these nuclei, which, at first inactive, afterwards became very active; the multiplication of nuclei in the yolk gives rise to the production of the vitelline endoderm. The blastoderm of the freshly laid egg is formed of two layers ; the upper consists of a single row of cells, which form a distinct ecto- derm; the cells of the lower layer vary in size, are in the stage of segmentation, and form an irregular mass from which arises both endoderm and mesoderm; this may be called the primitive endo- dermic mass. From the time when segmentation ends until the appearance of the primitive groove, the edge of the blastoderm passes through three stages ; it is at first raised into a ridge, and the ectoderm is continuous with the endoderm; the latter consists of several layers of cells and forms the greater part of the swelling. The ectoderm then separates from the primitive endoderm along the edges of the blastoderm, and, while the ectoderm extends very far over the yolk, the margin of the endoderm fuses with the yolk, to form an endodermo-vitelline enlarge- ment; as the yolk divides around each nucleus there appear large cells which, by further division, increase the surface of the endoderm. We next have a large vitelline layer (vitelline endoderm) with free nuclei, and finally a layer of yolk without nuclei. The author finds that it is necessary to distinguish the axial plate and the primitive line as two successive phases of one and the same ean the former has the same constitution as the blastodermic ridge. _ All along the axial plate the connections of the ectoderm with the primitive endodermic mass exist from the moment when there first appear the rudiments of this plate; when its groove becomes more ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 617 deeply hollowed, the connections between the ectoderm and the axial plate seem to become more intimate along its base, and, at the same time, the groove becomes divided into proper endoderm and meso- derm. It is the multiplication of the elements of this mesodermic plate that causes the greater distinctness of the groove of the primitive line. The axial plate of birds ought to be considered as the homologue of the anus of Rusconi in Batrachians; it is rudimentary, indeed, its lips being fused in a kind of antero-posterior median raphe, and it is at these lips that we have most actively multiplying the elements which are destined to form the mesoderm. At the bottom of the groove the mesoderm grows at the expense of a cellular mass which is common to the mesoderm and ectoderm; but this fact must not be ornare to prove the origin of the middle from the outer germinal ayer. In combining with his own the results of other workers, M. Duval takes occasion to consider the work of his predecessors. Physiological Purpose of Turning the Incubating Hen’s Egg.“ —The sitting fowl frequently turns her eggs during incubation, and when this process is carried on artificially, mechanical means must be adopted to effect the same purpose. M. C. Dareste finds that during the first week of artificial incuba- tion, eggs which are turned develope in essentially the same manner as those which are allowed to rest, but the monstrosities which have already been formed in the latter soon take on an excessive develop- ment, and in very few eggs which are allowed to remain unmoved during the whole period of incubation does the body-cavity of the embryo become closed in. ‘The cause of death in the unmoved eggs is, according to Dareste, the union by growth of the allantois with the egg-yolk, which latter is thus prevented from becoming finally absorbed into the alimentary canal preliminary to the closure of the body-cavity. These adhesions of the allantois with the vitelline membrane lead to frequent rupture of the latter, whose contents are thus largely lost to the embryo. Death of the chick in the unturned eggs usually occurs about the second week of incubation, When the eggs are turned over it is probable that the position of the allantois upon the yolk is shifted, and this daily movement prevents adhesion between the two surfaces, Sixteen eggs were placed under the same conditions of artificial incubation, but eight were allowed to remain unmoved, while the eight remaining were turned over twice aday. In the first set absorp- tion of the yolk did not occur in any specimen, and all the embryos died in the course of the second or third week. In the second set, in six eggs the yolk was absorbed in the normal manner ; in a seventh, opened on the twenty-second day, the chick was alive and hearty and the yolk was being absorbed; in the eighth egg the chick was dead on the twentieth day, and adhesion between the allantois and yolk had prevented absorption of the latter. * Comptes Rendus, c, (1885) pp. 813-4. See Amer, Naturalist, xix. (1885) pp. 619-20. 618 SUMMARY OF CURRENT RESEARCHES RELATING TO Colours of Bird’s Eggs.*—Dr. O. Laschenberg has published a short abstract of his investigations into this subject; the more im- portant results are as follows :—As Krukenberg has stated, the ground coloration originates in a different way from the spots and markings, though both are derived from the blood and not from special pigment- glands. The ground coloration is caused by a transudation through the uterus which is richly supplied with blood-vessels ; the spots are formed by particles of pigment which are found throughout the ovi- duct and probably arise in the Graafian follicle; the formation of pigment is no doubt to be referred to a process similar to that which causes the corpus luteum in the ovary of mammals. Development of Epicrium.j{— Herren P. B. and C. F. Sarasin have taken advantage of their visit to Ceylon to investigate the deve- lopmental history of Epicrium glutinosum. The ovarian eggs are more like those of reptiles than of amphibians, are oval in form, and about 9 mm. in their longest and 6:5 mm. in their shortest diameter ; there was a considerable quantity of yolk, and a rounded whitish germinal disk, in the centre of which is the darker germinal vesicle; the arrange- ment of the yolk was not unlike that which is seen in the bird; in the oviducts the ova become surrounded by a quantity of albumen, and a spirally coiled cord appears at either pole. Epicrium, unlike its American ally Cecilia, lays eggs, and also hatches them. Embryos about 4 cm. long move livelily in their shelis; on either side of and behind the head arises a tuft of three blood-red external gills, which constantly move about in the ovarian fluid. The three tufts vary in length, the shortest being 2, the longest 9 mm. long; the tail, which is short but quite distinct, has a well-marked fin; the eye appears to be proportionately very large and distinct; dermal sensory organs can be made out with the aid of a magnifying glass, and have the appearance of white dots: the body is of a greyish-blue colour, clearer below, and has a black stripe along the dorsal middle line; the two beautiful yellow bands which are found in the adult are absent from the embryo. The gills develope very early ; when they are lost, the young pass into the nearest pool and begin to lead a free life. In the water they grow to a length of about 16 cm., and lose their gill- clefts and caudal fin; the structure of the skin changes, and they become adapted to a terrestrial mode of life. The authors are of opinion that the Gymnophiona are to be asso- ciated with or stand quite close to the Urodela; as embryos they are perennibranchiata, as larve derotrematous, and in their adult terrestrial condition they correspond to the Salamandrina. Embryology is sup- ported in this view by histology, for the spermatozoa have been found to have an undulating membrane, and by anatomy, for there is a fourth arterial arch in the vascular system of the adult. Translocation forwards of the Rudiments of the Pelvic Fins in the Embryos of Physoclist Fishes, —Mr. J. A. Ryder cites the * Zool, Anzeig., viii. (1885) pp. 243-5. t Arbeit. Zool.-Zoot. Inst. Wirzburg, vii. (1885) pp. 291-9, $ Amer, Natural., xix. (1885) pp. 315-7. ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 619 observations of A. Agassiz on the translocation forwards of the rudi- ments of the pelvic fins in the young larva of Lophius, as demon- strating beyond any doubt that the Physoclisti have descended from the Physostomi. Silver-reducing Animal Organs.*—The success of Drs. O. Loew and T’. Bokorny with vegetable cells induced the former to try and see if the protoplasm of animal cells would not likewise have a silver- reducing effect. Into between fifty and one hundred cubic centimetres of a solution which contained about 5 per cent. of silver the author placed the kidneys freshly taken from a frog or toad, with the ventral side turned upwards; the light was immediately cut off, but within fifteen minutes the bright bands on the surface became darkened, and in less than two hours were quite black. This very remarkable reaction is only to be observed with living tissues. The tissue may be seen under the Microscope to be traversed by black dots, more or less closely packed together. If the kidneys are left for twelve hours in the solution, a number of black dots may be observed in the interior of the kidney, and especially in the neigh- bourhood of such canals and other spaces as afford an easy means of passage for the reagent. These experiments are sufficient to show that living animal protoplasm can effect a reduction of silver. Effects of .Very Low Temperatures on Living Organisms,,— Mr. J. J. Coleman and Prof. M‘Kendrick have made some remark- able experiments on the effects of low temperatures on living organisms, particularly microbes, using for this purpose the cold-air machinery invented by Mr. Coleman, which, in its ordinary working, delivers streams of air cooled to about 80° below zero (—63° C.), but by certain modifications as low temperatures can be secured as have yet been produced in physical researches. The experiments consisted in exposing for hours to low tempera- tures putrescible substances in hermetically sealed tins or bottles, or in flasks plugged with cotton-wool. The tins or flasks were then allowed to thaw, and were kept in a warm room, the mean tempera- ture of which was about 80° F. They were then opened, and the contents submitted to microscopical examination. The general result may be stated thus:—The vitality of micro-organisms cannot be destroyed by prolonged exposure to extreme cold. It is clear, there- fore, that any hope of preserving meat by permanently sterilizing it by cold must be abandoned, for the microbes, which are the agents of putrefaction, survive the exposure. Some of the experiments on which this conclusion rests are briefly described. Meat in tins, exposed to 63° C. for six hours, underwent (after thawing) putrefaction with generation of gases. Trials with fresh urine showed that freezing at very low temperatures delayed the appearance of the alkaline fermentation, but a temperature of 63° O, for eight hours did not sterilize the urine. Samples of fresh milk * Pfliiger’s Archiv f. d. Gesammt. Physiol., xxxiv. (1885) pp. 596-601, + Journ, of Anat. and Physiol., xix. (1885) pp. 335-44. 620 SUMMARY OF CURRENT RESEARCHES RELATING TO exposed to temperatures of from zero to —80° F. for eight hours, curdled, and showed the well-known Bacterium lactis; and so far as could be observed, freezing did not delay the process after the flasks were kept at a temperature of about 50° F. Similar results were obtained with ale, meat-juice, vegetable infusions, &e. It is probable that the micro-organisms were frozen solid. One cannot suppose that in these circumstances any of the phenomena of life take place; the mechanism is simply arrested, and vital changes resume their course, when the condition of a suitable tem- perature is restored. ‘These conditions led the authors to examine whether any of the vital phenomena of higher animals might be re- tained at such low temperatures. ‘They ascertained that a live frog may be frozen through quite solid in about half-an-hour at a tem- perature of —20° to —30° F. On thawing slowly, in two instances the animal completely recovered. After longer exposure the animals did not recover. In two cases frogs were kept in an atmosphere of —100° F. for twenty minutes, and although they did not revive, yet, after thawing out, their muscles still responded feebly to electrical stimulation. One experiment was performed on a warm-blooded animal—a rabbit. The cold-blooded frog became as hard as a stone in from ten to twenty minutes, but the rabbit produced in itself so much heat as enabled it to remain soft and comparatively warm during an hour’s exposure to —100° F. Still its production of heat was unequal to make good the loss, and every instant it was losing ground, until, at the end of the hour, its bodily temperature had fallen about 56° F. below the normal, but was still 143° F. above the surrounding temperature. When taken out the animal was coma- tose, and reflex action was abolished. Placed in a warm room, its temperature rose rapidly, and the rabbit completely recovered. The observations are of great value and highly suggestive. Those upon the rabbit indicate that death from cold is preceded by loss of consciousness, owing to the early suppression of the activity of the grey matter of the encephalon. This confirms the belief that death by freezing is comparatively painless. The viability of microbes at low temperatures has also been demonstrated by Pictet and Yung,* who found that various bacilli can survive —70° C. for 109 hours. After such exposure, Bacillus anthracis retained its virulence when injected into a living animal. “We cannot refrain from asking, Are not frozen micro-organisms the means of disseminating life through the universe? An affirma- tive answer is at least a better hypothesis than the assumption of Spontaneous generation to account for the origin of life on the earth. May not life be coeval with energy? May it not have always existed ?” f Bell’s ‘Comparative Anatomy and Physiology.’ t{—In this manual Professor I. Jeffrey Bell arranges the elementary facts of zoology by * See this Journal, iv. (1884) p. 432. + Mr. C. S. Minot in Science, y. (1885) pp. 522-3. ¢ Bell, F. J., ‘Comparative Anatomy and Physiology, 555 pp. and 229 fie 8vo, Cassell and Co., London, 1885, Y SSP Ub Gor de Sh ca ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 621 organs instead of by the groups of animals; he says in his preface that he has constantly kept before himself, and hopes “the student will faithfully bear in mind that there has been an evolution of organs as well as of animals, and that he who desires to understand the most complicated organs must first know the structure of such as are more simply constituted.” There are a large number of woodcuts, many of which are new to English text-books, and the more important discoveries of recent years appear to be incorporated with what the author calls “the general property of zoological workers.” There is @ copious index to the animals mentioned in the text. B. INVERTEBRATA. Action of Cocain on Invertebrates.*—M. Richard finds that an injection of hydrochlorate of cocain stops the heart of a snail in diastole ; the animal will recover from a dose of 0°003 gr.; it takes longer to recover from twice as large a dose, and if 0-025 gr. are given the animal takes two days to recover. An earthworm soon has the middle part of its body rendered insensible by the injection of a dose of 0-006 gr., but the two ends retain their power of movement ; a further dose of the same strength causes the voluntary movements to slowen gradually, but it takes 20 hours before they cease altogether. A small colony of Bryozoa was placed in 5 ec.c. of fresh water to which 0-5 c.c. of 100 per cent. solution of cocain were added; the animals remained extended ; ten minutes afterwards, a shaking of the glass made them retreat normally. Daphnie resist for a long time the action of the drug. Hydre in 5 c.c. of water ta which 1 ¢.c. of the solution was slowly added, died in an extended state, and for them and for Bryozoa the author suggests the use of the drug as enabling us to preserve these delicate animals in an extended condition. Enterochlorophyll and Allied Pigments.t—Dr. C. A. MacMunn in 1885 described the spectroscopic and other characters of entero- chlorophyll which was obtained from the liver or other appendage of the enteron of various invertebrates. It is now shown that this pigment is not due to the presence of symbiotic algw, or immediate food-products, but is built up by the animal containing it. Taking the six bands ¢ of vegetable chlorophyll in alcoholic solu- tion described by Kraus, the first two and the fourth are coincident with those of enterochlorophyll in a similar solution ; the third band is, however, frequently missing from the latter. The fifth and sixth bands belong to the yellow constituent, which Hansen shows to be a lipochrome ; the corresponding bands in the case of enterochlorophyll also belong to a lipochrome, and are not always coincident with the lipochrome bands of plant-chlorophyll. This was proved by saponi- fying enterochlorophyll by Hansen’s method. But saponification of vegetable chlorophyll changes it considerably, as bands of a solution, * Comptes Rendus, c. (1885) pp. 1409-11. + Proc. Roy. Soc., xxxviii. (1885) pp. 319-22. t The five bands in a leaf, as described by Kraus, can be secn by using a micro-spectroscope of small dispersion and a good substage achromatic condenser. 622 SUMMARY OF CURRENT RESEARCHES RELATING TOC before saponifying, do not éorrespond with those of a similar solution after saponifying. THansen’s results were confirmed as far as the separation of “chlorophyll-green” and “chlorophyll-yellow” are concerned, and the crystals described by him obtained. While the dominant band of “ chlorophyll-green” in solutions of plant-chlorophyil is moved much nearer the violet by saponifying, or split up into two in some cases, the corresponding band of entero- chlorophyll disappears in toto, or remains in the same place. Another difference was also noted in the case of enterochlorophyll and in the case of Spongilla-chlorophyll, namely, that it is impossible to bring about a complete separation of the constituents in most cases by saponifying and treating as Hansen directs. All the bands of asolution of Spongilla-chlorophyll are coincident with those of a similar solution of plant-chlorophyll, as already proved by Prof. Lankester and Dr. Sorby. From the enterochlorophyll of Uraster rubens crystals of “ chloro- phyll-yellow ” and “ chlorophyll-green ” were obtained by saponifying. Morphologically, enterochlorophyll occurs—as proved by the ex- amination of fresh-frozen sections—in oil-globules, granules, and dissolved in the protoplasm of the liver-cells ; no starch or cellulose could be found in such sections after adopting the usual botanical precautions. Hence enterochlorophyll is an animal product, and a chlorophyll of which there are probably several recurring in animals. Mollusca. Buccal Membrane of Cephalopoda.*—M. L. Vialleton has studied the morphological nature of the buccal membrane of cephalopods by the aid of its nervous supply, and comes to the conclusion that the muscular mass of the lobes, the presence of suckers, and, above all, the existence in each of the ganglionic cord, analogous to the nerves of the arms and of the same origin as they, show that we must regard these lobes as true rudimentary arms ; if this be so it is clear that the buccal membrane belongs to a series of arms in which the interbrachial membrane is proportionately better developed than the - arms themselves. He rejects the view that the membranes are to be regarded as hypertrophied lips, inasmuch as the nerves are received from the sub-cesophageal portion of the cerebral mass, whereas the labial nerves arise from the supra-cesophageal portion. Loligo vulgaris and Sepia officinalis were the two types studied. Pancreatic Function of the Cephalopod Liver.;—Mr. A. B. Griffiths, in addition to the facts already brought forward { to show that the cephalopod liver is pancreatic in function, now adduces the following. Portions of the organ removed from a fresh Sepia had an alkaline * Comptes Rendus, c. (1885) pp. 1301-3. i ae News, li. (1885) p. 160. See Journ, Chem. Soc.—Abstr., xl viii. (1885) pp. —30. + Chem, News, xlviii. (1884) p. 37. ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 623 reaction, converted starch into dextrose, and oil into fatty acids ; 6 mgrms. of the tissue of the organ rendered 15 c.c. of milk trans- parent in four hours. Moreover, the ferment, removed from the organ, previously hardened by treatment with alcohol, by extraction with glycerol and subsequent precipitation with alcohol, converted starch into dextrose, and fibrin into leucine and tyrosine. The organ contains neither glycoholic nor taurocholic acid nor glycogen ; it is therefore evident that this so-called “liver” is a true pancreas. Artificial Fecundation of Mollusca.*—Mr. W. Patten has suc- ceeded in the artificial fertilization of the ova of Haliotis and Patella ; this experiment has not been previously performed on any mollusc. Careful investigations were made in order to exclude the possibility of there having been a previous internal fertilization ; the absence of an albuminiparous gland and external sexual organs in these molluscs appears to show that the ova undergo naturally an external fecun- dation. Development of Generative Organs of Pulmonata.t—Herr J. Brock finds that the generative organs of pulmonate gastropods begin to be developed in the last stage of larval life; just below the cutis there is, on the right side and in front of the cesophageal ring, a fine cord of cells with a distinct lumen. A little later there is distinct evidence of the presence of a commencing hermaphrodite gland, and it is found that it and the efferent organs are developed in one and the same mesodermal blastema. Primordial ova appear very early. The author is convinced that in the formation of the external generative orifice the ectoderm does not take any share, by the formation of any invagination. After the formation of the oviduct the vas deferens appears; after this there is growth, but for a time no new formation ; then the receptaculum seminis appears in the form of a wide-necked outgrowth of the genital atrium. The author was not able to follow out the later stages, but he thinks it is clear that the simple condition of the generative organs which is permanent in the Prosobranchiata is passed through during the development of the Pulmonata. Microscopic Anatomy of Dentalium.{—Prof. H. Fol finds that the epidermis of Dentalium is nothing more than a simple epithelium, the characters of which vary in different regions; at either extremity of the tube formed by the mantle some of the cells are modified to form a mass of very large glandular cells; each of these is imbedded in the subjacent dermal tissue and has a more or less flask-shaped form, and is filled by a granular secretion; one of these unicellular glands may be one hundred times as large as the ordinary epidermic cells; they are the chief agents in the formation of the shell. The nerve-ganglia are formed of a cortical grey and an internal white substance; the latter consists solely of nevve-fibrils, without any neuroglia; the grey matter is made up of ganglionic cells which * Zool. Anzeig., viii. (1885) pp. 236-7. + Nachr. K. Gesell. Wiss. Gottingen, 1884, pp. 499-504. + Comptes Rendus, c. (1885) pp. 1353-5, 624 SUMMARY OF CURRENT RESEARCHES RELATING TO are all unipolar. In the central ganglia groups of very large cells alternate quite regularly with other masses which are formed of much. smaller cells. The muscles are composed of ribbon-shaped smooth fibres, disposed like those of the non-striated muscles of higher vertebrates; in each fibre there is a rod-shaped nucleus. In the foot the muscles are very regularly arranged, and form two external circular layers, within which are some thirty longitudinal bundles. — The digestive tube is clothed by a simple epithelium, which is in some regions distinctly glandular, and in others ciliated; the liver and the kidney are hollow pouches, the wall of which is a simple glandular epithelium ; below the anus there is a pouch common to the two halves of the kidney. The generative organs are filled by a compact mass of generative products; near the surface of the ovary there are young ovules, the greater part of which is occupied by the nucleus, within which there is a nucleolus composed of two very dissimilar halves. In the mature ovum the double nucleolus disappears. M. Fol has not been able to find the efferent genital canal which has been described by Lacaze- “Duthiers; the glands appear to him to empty themselves merely by dehiscence into the pallial cavity, the renal gland, or, as is most probable, by the anal gland. Nervous System of Fissurella.*—M. L. Boutan describes the nervous system of Fissurella aliernata and comes to a different con- clusion from that arrived at by Ihering from an investigation of F. maxima. In Fissurella, as in the typical nervous system of Gasteropoda, there are two cerebroid, two pedal, and five asymmetrical ganglia. There is, besides, a triangular nervous mass the morpho- logical signification of which has been pointed out by Lacaze-Duthiers. This triangle is a simple extension of the pedal and the two first asymmetrical ganglia, which, being linked together, have acquired an exceptional development and become drawn out. The nervous system of Parmophora is intermediate between that of Haliotis and of Fissurella ; Emarginula is likewise furnished with the nervous mass above named and ranks between Parmophora and Fissurella, for the coalescence of the pedal and asymmetrical centres is carried in each animal a little less far than in the last-named type. Anatomy and Systematic Position of Halia priamus Risso.;— M. J. Poirier gives a full description of the anatomical structure of Halia priamus Risso. With the exception of the operculum, which is wanting, the greater number of the organs resemble in form those of Buccinum. The formula of the radula is 1, 1, 1, not 1, 0, 1 as has been erroneously stated. Hence its systematic position is no longer with the Pleurotomide where lately it has been placed, but with the Buccinide. Tectibranchiata of the Gulf of Marseilles.;:—M. A. Vayssiére has examined thirty-seven species of Tectibranchs; they are all Opistho- * Comptes Rendus, c. (1885) pp. 467-9. + lbid., pp. 461-4. { Ibid., pp. 1389-91, ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 625 branchiata, and von Ihering was wrong in denying this. The incom- pletely known Notarchus has a small shell very like that of Gastro- pleron meckelii, its digestive tract and generative organs are almost exactly like those of Aplysia, and the same is true of its nervous system. In Umbrella mediterranea the nervous system, as in almost all Tectibranchs, has a very delicate subcesophageal intercerebral commis- sure; the presence of otocysts was determined, and these organs, though lying in the pedal ganglia, are attached by very small nerves to the cerebral ganglion. The cesophageal nerve-collar of Tylodina, though very like that of Umbrella, has three instead of two visceral ganglia, and the median one gives rise to the genital nerves. Leach’s name of Ascanius is applied to Pleurobranchus membranaceus and P. tuberculatus, and the genus is regarded as being intermediate between Pleurobranchus and Pleurobranchea. Classification of the Lamellibranchs.*—Dr. M. Neumayr gives a new classification of the Lamellibranchs, founded upon the hinge. The oldest forms have no, or only the faintest, trace of hinge- teeth, the shells are thin, and there is usually neither mark of muscle nor of pallial sinus. For these forms, supposed to have two equal adductor muscles and an entire mantle-line, the order Paleconche is proposed. From these are supposed to diverge the Desmodonta, with- out hinge-teeth, or with irregular hinge-teeth, with two equal adductor muscles and with a pallial sinus ; and the Taxodontx, with numerous undifferentiated teeth and two equal muscles. ‘T'o the first of these groups belong the Pholadomyide, Corbulide, Myide, Anatinide, Mactride, Paphide, Glycimceride, and Solenidz (?), and to the second the Arcide and Nucalide. The Tubicole forma suborder of the Des- modonta. From the Taxodonta branch off in one direction the Hetero- donta, with distinct cardinal and lateral teeth fitting into each other, and two muscle impressions (Najade, Carinide, Astartide, Crassatel- lide, Megalodontide, Chamide, (Rudistes) (Tridacnide), Erycinide, Lucinide, Cardiide, Cyrenide, Cyprinide, Veneride, Gnathodontide, Tellinidw, Donacide, and in another, the Anisomyaria, with irregular or no hinge - teeth, two unequal muscles or one only, and no pallial sinus. These form two suborders, Heteromyaria (Aviculida, Mytilide, Prasinide, Pinnidew ) and Monomyaria (Pectinide, Mytilide, Spondylide, Anomide, Ostreide). The Trigonide are considered a suborder of Heterodonta. Development of Cyclas cornea.t—Dr. H. E. Ziegler finds that the segmentation of the egg of Cyclas is, from the first, unequal ; and the small cells, as usual, divide more rapidly than the larger. The egg, like those of the Najadw, has a micropyle ; the carlier stages of cleay- age are passed through in the brood-sacs. The observations on the gastrulation were incomplete, but there was seen to be invagination, and two large primitive mesenchym-cells were detected. The differ- ences in the quantity of fluid found between the ectoderm and endo- * 8B. K. Akad. Wiss. Wien, Ixxxviii. (1884) pp. 385-420 (1 pl.). Amer. Natural., xix. (1885) pp. 404-5. See also this Journal, ante, p. 229, + Zeitschr. f. Wiss. Zool., xli. (1885) pp. 525-69 (2 pls.). 626 SUMMARY OF CURRENT RESEARCHES RELATING TO derm of various individuals seem to be due to physiological relations. The blastopore is in the form of a slit, the length of which is about equal to that of the archenteron; the hinder end of the gut never separates from the ectoderm, and the anus arises at their point of junction. Dr. Ziegler compares the mode of development which obtains in Lamellibranchs with what is found in Gastropods, and shows how they both point to a common primitive mode of develop- ment. The trochophore of Cyclas has all the organs homologous with those found in the corresponding stage of marine Lamellibranchs and Gastropods; as to the locomotor organs, the trochophore of Cyclas diverges somewhat from the marine Lamellibranchs and approaches rather the Pulmonata. In describing the development of various organs, the author insists that the pericardiac cavity is not, as has been thought, part of the blood-vascular system, its fluid is not blood, and contains no blood- corpuscles. The gill-lamella is, at first, a simple fold; and, as differ- entiation extends from before backwards, it is possible in one and the same gill to observe various stages in the process of differentiation ; from its lower margin the outer ectodermal layer gradually forms a fold which has the form of a groove, and this gradually grows up- wards; there then appears on the lower margin of the fold a small corresponding infolding of the inner ectodermal layer; the lamella fuse, and vertical clefts appear in their substance. After describing the appearance of the brood-pouches, the author concludes with a short account of the genital glands; these form at an early stage two club-shaped masses which touch in the middle line; the sexes are united, and the disposition of parts is such that there appears to be self-impregnation. Manner in which Lamellibranchs attach themselves to Foreign Objects.*—Dr. J. T. Cattie describes the means by which the common mussel attaches itself to foreign objects. When the foot commences to grope about, it may become two or three times as long as the body of the animal without finding any object within its vicinity ; it then moves about till it finds some point of support ; when this is effected there appears from the transverse cleft, which terminates the ventral groove, a whitish substance which gradually becomes more opaque ; sometimes the slit takes on the form of an equilateral triangle, and then the quantity of matter which exudes from it is greater; this matter obviously comes from the cylindrical tubes which are scattered in the glandular substance of the foot. A terminal plate having been formed the foot is withdrawn, and the plate and the byssus are merely connected by a delicate thread. The time necessary for an animal of average size to form the plate varies between 55 and 90 seconds; in some cases two connecting threads become developed. The terminal plate, when studied under the Microscope, was found to be formed of thousands of small granules, irregularly distributed, and varying considerably in size. The fine threads appear to be * Tijdschr. Neder]. Dierk. Vereen., vi. (1882-5) pp. 56-63. ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 627 formed by the agglutination of granules of various sizes, but large granules are formed by the fusion of several smaller ones. The formation of the byssus is regarded by the author as being very simple; the walls and the lamelle of the byssus-cavity con- tinually secrete a byssogenous matter; the lamelle in the anterior and narrow part of the cavity unite and fuse with one another, while the narrower shape of the orifice gives the byssus-threads their form. Owing to the relations of the ventral groove of the foot each byssus- thread is immediately fused to the main trunk. The author doubts the correctness of A. Miiller’s view that there is an agglutinating and a byssogenous substance; and speaks severely of the artificial character of that author’s classification of the species. General Characters of Cymbulia,*—The Pteropoda being so purely pelagic in their habit, places them out of the reach of zoologists in general; and even systematic writers, as in other cases, are often misguided by incorrect figures and descriptions made up probably from scanty or defective data, but which have, nevertheless, been handed down to us with a show of truth. Dr. J. D. Macdonald was impressed with the idea that the figures and descriptions of the species of Cymbulia extant were not reliable; and having had an opportunity of examining some specimens taken in the Indian Ocean, he found that such was really the case. In the natural position of the animal the toe of the hyaline slipper of Cymbulia should be taken as posterior, and the broadly notched heel as anterior. Both animal and shell are reversed in Mr. Adams’s figure of Cymbulia proboscidea, but this is, after all, an error of less importance than that in De Blainville’s figure, in which, although the shell is represented in its proper position, the animal is reversed. A pair of eyes are also given in a position where ears alone would be possible, while there is no more evidence of the existence of eyes in Cymbulia than in any other genus of Pteropods. The notion of a ventral connecting lobe between the fins is a mistake, though these organs are connected above and behind so as to form a broad, con- tinuous plate. Molluscoida. a, Tunicata. Development of Social Ascidians.t—Dr. O. Seeliger finds in the Salpidw, Doliolids, and Anchinia various modifications of a true alternation of generation which, as a developmental cycle, was peculiar to their common stem-form. This form was free-swimming and developed ventral buds, just as now the tailed Doliolum-larva developes the rosette-shaped organ. Primitively the solitary forms may have passed over their capacity to develope generative products to the buds, but very soon the whole of the embryonic material appears to have passed into the buds, which had probably a somewhat complicated structure. The developmental cycle of the Pyrosoma- tide is also to be referred to the budding of the same free-swimming * Proc. Roy. Soc., xxxviii. (1885) pp. 251-3 ( 1 fig.) + Jenaisch. Zeitschr. f. Naturwiss., xviii. (1885) pp. 528-96. 628 SUMMARY OF CURRENT RESEARCHES RELATING TO stem-form ; the generation of the ascidiozooid was, however, inter- calated between the sexually formed solitary form, and the first generation of ventral buds. The cycle of the composite Ascidians had a somewhat different origin, for it sprang from a bud which appeared after the free-swimming stem-form became fixed : the various differences which we now observe only appeared later in its history. It is probable that the pelagic Tunicates and the Ascidie are only connected by a very old larva-like stem-form, which was endowed with the power of multiplying asexually. This stem-form was distinguished from the Appendiculariz by the two arterial passages fusing into a dorsal cavity, which opened to the exterior by an un- paired orifice. In his second chapter the author considers the developmental history of the Ascidians in its relations to the theory of the germinal layers; he concludes that there is a fundamental difference between mesenchym and mesoblast, but that it is purely morphological, and that no genetic conclusions are to be based on its consideration. The mesoblast arises primitively from diverticula of the archenteron ; secondly, from paired mesoblastic mother-cells which lie near the blastopore, and give rise to the mesoblastic sacs which inclose the secondary ceelom; thirdly, in the Tunicata it arises directly from the lateral walls of the archenteron. The formation of the first two kinds of mesoblast is associated with the formation of a new secondary coelom; in the Tunicata, however, there is no secondary ccelom, but the primary, being narrowed not only by the peribranchial space, but also by mesenchymatous connective-tissue-cells, and by an inner mantle of cellulose (in some forms) must be regarded as a true pseudoceel. In the third chapter the genetic relations of the Tunicate phylum are discussed, and the following table is given :— Ascidian trunk Ase. Social. Botryllide / _—— Polyclinide SE renee t {Somes Didemnide Asc. Simpl. / ase Doliolide Pyrosomatidee Anchinia D on OS | Salpide Salpine trunk ZOOLOGY AND BOTANY, MICROSOOPY, ETC. 629 With regard to the homologies of the most important organs of the Tunicata, the following useful table is given :— | Ascidian Appendicu- | larvee lariz Ascidise Branchio-enteric cavity Digestive tract Ciliated arches Ciliated pit Pyrosoma | Doliolide | Salpida Respiratory cavity Digestive tract Ciliated arches Ciliated pit — — Hypophysial — — — gland Brain Sensory | Ganglion (?) Ganglion Ganglion vesicle _— Eye j — Eye — Eye Otolith Otolith — Otolith Otolith a Caudal muscle iaesent material and Nerve-cord fear naaene Eleoblast Eleoblast Notochord derm-eells 2 Atrial Cloacal |Peribranchial|Peribranchial) Cloaca Cloaca ducts vesicle cavity and tube cloaca 2 Spiracula Egestive orifice Egestive Egestive orifice orifice —_- Long. Muscle-cells | Mesenchym-| Scattered mesenchym- muscles muscle muscle-cells Circular aa (?) (?) Circular muscular muscle bands Dr. Seeliger regards the Vertebrata and Tunicata as being two separate branches derived from a common root-form; whatever be the real position of Amphioxus, it cannot, he thinks, be regarded as the bond of connection between the Vertebrata and the Tunicata. The stem-forms may have had close relationships to the segmented worms, and it is even possible that they have several common ances- tors; in such case the nerve-tube of the Tunicate larve might be the homologue of the ventral cord of worms. This view seems to be supported by the discoveries of Hatschek and Kowalevsky ; but it is to be noted that the gastrula of Ascidians is not completely homo- logous with the primitive form common to all the Metozoa, inasmuch as it contains the materials of three segments, derived by a double gemmation from the primitive one. Ser. 2.—Vo1. V. 27 630 SUMMARY OF CURRENT RESEARCHES RELATING TO Genetic Cycle and Germination of Anchinia.*—Dr. J. Barrois re- cognizes in the life-cycle of Anchinia one sexual and two sterile forms ; in all these we may regard the bud as being primitively formed of an ectoderm and endoderm, the latter composed of cells of various kinds ; there soon appears an endodermal nucleus, around which groups of three different kinds of cells become arranged—these are nervous, genital, and “‘ disseminated.” In the proliferous stolon this endoderm forms a solid rod which is at first formed of cells of one kind only, but which very soon becomes differentiated. The endcdermic nucleus, becoming constricted, forms on the ventral surface a pharyngo- stomachal mass ; below is the nervous mass; behind, the genital and disseminated cells ; the first of all of these comes into relation with the outer world by the buccal and anal orifices; the pharyngeal mass divides directly into pharyngeal sac and a pericardium, the endostyle is not formed till later, when it arises as a small swelling of the pharyngeal sac. In the sexual form the nervous mass is continuous posteriorly with a large cord which passes between the cloaca and the esophagus, and terminates in a ganglion which is covered by the genital mass. In one sterile form the coil is formed by the constric- tion of a cylindrical nerve-tube, which extends along the whole length of the embryo, whose anterior part corresponds exactly to the entire nervous mass of the sexual form. It is very probable that this cord corresponds to the large dorsal nerve which, in the Appen- diculariz, connects the cephalic ganglion with the large swelling which is formed at the base of the tube. The anterior swelling is converted into a hypophysis, but it also gives rise to nervous parts of great importance. The muscular layer divides into two bands, and then becomes broken up into six semicircles in just the same way as in Doliolum. The cloaca is the most important part which is formed by the ecto- derm. The genital mass and the disseminated cells form for a long time a mass which is placed posteriorly, and which in the sexual forms gives rise to two genital glands, and in the sterile becomes reduced to a few cells which are found in the neighbourhood of the visceral ganglion. The disseminated cells unite into a ventral plate which possibly represents the eleoblast. Especial attention is to be directed to three points in which the history of their development approximates Anchinia to the Appendicularie : these are— 1. The primitive constitution of the cloaca, the two short tubes being comparable to the respiratory orifices of the Appendicularie. 2. The presence of a nerve-tube along the whole length of the body, and its termination by cephalic and visceral enlargements. 3. The primitive presence of the anal orifice on the surface of the skin. The formation of the cloaca at the expense of the ecto- derm is a rare phenomenon. Anchinia may, in a sense, be regarded as representing a Doliolum with six (instead of eight) bands; the stolon is extremely like that of Doliolum, but differs internally from that of any member of the * Journ. Anat. et Physiol. (Robin), xxi. (1885) pp. 193-267 (4 pls.), ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 631 group of the Thaliacea, for there is but one cord, and that is solid, and is composed of endodermic cells; so far it resembles the cord rather of Ascidiz than of Thaliacea; at the same time this character is to be put against the precocious differentiation of the young bud, the cells of which are derived from the endodermic cord. New Species of Simple Ascidians.*—M. L. Roule describes three new species of simple Ascidians from the shores of Provence. The first is most like the members of the genus Molgula, but is remark- able for having, as has Hugyra, only one genital gland ; the structure of its gill is like that of both the genera just mentioned, so that it appears to be necessary to form for it a sub-generic division of Molgula, to which the name of Eugyriopsis may be applied. There is a new species of Microcosmos, most like M. vulgaris of Heller, but differing by its larger size, the colour of its tunic, and the form of its tentacles. It is called M. sabatierit. The other new Cynthiad is like Cynthia scutellata of Hiller, but is larger, has _ its siphons approximated instead of separated, and differs by other characters, among which is the fact that the genital glands are broken up into small parts, each of which has its own excretory ducts; it is of a fine red colour, and is to be called Cynthia corallina. B. Polyzoa. Structure and Development of Loxosoma.{—Mr. S. F. Harmer observed at Naples five species of Loxosoma, one of which, L. lepto- clini, is new ; it was not uncommon on the compound Ascidian Lepto- clinum maculosum. The term ventral is, in opposition to Caldwell, applied to the line of the body between the mouth and anus; the dorsal region is drawn out into a stalk, on which the calyx or body of the animal is carried; when, in his descriptions, the author speaks of a transverse section, he means one which passes in the plane of the stalk through the right and left side; a horizontal plane is one which is at right angles to the long axis. In Lozosoma the buds become free as soon as they reach maturity, and this genus ditfers therefore from all other Polyzoa in never forming colonies. The cells of the ectoderm were best studied by a special use of nitrate of silver; the tissues are washed “in a solution of a neutral salt (KNO,), which gives no precipitate with nitrate of silver, the solution having the same specific gravity as sea-water” ; there was thus no precipitate of silver chloride; these cells were found to be large and polygonal, or sense-cells, bearing one or more fine, stiff, tactile hairs which project into the water, and gland-cells ; the last differ in character in different species. The foot-gland is either retained by the adult or found only in the bud; in some species it has wing-like lateral outgrowths. It seems to be composed of two distinct portions—the gland, which consists of a small number of granular nucleated cells arranged round a central lumen, and a “duct,” which is really an open groove. * Comptes Rendus, c, (1885) pp. 1015-7. + Quart. Journ. Mier. Sci., xxv. (1885) pp. 261-338 ae ag ft. 632 SUMMARY OF CURRENT RESEARCHES RELATING TO Mr. Harmer considers that the true ganglion has been mistaken for part of the generative apparatus, and describes it as being dumb- bell-shaped and lying transversely across the intestine, as consisting mesially of a fibrous commissural portion and of two lateral ganglia, and as being altogether devoid of any central duct. The peripheral neryous system is best examined in living specimens, and the trans- parent L. crassicauda is a most favourable species for investigation ; it is described in detail. There is no striking objection to the idea that the posterior sense-organs are homologous with the “ osphradia” of Mollusca, but it is more probable that they are merely specialized sense-cells. After describing briefly the alimentary and muscular systems, the author comes to the excretory organs, our knowledge of which is exceedingly incomplete ; as described by Mr. Harmer they are seen to differ markedly from those of the Brachiopoda, but to have the closest similarity to the head-kidney of many Trochospheres. Dr. Meyer’s as yet unpublished drawings of the head-kidneys of various Annelid larve present a striking resemblance to Loxosoma in the number of the excretory cells, in the relative size of the lumen in different parts of the organ, and in the mode of termination in a flame-cell, as well as in other points. The generative organs are next described, and are stated to be ‘ idiodinic.” A careful account is given of the history of development, with numerous references to the illustrative figures, which must be seen if the account is to be fully understood; this much, however, may be here stated. The ova may be small, and be supplied with nutriment from the glandular epithelium of the brood-pouch, or large, when they take up the surrounding cells which play the part of a vitel- larium ; the blastopore appears to form the permanent anus, and a stomodceum is developed anteriorly ; the greater part of the mesoblast arises from two cells which are placed at the sides of the blastopore. The so-called dorsal organ is of epiblastic and not of hypoblastic origin, and is not a budding structure, but the supra-cesophageal ganglion. Between the mouth and anus two epiblastic invaginations appear, and, later on, fuse medianly; they form the deeper part of the vestibule, and, by the thickening of their floor, give rise to the subcesophageal ganglia; coming into contact with the “wings of the crescent-shaped brain,” they establish a complete circumcesophageal nerve-ring. The Entoproctous Polyzoa, both larval and adult, are true Trochospheres, with a ventral flexure of the alimentary canal, no true body-cavity, and a pair of head-kidneys. The metamorphosis of the Ectoprocta is a process of budding; the Entoprocta have certain affinities with Actinotrocha, while the affinity of the Polyzoa to the Brachiopoda is more doubtful than to Phoronis. The nearest allies of the Entoproctous Polyzoa are the Trochosphere larve of Molluses and Cheetopods, and the adult Rotifera; the Entoprocta are the most archaic of the Polyzoa, but their relations to the rest are, as yet, obscure. : ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 633 Australian Bryozoa.*—In the new decade, which completes the first volume of the ‘ Prodromus of the Zoology of Victoria, Professor P. H. MacGillivray continues his valuable contributions on the Polyzoa of Victoria. The present number deals with Retepora, a genus better represented in the southern hemisphere than in the northern. Twelve species are described and three varieties of the well-known Retepora monilifera MacG., and besides the figures of these, one plate is devoted to drawings of the opercula, which in Professor MacGillivray’s hands have proved of great value for specific determination. The preface is dated 1883, and the paper having been written nearly two years, there is consequently some overlapping with this and Mr. Busk’s work on the ‘ Challenger’ Polyzoa. Y. Brachiopoda. Anatomy of Crania.t—In continuation of a previous paper,t{ M. Joubin describes further points in the anatomy of Crania. The shell is formed of extremely fine calcareous fibres; it is traversed by perforations spreading out, in the upper valve, in arborescent ramifications, of which the final branches are attenuated filaments terminating on the external surface. In the ventral valve the perforations are only at the points where there are no muscular insertions. The mantle is composed of two portions—an interior and an exterior. There are three principal pairs of muscles, two of which are adductors; the less important muscles sustain the arms and perform other functions. The arms are not supported by any calca- reous loop. Respiration is not effected by any special organs, and there is no circulatory system. The nervous system, as in Lingula, is very poorly developed. Arthropoda. a, Insecta. Eye and Optic Tract of Insects.s—Dr. 8. J. Hickson, in the first portion of his paper, gives a detailed account of the eye and optic tract of Musca vomitoria, and afterwards discusses and attempts to clear up the differences between his results and those of other investigators. The account of the eye of Musca is only intelligible when studied with the aid of the accompanying illustrations; in it the following new terms are used: the oplicon is the ganglionic swelling which is separated from the cerebral by a narrow constriction, which is, as Beyer has shown, the homologue of the optic nerve of other arthro- pods: the second swelling, which is separated from the opticon by a tract of fine nerve-fibrils, is called the epi-opticun ; while the third, or peri-opticon, is separated by a bundle of long optic nerve-fibrils. The term neurospongium is given to the fine meshwork of minute * Prodromus of the Zool. of Victoria, decade x., 1885. + Comptes Rendus, ec. (1885) pp. 464-6. t Ibid., xcix. (1884) pp. 985-7. See this Journal, ante, pp. 233-4, § Quart. Journ, Mier. Sci., xxv. (1885) pp. 215-51 (3 pls.). 634 SUMMARY OF CURRENT RESEARCHES RELATING TO fibrils, which are similar to those described by Gerlach in the mammalian brain and spinal cord. ; The comparative anatomy of these parts is thus summed up: “In the young Periplaneta the optic nerve-fibrils which leave the peri- opticon pass without decussating, to the ommateum (eye proper); in the adult Periplaneta there is a partial decussation, in Nepa there is no decussation, but the anastomosis is complicated by the presence of looped and transverse anastomoses. In Musca, the fibrils are split up into little cylindrical blocks of neurospongium, which I have called the elements of the peri-opticon ; in bees, wasps, and many Lepidoptera, the elements of the peri-opticon are long, slender, and close-set; in Aischna they have partially fused with one another ; and in Bombyx, Hristalis, and the Crustacea they have completely fused to form a complete and continuous ganglion, similar in every way to the opticon and epi-opticon. Three series of pigment-cells are very constant throughout the Hexapoda; there are (1) a series of pigment-cells which insheath the cone and prevent extraneous rays of light from escaping; they may be called the cone pigment-cells. (2) In the outer region of the rhabdom there is a series of external pigment-cells, which have long processes passing between the retinule and elsewhere. (3) The name of internal pigment-cells is given to the series which usually rests upon the basilar membrane. This last varies considerably in thickness. In the historical and critical portion of his paper, Dr. Hickson deals only with what has been published since 1879, the date of Grenacher’s great work. With regard to the view of Mr. Lowne that the retinule are not the nerve-end-cells at all, and that the true retina is situated behind the basilar membrane, the author remarks that not only does anatomy teach us that the optic nerve-fibrils end in the retinule, but morphology teaches us that they are homologous with the nerve-end-cells of other animals, while the few physiological experiments yet made show that they are eminently adapted for light- perceiving purposes. These considerations are clenched by Leydig’s discovery of a true retina-purple in the retinula. The view of Ciaccio, Berger, and others, that the layer of retinulz and rhabdoms cannot be considered as the equivalent of the retina of other animals is accepted ; it is only part of the retina, or that which bears the nerve-end-cells, and corresponds functionally to the layer of rods and cones in the eyes of Vertebrates. We cannot compare layer for layer the different strata of eyes in different animals; all we can say is that in all animals with highly organized eyes, there are certain complicated nervous structures, between the nerve-end-cells and the brain, which have probably the function of elaborating and combining the sensations received by the end-cells. The author thinks that all the nerve-structure lying between the crystalline cone-layer and the optic nerve is analogous with the retina of other animals ; in other words, the retina of insects consists of the retinule, peri-opticon, epi-opticon, opticon, and all the intermediate nerve-tracts. ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 635 The best method of making sections through the eye of Musca vomitoria is to expose it to the fumes of 1 per cent. osmic acid solution for 40 minutes, then to wash for a few minutes in 60 per cent. spirit, and finally to harden in absolute alcohol. When the hardness of the chitin prevents the use of the automatic microtome, a Jung’s microtome with the razor set so as to give a long sweep at each stroke may be used. The best method of depigmenting the eye, is to expose the sections to the action of nitrous fumes ; for teasing the best solution is chloral hydrate. Tracks of Insects resembling the Impressions of Plants.*—M. R. Zeiller describes the burrows made by Gryllotalpa vulgaris in the clay soil at the bottom of a little pool of water, that was sometimes nearly dry. These tracks, owing to their arrangement and the marks made on their surface by the insect in traversing its burrow, bear a striking resemblance to the impressions of certain fossil plants. They suggest a comparison with Phymatoderma liasicum and present at the same time an analogy to certain impressions of conifers belonging to the genus Brachyphyllum, notably B. Desnoycrsi Brgt. from the oolite. Morphology of the Lepidoptera.;—Dr. A. Walter finds that the views of Savigny as to the morphology of the gnathites of the Lepi- doptera must now be definitely given up; the parts which he re- arded as mandibles are the projecting angles of a labrum, and the plate which he regarded as the labrum is an epipharynx. True and functional mandibles in the form of toothed appendages are found only in some of the lower Micropteryginez, such as Aruncella, and Anderschella. True mandibles without denticulations are to be found in the higher Micropterygine, such as Micropteryx, Purpurella, and Semipurpurella. Various stages of reduction are to be observed in various forms, and it is possible that remnants of mandibles are to be made out in all the’ Microlepidoptera. There can be no doubt that the lower Micropteryginz exhibit the most primitive form of gnathites found among the Lepidoptera. There are two maxillary palps, the outer of which forms the most primitive rudiments of a proboscis, while the inner forms a groove- like horny plate which affords a lateral support for the labium. The Lepidopterous proboscis is to be regarded as being primitively - derived from the outer palp of the maxilla; in the higher forms the inner palps are reduced. In the lower Micropteryginz the labium has the free palps and typical ligula of lower insects, the latter being formed by the fusion of the inner palps into a short tubule, which is open externally; a short hypopharynx is to be detected on the soft inner or hinder wall of this ligula. In the higher Micropteryginz the mandibles lose their teeth, and the maxillw the inner palp; the halves of the proboscis are applied to * Bull. Soc. Geol. France, xii. p. 676. See transl. by Prof. J. F. James in Journ. Cincinnati Soc. Nat. Hist., viii. (1885) pp. 49-52. + Jenaisch. Zeitschr. f. Naturwiss., xviii. (1885) pp. 751-807 (2 pls.). 636 SUMMARY OF CURRENT RESEARCHES RELATING TO one another to form the typical sucking tube, and the short organ is already capable of being rolled up; the labium is elongated, has no free outer palps, and the hypopharynx is still discernible at its base. The author inclines to the view that the nearest relatives of the Lepidoptera are, among other insects, the Hymenoptera. Number of Abdominal Segments in Lepidopterous Larve.*— Dr. A. 8. Packard finds that no caterpillars known to him have less than ten abdominal segments. The ninth segment, however, is liable to be much reduced in size and to more or less coalesce with the tenth or anal segment. The ninth segment is most rudimentary in the Sphinges. In the larval butterflies it is rather more distinct; whilst the tenth segment is, as in all caterpillars, represented by the supra-anal plate and anal legs. In the Algerians, Zigzenide, and Bombycide (the latter especially), the ninth segment is very distinct. In Halesidota the ninth segment is quite long, forming an entire segment. In Datana it is longer than the supra-anal plate. In Limacodes scapula and P. pithecium there are no traces of legs; the number of abdominal segments appears to be ten. In the Noctuide the ninth segment is distinct. In the Geometers it is distinct above, but below is merged into the infra-anal plate. In the Pyralid caterpillars, as well as the Tortricids and Tineids, the ninth segment is longer and more distinct than in the higher families. The Bombycide seem to be the oldest, most generalized group of Lepidoptera, and it is a question whether the Pyralids, Tortricids, and Tineids are not degenerate forms which have descended from the Noctuide and ultimately from the Bombycide; there are indica- tions that the Noctuide have descended from the Geometers. At any rate the primitive caterpillar had ten pairs of abdominal legs. The saw-fly larvee (Lophyrus) have eight pairs of abdominal legs, while the embryo honey-bee has ten pairs of temporary abdominal appendages. Structure of the Halteres of Diptera.t—Mr. A. B. Lee contributes some further details to our knowledge of these organs, which were believed by Leydig to be auditory in function. It appears that there are two distinct organs contained in each of these structures: one an auditory organ, the other an organ of problematical function, which may be olfactory; the structural details, which are briefly mentioned, will no doubt be published by the author in an illustrated form. Movement of Flies on Smooth Surfaces.;—Dr. J. E. Rombouts supports, as against the observations of Dewitz, his former conclusions on this subject already noticed in this Journal.§ It will be remem- bered that it was then established that flies attached themselves to smooth surfaces by the help of a liquid secretion from the feet; this liquid, however, is not sticky, but the attachment is brought about by capillary attraction; this conclusion is strengthened by another * Amer. Natural., xix. (1885) pp. 307-8. + Arch. Sci. Phys. et Nat., xiii. (1885) pp. 1-3. t Zool. Anzeig., vii. (1884) pp. 619-23. § See this Journal, iy. (1884) p. 787. ZOOLOGY AND BOTANY, MICROSCOPY,- ETC. 637 experiment described in the paper before us. Several flies are con- fined on to a glass plate by strips of paper, and the liquid that accu- mulates is sufficient to be perceptible to the naked eye; by the help of experiments with glass balls, detailed in the former paper, it was ascertained that the adhesive power of the liquid was less than that of water, and about equal to olive oil; hence capillary attraction is obviously the only force which could bring about the required result. Circulation in Ephemera Larve.*—M. N. Creutzburg finds that in the larve of certain Ephemerida—contrary to the statements of Verloren—the vascular ampulla which supplies the caudal sete is in communication with the dorsal vessel, and not with the body-cavity ; this portion of the vascular system is, however, separated from the dorsal vessel by a pair of valves. Macrotoma plumbea.t—Dr. A. Sommer gives a detailed account of this Podurid, a member of a group the anatomy of which has long required revision. Asin most insects the integument consists of three layers—the cuticle is transparent, thin, and flexible; the subjacent matrix varies considerably in thickness in different parts of the body, and itscells appear to be devoid of distinct boundaries ; the basal mem- brane is structureless. The excretory organs are rounded in form and extend through the whole of the abdomen ; the concretions are dirty white with reflected, and pale green with transparent ight; they vary somewhat consider- ably in form and size, but generally exhibit a distinct concentric striation, like starch-granules; they are insoluble in water and alcohol, but are, when fresh, dissolved by acetic acid. The simplest muscles consist of a single muscular fibre; the muscles are not inserted directly but by a tendon formed by the cuticle; they have a finely granular perimysium, in which a number of small round nuclei are imbedded ; their substance exhibits transverse striation and appears to be well adapted for the study of this curious phenomenon. The most interesting appendage of the body is the ventral tube ; the numerous cells found in it are elongated oviform in shape, are limited externally by a distinct membrane, and have a very finely granulated protoplasm. The cuticular tubules formed by the cells open to the exterior by rounded orifices, and it is clear that we have here to do with unicellular glands; their close connection with the muscles of the ventral tube, leads us to suppose that when the latter is put into function there is an evagination of the connected pouches, owing to the pressure of the secretion which flows out from the gland- cells. If the ventral tube really serves as an organ of attachment we may suppose that the secretion is a material which acts as an adhesive agent. P After describing in detail the structure of the digestive tract, the author passes to the dorsal vessel and the blood ; the former is a tube which extends from the eighth abdominal segment into the thorax, and passes between the dorsal longitudinal muscles ; it is continued * Zool. Anzeig., viil. (1885) pp. 246-5. + Zeitechr. f. Wiss. Zool., xli. (1885) pp. 683-718 (2 pls.). 638 SUMMARY OF CURRENT RESEARCHES RELATING TO forwards into an aorta; posteriorly it is attached by fine fibrils to the tergal region of the body; no posterior orifice was to be detected ; there are five pairs of ostia, and five pairs of alary muscles. The cardiac tube consists of a plexiform nucleated tissue, broken through at various points ; then follows a well-developed muscular layer which forms the chief part of the tube, and internally to it there is a delicate, hyaline, and structureless layer. The bloodis of a yellowish-red colour, and contains a fairly large number of blood-corpuscles. They have a clear, homogeneous ground-substance with dark refractive granules, and no investing membrane; they exhibit amceboid movements. The author was unable to find any traces of a visceral nervous system or of nervi transversi; the absence of the latter may be asso- ciated with that of a tracheal system. Sensory sete are to be observed on the legs, palps, and labium and labrum. The generative organs are carefully described, and there are some remarks on ecdysis; the author found that Gregarines, Cysticerci, and a number of Nematoid worms lived parasitically in Macrotoma. B. Myriopoda. Latzel’s Myriopods of Austria.*—The first volume of Dr. R. Latzel’s work dealt with the Chilopoda, while the second includes the Symphyla, Pauropoda, and Diplopoda. Nine years of close attention to the study of the Myriopods have enabled Dr. Latzel not merely to complete a monograph of the species inhabiting his native country, but to complete it in such a manner that he has written a book which must be useful to the student of the Myriopoda of any country. Minute descriptions of some 170 species are given, and also tables which make it a matter of ease to determine the genus of any Myriopod. : Where possible, full descriptions are given of the young stages of each species, and the results of all recent researches into the minute anatomy of the Myriopods are embodied. Embryology, indeed, has not received a very large share of attention, but references are given to all writings on the subject. Dr. Latzel differs from some American authorities in looking on Scolopendrella as a true Myriopod, and places its order Symphyla as intermediate between the Chilopoda and the Pauropoda. Dr. Latzel agrees with Menge in considering those organs which Ryder has described as trachee in Scolopendrella, as being merely chitinous supports for muscle-attachment. These are the same organs which Wood-Mason considers to be of the nature of segmental organs. Dr. Latzel looks on Peripatus as forming an order equivalent to other orders, the Chilopoda, the Symphyla, and the Diplopoda. A most useful bibliography, brought down to the date of publica- tion, is comprised in the work. f * Latzel, K., ‘Die Myriopoden der Oesterreichisch-Ungarischen Monarchie,’ 2te Halfte, xii. and 413 pp. and 16 pls., 8vo., Vienna, 1884. + See Nature, xxxi. (1885) p. 526, ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 639 §. Arachnida. New Hypothesis as tothe Relationship of the Lung-book of Scorpio to the Gill-book of Limulus.*—Prof. E. Ray Lankester with- draws his suggestion that by the enlargement of the hollow stigmata connected with the thoracobranchial muscles of an ancestral scorpion the branchigerous appendage might come to lie in the pit of the tendon of the muscle, and that eventually the hollow might inclose it, and replaces it by a more simple explanation. He was led to give up his earlier view by finding that the veno-pericardiac muscle attached to the apex of each lung-sinus in Scorpio had no relation to the thoraco-branchial muscles of Limulus, but was represented in it by exactly similar veno-pericardiac muscles, In Limulus, as in Scorpio, there is on each side of the sternal surface a great blood-sinus in free communication with the lamelli- gerous organs. If we suppose the mesosomatic appendages in the Scorpion branch of the family to grow relatively smaller and smaller, and to be purely respiratory in function, and to be aerial rather than aquatic ; we have only further to imagine the four hinder pairs to have taken on in the embryonic condition a very common trick of growth, viz. an inward growth of invagination, to have the exact condition of the modern scorpion’s lung-book. The best known example of such inward growth is seen in the hydatid-stage of Tcenia solium, and the introversion is probably due to external pressure. Now, it is to be borne in mind that in the modern scorpion development goes on within the ovary; the pressure of the ovarian tunic must be considerable, and is at any rate a possible cause of the invagination. Coxal Glands of Mygale.t—Dr. P. Pelsencer describes the coxal glands in a large South American Mygale (Theraphosa). The two glands, which are quite separate, are placed on each side of the cepha- lothorax, at the side of the entosternite (enthodére of Dugés) between the lower plate and the upward prolongations of it, to which latter they are intimately related in position, size, and form. As surmised by Prof. Lankester, this gland is not a simple ovoid glandular body, as in Scorpio, but is furnished with lobes correspond- ing to the cox of the cephalothoracic appendages, as in Limulus. In addit:on to these four coxal prolongations, the gland has two internal projections near its middle third, corresponding to two slight excava- tions of the entosternite, between its lower plate and its upper pro- longations. The colour of the gland is uniform, a brownish-yellow, not unlike that of the stomach and its lateral diverticula. Its appearance is coarsely cellular, showing distinctly the groups of cells of which it is made up. No efferent duct, either passing to the exterior, or to any internal organ, was seen. The gland in Mygale, like that of the adult Limulus and Scorpio, is therefore a closed gland. * (Quart. Journ. Micr. Sci., xxv. (1885) pp. 339-42, + Proc. Zool. Soc, Lond., 1885, pp. 3-6 (1 pl.). 640 SUMMARY OF CURRENT RESEARCHES RELATING TO Anatomy of Spiders.*—Dr. F. Dahl reviews certain statements of Bertkau with respect to the anatomy of spiders. This observer has mentioned that salivary glands have not been figured; Dahl calls attention to the fact that he has himself observed and figured them in Epeira cornuta, in the males of which species they are far better developed than in the females; this may be accounted for by the fact that the mature male takes little or no nourishment while the female after depositing her eggs spins a web and catches and devours insects. The paper contains rectifications of a few other statements made by Bertkau which are believed by Dahl to be erroneous. Hibernation and Winter Habits of Spiders.j—The Rev. Dr. McCook describes some observations on this subject. In the case of Theridion tepedariorum it would seem that the hibernation is not accompanied with a great degree of torpidity ; that the spiders pre- serve their activity and spinning habit while exposed to cold ranging from freezing point to zero (Fahr.); that after long and severe exposure, the recovery of complete activity when they are brought into a warm temperature is very rapid, almost immediate ; and that on the return of spring, even after a prolonged and severe winter, they at once resume their habits. In all the specimens experimented on the abdomens were full, indicating perfect health. Other spiders hung upon their webs with shrivelled abdomens, quite dead; but the author could not determine that they perished by the cold. There appeared to be no growth during hibernation. The same facts hold good as to the winter habits of orb-weayers. The young survive in the cocoons provided by maternal instinct. But early in the spring many adults of both sexes are found, who have also safely weathered the cold months. Many specimens of Hpeira vulgaris shelter within a thick tubular or arched screen, open at both ends, which is bent in the angles of woodwork, or beneath an irregular rectangular silken patch stretched across a corner. Many others burrow behind cocoons, and are quite covered up by the thick flossy fibre of which these are composed. Examples of EH. strix were found blanketed in precisely the same way during the winter months. e. Crustacea. Urinary Organs of Amphipoda,t—Mr. W. Baldwin Spencer finds that little is stated in the text-books as to the presence in certain Crustacea of small but well-defined appendages which open into the posterior part of the alimentary canal; the best method of examining these tubes is to cut sections through the whole of the body, when the course that they take and their relation to the neighbouring organs can be easily made out. The author has carefully investigated the tubes of Talitrus locusta ; the walls were found to be cellular in nature, and within these were * Zool. Anzeig., viii. (1885) pp. 241-3. + Proc. Acad. Nat. Sci. Philad., 1885, pp. 102-4. t Quart. Journ. Micr. Sci., xxv. (1885) pp. 183-92 (1 pl.). ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 641 very definite concretions, but in no case could any sign of a concretion be detected within or between the cells. The presence of these bodies, which are extremely minute, may be associated with the pro- cess of ecdysis ; phosphoric acid was found in them, whereas Nibeski found carbonate of lime in Orchestia cavimana. We must wait for a knowledge of their developmental history before we can say definitely whether or no they are homologous with the Malpighian tubes of the Tracheata. Development of the Egg and Formation of the Primitive Layers in Cuma Rathkii*—Dr. H. Blanc’s researches on this subject, of which mention has already been made,t} are now published in eatenso. Development of Cyclops.t{—The development of Cyclops has been studied by a great many authors, but little is known concerning the origin of the body-cavity and most of the internal organs. M. F. Urbanovies has addressed himself to solve these questions, and has arrived at the following results :— A dorsal organ is formed as in the Isopoda, which is composed of a single layer of cylindrical cells. The body-cavity is formed by paired excavations of a mesoblast band; each pair of cavities corre- sponds to a segment and the dissepiments dividing them from each other only disappear very late; the dorsal and ventral mesenteries persist throughout life; the dorsal mesentery contains a space which is a remnant of the blastoccel and plays an important part in the circulation in the absence of a heart. It is obvious that these facts indicate a far closer similarity with the Tracheata and Annelida than is admitted by Balfour in his ‘ Comparative Embryology.’ Anatomy of the Cirripedia.s—Dr. P. P. C. Hoek has issued a supplementary memoir on the Cirripedes of the “ Challenger,” which, as we have already stated, || he promised to prepare. The complementary male of Scalpellum has never been described since the time of Darwin’s first notice of it ; Dr. Hoek found this male in 19 out of 41 new species, and always at about the same place, that is, a little above the musculus adductor scutorum; in 18 of the species the testes were mature ; in thirteen cases the male was more degenerated than in S. vulgare. The 24 forms whose males are now known have either a special capitulum and a stalk, as in three species; or there is no division of the body, but there are rudi- mentary shell-valves, as in eight species; or there is no division of the body and no valves, as in thirteen species. The first of these are littoral in habitat; the second live at depths of at least 700 fathoms ; and the third (with three exceptions) live at depths greater than 1000 fathoms. Two of the three exceptions belong to the arctic fauna, where, as is now well known, deep-sea forms of other latitudes are found living at lesser depths. * Rec. Zool. Suisse, ii. (1885) pp. 253-75 (1 pl.). ¢ See this Journal, ante, p. 238. t Zool. Anzeig., vii. (1884) pp. 615-9. § Tijdschr. Nederl. Dierk. Vereen., vi. (1882-5) pp. 64-142 (6 pls.). \| See this Journal, iv, (1884) p. 891. 642 SUMMARY OF CURRENT RESEARCHES RELATING TO After describing the Cypris-larval forms, the author passes to the male of Scalpellum regium, where the microscopic body consists of an elongated sac, closed on all sides; there is only a very small cleft between the two scuta; the tentacles are the only appendages which still show their primitive form; the feet are functionless and straight, and the gnathites have disappeared. In young males the cement-apparatus is well developed, but in mature forms it is not so distinct; the enteron is aborted and functionless, and no signs of circulatory or respiratory organs are to be detected. The nervous system consists of arather small cerebral ganglion, a comparatively feeble esophageal ring, and a large ventral ganglion; the peripheral nerves are not well developed, and there do not seem to be any eyes, or other sensory organs. The generative system is the only one which is well developed, and of it only the male organs; even these are much more concentrated than in ordinary hermaphrodite Cirripeds; there is only one testis, which has the form of a compressed gland, and the seminal vesicle is single, instead of being double. In all these points the small males of other deep-sea species agree with S. regium. In the genus Scalpellum Dr. Hoek distinguishes three stages of sexual differentiation. J. True hermaphrodite species, all members of which have both female and male genital products; they are probably self-fecun- dating. Ex. S. balanoides. II. Species with large hermaphrodite members, and small males ; the latter may (S. villosum), or may not (S. vulgare) have a stalk, a mouth and a stomach. III. Species with the sexes separate; the females large, the males small, and, probably, short-lived; e. g. S. regium. The Cirripedes are rich in organs of an unknown, or at least problematical function, and those first discussed are the “‘ Segmental organs”; these were regarded by Darwin as being sensory in func- tion, but Hoek ascribes to them the duty of excretory organs: he is supported in this view by the presence of muscular fibres connected with the numerous lacune, similar to those seen by Grobben in the region of the antennary gland of the Decapoda. The cement-glands are next discussed ; and then the “ true ovaries ” of Darwin, which Hoek looks upon as having a function in relation to the digestive tract, though it is clear that they are not salivary glands; they probably approximate to pancreatic or hepatic cells. The eye of a Cirriped was first seen by Leidy, who described the two small lateral eyes of Balanus ; Dr. Hoek describes the eye of Lepas, and points out that there are certain points of resemblance to what Leydig has described in insects. The paper concludes with an account of the female generative organs; the apparatus which is found at the end of the oviduct possibly represents a second segmental organ; the sac is regarded as representing the infundibulum of the primitive segmental organ, and it is no objection against this homology that it serves for the ZOOLOGY AND BOTANY, MICROSCOPY, ETO. 643 evacuation of genital products, or that its cells, in place of being excretory, have the function of providing a cementing mass for the ova. Embryology of Balanus.*—According to M. N. Nassonow the ovum divides vertically into two sub-equal segments, of which the anterior forms the later ectoderm, whilst from the posterior and granular segment is exclusively derived entoderm and mesoderm. An amphigastrula is formed, the blastopore closes, and the entoderm divides, beginning ventrally, to form a symmetrical plate of mesoderm. The chief part of the mesoderm goes to form the three pairs of ventral projections which are the rudiments of the limbs of the nauplius, and does not take any share in the formation of the muscular system. The anus is formed at the spot where the blastopore originally occurred. Vermes. Oogenesis and Spermatogenesis in Branchiobdella.tj—Dr. W. Voigt finds that the reproductive organs of Branchiobdella are formed on the type of the Oligocheta; the two ovaries are in the eighth segment, and, even in living forms, are distinguishable by their whitish coloration; each consists of a compact mass of cells attached to the septum by a muscular stalk; the testes are found in the sixth segment, but their stalk of attachment is not provided with muscular tissue. During its development the cells of the ovary exhibit great powers of multiplication; the ova derive their nourishment from a pair of vascular loops which extend from the dorsal to the ventral trunk. in treating of spermatogenesis, the author makes use of the terminology of La Valette St. George, who recognizes five stages—those of the sexual cells, spermatogonia, spermatocytes, spermatids, and spermatosomata. What Mr. Blomfield called the blastophor is here called the cytophor. The sexual cells give rise to spermatogonia in the ordinary way, and by indirect division of the latter to spermato- germs. The author has been able to observe in both testes and ovaries degenerated cells, the cause of which is often due to the taking in of a large quantity of fluid. New Parasitic Leech.}—Dr. J. Leidy describes a new parasitic leech infesting the mouth of the so-called Colorado pike (Ptychochilus lucivs). From its conspicuous gland-like organs and habit, Dr. Leidy proposes to name it Adenobdella oricola. Archenchytreus Mobii.§—The structure of this new species is briefly described by M. W. Michaelsen. The worm has about sixty sete-bearing segments, and the sete are aggregated in bundles of three to five. The testes are developed on the mesentery, separating segments 10 and 11, the ovaries on the succeeding mesentery. The * Zool. Anzeig., viii. (1885) pp. 193-5. ¢ Arbeit. Zool. Zoot. Inst. Wirzburg, vii. (1885) pp. 300-68 (3 pls.). $ Science, v. (1885) pp. 434-5 (1 fig.). § Zool. Anzeig., viii. (1885) pp. 237-9. 644 SUMMARY OF CURRENT RESEARCHES RELATING TO vasa deferentia open on to segment 12; the oviducts on to segment 13. The spermathece are in segments 4 and 5; each is furnished with a pair of diverticula. During sexual maturity the spermathece com- municate with the lumen of the intestine; in the neighbourhood of the spermathecal apertures are peculiar aggregations of cells con- nected with nerves and apparently sensory ; the buccal cavity contains a projecting process of the mucous membrane, similar to what has been described by Vejdovsky in Anacheta bohemica ; it appears, how- ever not to be a gustatory organ but a sucker. Nervous System of Polychetous Annelids.*—M. G. Pruvot finds that the nervous system of Annelids is always, even when it is more deeply situated, continuous with the hypodermis by at least part of the surface of its ganglia; it is always composed of a cortical sub- stance which encloses nerve-cells in a stroma of anastomosing fibres, and of a medullary substance which consists of peripheral nerve-cells in a central dotted substance; this last is to be regarded as the true centre, and all the nerves really arise from it. The medullary sub- stance forms four longitudinal trunks in the ventral chain, and of these the two external do not communicate directly with one another, but only with the two internal. The ganglia which are sometimes found on the cesophageal con- nectives are only the first ventral ganglia which have ascended, and have lost their transverse commissure. ‘The stomatogastric has some- times a double (cerebral and sub-cesophageal), sometimes only sub- cesophageal or a cerebral origin; when well developed it may, as in the Euniceide, reveal the characters of the general nervous system, by forming a small ventral ganglionic chain, and an cesophageal collar ; or, as in the Nepthydez and Phyllodoceide its elongated roots may terminate in a small peri-proboscideal ring formed by a large number of small similar ganglia. In each segment the pedal nerve arises from the two ventral cords by two roots; it follows the integument for the whole of its course, and divides into two branches, which again divide into two trunks for the setigerous bulb and the pedal cirrus. AIl the appendages of the somites are to be regarded as more or less modified feet; the author points out the differences which are to be found in different appendages of various parts of the antenne, especially with regard to their nervous supply. As the investigation of this necessitates the destruc- tion of the animal, he points out that palpi may always be dis- tinguished from antenne by their insertion in the ventral surface of the body, and by their form or size. Larval forms of Spirorbis borealis.;—Mr. J. W. Fewkes gives a detailed description of the larval forms of Spirorbis borealis Dandin. The ova are in bead-like strings, composed of from one to four rows with ten to fifteen or more eggs each. The later stages in the segmentation of the egg resemble those of other chaetopod eggs: the younger stages were not found. * Arch. Zool. Exper. et Gén., iii. (1885) pp. 211-336 (6 pls.). + Amer. Natural., xix. (1885) pp. 247-57 (2 pls.). ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 645 The larve described differ in some particulars from those of S. spirillum Gould, described by A. Agassiz, and even more widely from the young of S. spirillum, described by Pagenstecher; but are considered by the author to be of the same species as that described as S. spirillum by A. A. Gould. On escaping from the egg capsule, the young larva swims about in the water with considerable activity, and is often captured with the dip-net in surface fishing. The free larva often does not im- mediately settle to the bottom prior to the secretion of the case in which it lives, but passes through the preliminary stages while floating on the water, until the increasing specific gravity of its body sinks it. The case or shell is not at first coiled, but horn-shaped. The most prominent structure about the body of the larva at this stage is an oblong mass of cells of brick-red colour seen through the transparent walls of the shell, but of their probable function nothing is said. Skin and Nervous System of Priapulus and Halicryptus.*—Dr. R. Scharff finds in the skin of these Gephyrea a third layer, or one additional to the cuticle and hypodermis described by Ehlers; this is extremely thin, and consists of connective tissue ; it is well developed in Sipunculus nudus, where it is the seat of secreting glands and of accumulations of pigment; the cuticle lines the interior of the cesophagus; around the anus of P. caudatus the hypodermis is curiously modified, its cells being much elongated, and at the same time expanded so as to form a compact mass, to which the author is inclined to ascribe an excretory function. The proboscis of both Priapulus and Halicryptus is provided with small dermal projections arranged in numerous longitudinal rows ; on the body there are circular rows. In Priapulus caudatus the spikes have the form of small trugcated cones, just visible to the naked eye; through the circular opening at their top there project a number of delicate hairs; the spikes appear to be retractile. The most striking analogy between these and sensory organs in other animals is to be found by comparing them with the organs of the lateral line in fishes. As to the nervous system, the author’s results agree generally with those of Horst; in both genera examined the system lies entirely in the-ectoderm ; the position of the cord is marked externally by a shallow groove on the ventral surface ; the apparent swellings seen at regular distances along the nerve-cord seem to be due to the power- ful contractions of the annular muscles, by means of which the cord is found to bulge out in the intervening spaces. Dr. Scharff differs from all his predecessors in stating that the nervous system lies not immediately under the hypodermis, but within it. The ganglionic are merely modified hypodermic cells. Unlike Saenger, he was unable to detect lateral nerves given off from the main trunk and surrounding the body as in Sipunculus nudus; though thinking it rash to deny the presence of peripheral nerves, the author inclines to the view that the whole of the hypodermis acts as a kind of nervous * Quart. Journ. Micr. Sci., xxy. (1885) pp. 193-213 (1 pl.). Ser. 2.—Vou. V. ZU 646 SUMMARY OF CURRENT RESEARCHES RELATING TO layer ; at the same time he recognises that the well-developed sensory organs and the organisation of the nerve-cord hardly support this idea. Development of Spherularia bombi.*—M. L. Joliet has a note on Schneider’s account of his recent observations on the development of this parasite. Female Bombi, infested by Spherularia, do not prosper, but die at the beginning of June, when the embryos of the parasite are set at liberty. These require a damp, well-aerated, and non-putrefying situation; «fter two successive moults they acquire their sexual characters. During the free stage they take no food, and do not copulate. If they succeed in introducing themselves into the intestine of a larval Bonbus they continue their development. New Nematoid from Merlangus.j—M. L. Ferument describes a new nematoid from the intestines of Merlangus vulgaris, for which he proposes the name of Spinitecius oviflagellis; it 1s very delicate in form, and has its integument completely covered by an armature of spines arranged in transverse rings, by means of which it is enabled to fix itself firmly to the mucous membrane of its host. The head is unarmed. There is no swelling of the digestive tube. The eggs are proportionately large, being one-fifth of the width of their parent; they are characterised by having at either pole a small appendage in the form of a flattened button; at its circumference there are, at definite distances from one another, three very fine fila- ments which, when unrolled, are fourteen or fifteen times as long as the egg. The new genus appears to belong to the family of the Filaride and to stand nearest to the genus Hystrichis. Nervous System of Bothriocephalide.t—M. J. Niemiec has investigated the nervous system of Bothriocephalus latus, and of a species of the same genus which is parasitic in the dog. The lateral nerve-cords ascend into the scolex where they continue their original direction ; there are no ganglia or any commissures in the hinder part of the scolex, as has been asserted by some previous observers. It is only in the anterior extremity of the scolex that the lateral cords turn towards one another, and, after an inconsiderable enlargement, unite by a well-developed commissure ; this last contains ganglionic cells, and may be called the central ganglion, though it is not so sharply delimited as in Tenia. The lateral cords give rise, just below the commissure, to four nerves on either side, which spread out radially, and then curve backwards to accompany the principal cords. The latter give off a series of short nervous filaments which pass to the epithelium. The author points out the value of the study of the nervous system of Bothriocephalus as explaining that of Tenia ; it is simpler and more primitive in character. * Arch, Zool. Expér. et Gén., iii. (1885) p. Ixxii. + Ann. Sci. Nat.—Zool., xvii. (1885) 8 pp. and 1 pl. { Comptes Rendus, c. (1885) pp. 1013-5. ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 647 Parasites of Fresh-water Fishes.*—M. F. Zschokke has been in- vestigating the organization and zoological distribution of the para- sitic worms of fresh-water fishes. He has examined twelve species from the Lake of Geneva, among which are Perca fluviatilis, Cyprinus carpio, Trutta variabilis, Salmo umbla, and Esox lucius. The first result of these studies is to demonstrate the presence of 87 species of parasitic worms; three at least of these are new species; they are found in nearly all the organs of the body; six of the eleven species of Cestoda were found in the strobila-stage, two in the scolex, and three in both. Only three of the species had no special parasite (namely, Coregonus, Trutta, and Cyprinus carpio). A table of distri- bution shows that the rapacious fishes (Salmonide, Gadide, Esocide) are the richest in different species of parasites. The genera of parasites have a close relation to the food of their host; thus the carniyorous forms have a very remarkable preponderance of adult Cestoids ; on the other hand, the Cyprinide, which are herbivorous, are rich in Acanthocephali, for with their vegetable nutriment they take in a number of small Crustacea. The Trematoda are very regularly distributed ; Nematoids are found in nearly all. The author further directed particular attention to the difficult question of whether the parasites are the same throughout the year, or vary with different seasons, and, so far as he was able to judge, he found that the number of parasites does not vary considerably during the year. He notes, lastly, what must have struck other ob- servers, that the number of female Ascarids is excessively large in proportion to the males. The preceding introduction to the paper is amply supplied with very valuable tables of statistics. Dealing with the species in detail, the author gives notes on the various forms: Tenia salmonis umble is a new species found in the intestines of Salmo wmbla ; it is from three to five centimetres long, the jointing is only feebly indicated, and the head has, on its anterior surface, a slight depression, which has the appearance of being a large but very shallow sucker. The genital orifices are placed in pits, and alternately, though not regularly, on either side. No ripe proglottids were detected. The author proposes to unite the species distinguished by Rudolphi as Bothriocephalus infundibuliformis and B. proboscideus. Nothing is to be added to the excellent account given by Pintner of the excretory system of Tricnophorus. Distoma nodulosum was found in eight of the twelve hosts ex- amined, and D. globiporum is very widely distributed; D. tereticolle is most common in the trout. With some hesitation, Diplozoon paradoazum, in its Diporpa-stage, is reported from the gills of Lota vulgaris and Cottus gobio. Sporocystis cotti n. sp. was very frequently found in the muscles of Cottus gobio, under the form of small, whitish, elongated cysts, but the Distomum to which they belong has not yet been discovered. * Arch. de Biol., y. (1884) pp. 153-241 (2 pls.). 202 648 SUMMARY OF CURRENT RESEARCHES RELATING TO Echinorhynchus proteus and EH. angustatus are very common, but E. claveeceps was only found once in the rectum of Leuciscus rutilus. With a good deal of hesitation, a specimen found in the intestine of Thymallus vulgaris is regarded as being a young form of Gordius aquaticus ; such characters as were to be detected seem to justify the author’s view, but they are hardly sufficient for certainty. In an appendix a report is made on certain psorosperms which were found under the skin of Coregonus fera, and appear to be the cause of an affection to which this fish is subject, especially in the spring; agrecing generally with the piscine psorosperms described by Balbiani, they do not exactly resemble those seen by Lunel and described by Claparéde ; they have two vesicles at the end opposite to the “ tails,” whereas, in all species, according to Balbiani, they are found near the tails; as, however, these vesicles give off an extremely fine canal, which passes to the base of the tail, it is probable that, as in others, they serve as a sheath for these processes. Free-swimming Sporocyst.*—Prof. R. Ramsay-Wright records the existence of a hitherto unknown form of sporocyst, one specimen of which he observed recently swimming very actively in an aquarium containing a few water-plants and fresh-water mollusca. In form and size it recalls the larger Cercarie with forked tails, and contains a single tailless Cercaria or larval Distome. In accordance with its free life, the muscular system is much better developed than usual, and the same is true of the water-vascular system. Of special inte- rest are tactile papille, which beset the surface, and which obviously enable the sporocyst to find the definitive host for its contained larva. Development of Turbellaria.j—Mlle. 8. Pereyaslawzew communi- cates a short abstract of her results obtained by studying the develop- ment of the Turbellaria Accela. The ovum divides into two equal halves, from each of which a small cell is detached; the further pro- cesses of cell-division are detailed; they result in the formation of a gastrula, the smaller cells becoming the ectoderm; the larger cells form the endoderm, and also give rise to the mesoderm ; as develop- ment advances the embryo takes on an angulated contour such as has been figured by Metschnikoff; when it reaches the gastrula stage it becomes again rounded and clothed externally with cilia. Fresh-water Turbellaria of North America.{—Mr. W. A. Silliman has been engaged in studying the fresh-water T'urbellaria of Monroe County (State of New York), and as the area is rather limited, he thinks it probable that he has found all the forms that live there. A comparatively large number of new species are described. Macrostoma sensitivum n. sp. has generative organs of much the same character as those of M. hystrix, but the male orifice is not at the end of the penis, but some distance behind it. The author finds that forms with no schizoccel have a more richly branched water- vascular system, while Microstoma and others which haye a well- * Amer. Natural., xix. (1885) pp. 310-1. + Zool. Anzeig., viii. (1885) pp. 269-71. + Zeitschr. f. Wiss. Zool., xli. (1884) pp. 48-78 (2 pls.). ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 649 developed ccelom have a proportionally smaller number of vascular branches; the physiological cause of this appears to be that, in the latter, the ciliated funnels are nearer to a larger quantity of lym- phatic fluid, and so are more easily able to conduct it into the capillaries of the water-vascular system. The integument of Platy- helminths appears to be capable of endosmosis but not adapted to exosmosis ; in consequence of this the received water has to make its way out by special efferent canals. The two species of Micro- stoma described are M. lineare of Oersted, and M. caudatum of Leidy. Stenostoma agile is a new species, in which the ciliated pits lie far forwards, and are innervated by nerves from the anterior lobes of the cerebral mass. There are four new species of Mesostoma. M. gonocephalum, in which the eyes are reniform and appear to have small lenses, which are not, however, highly refractive. MM. cecum, which has no eyes, is without true pigment, and is only occasionally coloured by its food; there are no flagella or other tactile hairs; it was found in mud, under stones. M. pattersoni has a number of cells and cell-spheres in its perienteric fluid, and these are driven about by every contraction of the body-wall; the water-vascular system is particularly easy to detect, and the ciliated lobes are most numerous in the cephalic region. The interesting peculiarity of M. viviparum is denoted by its specific name; there appears to be no vitellarium, the ovary is not well defined in area, the ova lying in the parenchyma, near the genital orifice. There is no sign of any bursa copulatrix or receptaculum seminis. All the embryos of one mother appear to be at about the same stage in development. The author hopes to describe the developmental history at a future time. True viviparous Turbellaria are extremely rare, none being known in Europe, though two have been described by Girard from North America, Chlorophyll- bodies are richly developed, and the author refers them to the pre- sence of alg; he goes so far as to correlate with their presence the absence of a vitellarium, and the habit of viviparity, thinking that the embryos find the maternal body a suitable place for development in consequence of the abundance of food and oxygen. Gyrator (?) albus n. sp. is the name given to a sexually immature species. In Vortex pinguis n. sp. the testes are irregular sacs, and the penis is completely separated from the seminal vesicle; the sperma- tophores are fairly simple in structure ; the vestibule of the generative organs is s0 spacious as to serve for a uterus, in which the ova are invested by yolk after fertilization. V. blodgetti n. sp. has the copu- latory organ provided with six spines. Plagiostoma(?) planum is the name of a new species which is founded on a single example, with an extensile terminal mouth, and with a spacious intestine which is provided with a pair of diverticula ; these are not mere constrictions as in some species. Spaces or lacune in the body-parenchyma are very rare. The author takes the opportunity of describing Tetrastemma aquarum duleium to express his belief that the four groups of Rhabdocela, Triclada, Polyclada, and Nemertinea are of the same 650 SUMMARY OF CURRENT RESEARCHES RELATING TO classificatory value, and are four orders of the class Turbellaria. He enumerates in all twenty-one species, and expresses his opinion that a considerable proportion will be found to be common to North America and Europe; into the interesting remarks that he makes on already known species our space forbids us to enter. Later Stages in the Development of Balanoglossus.*— Mr. W. Bateson gives an account of his observations on the later develop- mental stages of Balanoglossus Kowalevskii, and makes a suggestion as to the affinities of the Enteropneusta. A notice of Mr. Bateson’s work on the earlier stages of the species has been already given. As the cilia of the larva disappear a peculiar organ, in the form of a small papilla, bearing long cilia and mucous glands, appears on the central part of the posterior surface ; this serves as asucker, and then entirely disappears ; it is essentially similar to the larval suckers of Tunicates, Ganoids, and Amphibians, but it is not, apparently, an ancestral character. Owing to the transparency of the body at an early stage the ali- mentary canal may be easily seen to consist of an anterior branchial tract, a middle digestive, and a posterior intestinal portion. As the animal loses its cilia and before the second pair of gill-slits become developed it creeps into the upper layer of mud, its mouth comes to be directed forwards, a notochord becomes distinctly visible, and the opercular fold appears in the form of a circular thickening. As the body increases in size it becomes more and more trans- parent, but this phenomenon is, possibly, of no real significance, being due merely to the rapid growth of the animal. As the body grows, the number of gill-slits increases ; it seems probable that they go on increasing during the greater part, if not the whole, of the life of the animal; the largest number of pairs of slits observed was fifty-seven. As the gills appear in greater number the distinction between the digestive and intestinal regions of the animal becomes better marked. Balanoglossus appears to have a very peculiar odour, which is described by Mr. Bateson as being “very penetrating and persistent, resembling that of chloride of lime with a fcecal admixture.” Ina new and as yet undescribed species—B. Brooksii—the smell, which is strongly suggestive of iodoform, is very distinct after some months’ preservation in spirit (often changed), and is “a considerable draw- back to investigating the species.” There appears in the anterior dorsal wall of the gut, a most remarkable structure which is regarded by Mr. Bateson as the noto- chord ; it first arises by a forward growth of the anterior dorsal wall of the pharynx, which thus shuts off a short diverticulum of hypo- blast; this is aided by a longitudinal constriction of the dorsal region of the pharynx which gradually travels backwards, separating a hollow hypoblastic tube, which remains open to the gut behind, and by a forward growth from the point of junction with the gut. The skeletal rods first appear as two short rods of a deeply stained, structureless substance which lie in the angles between the * Quart. Journ. Micr. Sci. Supplement (1885) pp. 81-122. + See this Journal, ante, p. 461. ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 651 notochord and the dorsal wall of the pharynx; they appear to be of hypoblastic origin, and it is possible that they are formed at the expense of the notochord. Later on, the notochord increases greatly in size, and becomes vacuolated just like the notochord of young Lampreys and Elasmobranchs; the skeletal rods, becoming of con- siderable size, unite anteriorly to form a single bar, while the whole structure forms the support of the proboscis. “ From its development, position, relations to surrounding parts, histology, and function,” Mr. Bateson says, “it appears to me to be comparable with the notochord of the Chordata, and this name is strictly appropriate to it. Even if the suggestions which will be made hereafter as to its phylogenetic significance be not accepted, this rejection would in no way militate against the fact that this structure is to all intents and purposes a notochord, which can only be designated as a longitudinal dorsal supporting rod, derived from the hypoblast.” Particular attention is given to the resemblances between the Enteropneusta and Amphioxus ; as to the position and mode of origin of the central nervous system there is great similarity, the only im- portant point of difference being that the invagination of the dorsal cord is only partial in Balanoglossus, but is complete in Amphioxus. Echinodermata. Phylogeny of Echinoderms.*—Mr. H. F. Nachtrieb records some observations made on the development of many of the Echinodermata of Beaufort, and concludes with some remarks on the phylogeny of Echinoderms. If we compare the origin of the body-cavity and water- vascular system in the different classes, we see that in the Holo- thurians we have one median pouch given off from the enteron, and that it, by division, gives rise to the body-cavity and water- system. In the Echinoids there is a two-horned pouch given off. In the star-fish there are two separate lateral pouches given off, of which the left gives rise anteriorly to the water-system, and the right and the posterior part of the left become the body-cavity. In Ophiurids so far as known, there are two separate pouches, both of which divide, the anterior part of the left becoming the water-system, the anterior of the right atrophying, and the posterior parts of the right and left becoming the body-cavity. In the Crinoids there are first given off two separate pouches, which become the body-cavity, and then a single one, that becomes the water-system. Assuming that the story of the Ophiurids and Crinoids is correct, we have here a rising scale, in which the Holothurians occupy the lowest, the star-fish the middle, and the Crinoids the highest position. In favour of this there are some anatomical facts. The objections of paleontology are not very difficult to answer. In assuming the Holothurians as the primitive forms it is not necessarily implied that the line of development is a straight one, as it is repre- sented above. It is quite probable that the line began to break with the appearance of the star-fish. * Johns-Hopking Univ. Cire., iv. (1885) pp. 67-8. 652 SUMMARY OF CURRENT RESEARCHES RELATING TO Arbaciade.*—In this first part of their paper on the family Arbaciade Gray, Dr. P. Martin Duncan and Mr. W. P. Sladen treat of the morphology of the test in the genera Colopleurus and Arbacia. These two forms, as is shown by a minute study of the fossil and recent species, have a great similarity of structure. In all (for Arbacia nigra belongs to a different genus) the compound plates of the ambulacra are formed of an adoral and an aboral demi-plate with a large central primary plate. In all forms the optic pores are double, and the perforation is in the adoral edge of the plate, a process separating the pores. In all the forms the median or vertical sutures of the interradia are marked with knobs or ridges, which correspond with sockets or short grooves on the opposed plate edges. This kind of dowelling is even seen in the ambulacra of Arbacia and along the transverse interradial sutural edges of Calopleurus. : Celopleurus is the oldest of the two genera: there are species with the peculiar ambulacra in the Eocene, Oligocene, and Miocene. The recent species from the Indian Seas only differs from the Miocene form in having high and not oblique interradial plates. All the species of Arbacia, which are recent forms, that were examined pre- sent no greater differences than can be accounted for on the theory of descent. Histology of Asterida.;—Dr. O. Hamann has a preliminary notice on the histology of star-fishes, in which he points out that the body-wall consists of an epithelium, which is followed by a layer of connective tissue, in which the calcareous structures are developed. Internally to it are a layer of circular and a layer of longitudinal muscles; the latter was described by Ludwig as the lamella of sup- porting substance ; in it the so-called ossicles are developed. In the layer of supporting substance which lies on the muscular layers we find the canal-system of the body-wall, which is invested by an epithelium. Muscular bundles, passing off from the circular layer, traverse the lumen of the canals, and end or branch at definite points in the layer of supporting substance. The muscular layers may be traced to the ossicles; and it is pointed out that the discovery of these muscles enables us to explain the movement of a star-fish and its arms. ‘The ambulacral gills are to be regarded as evaginations of the dorsal wall, and have the same structure as it; their protrusion and retraction is to be explained by their possession of a similar system of muscles. In addition to the well-known oral nerve-ring the author was able to detect a nerve-plexus in the oral disk; this consists of nerve-fibrils with scattered ganglionic cells, which pass into the epithelial cells of the disk. It is pointed out that we have here an arrangement which is comparable to that which Dr. Hamann has already described as obtaining in Holothurians. In the dorsal integument there are nerve-trunks which are ordinarily set at right angles to the long axis of the arm. The dorsal epithelium consists of simple supporting * Journ, Linn, Soc. Lond. (Zool.), xix. (1885) pp. 25-57 (2 pls.). + Nachr. K. Gesell. Wiss. Gattingen, 1884, pp. 885-6. ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 653 cells among the basal prolongations of which we find nerve-fibrils, of sensory, and of goblet-shaped glandular cells. Stalked Crinoids of the ‘Challenger’ Expedition.*—Dr. P. Herbert Carpenter has published in the ‘ Challenger’ reports a very full monograph of the morphology of Crinoids generally, and an extensive account of the stalked forms. The first, or morphological, portion deals with the skeleton gene- rally, and the mode of union of its component joints; in the second chapter the stem and its appendages as seen in the Pentacrinide, Bourgueticrinide, and Hyocrinide are considered, and the differences in the three groups are pointed out; the author thinks that “the resemblance and ‘ probable homology’ which Prof. Perrier sees be- tween the arms and the root of a Crinoid are .... forced in the extreme”; for the former are merely extensions of the body, while the branches of the root have a very different structure, or, in other words, that of the stem, as is indeed allowed by Perrier himself. The terminal faces of the stem-joints of Hyocrinus are interesting as being of the same nature as those of the Apiocrinide and many of the Palezocrinoids. In the third chapter the calyx, and in the fourth the rays are dealt with; the characters of the pinnules of Paleocrinoids are dis- cussed, and the view of Wachsmuth and Springer that the alternate plates of Cyathocrinus are rudimentary pinnule is objected to, analogy being apparently confused by them with homology. The three functions of pinnules are, it is pointed out, that of protecting the fertile portions of the genital glands, of serving as respiratory organs, and of aiding in alimentation; in Cyathocrinus all these functions might have been performed by the branching arms. The division by Ludwig of the ccelom into an intervisceral and circumvisceral portion is regarded as convenient, but it is pointed out that in some species—such, for example, as Antedon eschrichti among the Comatulids, and in the stalked Crinoids—it is difficult to fix a definite boundary between them. The oral plates which, formed in Pentacrinoid larvew, are absorbed during development, are retained throughout life by Holopus, Hyocrinus, Rhizocrinus, and Thawmato- erinus. \Vyville Thomson’s name of perisomatic skeleton is adopted for “the basal and oral plates, the anal plate, the interradial plates, and any other plates or spicules which may be developed in the perisome of the cup or disk,” while that of “visceral skeleton” is used to denote the “numerous spicules and networks of limestone which occur more or less plentifully in the bands of connective tissue that traverse the visceral mass of the Comatule” and the more or less regular plates which are found within the disk of Pentacrinus ; these are formed of a calcareous network interpenetrated by an organic basis, which is of the same nature as in the joints and arms. In the sixth chapter the minute anatomy of the disk and arms is dealt with, and the author states that his extended observations on * Report of the Voyage of H.M.S. ‘Challenger’—Zoology, xxxii, (1884) 440 pp. and 69 pls. 654 SUMMARY OF CURRENT RESEARCHES RELATING TO Comatule and on Pentacrinus, Bathycrinus, and Rhizocrinus, enable him to confirm in almost every respect the investigations of Ludwig on Antedon rosacea ; especial attention is, as may be supposed, given to the nervous system. In the discussion on the characters of the colouring matter, it is interesting to observe that pentacrinin was found in Holopus; one species of the new genus Metacrinus has a different colouring matter, which is light pink when fresh. The seventh chapter deals with the habits of Crinoids and their parasites; the eighth with their geographical and bathymetrical dis- tribution, the results of which are usefully arranged in tabular form. A characteristic of the work is the attention which is given to paleontological discoveries, and the relations of the Neocrinoids to the Paleocrinoids. The following table shows the mutual homologies of the principal plates in the actinal and abactinal systems of Kehinoderms. URCHINS. OPHIURIDS. CRINOIDS. Abactinal | Abactinal | Actinal | Abactinal Actinal MAT a aS Symbatho- Actino- crinus erinus 1. Central plate | Dorso- Dorso- 0 Terminal Oro- Oro- central central plate at central -| central base of larval stem 2. First series, fd Under- Ne Under- radial basals basals (variable) variable. 3. Second serics,| Genitals Basgals Mouth- Basals Orals Proximal interradial shields dome- plates 4. Third series, | Oculars | Radials 36 Primary bo Primary radial calyx dome- radials. radials, Orders of Orders of calyx radials. radials, Dome Calyx interradials interradials The following is the classification adopted :— Phylum. Echinodermata. Branch. Pelmatozoa. Class 1. Crinoidea. », 4. Cystidea. s,s o» Blastoidea. In the order Neocrinoidea we have descriptions of the several ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 655 forms ; the first family is that of the Holopide, under which Holopus is very fully described; the second family, that of the Hyocrinida, is new, the character of Hyocrinus being sufficient to distinguish it from the Apiocrinide ; de Loriol’s family name of Bourgueticrinide (1882) is accepted for Bathycrinus and Rhizocrinus, the characters of which are emended. In the Pentacrinide there is the new genus Metacrinus for forms which appear to be confined to the Eastern seas. Various problems are discussed in an appendix, and the whole work concludes with a full bibliography of the Neocrinoids and an excellent index. Development of Comatula.*—Professor E. Perrier in a preliminary notice brings forward the following facts concerning the organogeny of Comatula. From the archenteron are developed three diverticula; two form the general body-cavity, while the third gives rise to the ambulacral ring; directly the latter is formed it communicates with the exterior by a single “stone canal.” The rudiment of the structure termed by Ludwig the dorsal organ arises by a columnar thickening of one of the layers of the right peritoneal sac; round the prolonga- tion of the right peritoneal sac into the axis of the peduncle the mesodermic tissue becomes differentiated into the chambered organ ; a similar differentiation takes place in the walls of the calyx to form five cords, which pass to the septum, separating the two halves of the body-cavity ; these cords as well as the two peritoneal sacs and the ambulacral sac share in producing the rudiments of the arms, which thus contain (1) an ambulacral canal, (2) a subambulacral cavity con- tinuous with the left peritoneal sac, and (3) a much smaller cavity connected with the right peritoneal sac; later this cavity enlarges and a new cavity—the genital space—appears between it and the subambulacral cavity. The young Comatula is set free at the period when each arm has only a single pair of pinnules; there are at that time five “stone canals” which open directly on to the exterior; these tubes generally rupture at the point where they enter the body- walls, and appear therefore to open into the body-cavity, which they never do in reality, even in the adult. At the same period of deve- lopment a number of fibro-cellular cords appear around the cesophagus and along the dorsal organ, which form a plexus of vessels which send off branches, some opening on to the exterior of the body, and some into the body-cavity and into the ambulacral vessels; a plexus of these vessels envelope the dorsal organ, and has been compared by Claus with the heart of sea-urchins and star-fishes. The ambulacral system, therefore, together with these vessels, forms a single vascular system functionally one, though developmentally composed of two distinct and separate systems. The dorsal organ is prolonged into the arms and into the pinnules, and forms the genital rachis; the dorsal organ itself consists of pyriform cells which come to be grouped round a central cavity ; this gives off short diverticula, and transverse * Zool, Anzeig., viii, (1885) pp. 261-9. 656 SUMMARY OF CURRENT RESEARCHES RELATING TO sections of the whole organ occasionally present the appearance of a glandular organ like the salivary glands; it is these numerous cavities, no doubt, which led Ludwig to describe the dorsal organ as a plexus of blood-vessels. Ccelenterata. Australian Hydroid Zoophytes.*—Mr. W. M. Bale has compiled a catalogue of the Australian hydroid zoophytes, with a view not only of affording a guide to the collections in the Sydney Museum, but of providing students of natural history with a compact account of all that has been done in the description and illustration of the Australian representatives of this group. A general introduction on the morphology of the Hydroida is prefixed to the systematic portion of the catalogue, which contains a large amount of new and valuable matter, including descriptions of 23 new species:—Pennaria (1), Campanularia (3), Lineolaria (1), Sertularia (7), Thuiaria (2), Plumu- laria (4), Antennularia (1), Halicornaria (4). Ceelenterates of the Southern Seas.+—Dr. R. von Lendenfeld, in his fifth communication, deals with the Australian Hydromeduse ; in his introduction he notes the great abundance of marine animals in Port Jackson, and states that his investigations have been greatly aided by the liberality of Mr. W. Mackay. The list of species amounts to no less than two hundred and forty-one. In his sixth communication ft the author deals with Neis cordigera of Lesson, a Beroid which was first discovered in 1824; from Beroe the species differs by having high lobes which project far above the sensory poles, and by not having the vascular system of the gela- tinous tissue of one-half of the body separated from that of the other. In form, Neis is intermediate between Beroe and the Lobate; four of the ctenophores are longer than the other four; the sensory organ at the aboral pole has no special peculiarities; the generative products appear to be confined to the parts of the vascular plexus which are widely separated by the meridional canals, and in this point this Australian species differs essentially from Beroe. Chromatology of Actinie.§ — Dr. C. A. MacMunn finds that Actinia mesembryanthemum contains a colouring matter which can be changed into hemochromogen and hematoporphyrin; this is present in other species, and from its characters it is provisionally named actiniohematin. It is not actiniochrome (a pigment found by Prof. Moseley in the tentacles of Bunodes crassicornis), as its band occurs nearer the violet than that of actiniochrome. Moreover, both actiniochrome and actiniohematin- can be extracted with glycerin, in which the latter is convertible into hemochromogen, but the former remains unchanged. Actiniochrome is generally confined to the * Bale, W. M., ‘Catalogue of the Australian Hydroid Zoophytes,’ 8vo, Sydney, 1884, 198 pp. (19 pls.). + Zeitschr. f. Wiss. Zool., xli. 1885) pp. 616-72. t{ Tom. cit., pp. 673-82 (1 pl.). § Proc. Roy. Soc., xxxviii. (1885) pp. 85-7. See this Journal, ante, p. 464, ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 657 tentacles, and is not respiratory ; actiniohematin occurs in the ecto- derm and endoderm, and is respiratory. A special colouring matter is found in Sagartia parasitica, different from either of the above, and this too exists in different states of oxidation. It is not apparently identical with that obtained by Heider from Cerianthus membranaceus. In the mesoderm and elsewhere in Actinia mesembryanthemum and other species, a green pigment occurs which alone and in solution gives all the reactions of biliverdin. Anthea cereus, Bunodes ballii, and Sagartia bellis, yield to solvents a colouring matter resembling chlorofucin, and all the colouring matter, which in them shows this spectrum, is derived from the yellow cells” (= symbiotic alge) which are abundantly present in their tentacles and elsewhere. It is not identical with any animal or plant chlorophyll, as is proved by adding reagents to its alcoholic solution. When “yellow cells” are present, there appears to be a sup- pression of those colouring matters which in other species are of respiratory use. Porifera. Relationship of Sponges to Choano-flagellata.*—Dr. F. E. Schulze criticizes the views held by Saville Kent and others, respecting the systematic position of the sponge; the so-called collared cells are closely similar to certain flagellate Infusoria; and this resemblance was held by these authors as a proof of the close affinity between the two groups. Saville Kent has brought forward other reasons in support of this opinion ; in the first place he has studied the larve of certain sponges, and has inferred from their development and struc- ture that they do not correspond in any sense to a gastrula, but are to be interpreted as simple colonies of Choano-flagellata; a mature sponge larva consists of a hollow sphere surrounded by a single layer of collared cells, and those cases where the larva consists of simple flagellate cells in one half of the sphere and granular non-ciliated cells in the other half are believed by him to be later developmental stages. Schulze points out that Saville Kent’s statements have not been borne out by other investigators, and that no one but himself has seen the collared cells in the larve ; he suggests further that the so-called “larve” are in reality nothing more than portions of sponge tissue separated by teasing, which would account for the appearances observed and described by Saville Kent. Evenif Kent’s observations are correct, the fact of the development of the sponge gemmule from an ovum fertilized by true spermatozoa at once sets aside any possibility of a comparison with a colony of Choano- flagellata. The discovery of a Choano-flagellate (Protospongia) con- sisting of numerous collared cells imbedded in a common gelatinous matrix is not, as Saville Kent thought, an argument in favour of his hypothesis, since in sponges the gelatinous tissue compared by him * SB. K. Preuss. Akad. Wiss. Berlin, 1885, pp. 179-91. See Ann. and Mag. Nat. Hist., xy. (1885) pp. 365-77. 658 SUMMARY OF CURRENT RESEARCHES RELATING TO to this matrix is a true connective-tissue and has indeed been recently shown by Von Lendenfeld to contain nervous and sensory cells; it is true that in the Choano-flagellate amceboid cells wander into the gelatinous matrix, but this is connected with spore formation, and “no fixed connective-tissue cells at all are formed,” not to mention the nervous structure already referred to. New Variety of Meyenia fluviatilis.* — Mr. H. J. Carter de- scribes a new variety of Meyenia fluviatilis, for which he proposes the varietal name of angustibirotulata. 'The specimens were obtained near Brentwood in Essex, and from the Calumet River, U.S.A. The dis- tinguishing features of this new variety are the length and hour-glass shape of the birotules, and the smooth skeletal spicule. The only variety of M. fluviatilis with which it can be confounded is that of Bombay. In this last, however, the shaft of the birotule is equal in thickness throughout, and the skeletal spicule may be spiniferous as well as smooth. New Fresh-water Sponge.t—Mr. E. Potts describes a new fresh- water sponge, Heteromeyenia Pictouensis nu. sp., from Pictou, Nova Scotia. It is near H. Ryderii, but the peculiarities of its birotulates distinguish it from that or any other species. It appears to be an “evergreen,” continuing its life in the normal state throughout the year, and for this reason seems not to form “ protected gemmules” in such abundance as do other species. Sponges of the Norwegian North Sea Expedition.{—Dr. G. A. Hansen gives an account of forty-five species of sponges collected during the Norwegian North Sea Expedition of 1876-8; there is one new genus Clavellomorpha, which is placed next to Thenea. 'There is a new species of Hyalonema, H. arcticum, many of the long spicules of which are enlarged in the middle, where the axial canal is divided. Twelve new species are placed in the genus Reniera, five with Suberites, four with Myxilla, and two with Sclerilla ; there are four new species of Desmacidon, and one of Gerodia. The five calcareous sponges have all been described, and the nomenclature of Hickel is adopted. Many of the specimens were incompletely preserved owing to the evaporation of the alcohol, and the author was unable to trace out the canal system; the species are, therefore, discriminated by their spicules, in the description of which the stenographic system of Vosmaer is made use of. Protozoa. Further Experiments on the Artificial Division of Infusoria.s— Herr A. Gruber has been making some further observations on Stentor ceruleus. An example a was cut transversely into two pieces; on the next day both had become perfect organisms a’; one was again * Ann. and Mag. Nat. Hist., xv. (1885) pp. 453-6. + Proc. Acad. Nat. Sci. Philad., 1885, pp. 28-9 (1 fig.). { Hansen, G. A., ‘Den Norske Nordhavs-Expedition, 1876-8, xiii., Spon- giade,’ fol. Christiania, 1885, 25 pp., 7 pls. and 1 map. § Biol. Centralbl., v. (1885) p. 137. See Naturtorscher, xviii. (1885) p. 204. ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 659 divided into two, and on the next day there were two complete a’; one of these was again cut with the same result, and one of the a’”’ in a similar way, with the like result. Further experiments have - strengthened the belief of the author in the value of the nucleus in regeneration ; pieces without a nucleus did well, but never grew up into complete animals. Vorticelle with Two Contractile Vesicles.*—Dr. A. C. Stokes points out that besides Vorticella Lockwoodii Stokes, and V. monilata Tatem, the following species of the genus possess two pulsating vacuoles, a point in their structure which has been overlooked, viz. :— V. vestita Stokes, and V. rhabdophora Stokes. The presence of double vesicles has so far been observed only in such members of the genus as possess some form of cuticular investment or of surface ornamenta- tion rather.than transverse stria. As these species are apparently more highly organized, and presumably somewhat higher in the scale than are the smooth or simply striated forms, so are they slightly more complex in structure. New Fresh-water Infusoria.t—Dr. A. C. Stokes describes some new fresh-water Infusoria from shallow ponds in central New Jersey. Heteromita mutabilis n. sp. is remarkable for the presence and variety of the posterior protrusions of the body-sarcode. From H. lens (Mull.) S.K., it can be distinguished by its normally ovate or sub- pyriform contour, but chiefly, apart from the posterior changes of shape, by the diverse length and thickness of the flagella. Petalomonas carinata n. sp. seems to combine the characters of P. abscissa (Duj.) Stein and of P. mediocanellata Stein, the former bearing one or two dorsal keel-like elevations, and the latter having a groove traversing its ventral surface, while P. carinata possesses both in a marked degree. It is much the smallest member of the genus hitherto observed. Zygoselmis acus nu. sp. has its favourite haunt in dead and partially empty algal cells. Anisonema emarginatum n. sp. LEntosiphon ovatus n. sp. is much larger than EF. sulcatus (Duj.) Stein. Tillina flavicans n. sp. somewhat closely resembles T. inflata Stokes, which is here diagnosed and figured for comparison. Lacry- maria truncata n. sp. is the only fresh-water member of the genus thus far observed. It is remarkable for the very long and band-like nucleus, and especially for the capacious conical pharyngeal passage which has hitherto not been recorded as appearing in any of the several marine species. Colpidium truncatum n. sp. differs from the hitherto single known member of the genus in the oblique truncation of the frontal border, the single nucleus, and the position of the con- tractile vesicle. Vorticella octava n. sp. is characterized by the peculiar twisted appearance of the sheath about the pedicle ; in none of the previously described Vorticelle has such an appearance been noted. Urostyla trichogaster n. sp. was for some time the pre- vailing form in a vegetable infusion, gliding over the fungoid slime on the surface as visible whitish spots.. By transmitted light it is * Amer. Mon. Mier. Journ., vi. (1885) pp. 52-3. + Ann. and Mag. Nat. Hist., xv. (1885) pp. 437-49 (1 pl.). 660 SUMMARY OF CURRENT RESEARCHES RELATING TO brown and semi-opaque. Opisthotricha emarginata n. sp. in its move- ments is rapid and erratic. The contractile vesicle expels its contents through the dorsal surface, forming there at complete systole a con- spicuously projecting elevation of the cuticular surface. Stylonycha notophora n. sp. differs from S. mytilus Ehr., which it most resembles, in that the extremities are subequal in width, in the rounded posterior margin beyond which project three instead of two anal styles, in the possession of motionless bristle-like hairs on the dorsal surface, and especially in having the opening of the anal orifice on the superior or dorsal aspect. Podophrya brachypoda n. sp. may be recognized by the foot-stalk being very short and inconspicuous; unless seen in profile or side view, or in longitudinal optic section and attached to the sup- porting object from which it is readily separated, it bears a not remote resemblance to Spherophrya. Dr. Stokes suggests that P. Buckei S.K. is probably an immature form of an unobserved, more distinctly pedicellate member of the present genus, and not, as Keni thought, likely hereafter to become the type of a new genus. In Solenophrya inclusa n. sp. the frontal convexity or roof is so hyaline that its existence can be satisfactorily observed only by the use of some chemical means of removing the enclosed zooid. This is readily accomplished by a drop or two of caustic potash in solution. Dr. Stokes has been unable to detect openings in the upper surface or dome-like roof of the lorica. S. pera n. sp. The form of this lorica is so much like that of the ordinary hand-satchel now popular among ladies that it suggested the specific name. Acineta urceolata n. sp. is the last species described. Dr. A. C. Stokes also describes * some new fresh-water Infusoria from the shallow ponds and streams of New Jersey. Physomonas vestita n. sp. differs from the hitherto single known member of the genus in the absence of the truncated anterior border, and in the presence of a linear, dark-bordered band or depression near the frontal margin, as exists in Spumella. Bicoseca lepteca nu. sp. is among the largest, if not the largest of the genus. It differs widely from the only fresh-water species, B. lacustris J.-Clk., hitherto observed in American lakes, JB. lepto- stoma n. sp. most closely resembles the salt-water B. tenuis S.K., and may be considered its fresh-water representative. B. longipes n. sp. Stylobryon Abbotti n. sp. This polythecium, unlike that of S. petiolatum (Duj.) 8.K., which it most resembles, is subject to but little variation in its mode of colony-building. Tillina helia n. sp. has the nucleus placed subcentrally, but its position in reference to any special region is not constant. Derepyzxis nu. gen. is near Stein’s Chrysopyxis, but differs in the con- stantly pedicellate character of the lorica. Two new species, D. amphora and D. ollula, are described. Chilomonas ovata n. sp. is the most minute fresh-water species yet recorded. Loxophyllum flexilis n. sp. is remarkably irregular in outline, and this peculiarity is increased by the presence of two little projections, on the posterior * Amer. Journ. Sci., xxix. (1885) pp. 313-28 (1 pl.). ZOOLOGY AND BOTANY, MICROSCOPY, ETO. 661 part of the dorso-lateral border, that are constantly present but which vary somewhat in size and form. Spirostomum loxodes un. sp. in ex- ternal contour bears a striking resemblance to Loxodes ; it approaches nearest to S. teres C. & L. The lorica of Vaginicola leptosoma n. sp. resembles in form V. attenuata (From.) 8.K., but is just twice as large, besides differing in the proportion borne by the length to the width. In Cothurnia annulata n. sp. the enclosed animalcule differs from all hitherto known species in the possession of a transversely striated cuticular surface, and the ridge-like elevation encircling the central portion of the body ; the lorica also differs in form from that of other species. Litonotus vesiculosus n. sp. resembles L. Wrzesniowskit 8.K. Its chief diagnostic characters, in the internal structure, are the presence of very many minute, quickly and irregularly pulsating contractile vesicles scattered about the cortex, while in the animalcule most resembling it the pulsating vacuole is large, single, and located near the origin of the caudal extremity. Litonotus carinatus n. sp. cannot easily be mistaken for any other species of the genus. Litonotus trichocystus n. sp. to a certain extent resembles LD. fasciola (Ehr.) §.K. It is, however, easily distinguishable by its shorter and less conspicuously flattened neck-like part, and especially by the number and arrangement of the trichocysts, which are constant. Chilodon fluviatilis nu. sp. differs from all other forms in its shape, and its preference for water not entirely still. Chilodon caudatus un. sp. has the postero-terminal border of the dorsum continued as an acuminate and rigid spur which, with the prominent anterior lip, renders this infusorian readily recognizable. Dewiotricha n. gen. approaches nearest to the Bursariade of Stein; but diverges widely from the members of that family in the absence of the conspicuous, excavate peristome field, and especially in the presence of the row of adoral cilia on the right-hand side instead of the left, and in the presence of a ciliated pharynx, a feature to be distinguished only under high amplification and the most favourable position of the infusorian and the direction of the illuminating ray. One species, D, plagia n. sp. is described. Dr. A. C. Stokes also describes and figures * the following. Atractonema tortuosa nu. sp. differs from the hitherto only known species, A. teres Stein, in being less fusiform. The single fla- gellum arises within the pharyngeal passage, a point on the wall, pre- sumably the roof, serving as the basis of attachment. In Noto- solenus, primarily described by the author as Solenotus, although an oral aperture has not been actually discerned, yet the appearance of what seems to be a short pharyngeal tract is so constantly present that an oral orifice probably exists and the animalcules must be re- moved from the neighbourhood of Stein’s Colponema and placed near Dujardin’s Anisonema. In N. sinuatus n. sp. the appearance of a pharyngeal tract is more clearly defined than in the other species, and the infusorian is by far the largest of those hitherto observed. Paramecium trichium un, sp. is nearest to P. bursaria (Ehr.) §8.K., * Amer. Natural., xix. (1885) pp. 433-43 (10 figs.). Ser. 2.— Vou. V, A 662 SUMMARY OF CURRENT RESEARCHES RELATING TO but differs from it conspicuously in form, especially in the apparently oblique curvature of the anterior extremity, in the absence of the truncation of the same part, the absence of the rapid and continuous circulation of the endoplasmic contents, and particularly the green coloration of the cortex and sarecode. Trichocysts are very abundant. Cyrtolophosis nu. gen. forms and inhabits singly or several in company a very soft, shapeless, coarsely granular zoocytium. This sheath or zoocytium appears to be formed primarily by a thin exudation from the creature’s body, that would be nearly invisible were it not for the extraneous particles that adhere to the surface, and especially for the zooid’s excrementitious matter which seems to be the principal building material, and the cause of the coarsely granular aspect. The infusoria are ovate in form and entirely ciliated. One species, C. mucicola, is described. Euplotes carinata n. sp. differs from all other species in the number of the frontal styles, the character and arrangement of the anal styles and caudal set, and in the shape of the carapace, which has a very conspicuous keel or high acute ridge traversing the dorsum from the frontal to the posterior borders. In conclusion, a corrected drawing of EH. plumipes Stokes is given and the species described. Infusorial Parasites of the Tasmanian White Ant.*—Mr. W. Saville Kent describes the parasitic Infusoria from the intestine of the Tasmanian white ant. Like the types described by Dr. J. Leidy, from the North American white ant, they belong to three distinct varieties. Trichonympha Leidyi n. sp. differs from Dr. Leidy’s T. agilis in the relative shortness of the hair-like cilia which clothe the entire surface of the body. The mouth of Trichonympha, left undetermined by Dr. Leidy, is shown by Mr. Saville Kent to take the form of a transverse slit developed upon one side of the body at a short distance only from the apical extremity. It is followed by a narrow ceso- phageal track which opens into the capacious digestive cavity that occupies one-half or two-thirds of the posterior region of the body. When placed in diluted milk the adult and immature forms of both the American and Tasmanian species, have a habit of anchoring themselves by means of the long fascicle of hair-like cilia that are produced from their posterior extremity. Of the two remaining Infusoria, the one is apparently referable to Leidy’s genus Pyrsonympha, while the other belongs to Stein’s Lopho- monas, so far recorded as a parasite only of Blatia and Gryllotalpa. Unstalked Variety of Podophrya fixa.t—Dr. E. Buck describes the form of the unstalked variety of Podophrya fixa as being rounded ; four phases in its life-history were observed. In the first or swarm- ing stage the plastids consist of a finely granular parenchyma, the body is rounded at either end, somewhat constricted in the middle, and has a round projecting nucleus. In the second or Spherophrya- * Papers and Proc. Roy. Soc. Tasmania, 1884 (1885) pp. 270-3. See also Ann. and Mag. Nat. Hist., xv. (1885) pp. 450-3. + Ber. Senck. Naturf. Gesell., 1884, pp. 298-314. ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 663 stage the tentacles developed from, as it seemed, the middle of the ventral surface ; food was taken in abundantly, but there did not seem to be any parasitic habit. The third stage is that of the free Podophrya, in which the body forms an elongated ellipse, and has the two tufts of tentacles carried to either end of the body, the form of which varies with the amount of food ingested. The fourth phase is that of the fixed or Acineta condition, which is entered upon by the organism surrounding its hinder end with a kind of gelatinous material, which gradually elongates into a more or less tail-like pro- cess. The gelatinous material gradually increases in consistency, and takes on a cup-shaped or infundibular form. Pseudo-cyclosis.*— Under this heading Dr. 8. Lockwood describes the movement of the food-particles (green unicellular alge) that he witnessed in a specimen of Ameba diffluens, and which at first sight he mistook for the phenomenon of cyclosis. “ As the Ameba advances, the green bodies are left in a cluster at its hinder part. Now the Ameba’s movement stops, and now the little spheroids begin rushing in a well-defined stream towards the advanced portion of the protoplasm. . . . Again the containing body advances, and those contained recede—that is, are left at the hinder part of the protoplasm. We notice also a resting of the host, and the rush forward of the smaller bodies. The Ameba again advances, this time but a very little. It seems even to recede. Really it contracts, then spreads out unsymmetrically on two sides, producing an object not unlike the ankle and foot. Now comes the usual rest succeeded by the movement of the contained bodies, which this time start in two streams, the smaller group towards the heel and the larger to the toes of the so-called foot. This alternating of the two kinds of activities is quite interesting to witness: the streaming inner move- ment always obeying two facts—following a rest of its own, and taking the occasion of a rest of the Ameba.” In every instance the food-propulsion was a movement in the direction of the outward or forward flow or progression of a part of the Ameba, and this was always followed by an illusory recession, that is a seeming stream of the little alge backward caused by the advancing protoplasm leaving these objects behind until the new pseudopodium rested, when the trend of the little bodies immediately advanced. The object of this movement is to bring the food into actual contact with every molecule of the gelatin body, thus making the entire body take part in the process of digestion, and securing to the whole an equal alimentary distribution. New Protozoon.{—Mr. T. Deecke describes an unnamed protozoon which produced perforations in the plates at the bottom of a water- tank made of tinned copper. Furrows radiated irregularly from these perforations as if excavated by a graving tool. The holes and furrows were filled out with an earthy material, consisting mostly of carbonate of copper. When a small piece, still moist, was placed in * Amer. Mon. Micr. Journ., vi. (1885) pp. 46-7. + Scientific American, ii. (1884) p. 136. pe Fe 664. SUMMARY OF CURRENT RESEARCHES RELATING TO the centre of a drop of water on a life-slide provided with a circular air space, and covered with a cover-glass, the clear water surrounding the opaque mass was filled in a short time with a protozoon be- longing to the Protamceebe. It was not difficult to see them, in all possible shapes and sizes, creep out from the dark mass and wander slowly toward the margin of the drop bordering the air space, and the more numerous they were the more the air contained in the water was consumed. This is a very convenient method, the author adds, to which he has often resorted for bringing micro-organisms, which live in hiding places, into view. It is air that they, like all living beings, need for their existence, and the scarcer this becomes in the isolated drop of water the more they approach from the centre of the drop to its margin, which remains in contact with the air. The protamcebe observed differ from the ordinary species, not so much in the peculiar shapes they assume as in the dark colour of their contents, or rather in the presence of a dark, finely divided substance imbedded in the otherwise transparent and colourless gelatinous little mass. By the action of dilute hydrochloric acid, under the development of a gaseous product (carbonic acid) the dark contents are dissolved into a colourless fluid, while the bodies of the protamcebe mostly assume more or less spherical forms, resembling drops of oil. “Considering the great numbers in which these micro-organisms are present, their peculiar mode of life by adhering to, and of loco- motion by slowly creeping over a surface, their feeding by the simple extension of their sarcode body over any material in their way, a process very likely associated with some secretory function, it seems quite probable that they exert an observable influence wherever they happen to locate. This influence is probably of a mechanical as well as of a chemical nature. When the material which fills out the furrows is removed, the perfectly pure metallic surface of the copper is brought to view, as if acted upon by the use of an acid. Thus, at first, as it seems, the copper is dissolved in minute quantities, which afterwards, by the interchange of. the acid with the carbonic acid of the lime salt contained in the water, forms a soluble organic lime compound and carbonate of copper, the latter of which is deposited in the furrows. That a portion of this as a comparatively indifferent material is taken by the protamcebe is not surprising. They certainly do not feed on the copper. Its presence is merely accidental, and the whole pheno- mena, as I believe, should be looked upon from this point of view. The species, even if brought into existence only by this peculiar combination of circumstances, may be regarded as distinct, since it has developed peculiar qualities and a mode of life of its own. The origin of the protozoon is easily explained, and must be sought in the rain-water which occasionally flows into the tank, carrying down from the roof of the buildings microscopic forms of life.” The author suggests that perhaps in other similar cases hitherto ascribed to galvanic action or that of air and water, processes asso- ciated with micro-organic life are of greater importance than has been recognized. ZOOLOGY AND BOTANY, MICROSCOPY, ETO. 665 Development of Monocystid Gregarines.*—Herr G. Ruschhaupt has been closely studying the Gregarine which is found in the testicles of Lumbricus agricola ; the species of Gregarines found in earthworms are Zygocystis cometa, Monocystis magna, M. cristata, M. porrecta, M. cuneiformis, M. agilis, and M. minuta, the characters of which are described by the author. Encystation of solitary forms was very frequently observed, the cuticle of the Gregarine forming the outer envelope of the cyst, while the subcuticular sarcocyst formed a second inner envelope ; M. porrecta frequently, and M. cuneiformis sometimes complete their development within the sperm-mother-cells of the Lumbricus. Obser- vations made on M. magna showed that the sporoblasts were formed in the neighbourhood of the nucleus, and afforded pro tanto evidence against the formation of sporoblasts by budding at the periphery of the cyst. Attention is directed to the presence of macrospores and microspores within one and the same cyst; the “ restmasse” of the spore or nucléus de relicat is seen to represent the true germ, and may be compared to what is to be seen in the ova of more highly differentiated animals. The author was on three occasions able to observe the entrance of spores into the sperm-mother-cell ; within it there occurred the following set of changes: the rapidity of these changes were, it may be premised, dependent on the state of matura- tion of the spore; the spore filled its shell as a homogeneous and clear mass of protoplasm which was inclosed by a quite fine envelope; changes began to be apparent in the shell itself, which were similar to those observed in degenerating spores; at last the contents were naked. Later on these exhibited ameboid movements of a highly differentiated character. In conclusion the author discusses the connection between the Gregarines and the generative products of the earthworm, the in- fection of earthworms with Gregarines and the relations between these parasites and coccidia, BOTANY. A. GENERAL, including the Anatomy and Physiology of the Phanerogamia. a, Anatomy.t+ Circulation and Rotation of Protoplasm as a means of Trans- port of Food-material.{—Dr. H. de Vries points out that the pro- cess of diffusion acts so slowly that it can be of no practical im- portance in determining the transport of food-material from one part * Jenaisch, Zeitschr. f. Naturwiss., xviii. (1885) pp. 713-50 (1 pl.). + This subdivision contains (1) Cell-structure and Protoplasm (including the Nucleus and Cell-division) ; (2) Other Cell-contents (including the Cell-sap and Chlorophyll); (3) Secretions; (4) Structure of ‘issues; and (5) Structure of 0 rgans. t Bot. Ztg., xliii. (1885) pp. 1-6, 17-26. 666 SUMMARY OF CURRENT RESEARCHES RELATING TO of the plant to another. During the brief duration of a summer night the whole of the starch accumulated during the day in the large leaves | of Helianthus and Cucurbita passes through the leaf-stalk into the stem. Researches into the rapidity of diffusion show that if this pro- cess were the sole cause of the movement it would take months or even several years to accomplish. The author is of opinion that it is effected mainly by the rotation and circulation of the protoplasm. In order to determine the wide distribution of these phenomena, the author subjected a number of plants to examination. In Tades- cantia rosea he found these movements in the conducting cells of the phloém of the vascular bundles; in this instance a true rotation passed up one longitudinal wall of the cell and down the other wall, the movement being at the rate of 0:2-0°4 mm. per minute. The movement was observed in the young half-developed branches, in all the internodes of the stem, in the central veins of the leaves and of the leaf-sheath, and in the rhizome and roots, always in the paren- chymatous cells, the rotation of the protoplasm carrying with it the microsomes, chlorophyll-granules, and starch-grains. A movement of circulation was equally universal in the epidermal cells of all organs, and one of rotation in the xylem-cells and in the young, thin-walled, but very elongated elements of the stiffening-ring. Similar phenomena were observed in Tropeoleum majus, Cucurbita Pepo, Elodea canadensis, Hydrocharis morsus-rane, and Limnocharis Humboldtii, in some cases also in the young bast-fibres, the wood-cells, and the epidermal cells; all intermediate stages being noted between typical rotation and circulation. The movement is, however, most easily seen in the conducting-cells of the phloém. The author concludes that movement of the protoplasm is a uni- versal phenomenon in tissues adapted for the accumulation and conduction of food-material; and that the protoplasm, not only in special cases or during particular periods of life, but everywhere and so long as it is active, has portions which are in motion. Division of the Cell-nucleus in Plants and Animals.*—M. L. Guignard continues his researches on this subject, and has further established the identity of the process of indirect division in the two kingdoms. He finds the highest of the vegetable types, and the one which displays most completely the analogy with the animal kingdom, in the nucleus of the embryo-sac of Lilium candidum. The nucleus is composed of a single filament, the folds of which frequently anastomose to form a network; and the author considers that the difference on this point between the views of Prof. Strasburger and M. Flemming is apparent rather than real. The granulations or chromatic microsomes are arranged in a single row in the hyaloplasm of the filament. Their size varies not only in different filaments, but even in the same. The nucleoli, from their first appearance, present distinct reactions, showing that their chemical composition differs from that * Ann. Sci. Nat.—Bot., xx. (1885) pp. 310-72 (4 pls.). See this Journal, iii, (1883) p. 864; iv. (1884) p. 915. ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 667 of the chromatic granulations ; they are not really comprised in the hyaloplasm, but probably contain a certain quantity of the chromatin of the nuclear filament. On attaining a certain size they detach them- selves from the folds of the filament; their presence can only be detected with certainty when their volume considerably exceeds that of the largest of the chromatic granulations. Their function in the life of the nucleus is at present unknown. The nuclear membrane is sometimes extremely delicate, as in the endosperm, sometimes thicker, as in the large nucleus of the embryo- sac. It is composed of a single layer of granulations, which may be isolated from the cytoplasm. The currents between the nucleus and the cytoplasm are the result of osmosis; the cytoplasmic reticulum and the framework of the nucleus are both in intimate connection with this membrane. It is achromatic and derived from the cytoplasm. As regards the chemical composition of the different parts of the nucleus, they may be divided into two groups, although their exact nature cannot at present be determined. The chromatic granulations of the filament, which alone enter into the constitution of the nuclear plate, contain the nuclein of Zaccharias, or the soluble nuclein (in caustic soda) of Miescher. The hyaloplasm and nucleoli are com- posed, according to Zaccharias, of insoluble nuclein or plastin. In the process of indirect division of the nucleus, Strasburger has adopted a distinction into three phases :—prophasis, metaphasis, and anaphasis; Guignard prefers to admit simply progressive and regressive phases, with the separation of the elements of the nuclear plate as the culminating point. The first change is usually to be observed in the nucleus itself; this is much less often preceded by a striation of the surrounding cytoplasm. This change consists in the formation of the knot (peloton), the folds of which gradually contract and thicken. The nuclear membrane becomes more visible; and towards the end of this stage two rows of chromatic granulations are sometimes seen in the hyaloplasm of the filament. The segmentation of the filament takes place most often before, less often after, the disappearance of the membrane. As soon as the segments are formed, the doubling of the chromatic granulations in the hyaloplasm makes itself manifest. At whatever time this doubling takes place, the segments have always the form of a ribbon at the moment when their longitudinal fission is about to take place in the nuclear plate. In pollen-mother-cells and in the embryo-sac their halves remain recognizable after the formation of the two rows of chromatic granulations. When the nuclear membrane is resorbed, the cytoplasm penetrates into the nuclear fluid. The achromatic threads of the spindle are then formed at the same time as the poles, which always appear as if situated, not in the interior of the nucleus, but in the cytoplasm itself. The threads, which are continuous from one pole to the other, are derived entirely from the cytoplasm in all cases in the vegetable kingdom which have yet been observed; while in the salamander and 668 SUMMARY OF CURRENT RESEARCHES RELATING TO hydra, the nuclear hyaloplasm takes part in their formation. In the embryo-sac of Lilium the amphiaster is visible before the poles act as centres of attraction ; in other cases it originates later. When once the nuclear plate is completely formed, the longitu- dinal fission of the chromatic elements commences at the extremity nearest to the centre; the two halves, separating more and more, glide in the direction of the poles. With complete separation the progressive phases of the division end. This is the stage designated by Flemming metakinesis. The regressive phases commence with the movement of the two chromatic groups towards the poles, between which remain the threads of the spindle. In each group the rods form together a radiate figure, the star (étoile) of the daughter-nucleus. Arrived at the poles, the rods contract and curve in various directions, so as to bring their free ends into contact, which then unite so as to form a con- tinuous filament from one pole to the other. Finally, the contraction and reconstitution of the filament is succeeded by the separation of the folds, accompanied by the formation of the nuclear fluid and membrane. The chromatic granulations become distinct in the hyaloplasm, at the same time that the nucleoli make their appearance in contact with the folds. The filaments may now remain as such, or may be converted into a new network resembling that of the parent nucleus. Changes in the Cell-walls of Epidermal Cells and in the Hairs of Pelargonium zonale.*—In the course of an article on this subject containing a very large amount of detailed observation, Dr. C. Frommann makes the following statements with regard to the inter- cellular protoplasm :—Many intercellular spaces, together with the cleft-like prolongations into which they run out, are so densely and uniformly filled up by granular protoplasm throughout their entire contents, and are, as it were, thus stopped up, that it is impossible to make them absorb water. In cases where the cell-walls are penetrated by threads which connect the parietal intracellular protoplasm with that contained in the intercellular spaces, it is impossible to doubt that the latter has pre-existed as such. There are sometimes small intercellular cavities filled with protoplasm and situated beneath the cut surface, completely surrounded and isolated by cellulose, where there is no possibility of the protoplasm being detached portions which have forced their way in, The granules and threads inclosed in a slightly refractive layer of cellulose by the solidification of the intercellular spaces, which are yet distinctly differentiated, show the same properties as those which still lie free in the inter- cellular spaces, Even after the intercellular spaces have become completely solidified, chlorophyll-bodies and denser protoplasm- granules can sometimes be distinguished in them, even when the fine granules and filaments have completely disappeared or become indis- tinguishable. It is evident that in these cases also the protoplasm imbedded in the cellulose must have previously existed free in the intercellular spaces. * Jenaisch. Zeitschr. f. Naturwiss., xviii. (1885) pp. 597-665 (2 pls.). ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 669 ° Carnoy’s Biology of the Cell.*—In this work Prof. J. B. Carnoy arranges his account of the structure of the cell under three heads :— The protoplasm and its contents; the cell-membrane; and a general account of the entire cell, The book on the nucleus consists of three chapters, treating of the chemistry of the nucleus, its structure when at rest, and its morphography. The nucleus consists, accord- ing to the author, of a membrane, a protoplasmic portion (reticulum and echylema) and a nuclein-filament, which contains the nuclein, and forms, in typical nuclei, a continuous thread, but may break up into pieces of various form, or may become absorbed and disappear altogether. In his account of the structure of the nucleus, the author differs in some essential points from that of Strasburger. He main- tains that outside the nuclein-filament is a protoplasmic network, out of which the spindle-threads are produced by division, He states also that the nucleoli are sharply differentiated from the nuclein- elements by containing no nuclein, The nucleolus forms a kind of reserve of nuclear protoplasm, and disappears altogether when the nucleus divides. ‘The “para-nucleolus” of Strasburger is the nucleolus itself. Decomposition of Solutions of Chlorophyll by Light.t—Dr. J, Reinke describes a series of experiments on this subject, from which he derives the general conclusion that the groups of rays of the solar spectrum may be arranged in the following series according to their power of decomposing chlorophyll :—red, orange, violet, yellow, blue, dark red, green. This series shows further that the power of any given rays to decompose chlorophyll is a function of the degree of their absorption in a solution of chlorophyll. The absolute maximum of the curve of this power coincides with the maximum absorption between the lines B and C; from here the curve falls rapidly to the ultra-red, more slowly through the orange and yellow to the green, where its minimum again coincides with the minimum absorption, rising then, through the blue, to a second smaller maximum in the violet. The separate values obtained by observation for alcohol- chlorophyll and benzol-chlorophyll nearly agree ; aleohol-chlorophyll does not show any stronger decomposibility in the blue and violet than benzol-chlorophyll does, which might have been expected, because in the former the absorption between F and G is increased by the greater proportion of xanthophyll. The curve of the action of the colours of the spectrum is perhaps a function of the absorption in pure chlorophyll; xanthophyll does not appear to act as a sensitizer in this process. The author claims to have shown that the decomposition of chlorophyll by the rays of the sun is in proportion to the absorption of the latter; and chloro- phyll no longer furnishes an exception to the general law with regard to substances sensitive to light, * Carnoy, J. B., ‘La Biologie Cellulaire: Etude comparée de la cellule dans les deux régnes. Fasc. 1. Technique microscopique.’ 8vo, Lierre, 1884, 271 pp. and 141 figs. + Bot, Ztg,, xliii, (1885) pp. 65-70, 81-9, 97-101, 113-7, 129-37. 670 SUMMARY OF CURRENT RESEARCHES RELATING TO Spectra of the Pigments of Green Leaves and their Derivatives.* —Herr R. Wegscheider gives particulars, in the form of comparative tables, of the position of the bands and the maximum of absorption in the cases of the spectra of (1) the living leaf; (2) tincture of chloro- phyll; (8) alcoholic solution of the crystallized chlorophyllan obtained by Tschirch; (4) the pure chlorophyll of Tschirch ; (5) the alkali-chlorophyll of Tschirch; (6) the y-xanthophyll of Tschirch in etherial solution. ‘— Red Pigment in Flowering Plants.t—Dr. J. Wortmann replies to the statements on this subject by Dr. H. Pick, many of which he considers to rest on erroneous observation. Especially he objects to Pick’s view on the influence of the red pigment in the transport of starch, in which he neglects the fact of the difference in the ob- jective intensity of rays of the same wave-length which have passed through media of different colours. Identity of the Orange-red Colouring Matter of Leaves with Carotine.{—M. Arnaud has prepared from the leaves of the spinach the orange-red colouring matter called by Bougarel erythrophyll. After purifying by repeated distillations in benzine it appears in small flattened rhombic crystals, dichroic, and with the iridescence of certain anilin colours. He finds this substance to be identical in its crystalline form, its solubility, its fusing point (168° C.) and in other characters, with carotine, the red colouring matter of the carrot, to which Husemann gives the formula C,,H,,0. The same substance occurs also in the leaves of the mulberry, the peach, the sycamore, and the ivy, and in the fruit of the gourd. Formation of Starch in the Leaves of the Vine.§—In pursuance of the experiments of Prof. Sachs || on the formation of starch in leaves, Sig. G. Cuboni has made a series of observations on its presence in the leaves of the vine. In March and April, when the leaves are first formed, starch was never found, even in bright sunshine. It first made its appearance in May, and the quantity increased con- tinually till July. This is not solely dependent on difference in temperature, since starch is still formed in the leaves at the end of October and in November; while even in the height of summer the young leaves and shoots are not able to form starch until they are at least a month old. It depends, however, to a certain extent on the maturity of the chlorophyll-grains. In a leaf containing no starch at the outset, abundance was found after an hour’s exposure to the direct action of the sunlight; and the maximum quantity was obtained by two hours’ intense sunshine. Four hours of complete darkness is sufficient to cause the whole of the starch to become absorbed. Although the youngest leaves are unable to form starch, the * Ber. Deutsch. Bot. Gesell., ii. (1885) pp. 494-502. + Bot. Ztg., xliii. (1885) pp. 39-43. See this Journal, iv. (1884) p. 257. ~ Comptes Rendus, c. (1885) pp. 751-3 § Rivista di Viticoltura ed Enologia Italiana, ix. (1885) p. 13. See Natur- forscher, xviii. (1885) p. 224. || See this Journal, iv. (1884) p. 089. ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 671 maximum development is not obtained by the lowest leaves on a branch, but by those on the middlemost nodes; on a branch containing sixteen leaves by those from the seventh to the eleventh, the lowest showing less than half the maximum power of production. Tf an annular incision is made above and below a leaf, separating the elements of the soft bast, the starch in the leaf is not absorbed and transformed in the dark; but if a similar incision is made only below or only above the leaf, the ordinary process is not disturbed ; and this is also the case if a leaf separated by an incision on both sides has a panicle of fruit or flowers opposite it on the same node. No starch is formed if the leaves are etiolated or attacked by Perono- spora viticola. Starch in Vessels.*—Dr. A. Fischer records the abnormal occur- rence of starch in vessels in the leaves of Plantago major. He found them only in the vessels of the leaf-stalk, not in those of the veins of the leaf itself, and mostly only in the spiral vessels of the stronger bundles. Portions of these vessels were filled with starch-grains, while in other parts they were entirely wanting. Presence of Manganese in Plants.t—According to M. E. J. Maumene, manganese occurs in small quantities in most vegetables. Tea is particularly rich in manganese, from 0°5 to 0°6 p. c.; so also is tobacco, especially the Kentucky variety, which contains from 1°5 to 1-6 p.c. Both yellow and red cinchona bark appear to contain more than traces of manganese. Nutritive Properties of the various portions of the Grain of Wheat.i—M. A. Girard states that of the three parts of which the grain of wheat may be said to consist, viz. (1) the integument, in- cluding the outer envelope of the endosperm, (2) the endosperm, and (3) the embryo, the value for nutritive purposes resides almost ex- clusively in the second. Both the integument and the embryo contain a considerable proportion of nitrogenous substance ; but this is chiefly in the form of cerealin, a substance almost valueless for nutritive purposes from its insolubility. Its fermenting properties render cerealin absolutely injurious in the making of bread. The embryo contains in addition an easily oxidizable oil, which has a very pre- judicial effect in promoting the rapid decomposition of the bread. Assimilating Cavities in the interior of Tubers of Bolbo- phyllum.§—Prof. E. Pfitzer describes the structure of the remark- able Bolbophyllum minutissimum, from Port Jackson, one of the minutest flowering plants. One of the most remarkable features is the occurrence in the disk-shaped tubers of peculiar chambers opening out into the external air only by a narrow cleft, the epidermal layer * Bot. Ztg., xliii. (1885) pp. 89-95. + Bull. Soc. Chim., xlii, pp. 305-15. See Journ, Chem. Soc.—Abstr., xviii. (1885) p. 421. ¢ Ann. Chim. et Phys., iii. (1884) p. 289. See Naturforscher, xviii. (1885) p- 44. § Ber. Deutsch. Bot, Gesell., ii. (1885) pp. 472-80 (1 pl.). 672 SUMMARY OF CURRENT RESEARCHES RELATING TO of which is abundantly provided with stomata, and which apparently serves for purposes of assimilation. Similar structures were found in a previously undescribed species, B. Odoardi, from Borneo. Tdioblasts containing Albuminoids in some Cruciferee.*—Herr E. Heinricher describes the structure of peculiar cells found beneath the epidermis in the leaves of Moricandia arvensis, not readily dis- tinguishable in the living state from the ordinary assimilating cells, but easily differentiated on treatment with alcohol, when their con- tents are seen to be chiefly, if not exclusively, of an albuminoid character; they contain neither sugar, starch, nor tannin. In Mor- candia these peculiar cells occur also in the floral organs with the exception of the petals and stamens; and the author has detected them also in four other species belonging to the tribe Brassicese of Crucifere, viz. Diplotaxis tenuifolia, Sinapis alba and nigra, and Brassica Rapa, where they are found within the assimilating paren- . chyma of the leaf, and in the deeper layers of the cortex of the stem and root; in Diplotaais tenuifolia even in the pith. These cells are certainly not excretion-receptacles, and it is doubtful whether they serve physiologically for the formation or for the storing-up of albuminoids. Morphologically they appear to be most closely related to laticiferous tubes, and are possibly derived from these organs by degradation, thus indicating a phylogenetic affinity with the allied order of Papaveracee. Annular and Spiral Cells of Cactacee.;—M. P. van Tieghem describes the structure and arrangement of these cells, the latter of which may be arranged under three types, all found in different species of the genus Opuntia. In O. flavicans the stem possesses four fibrovascular bundles separated by large rays, and surrounding a small pith. In these rays and pith the spiral and annular cells are found in large numbers, but not in the bundles themselves. After the formation of the secondary tissues the four fibrovascular bundles are very narrow, but strongly elongated radially, and are separated by four large fan-like secondary rays, which are composed exclusively of spiral and annular vessels, the secondary wood being again entirely destitute of them. The same is the case in O. flavicans and cylindrica. In O. tunicata, on the contrary, these cells are localized in the primary and secondary wood, and are wanting in the pith and rays. The same mode of distribution occurs in the genera Mamillaria, Echinocactus, and Melocactus. O. Salmiana, pubescens, and some other species display a combination of these two arrangements, the spiral and annular cells forming a more or less thick continuous sheath enclosing the wood, and they are also found in the primary and secondary wood. Finally, in O. Ficus-indica, brasiliensis, and in most species with flattened stem, these elements are altogether wanting. As far as their structure is concerned, they are living cells, with perfectly closed cell-wall, protoplasmic body, and nucleus. They constitute in fact a remarkable kind of parenchyma. * Ber. Deutsch. Bot. Gesell., ii. (1885) pp. 463-6 (1 pl). ¢ Bull. Soc. Bot. France, xxxii. (1885) pp. 103-5. ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 673 Formation of Secondary Cortex.*—M. E. Heckel describes the peculiar structure of the wood of a young branch of Sarcocephalus esculentus from ‘Tropical Africa. During the various stages of development of the primitive cortex to the condition of definite secondary cortex, all the initial layers disappear in succession, either by compression or by giving rise, by cell-division and multiplication, to new zones, two of which have a permanent existence. A cortex is thus again formed, constituted definitely of two tissues of secondary or even tertiary formation, entirely destitute of liber, the place of which is taken, from a physiological point of view, by certain elements which have become sclerotized. The author believes this structure to be not uncommon in tropical woods, Pericycle of the Root, Stem, and Leaves.t—According to M. L. Morot, there exists in all flowering plants, outside the central cylinder of the root, between the endoderm and the outermost part of the fibrovascular bundles, a layer of tissue, of the same origin as the pith and the medullary rays—the pericycle. It is the most important part of the internal conducting system of the root, from the secondary and tertiary formations to which it gives birth, and from the frequent absence of the pith in consequence of the fusion of the primary bundles, and also of the medullary rays. Although most often re- duced to a single layer of cells, it sometimes constitutes a layer of considerable thickness. It is usually homogeneous, but sometimes contains secreting canals. It is from the pericycle that the secondary roots always proceed; and it may, by the repeated divisions of its cells, produce cork, secondary parenchyma, and secondary or tertiary fibrovascular bundles. The presence of the pericycle is nearly as invariable in the stem, where it may also persist in the absence of the pith and medullary rays. The only instances of its being entirely wanting are in certain aquatic plants of degraded structure. Occasionally it forms a separate envelope round each bundle; in the vast majority of cases it consti- tutes a continuous sheath round the whole of the central cylinder. It usually consists of a number of layers of cells, but is sometimes reduced to only one. Its structure is more complex than in the root. Sometimes it remains entirely parenchymatous ; but it is most often partially sclerotized, and then contributes largely to the constitution of the stereome of the stem. In addition it may inclose laticiferous vessels, resiniferous cells, and secreting canals. Like that of the root, the pericycle of the stem may generate new tissues. From it proceed underground or aerial lateral roots; or it may develope intercalary vascular bundles between the primary ones, cork, secondary parenchyma, and centrifugal layers of meristem. The pericycle occurs equally in the leaves, where it is inclosed, like the endoderm, between the bundles, rarely forming a complete ring round them. Its composition varies greatly as in the stem; it * Bull. Soc. Bot. France, xxxii. (1884) pp. 95-9 (1 pl.). + Ann. Sci. Nat.—Dot., xx. (1885) pp, 217-309 (6 pls.). 674 SUMMARY OF CURRENT RESEARCHES RELATING TO rarely forms new tissues, but it may be the seat of the formation of adventitious roots. The recognition of the pericycle as a distinct element in the con- stitution of the root, stem, and leaves, greatly facilitates the distinc- tion between the central cylinder and the cortex. The imnermost layer of the cortex is the endoderm; but this frequently loses the special characters by which it is ordinarily distinguished, and the boundary of the cortex can then be determined by the pericycle, which is always recognizable by the presence of scleric elements and by its generating power. It also serves to define more exactly the position and constitution of the liber. To this latter have frequently been erroneously referred certain lignified elements which really belong to the pericyclic layer between the outermost portion of the bundles and the endoderm. Furthermore the recognition of this structure permits the place of formation to be exactly defined of elements hitherto referred to various anatomical regions. A good illustration of this is afforded by Van Tieghem’s observations * that the oleiferous canals of Umbelliferze, Pittosporee, and Hypericum, originate in the peri- cycle, equally. in the root, stem, and leaves; while the laticiferous vessels of Cichoriacez have their origin in the pericycle in the stem and leaves, in the liber in the root. Changes of Structure in Land-Plants when growing sub- merged.j—Herr H. Schenck describes these changes, which are espe- cially pronounced in the case of Cardamine pratensis when growing entirely submerged in water. They are all in the direction of the structure of the organs and of the tissue in plants which grow ordi- narily beneath the surface of the water. The leaves acquire long stalks; the mechanical elements are greatly reduced; the cuticle of the epidermis being thin, and the fibrovascular bundles reduced in size, especially the xylem. On the other hand, the assimilating tissue of the leaves is much more strongly developed, the cells of the mesophyll being rounded and very loosely associated. Epidermis of the Leaves of Aquatic Plants.;—M. J. Costantin disputes the statement of Brongniart and Jussieu that the leaves of aquatic plants are destitute of an epidermis. This statement rests on the hypothesis that epidermal cells do not contain chlorophyll, and that the leaves of aquatic plants do not possess stomata; but the author points out that both these assertions can only be accepted with a considerable amount of exception. He states also that the number of stomata varies in leaves of precisely the same character in the same species, and that the water surrounding the leaves has a direct influence on the formation of stomata. Structure of Ranunculacee.$—M. P. Marié has made a close examination of the structure of the different organs in the various genera and subgenera of Ranunculacex, which he describes in detail, * See this Journal, iv. (1884) pp. 767-70. + Ber. Deutsch. Bot. Gesell., ii. 1885) pp. 481-6 (1 pl.). } Bull. Soc. Bot. France, xxxii. (1885) pp. 83-92. § Ann. Sci. Nat.—Bot., xx. (1885) pp. 5-180 (8 pls.). ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 675 giving also a number of characters which are common to the whole order, in the form and arrangement of the stomata, the structure of the tissues, arrangement of the fibrovascular bundles, &c. Opening of the Anthers in Ericacee.*—Mr. H. H. Rusby de- seribes the position in which the pores are found through which the pollen escapes from the anthers in this order, which differs materially in the different genera. The basal position of the pores in some genera, and their apical position in others, depends on variations in the mode in which the filament is folded in the bud. The “horns” attached to the anthers have an important function in determining the direction in which the pollen is discharged. Anatomy of the Leaf in Vismiew.j—M. J. Vesque gives details of the anatomical structure of the leaf in the four genera which make up this tribe of Hypericaceee. They are characterized by the stomata being accompanied by two parallel cells at the mouth, by stellate hairs with conical or cylindrical rays, by rounded schizogenous glands in the mesophyll, canaliform glands in the pericycle and secondary liber, and by agglomerations of crystals. Reduced Organ in Campanula.{—Dr. E. Heinricher describes a peculiar structure, hitherto unnoticed, in the epidermal cells, most commonly of the upper surface of the leaf, of Campanula persicifolia. They consist of protuberances of the cell-wall nearly in the middle of the outer wall of the cells, often projecting considerably into the cell- cavity ; corresponding to these were frequently also projections from the outer surface of the cell-wall. This species has two distinctly marked forms, hairy and glabrous; and the author regards these peculiar structures as reduced trichomes. The application of reagents showed that they do not consist of pure cellulose. They were observed in all specimens examined of C. persicifolia, also in C. grandis and patula. Hypertrophy of the Bud-cones of the Carob.S—M. L. Savastano describes an abnormal growth of the singular organs which he terms “bud-cones” in the carob-tree (Ceratonia siliqua) in the south of Italy. Ordinary buds appear in the axil of a branch, and develope either into a branch the following year or into one or two inflorescences during the third year, which rarely bear fruit. At the same time is formed the “ bud-cone,” which will put forth an annual succession of inflorescences for fifteen or twenty years, after which its activity ceases and it disappears. These bud-cones are subject to a disease which causes them to swell to the size of a wen, producing each year an unusual large number of inflorescences which, however, wither without fruiting, and after a time cease to be produced. These wens are found to consist mainly of a uniform tissue of irregular cells of * Bull. Torrey Bot. Club, xii. (1885) pp. 16-21 (13 figs.). [The author uses the term “anthesis” incorrectly for the Diicstitig of the anther instead of the opening of the flower.—Eb. | + Comptes Kendus, c. (1885) pp. 1089-92. ¢ Ber. Deutsch. Bot. Gesell., iii. (1885) pp. 4-13 (1 pl.). § Comptes Rendus, c, (1885) pp. 131-3. 676 SUMMARY OF CURRENT RESEARCHES RELATING TO large size without any woody elements. The malformation is due neither to the attacks of parasites nor to external causes, nor to a formation of gum, but to simple hypertrophy of the tissues. Homology of the Floral Envelopes in Graminee and Cyperacee.* —Mr. F. Townsend seeks to prove that the pale in the floret of grasses is the homologue of the ochrea and utriculus in Carex, and that the latter is a single floral envelope; hence the pale is also single. “The author gives notes on several species of the order Cyperacee, more particularly with the view of ascertaining the homology of the parts of the inflorescence; and records a few instances of abnormal development in the order Graminez which bear on the subject. The utriculus of Carex, like the inner and lower barren glume of grasses, is always next the rachis, and the position of the subtending bract of the female spike of Carex is exactly that of the usually suppressed bract at the base of the spikelets of grasses. The tendency of the utriculus or ochrea is to become divided, and this division occurs in the lower barren glume of Festuca, and also in the pale of grasses generally, which is the homologue of the utriculus of Carex; as the fertile glume of the spikelet in grasses is the homologue of the subtending bract of the utriculus in Carex. The seta, more or less developed in many species of Carew, is the rudi- mentary development of a secondary axis, while the “acicula” of Dumortier is the terminal portion of the spikelet. Bulbils of Begonia socotrana.;—M. P. Duchartre describes the peculiar bulbils of this species, formed in large quantities on the rhizome. 'They have a peculiar organization which enables them to develope, after a period of repose, into a new plant bearing flowers and bulbils. This organization is extremely complex, each bulbil containing within it a rudimentary branch, consisting of a well- developed axis to which are attached thick fleshy bodies 4-5 mm. in length, the rudiments of leaves. This structure is itself a store of nutriment for the young plant, its envelope consisting simply of two large but very thin leaf-scales, superposed entirely one on the other, except at the base. Petalody of Ovules.{—Dr. M. T. Masters describes a remarkable case of malformation in Dianella cerulea, belonging to the Aspara- gacez, from Australia. The flowers are very much more densely crowded than in the normal form, and in a large number of the flowers a multiplication of perianth-segments has taken place at the expense of the stamens and carpels, but with scarcely any intermediate forms. In other flowers the amount of change has been much legs; the perianth retaining itsnormal condition while the thickened fleshy filament is replaced more or less completely by a slender ribbon-like stalk, to which the anther is dorsifixed instead of basifixed. The ovary is transformed from a trilocular condition with axile to a * Journ. of Bot., xxiii. (1885) pp. 65-74 (19 figs.). + Bull. Soc. Bot. France, xxxii. (1885) pp. 58-63. t Nature, xxxi. (1885) pp. 487-8. ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 677 unilocular condition with parietal placentation. But the most remarkable changes are in the placenta, consisting in the outgrowth from the ventral suture of two narrow parallel longitudinal plates of a bright blue colour extending the whole length of the carpels. In flowers in which this petalodic condition of the placenta is present, there are no ovules in carpels which are closed and unilo- cular, while in cases where the ovary is still trilocular ovules in a very rudimentary condition are present, reduced to a funicle and irregular plate of cellular tissue more or less blue in colour, but without any nucellus. This is the first instance recorded of petalody or of any form of phyllody of ovules in Monocotyledons. Haberlandt's Physiological Anatomy of Plants.*—The special characteristic of this work is that it k«mgs prominently forward the function of the various kinds of tissue, classifying them as formas tive, epidermal, mechanical, absorptive, assimilating, conducting, accumulating, aerial, and secreting. It will illustrate the treatment to mention that such terms as bast, cambium, &c., are not used by the author as defining tissues found in special positions, but as tissues performing special functions. ; Behrens’s Text-book of General Botany.}—The speciality of this text-book (translated from the German and revised by Prof. P. Geddes) is the abundant detail in the account of the morphology of the various organs of flowering plants. Under the head of Physio- logical Botany large space is devoted to the phenomena of pollina- tion and fertilization, and the illustrations are numerous and good. 8B. Physiology.t Production of Male and Female Plants.s—Dr. H. Hoffmann has attempted to determine the conditions under which male or female individuals are produced in the case of the following dicecious plants :—Lychnis diurna and vespertina, Valeriana dioica, Mercurialis annua, Rumex Acetosella, Spinacia oleracea, and Cannabis sativa. He finds that in most, if not all these cases, dense sowing increases the proportion of male plants produced, and this results from an insuffi- cient supply of nutriment. As a general law, the production of male plants is promoted by the want of an adequate supply of food when in an embryonal condition. Fertilization of Naias and Callitriche.||—According to Dr. B. Jonsson, the fertilization of the Naiadacesw is purely hydrophilous, and takes place in the following way. The flowers are either mone- cious or diccious; in the monccious species the male flowers are * Haberlandt, G., ‘ Physiologische Pflanzen-anatomie im Grundriss dar- gestellt, 140 figs. 8vo, Leipzig, 1884. + Behrens, W. J., ‘Text-book of General Botany,’ revised by P. Ged les. viii. and 374 pp., 408 figs. 8vo, Edinburgh, 1885. ¢ This subdivision contains (1) Reproduction (including the formation of the Embryo and accompanying processes) ; (2) Germination ; (3) Growth ; (4) Respira- tion; (5) Movement; and (6) Chemical processes (including Fermentation). § Bot. Ztg., xliii. (1885) pp. 145-153, 161-9. || Lunds Univ. Ars-skr., xx. (1884) 26 pp. (1 pl.). Ser. 2.—Vo.. V. 2Y¥ 678 SUMMARY OF CURRENT RESEARCHES RELATING TO seated higher on the axis than the female, which are mature about the same time; the male flowers being very much the more nume- rous. When the anther is ripe, the pollen-mass, in which the last ordinary stages of development are suppressed, becomes free ; and the elliptic-cylindrical pollen-grains, which are completely filled, except at the two polar ends, with starch-grains, sink in the water in conse- quence of their greater specific gravity, and are caught by the detaining apparatus of the female flowers. In diwcious species the process varies only in the pollen having to be carried to the stigma of another plant.. When once the pollen-grain is detained, the pollen-tube passes into the canal of the style, by the wall of which it is attracted and hindered in its growth, in consequence of which it becom7s separated by collenchymatous septa, so that the rapid access of 1ood-material is prevented. From the conducting tissue at the mouth of the canal, the pollen-tubes usually find their way direct to the conducting tissue at the mouth of the micropyle, whence they reach the wall of the embryo-sac. In Callitriche autumnalis the pollen-grains are round, filled with oily protoplasm, and lighter than water. They are carried actively by the water to the stigma, whence they reach the canal of the style. The difference in the mode of fertilization in Naias and Callitriche corresponds to the difference in their habit, the former preferring still, the latter running water. Influence of direct Sunlight on Vegetation.*—M. Buysman calls attention to the influence of direct sunlight on vegetation, tracing in the first place the effect of the sun’s rays in the tropical regions and afterwards in the temperate and arctic zones. The constant high temperature within the tropics is the cause of the plants being less dependent on the direct solar heat than is the case in the greater part of the temperate and cold zones. Plants in the high northern regions when they vegetate receive more warmth by insolation than is often supposed—Ist by the direct solar light itself, and 2nd by the heated surface of the ground. The snow and ice being melted by the sun, the necessary water and humid atmosphere never fail; thisis the cause of the luxuriant growth of grass on some places of the Tundra. The flowing water gradually communicates its warmth to the soil, and prevents also nightly radiation. In the temperate regions vegetation commences in spring when the difference in temperature between night and day is greatest; in the high north this difference is often insignificant because the sun remains above the horizon ; but the temperature of the soil being at this time very much lower than that of the objects exposed to the sun’s rays, even this great difference is the cause of the very rapid vegetation in sheltered localities and under the influence of the solar light, Absorption of Oxygen and Evolution of Carbon dioxide in Leaves kept in Darkness.;—MM. P. P. Dehérain and L. Maquenne, repeating * Nature, xxxi. (1885) pp. 324-6, + Comptes Rendus, c. (1885) pp, 1234-6, ZOOLOGY AND BOTANY, MICROSCOPY, ETO. 679 the experiments on this subject of MM. Bonnier and Mangin,* have arrived at somewhat different results. They describe the apparatus used, the plant experimented on being Euonymus. Instead of the value of Le being usually less than unity, they found it to vary from 0-96 (in February) to 1°20 (in April), being most often greater than unity. The cause of this difference the authors suggest to be that the carbon dioxide measured by MM. Bonnier and Mangin included a portion of that formed by respiration. They consider the facts observed to show that in the plant examined a portion of the carbon dioxide given off is the result of internal combustion similar to that which takes place in fermentation. Commenting on this paper, M. Th. Schleesing t considers the results obtained by MM. Bonnier and Mangin to be very well authen- ticated, and points out the singular fact, which he does not attempt to explain, that the proportion of hydrogen in the plant is larger than might be expected to result from the fact that it becomes fixed in the plant along with oxygen in the proportion in which the two together constitute water. Variation of Respiration with Development.{—As the result of further experiments on the relation between the amount of oxygen inhaled and of carbon dioxide exhaled by plants, Messrs. G. Bonnier 2 and L. Mangin state that the value of the fraction “OF is not constant for the same species in different stages of development; but that at the same stage of development it is always constant whatever the temperature. This corresponds to the law already established by the authors for the relationship between the gases absorbed and exhaled by leaves in darkness. Thermotropism of Roots.s—New experiments on the pheno- menon to which Dr. J. Wortmann has given this name,|| made on seedlings of Ervum lens, Pisum sativum, Phaseolus multiflorus, and Zea Mais, have led him to the general conclusion that not merely the tip, but the entire growing region of the root, is sensitive to heat striking it on one side. By the application of higher temperatures, decapitated roots displayed the same energy in their thermotropic movements as normal roots. A similar sensitiveness was shown by the secondary roots of the scarlet runner. Air in Water-conducting Wood.{—Dr. M. Scheit lays down the following propositions on this subject :—So long as the cell-walls are moist, as is the case with living plants under normal conditions, no air can diffuse through the tracheids ; for it can be demonstrated that even under pressure, lasting for weeks, greater than that which is * See this Journal, iv. (1884) p. 591; ante, p. 488. + Comptes Rendus, c. (1885) pp. 1236-8. ¢ Ibid., pp. 1092-5. See this Journal, ante, pp. 94, 488. § Bot. Ztg., xliii. (1885) pp. 193-200, 209-16, 225-35. || See this Journal, iii. (1883) p. 873; iv. (1884) p. 588. § Jenaisch. Zeitschr. f. Naturwiss., xviii. (1885) pp. 463-78. ZY 2 680 SUMMARY OF CURRENT RESEARCHES RELATING TO exerted on the plant from without, no diffusion takes place. When the consumption of water is greater than the supply, bubbles, not of air, but of aqueous vapour, arise so soon as the conducting elements are protected from the access of the external air. The bubbles which make their appearance in microscopic sections can only be air-bubbles when the making of the section does not prevent the access of the external air. Even with the water of transpiration no air can reach the woody elements in which this takes place. The escape of bubbles of gas from “ weeping” rootstocks and other parts of plants, and the mixture of bubbles of aqueous vapour with those of air, can be ex- plained by the access of the external air on making the section, and to the opening of cells or vessels which are filled with aqueous vapour and impermeable to air when closed. The observations of the author confirm the statement that no bubbles of air occur in the conducting organs of growing plants. Ammoniacal Ferment.* — According to M. A. Ladureau, the ferment which transforms urea into ammonium carbonate occurs in the soil, the air, water, rain, &c. It acts in vacuo as under normal pressure, also under the pressure of three atmospheres, and in the presence of oxygen, hydrogen, nitrogen, carbon, &c. Antiseptics act on this ferment only when present in large quantities; of anesthetics chloroform only modifies its action. Source of the Nitrogen of the Leguminosz.t—M. B. E. Dietzell has grown clover and peas under conditions as nearly natural as possible, in pots of ordinary garden soil, in the open air, but sheltered from the weather and watered with pure distilled water. The quantity of nitrogen in the soil, the seeds, and the mature plant was deter- mined, and the result arrived at was that peas and clover do not absorb combined nitrogen from the air. In all cases except two there was an actual loss from 5-1 to 15°82 per cent. of the nitrogen in the soil. Absorption of Atmospheric Nitrogen by Plants.t—Mr. W. O. Atwater describes a series of experiments in growing peas in a nutrient fluid composed of potassium nitrate, calcium nitrate, calcium phos- phate, magnesium sulphate, and chloride of iron, and protected from rain and dew. He finds as a uniform result that the mature plant contains much more nitrogen than it could have obtained from the nutrient fluid and from the store cf food-material in the seed. The amount of nitrogen thus obtained from the atmosphere increased in proportion to the supply of nutrient material in the root. In some of the experiments from one-third to one-half of the total amount of nitrogen in the plant must have been obtained in this way. The author is unable to determine in what form and through what organ this nitrogen was absorbed by the plant, whether as free nitrogen, or aS ammonia, nitric acid, or any other compound, and * Comptes Rendus, xcix. (1884) p. 877. + Ann. Agronomiques, x. pp. 543-4. See Journ. Chem. Soc.—Abstr., xviii. - (1885) p. 418. { Amer. Chem. Journ., vi. (1885) p. 365. See Naturforscher, xviii. (1885) p. 237. ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 681 whether through the leaves or in the nutrient solution through the root; any one of these modes being in opposition to well-attested experiments. A possible explanation seems to be that free nitrogen is absorbed by decaying vegetable substances by the assistance of electricity. B. CRYPTOGAMIA. Cryptogamia Vascularia. Affinities of Laccopteris.*—The genus Laccopteris is formed of several species of fossil ferns the remains of which are found in strata from the Rhetian to the Cretacean, and has been referred to the Gleicheniacew. This distribution is confirmed by M. R. Zeiller, who points out that the structure of the sporangia is almost identical with that in Matonia. The sori are composed of from 5-11 large sporangia, arranged in a stellate manner, differing only from those ot Matonia in the absence of the membranous indusium, which may not be constant. The sporangia are furnished with a large complete oblique annulus. The spores have the same tetrahedral form. Composition of the Ash of Equisetacez, and its Bearing on the Formation of Coal.t—M. Dieulafait has examined 168 samples of the ash of various existing species of Equisetacee collected in different localities. Although the ashes of different species vary considerably in composition, they are all characterized by the presence of. calcium sulphate in large excess, and the total absence of alkaline carbonates. The proportion of ash varied from 5*2 to 8°3 per cent. of the fresh plant, and the mean amounts of potassium sulphate and calcium sulphate in the ashes were 12:0 per cent. and 14°3 per cent. respec- tively. ‘The mean percentage of sulphuric acid was 13°91, whilst the amount of this acid in the ashes of other plants collected in the same places was not more than 1 per cent. ‘These latter ashes also contained a large proportion of alkaline carbonates. The presence of such large quantities of sulphuric acid in the Equisetacez is obviously one of the causes of the presence of sulphur in coal. Transitional Equisetum.{—Herr A. Tépffer describes an Hqui- setum found at Gastein intermediate between EH. variegatum and E. scirpoides, agreeing in all respects with EH. variegatum var. anceps, but possessing the peculiar “root-felt” of H. scirpoides. Muscinee. Conduction of Water in the Stem of Mosses.§—Dr. G. Haber- landt replies to the observations of Herr F. Oltmanns || on this subject. He objects to the experiments of the latter on Mnium that he allowed the plant to become too dry; and contends that the central bundle is the organ by means of which the plant raises water out of the soil. * Bull. Soc. Bot. France, xxxii. (1885) pp. 21-5 (1 fig.). + Comptes Rendus, ec. (1885) pp. 284-6. $ Oesterr. Bot. Zeitschr., xxxv. (1885) pp. 121-2. § Ber. Deutsch. Bot. Gesell., ii, (1885) pp. 467-71. || See this Journal, ante, p. 493, 682 SUMMARY OF CURRENT RESEARCHES RELATING TO To this critique Herr Oltmanns * again rejoins, maintaining that even in the case of Polytrichum and Mnium the power of conduction of the stem is so small that only in an atmosphere of at least 90 per cent. relative moisture is it sufficient to meet the consumption. The internal conduction must therefore in any case be of very subordinate importance. Pottia Gussfeldti, a new Moss.j— Under this name, Herr K. Schliephacke describes a new species of moss from the mountains of the Argentine Republic, of interest as belonging to a European type, and replacing in that country the P. latifolia of our Alps. The author dissents from Venturi’s proposal to establish from P. latifolia a new genus Stegonia dependent on the peculiar character of the cells and nerve of the leaf; but proposes, on the other hand, to form under the same name a subgenus of Pottia which shall comprise the two species P. latifolia and Giissfeldti. Elaters of Hepatice.{—M. Leclere du Sablon defines the part played by the elaters in the dissemination of the spores of the Hepatice. He points out the resemblance in the structure and the mode of dehiscence of the sporogonium of Hepatic and the anther of flowering plants, and describes the former in detail in the case of Pellia epiphylla, Calypogeia Trichomanis, and Frullania dilatata. As the elater dries it contracts considerably, and the coils of the spiral become closer, expanding again on moistening. The intervals be- tween the coils of the spiral contract more than the spirals themselves, which are lignified. In addition to their contraction, the elaters also change their position when the sporogonium dehisces; before de- hiscence they are parallel, afterwards divergent; and this last is the chief agency in violently separating and dispersing the spores. Algee. Protoplasmic Continuity in the Fucaceze.§—In continuation of his previous observations on the continuity of protoplasm from cell to cell in the thallus of the Floridez, || Mr. T. Hick now describes the same phenomenon in several species of Fucacex, especially Fucus nodosus (Ascophyllum nodosum), F. vesiculosus, and F’. serratus. In the first species named, in the cortical layers and in the filaments of the central tissue, the protoplasm appears to run uninterruptedly from cell to cell in the longitudinal direction. At the ends of the cells, i. e. at the point where two adjacent cells are united, there is an annular thickening on the internal wall not unlike a strongly developed ring of an annular vessel. The material of which this ring is composed differs from that of the cell-walls in not dissolving or undergoing gelatinization under the influence of reagents. It seems to resist alike the action of the strongest acids * Op. cit., iii. (1885) pp. 58-62. + Ber. Deutsch. Bot. Gesell. ii. (1885) pp. 461-2. t Bull. Soc. Bot. France, xxxii. (1885) pp. 30-4. § Journ. of Bot., xxiii. (1885) pp. 97-102 (1 pl.). || See this Journal, iv, (1884) p. 101. ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 683 and the strongest alkalies, as well as the disintegrating action of a solution of bleaching powder. Within this ring the arrangements are not the same in all cases, but for the most part they conform to one of four types. 1. In the first type the ring surrounds a comparatively wide and open pore, through which the protoplasm is continuous in a single thread. This type is not very common, but isolated cases are to be met with here and there. 2. In the second type a delicate diaphragm stretches across the space inclosed by the ring, and through this the protoplasm is con- tinuous, as through a sieve-plate, by a number of delicate threads. This is perhaps the commonest form of continuity, and bears the closest possible resemblance to that met with in the sieve-tubes of higher plants. 3. The third type agrees with the second, except that continuity is effected by a thin and delicate ribbon of protoplasm which passes through a narrow slit in the diaphragm. This form is not abundant, and appears to be intermediate between the second and the fourth. 4, In the fourth type the diaphragm is complete and impervious, except at the centre, where there is an extremely minute pore, through which a single delicate strand of protoplasm maintains the con- tinuity. The delicate diaphragm met with at the ends of the cells, like the annular thickening which incloses it, does not swell up under the action of reagents, nor does it stain like the rest of the walls. In Fucus vesiculosus and serratus the same phenomena of con- tinuity were observed, both in the layers of cortical cells and in the fibres which arise from them and curve inwards to interlace with the central filaments. Fertilization of Cryptonemiacew.*—Dr. G. Berthold publishes a monograph of the species of this family of Floridew found in the Bay of Naples, belonging to the genera Halymenia, Grateloupia, Cryptonemia, Schizymenia, Sebdenia, Halarachnion, Nemastoma, Gym- nophiea, Calosiphonia, and Dudresnaya. These are classified by the author under four tribes:—Halymeniex, including Halymenia, Cryptonemia, Grateloupia, and perhaps Schizymenia; Nemastomes, including Dudresnaya, Calosiphonia, Nemastoma, and Gymnophlea ; while Sebdenia and Halarachnion each constitutes a tribe by itself. The vegetative structure presents nothing very remarkable. In most forms there are found at the apex several apical cells, from which, lying side by side, the thallus is constructed. Dudresnaya and Calosiphonia differ from the remaining genera in presenting only a single apical cell. In none of the Cryptonemiacex are tetraspores found on the same individual as the sexual organs. The mode of fertilization presents in all the genera the same essential features as that already known in Dudresnaya and Polyides, The lower portion of the impregnated trichogyne is separated off by * Berthold, G., ‘Oryptonemiaceen. Fauna u. Flora des Golfes v. Neapel. Monog. xii., 27 pp. (8 pls.). 4to, Leipzig, 1884. 684 SUMMARY OF CURRENT RESEARCHES RELATING TO a septum as the carpogonium. The cells with which the trichogyne or tubes which proceed from it, conjugate, the auxiliary cells, are of two kinds:—fertile, those which, after conjugation with the connect- ing filaments which proceed from the carpogonium, form cystocarps ; and sterile, which do not bring about this result. These sterile auxiliary cells occur in Dudresnaya, Calosiphonia, and Nemastoma, but not in the other genera. When present they are always in the immediate vicinity of the carpogonium, while the fertile cells are often at a greater distance from it. In the Halymeniez (Halymenia, Grateloupia, and Cryptonemia) the auxiliary cell is homologous morphologically with the carpogonium, and is surrounded by a similar group of investing filaments. Hach fertilized carpogonium may give birth to a large number of auxiliary cells for the purpose of forming a cystocarp; and this is especially the case in the Halymeniee and in Nemastoma. The number of species described is twenty, among which are two new ones, Gymnophlea pusilla and Calosiphonia neapolitana. Sieve-hyphe in Algw.*—Dr. N. Wille states that in the stipes of certain Laminariacez, a portion of the hyphe running through it in a longitudinal direction have long narrow cell-cavities, and that the transverse walls of these cells are perforated in the same way as those of the sieve-tubes of Phanerogams. These sieve-hyphe are also connected with one another transversely by short branched hypha, thus causing a complex system of communication of the sieve-hyphe with one another, and between these and the assimilating system. The sieve-hyphe occur also as'a middle lamella between the two assimilating layers in the leaves of Laminaria ; and evidently per- form a very important function in the conveyance of nutriment from one part of the plant to another. These sieve-hyphe were observed in Laminaria digitata, Clustont and saccharina. A somewhat similar structure occurs in the leaves of Fucacee ; andin Chorda filum,a similar though less developed system ; also in Chordaria flagelliformis. In the Floridee conducting hyphe of various kinds are also found. In Cystoclonium purpurascens the eutire conducting system is surrounded by a protecting ring of large thick-walled cells. Algez of Bohemia.j— Dr. A. Hansgirg enumerates the fresh- water alge found in Bohemia, which have not previously been observed, and describes the following new species :—Micrococcus ochraceus, Gloeocapsa salina, Nostoc halophilum. Pelagic Alge.t—Dr. R. F. Solla gives a list of twenty-three species of marine algz (besides four unnamed) obtained from the island of Lampedusa, and eighteen from the island of Linosa, both off the coast of Sicily. They belong to the families Porphyracez, Ceramiaceze, Spyridiaces, Rhodymenacer, Hypneacer, Gelidiaces, * Ber. Deutsch. Bot. Gesell., iii. (1885) pp. 29-31 (1 pl.). + Oesterr. Bot. Zeitschr., xxxy. (1885) pp. 113-7, 161-6. { Ibid., pp. 48-53. ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 685 Rhodomelacesw, Corallinacese, Fucacez, Dictyotese, Scytosiphonaceer, Ulvacez, Confervaces, Valoniacex, Bryopsides, Codiacerw, Dasycla- dacez, and Nostocacee. Rabenhorst’s Cryptogamic Flora of Germany (Marine Algz). —We have now the completion of this, which constitutes the second volume of the entire work. The last two parts (9 and 10) include the completion of the genus Cladophora, and the families Anadyo- -menez, Valoniew, Dasycladee, Nostocacez, and Chroococcaceer, in- cluding under the Nostocaceew the genera Rivularia, Lyngbya, Oscillaria, and others. The mode in which this section of Dr. Rabenhorst’s great work has been accomplished reflects the greatest credit on Dr. F. Hauck, to whom it has been intrusted. Diatoms and Bladderwort.*—Mr. H. Taylor has forwarded to ‘Science Gossip’ a slide containing a bladder of Utricularia upon or within which are to be seen numerous frustules of diatoms, upon the decomposing endochrome of which he thinks the plant may have fed. He says that Mr. Darwin, who does not, in his work on carni- yorous plants, mention Diatomaces being found in the bladders of any of the species, “appears to think the taking-in of food by the bladders is not owing to any voluntary act on their part, but that the different things found in them have merely forced their way in; but as many of these diatoms are stipitate and attached forms, having no power of locomotion, like the free frustules, this looks very much like their being seized by the antenne round the valve of the blad- der, and conveyed or swallowed in.” Mr. Taylor is not, however, certain whether the diatoms are inside or outside the bladder, and even if they be inside it still remains to be shown that they are utilized as food by the plant. Mr. F. Kitton has given his opinion as to the position of the diatoms. Speaking about the slide forwarded, Mr. Kitton says: “The diatoms are, I have no doubt, upon the bladder of the Utricu- laria as the species are all parasitic (and no doubt occurred on other parts of the plant); they could not have been injected by the bladder, as it possesses no prehensile organs which would be necessary to detach the diatoms from their stipes. The following are the species attached: Gomphonema constrictum, Synedra capitata, Cocconema lan- ceolatum, Diatome vulgare.’ The point, however, is one of some interest, and it would be well if it were thoroughly cleared up by means of the examination of fresh specimens, Mr. Taylor's having been a dried one. Structure of the Cell-wall of Diatoms.t—Dr. O. Miiller replies to the paper by Dr. J. H. L. Flogel { which has appeared in this Journal. He states the difference between Dr. Flégel’s view and his own to be that the former considers he has proved the existence within the cell-wall of Pleurosigma of numerous closed cavities corresponding to the well-known polygonal markings on the surface ; * Sci.-Gossip, 1885, p. 164. + Ber. Deutsch. Bot. Gesell., ii. (1885) pp. 487-94 (1 fig.). t See this Journal, iv. (1884) pp. 505-22, 655-96 (5 pls.) 686 SUMMARY OF CURRENT RESEARCHES RELATING TO whilst he objects that these chambers cannot be closed on all sides. This is the kernel of the dispute, everything else is unim- portant. Dr. Flogel objects to Dr. Miiller’s experiments in flooding the walls of the diatoms with fluids of different densities, on the ground that “all the fluids named by him will penetrate the inter- stitial molecules of thin membranes with the greatest facility ” ; from this assertion Miller dissents as regards the silicified cell-walls of diatoms, while pointing out the ambiguity of the term “ interstitial molecules.” He objects also to Dr. Flogel’s application of the term endosmose to processes which have not the slightest connection with diosmose, e.g. to the passage of fluid through a porous membrane which is bounded on the other side by air. The fact of the rapid filling up of the chambers and their emptying by evaporation is, according to Dr. Miiller, explained in the simplest manner, if the structure of the cell-wall of Plewrosigma is regarded as analogous to that of Triceratiwm in this respect, that every chamber is in free communication with the air. This analogy might be carried further, and the author is inclined to assume a double communication, on one side with the outer air or water, on the other side with the cell- cavity. In Triceratiwm this double connection can be proved—out- wardly a large circular opening, towards the cell-cavity a number of visible pores; it is very doubtful, however, whether the hypothetical openings in LPleurosigma correspond anatomically to those of Triceratium. Dr. Miller considers it most probable that the cell-wall of Pleuro- sigma consists simply of a poly- gonal network of minute thin bands placed at right angles to the sur- face, and more strongly thickened at the angles on both sides, inwards and outwards. Both the inner and outer edges of transverse sections would therefore have a moniliform appearance (see fig. 135). A com- plete separation of the separate Diagrammatic representation of * pearls” or transverse sections of Pleurosigma. a, chambers; 6, openings. the thickened angles can scarcely be expected, since in that case the section must be thinner than the diameter of the openings. In the general way the projections of the margins of the cut openings which lie somewhat higher or lower must unite the separate “pearls ” with one another, which will readily give the impression of closed chambers. Van Heurck’s Synopsis of the Diatoms of Belgium.* — This magnificent work gives a description of every species of diatom as yet gathered in Belgium. The introduction commences with an account of the structure and life-history of diatoms, including their Fig. 135. * Van Heurck, H., ‘Synopsis des Diatomées de Belgique.’ Texte. 235 pp. 8vo, Anvers, 1885. ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 687 mode of reproduction. Then follows a guide to their study, the mode of collection and cleaning, the best instruments to employ in their examination, the most advantageous methods of preparation and media for mounting. A glossary is given of all the terms employed in diatomography, and an account of the best systems of classification, the one followed in the book being that of Prof. H. L. Smith, de- pendent entirely on the characters of the siliceous envelope, without reference to the endochrome. In the determination of species, since the work is intended for beginners as a guide to the naming of diatoms, the term (“species”) is used in its widest significance; a comparatively small number of primitive types being adopted under which the secondary types are ranged. A bibliography is appended ; followed by the detailed descriptions of the genera and species, Lichenes. Structure of Lichens.*—Herr H. Zukal describes the “ gono- cysts” of Manzonia Cantiana, where they occur on the surface of the thallus, and especially on its outer margin. On the blue-green short- celled hyphe are found globular “capsules ” of various sizes, opaque, of a dark colour, and consisting of one, two, four, or more chambers, each containing a green spherical or elliptical cell, or gonidium. Sooner or later the wall of this capsule becomes mucilaginous, and the gonidia are now inclosed by hyphz from the adjacent thallus, the thallus itself thus increasing in size. In other cases the gonocysts become detached from the thallus, are carried away, and, when reaching a suitable nidus, develope into a new thallus formed from the fragments of hyphe which remain attached to these. The gono- cysts are now formed by gonidia making their appearance on the margin or surface of the thallus, which become enveloped in a thick dark-coloured membrane. The gonidium divides within this “cap- sule” into a number of daughter-cells, until the wall of the capsule finally becomes absorbed. The gonangia are roundish bodies, consisting of a brown pseudo- parenchymatous envelope, in connection with a hypha, and containing in their cavity a number of green pleurococcus-like cells, which are not formed either in the envelope or from it. They occur in large quantities in all situations, especially on bark and wood, and are surrounded by the hyphw, which in the lower cortical layers are colourless and thin-walled, on the surface thicker, brown, and com- posed of short cells, forming the pseudo-parenchymatous envelope round the gonidia or algal cells. The gonangia apparently assist in the dissemination of the lichens, and are found in those species which inhabit bark, though comparatively rarely. Many lichens pass, when under certain conditions, into a vegeta- tive condition characterized by peculiar changes in the contents of the hyphal cells. The protoplasm becomes nearly homogeneous, strongly refringent, and has a distinct green tint. It then breaks up readily into regular minute spherical bodies, uniform in size, the * Denkschr. K, Akad. Wiss. Wien, xlviii. See Hedwigia, xxiv. (1885) p. 43, 688 SUMMARY OF CURRENT RESEARCHES RELATING TO microgonidia, arranged in a moniliform manner and filling up the hyphe. The protoplasmic nature of these bodies can be readily proved ; but no cell-wall can be detected nor any green pigment. They may lie for weeks in absolute alcohol or ether without the green colour being removed ; this colour depending on a peculiar property of absorption and refraction of these very dense protoplasmic bodies. In Verrucaria rupestris var. rosea and Hymenelia cerulea the thailus is composed for the most part of branched colourless thin- walled hyphe, containing a larger or smaller number of bladder-like bodies of roundish, ovoid, pear-shaped, or ellipsoidal form. In the upper zone of the thallus which bears the gonidia, these bladders not unfrequently contain two or four daughter-cells, which are not gonidia although possessing a green tint. With iodine and sulphuric acid the cell-walls of these bladders and of their daughter-cells become yellow, while those of the gonidia turn a beautiful blue. In Petractis exanthematica the alga which forms the gonidia is a Scytonema, and the lichen possesses the peculiarity of that genus that the hyphe are of very different thicknesses. In Verrucaria fusca we find also a Scytonema in the form of gonidia, and in addition masses of blue-green cells resembling a Gleocapsa, and apparently resulting from the breaking up of the Scytonema-filaments. ‘The same genetic connection between Scytonema and Gleocapsa occurs, therefore, within the lichen-thallus as in the free alge. The author describes a new genus of lichens, Holichen, with the following characters:—Thallus roundish, gelatinous, pellicular, 1-5 mm. in diameter, adhering to the substratum by the entire surface. The gonidia are species of Sirosiphon and Scytonema; the hyphe are segmented in a leptothrix-fashion. Apothecia globular, brownish-red, pellicular, perforated at the apex. Spores in eights, in two indistinct rows, inclosed in a narrow club-shaped ascus. Para- physes wanting. Three species are described :—EH. Heppii, compactus, and clavatus. In the last species the nutrient alga is a Scytonema, in the two others a Sirosiphon. Algo-Lichen Hypothesis.*—Reyv. J. M. Crombie says that “in addition to the various direct and indirect arguments which have been adduced against this theory, another, and in some respects, a still more convincing proof, has quite recently been brought under notice by Dr. Nylander.t In his observations upon Gyalecta lampro- spora Nyl., a new species from North America, collected by Mr. Willey, of which a full diagnosis is given, he writes: ‘ Hach goni- dium of this Gyalecta is distinctly seen to emit from its thickish cellular wall (as do also the young gonidia) a firm medullary filament and often two such filaments, characteristic of the nature of lichens. It is most manifest that these licheno-hyphe are productions, and indeed continuations, of the cellular wall of the gonidium itself’ In the species under notice it may be mentioned that the thallus is not corticated, and that the gonidia are most frequently chroolepoidly * Journ. of Bot., xxiii. (1885) p. 219. + Flora, Ixviii. (1885) p. 313. ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 689 seriated and moderate. Now this very important discovery of the veteran and distinguished lichenist is, beyond all question, sufficient of itself at once to disprove Schwendenerism in all its phases. For if the gonidia thus send forth filaments in the manner stated, then the gonidia clearly cannot be algals; and if licheno-hyphe are thus pro- duced by gonidia, then these hyphe as clearly cannot be parasitic fungal mycelia. On these grounds alone (apart from other considera- tions), this plausible hypothesis necessarily collapses, and ‘ symbiosis’ is seen to be but a mere fable.” Fungi. Classification of Fungi.*—In Cohn’s ‘Kryptogamen-Flora von Schlesien,’ Dr. J. Schréter proposes the division of the Fungi into the three following primary groups :—I. Myxomycetes; II. Schizomycetes (parallel to the Phycochromacex); IIT. Eumycetes, distinguished by their spores being formed by a sexual act. The Eumycetes are again divided into seven families, viz.: 1, Chytridiei; 2, Zygomycetes ; 3, Oomycetes (related to the Siphonex); 4, Ascomycetes; 5, Uredinei; 6, Auriculariei; and 7, Basidiomycetes. The Basidiomycetes are divided into (1) Tremellinei; (2) Dacryomycetes ; and (3) Eubasi- diomycetes, which again are made up of (a) Hymenomycetes, (6) Phalloidei, and (c) Gasteromycetes. Development of Ascomyces.t—Herr C. Fisch has studied the structure and development of this genus of Fungi, and especially of a species which he calls A. endogenus, formerly known as A. Tosquinetii and as Exoascus Alni. It is found on the leaves of the alder, but only in the epidermal cells, the formation of asci being usually confined to the under side. The production of asci is pre- ceded by a reticulate condition of the protoplasm, and is first indicated by a slight protuberance in the outer surface of the epidermal cells, which the ascus finally breaks through. The contents of the asci are at first a perfectly homogeneous and finely granular protoplasm, with a moderately large round nucleus, in which, during the formation of the ascospores, the process of nuclear division can be watched with great ease. The commencement is indicated by the appearance of smaller and larger granules in the nucleus, this being immediately followed by the spindle-stage. The number of spindles is always very small; they are thick, and converge strongly at their ends, the whole structure having a barrel-like appearance. In this stage the nucleus differs in nothing except its small size from that in the embryo-sac of flowering plants. In the subsequent stages the processes differ from that in the higher plants, and also from that described by Strasburger in Trichia, in the threads which connect the secondary nuclear plates being parallel to one another, and in the invariable absence of a cell- plate. After division, the eight nuclei are distributed nearly uniformly through the ascus, and form the centres of the ascospores. * Cohn’s ‘Kryptogamen-Flora von Schlesien. III. Band: Pilze, bearb. v. Dr. J. Schréter. 1 Lieferung. Breslau, 1885. See Hedwigia, xxiv. (1885) p. 121. + Bot. Ztg., xliii, (1885) pp. 33-9, 49-59 (1 pl.). See also Bot. Centralbl., xe1ly (1885) p. 126. 690 ' SUMMARY OF CURRENT RESEARCHES RELATING TO With regard to the genetic relationship of the genus, the author inclines to the opinion that the three genera Ascomyces, Exoascus, and Saccharomyces should be united together into the group Hxoascex, the species of which exhibit themselves in three different forms, viz. :—(1) Not parasitic (Saccharomyces); (2) growing outside the host-plant, and producing within it asci only (Ascomyces, including the species A. endogenus on Alnus glutinosa, A. Tosquineti (?), on the same, and A. polyporus on Acer tataricum); (8) growing outside the host-plant, and producing within it both asci and mycelium (Hxoascus). Nocturnal Spore-formation in Botrytis cinerea.*—Dr. L. Klein records a series of experiments for the purpose of determining why Botrytis cinerea (Peziza Fuckeliana) forms its spores only in the night-time, under whatever conditions the development takes place. The conclusion arrived at is that the red-yellow half of the solar spectrum promotes, while the blue-violet half acts prejudicially on the formation of spores; and this retardation is sufficiently strong to render the net result in the daytime nil. Lamplight, on the other hand, in which the red-yellow half is stronger, acts as a positive inciter. Darkness favours the formation of spores, as is shown by shutting off the light from young cultures. Rabenhorst’s Cryptogamic Flora of Germany (Fungi).—Dr. G. Winter has now (in parts 16 to 18) given a further instalment of Dr. Rabenhorst’s important work, still concerned with the Pyrenomy- cetes (Hypocreaceze and Spheriacee). This difficult family is being worked out with very great care, the synonymy and literature are referred to, a point of great importance in determining species, and each species is illustrated with well-executed and characteristic woodcuts. Zopf’s Myxomycetes.j—Of this most exhaustive account of the structure, development, and affinities of a most difficult group, we can give only the outlines of the classification, viz. A. Monapinnz; mostly hydrophytes, partly parasites; usually with a zoocyst form; plasmodia wanting, or arrested at early stages of development. I. M. azoosporee. (1. Vampyrellee; 2. Bursullines; 3. Mono- cystacee.) II. M. zoosporee. (1. Pseudospores ; 2. Gymnococcacee ; 3. Plasmodiophore.) B. Humycrtozoa: aerial organisms, never parasites; plasmodia never wanting, usually highly developed; fruc- tification generally highly developed. I. Sorophoree. (1. Guttulines ; 2. Dictyosteliaceze.) II. Hndosporee. (a) Peritrichee (1. Clathro- — ptychiacee ; 2. Cribrariacee); (6) Endotrichee; a. Stereonemes (1. Calcariacew ; 2. Amaurochetacez); 6. Coelonemex (1. Trichiacen ; 2. Arcyriacese ; 3. Reticulariacee; 4. Liceacee; 5, Perichenaces). III. Exosporee. Zopf adopts Rostafinski’s term, plasmodiocarp, to express sporo- cysts (or cysts which contain resting reproductive cells) which remain in the condition of plasmodia. * Bot. Ztg., xliii. (1885) pp. 6-15. + Zopf, W., ‘ Die Pilzthiere oder Schleimpilze’ (Breslau, 1884) (Schenk’s ‘Handbuch der Botanik,’ in Encyklop. der Naturwissenschaften). ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 691 Protophyta. Distribution of Chromatophores and Nuclei in the Schizo- phycee.*—Dr. A. Hansgirg describes a new genus of Cyanophycee, Chroodactylon, with the following characters :—Thallus small, hemi- spherical, gelatinous, pale-blue, attached to rocks. Vegetative cells oblong-cylindrical or ellipsoidal, rounded at both ends, united into filiform-cylindrical families more or less irregularly lobed or appa- rently branched ; lobes uniseriate, inclosed in a common colourless gelatinous integument. Cytoplasm homogeneous; chromatophores distinct, star-shaped, central, inclosing globose pyrenoids. Cell-wall colourless, more or less thickened ; cell-multiplication by successive transverse bipartition, in one direction only. Spores unknown. The typical species, C. Wolleanum, was found on moist siliceous rocks in Bohemia. Chroodactylon is distinguished from most of the blue-green uni- cellular Alge by its distinct cell-nucleus, and by the peculiar form of the chromatophores, which inclose moderately large pyrenoids. Both were stated by Schmitz to be wanting in the Phycochromacez, but have since been found by Schmitz himself, Zopf, and Lagerheim. The author claims to have determined that Zopf’s Phragnomena sordidum is a true Phycochromacea, and connected genetically with other blue-green alge; also that Porphyridium cruentum Nig. (Pal- mella cruenta Ag.) is connected in the same way with Lyngbya antliaria Hansg. (Oscillaria antliaria Jiirg.), and is in reality an Aphanocapsa. In both these species are evident nuclei and star-shaped chromato- phores inclosing globular pyrenoids. The reason why they have hitherto generally escaped observation is probably that they are to be found only in the living cell, and not in prepared specimens. It is stated by Hansgirg to bea general rule that in the more highly developed Phycochromacezx, viz. the Lyngbyacer, Calotri- chacez, and Scytonemacee, nuclei, pyrenoids, and chromatophores are not to be found except when they are in a condition of retrogression from the filiform state, and are breaking up into the unicellular condition. Chroodactylon is distinguished from its nearest ally among the Phycochromacee, Chroothece, by the formation of cell-families branch- ing in an arborescent manner, and by the star-shaped chromatophores with long rays; from Synechococcus and Aphanothece by the clearly developed cell-wall of the several vegetative cells and by the forma- tion of a common gelatinous envelope which does not deliquesce. Agreeing with all these genera of Schizophycee in its cells dividing by transverse septa only, it differs from them not only in the peculiar form of the chromatophores, but also in the cells of successive genera- tions being inclosed in a common branched gelatinous envelope. With the genus Chroodactylon the author unites Thwaites’s Hormo- spora ramosa under the name C. ramosum. Chromatophores with inclosed pyrenoids have been detected by * Ber. Deutsch. Bot, Gesell., iii. (1885) pp. 14-22 (1 pl.). 692 SUMMARY OF CURRENT RESEARCHES RELATING TO Hansgirg also in Chroothece Richteriana Hansg., Chroococcus turgidus Nag., and Urococcus insignis Ktz. (Chroococcus macrococcus Rbh.). True chromatophores are not to be found in the filiform conditions of species of Lyngbya or Oscillaria growing in air or water. The paper concludes with the description of a new species of Oscillaria, O. leptotrichoides, found on the walls of hothouses in Prague, associated with Lyngbya calcicola. Formation of the Spores of Cladothrix.*—M. A. Billet has observed the formation of spores of Cladothrix dichotoma ‘xr water in which human bones had been macerated. They are formed in the interior of filaments with false ramification, not differing in appearance from the vegetative filaments. When a spore is about to be formed, the protoplasm of the filament, hitherto homogeneous throughout, contracts into a rounded corpuscle of greater refrangibility, resembling a cell-nucleus. This body elongates, contracts in the middle into an hour-glass shape, and then divides transversely into ten cells of rectangular form, each having a nucleus. These rectangular cells round themselves off, and become elliptical sporiferous cells of which the nucleus is the spore with a diameter of 1-1-5 ». The spores are united together into a zooglea-like mass, and, on germinating, put out a filament of smaller diameter than that of the spore, which elongates into a new filament. The reagent used was dilute sulphuric acid (1 part acid to 3 of distilled water); a dilute aqueous solution of methyl-blue and hema- toxylin being the best staining reagents. Aulosira.t—MM. E. Bornet and C. Flahault describe this genus as forming a remarkable exception to the group of Alge (or chloro- phyllaceous Protophyta) to which it belongs, viz. the Nostocacez. While in the other genera, Anabena, Nodularia, Cylindrospermum, Spherozyga, and Nostcc, the trichomes are naked, or if inclosed in a sheath the latter is soft, gelatinous, and diffluent, the sheath of Aulosira is thin, membranous, and dry. The relative position of the spores and heterocysts is not sufficiently constant to be used as a diagnosis of the genera. A new species, A. implexa, from Montevideo, is described and figured. Microcystis.t—Dr. P. Richter gives reasons for suppressing this genus of Kiitzing, and for regarding it as a resting condition of Huglena, which he agrees with Klebs in placing under Alge (or chlorophyllaceous Protophyta) rather than under Infusoria. Of the four species described by Kiitzing, M. Noltii (red), olivacea (olive- brown), and austriaca (yellow), may all be determined to be forms of development of Huglena viridis, M. olivacea agreeing exactly with Klebs’s description of the encysted condition of E. viridis B olivacea. M. minor the author was not able to identify specifically with a corresponding Euglena. * Comptes Rendus, ¢. (1885) pp. 1251-2. + Bull. Soc. Bot. France, xxxii. (1885) pp. 119-22 (1 pl.). t Hedwigia, xxiv. (1885) pp. 18-20. ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 693 Degeneration of Yeast.*—M. H. Bungener states that yeast which has been repeatedly employed for fermenting purposes becomes after several generations unfit for further use. This is apparently due to differences in the composition of the wort, especially with reference to its nitrogenous constituents. After each fermentation the quantity of the nitrogen in the yeast increases, as does also its fermenting power; but after a time the fermentation ceases, leaving the cells still suspended in the liquid, and the yeast is no longer fit to use. Effect of High Pressures on the Vitality of Ferments and on Fermentation.{—In continuation of previous experiments on the effect of high pressures on low organisms by M. A. Certes,t MM. Certes and D. Cochin state that the vitality of Torula is not destroyed by a pressure of 300-400 atmospheres continued for several days. Exami- nation under the Microscope shows no perceptible change in the form or appearance of the cells; and when afterwards brought into contact with saccharine solutions, they multiply and otherwise behave in the normal way. Under the same pressure alcoholic fermentation always takes place after some time. When fermentation occurs under high pressures, the development of carbon dioxide appears to ensue under special conditions of molecular equilibrium. Organisms Productive of Zymosis.s—M. A. Béchamp, &@ propos of communications by MM. Duclaux and Pasteur,|| claims priority for the discovery of the production of diastases by germs and the réle of these same germs in digestion. He cites passages from the ‘ Comptes Rendus,’ and states that it would be easy to prove by other quotations from the same source that diastase, synaptase, the soluble ferment of the pancreas, pepsine, &c., are equally products of the physiological activity of microzoa, bacteria, or autonomous cells. Microbes in the Soil.{—Dr. E. Wollny states that the changes, physical and chemical, which take place in earth containing humus, or the organic remains from which it is formed, have important bearings on the fertility of the soil. In well-worked porous and aerated ground the decomposition of organic matter under favourable conditions liberates carbon dioxide, water, ammonia, and a little free nitrogen, some of which combine with the inorganic substances necessary for the growth of the plant. In well-aerated soil little ammonia is formed; it is quickly oxidized to nitric acid. The agent in this nitrification consists of small filiform bodies which are widely diffused in arable soils, but apparently do not exist in the air. If this organism is destroyed by treatment with chloroform or carbon bisul- phide, or by heat, the ammonia remains or the nitrites and nitrates are reduced. Heat greatly influences the growth of this ferment; at * Bull. Soc. Chim., xlii. pp. 567-73. See Journ, Chem. Soc.—Abstr., xlviii. (1885) p. 417. ¢ Bul). Acad. R. Belg., viii. (1884) pp. 652-4. ¢ See this Journal, iv. (1884) p. 867. § Comptes Rendus, c. (1885) pp. 458-61. || See this Journal, ante, p. 295. { Bied. Cent., 1884, pp. 796-814. See Journ. Chem. Soc.—Abstr., xlviii. (1885) p. 426. Ser. 2.—Vo.. V. 2 2 694 SUMMARY OF CURRENT RESEARCHES RELATING TO 5° C. the process goes on slowly; at 12° it is clearly perceptible; at 87° it reaches its maximum; at 55° it ceases. Light is unfavourable to their development. The oxidation of the carbon of organic matter is caused in a similar way by minute organisms, and under conditions very similar to those of nitrification. Treatment with vapour of chloroform, the addition of antiseptics such as carbolic or boric acid or thymol, or a high temperature, very materially retard the production of carbon dioxide. Organic substances used as manures decompose more rapidly in well-aerated sandy or gravelly than in close loamy or argillaceous soil. The reduction of the nitrates already formed must be regarded as a physiological process, dependent on the presence of organisms which do not require oxygen, Pasteur’s anaerobes. Deprived of air, the organic matters yield small quantities of carbon dioxide, water, ammonia, free nitrogen, and a carbonaceous black peaty mass, an acid humus difficult of decomposition. The chemical composition of soils has an important bearing on the decomposition of organic matter; the presence of lime facilitates it greatly. The amount of humus is also a factor; the production of carbonic dioxide does not always proceed at so rapid a rate as at first ; and too great a quantity may hinder the activity of the microbes. Microbe of Yellow Fever.*—Messrs. D. Freire and Rebourgeon cultivated in bouillon of 38° C. micrococci obtained from the blood of a patient who had died of yellow fever. He found minute hyaline micrococci cells about one-quarter the size of a blood-corpuscle, larger cells of the same kind, and black cells resembling epithelial cells out of which micrococci were produced. Under cultivation the micrococci went through all these stages; the lowermost layers were black, and exhibited, like the black cells found in the dejections, the reaction of ptomain. The dead black remains of these organisms act pathogenetically by the formation of ptomain. Micro-organisms as a cause of Diphtheria in Man, Pigeons, and Calves.;—For demonstrating the presence of micro-organisms in the diphtheritic process, Herr Loffler used the following staining solution :—30 c.c. of a concentrated alcoholic solution of methylen- blue to 100 ¢.c. of an aqueous solution of caustic potash (1/10,000). It is sufficient to leave sections for only afew minutes in this solution to deeply stain most known bacteria. They are then washed in a 1/2 per cent. solution of acetic acid, dehydrated, clarified in cedar oil, and mounted in balsam. In twenty-seven cases in which the diphtheritic membrane was ex- amined, two definite species of micro-organism were found—a chain- forming micrococcus and abacillus. The former was cultivated pure on meat-jelly, blood-serum, and cooked potatoes. It bears a very strong resemblance to the micrococcus of erysipelas, both morpho- logically and as regards its mode of growth, but is only of secondary importance with respect to the diphtheritic process. * Comptes Rendus, xcix. (1884) p. 804. + MT. K. Gesundheitsamte, ii. (1884). ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 695 The bacillus could not be grown on meat-jelly or potatoes, but on blood-serum at 37° C. it formed within three days, whitish, opaque colonies, which did not liquefy the serum. The bacilli are of about the same length as the tubercle bacillus, but about twice as thick ; they are generally more darkly stained and slightly thickened at the poles. A definite spore-formation was not observed in the cultiva- tions. A variety of animals were inoculated with the pure cultivation, and in some an appearance was produced at the seat of inoculation, e.g. the formation of a false membrane on the tracheal, conjunctival, and vaginal mucous membrane, which closely resembled the local appearances in man. Herr Léffler also found on the surface of a condyloma a bacillus which possessed a great resemblance, both morphologically and as regards its pathogenic action, to the bacillus of diphtheria of calves, and gave rise to diphtheritic infection in rabbits. Bacteria.*—Herr L. Brieger in a previous paper described the method by which he obtains pure cultures of bacteria from human feces; the sample was placed in a sterilized half-litre flask in which water had been long boiled, shaken up so as to be finely divided; 20- 30 c.cm. of the mixture was then placed in a shallow dish containing 200-300 c.cm. of Koch’s peptonized gelatin, slightly warmed, the contents mixed by agitation, the dish covered with another of larger size, but inverted, and so closed as to prevent the entrance of bacteria from the air, and the whole arrangement covered with a bell-glass. The arrangement was kept at ordinary chamber temperature ; after a short time micrococci made their appearance in different places, and the species could be isolated. In a previous paper, the author described the bacteria which decompose carbohydrates, and also a coccus which produces ethyl-alcohol from both grape- and cane-sugar, but is not dependent on the last two for its existence, as it also lives on albumen, white of egg, serum-albumen, and fibrin; it has not, however, the power of liquefying those substances, nor does it produce any chemical change in them at any temperature. A bacillus is also described which forms irregular concentric rings on Koch’s gelatin, and which, when injected into guinea-pigs, kills them instantaneously ; it has not the power of decomposing albumen; it is a remarkable feature of this bacillus, that when left a long time in the nutritive matter its central portions assume a yellowish-white colour caused by an incrustation of salts—no matter whether cultivated on carbo- hydrates or albumen, at high or low temperatures; when injected into the blood of guinea-pigs it is injurious, but rabbits and mice are not affected ; its action on sterilized grape-sugar at 36-38° produces propionic acid. Other species of bacteria have been obtained by the author from feces, but are not described. Experiments were also made with the coccus which has been * Zeitschr. Physiol, Chem., ix. (1885) pp. 1-7. See Journ. Chem. Soo.— Abstr., xlviii. (1885) pp. 578-80. 222 696 SUMMARY OF CURRENT RESEAROHES RELATING TO described by Friedlander as the excitant of the croupous form of pheumonia ; it was cultivated with success in solutions of grape- and cane-sugar neutralized with lime and containing fibrin and nutrient salts, sodium chloride, potassium phosphate, and magnesium sulphate. The author describes the precautions used in preparing sterilized flasks, &e. Bacterium ures.*—This microbe, hitherto known only in the micrococcus form, has been observed by M. A. Billet also in the diplococcus, streptococcus, bacterium, diplobacterium, streptobac- terium, leptothrix, and vibrio conditions. The different forms may be associated in the same filament, showing that they all belong to a single species. The micrococcus and torula forms occur always in ammoniacal urine; the leptothrix, bacterium, streptobacterlum, and vibrio forms are more frequent in acid urine left in contact with the air. In proportion as the acidity diminishes, the elements of a filament divide more and more and separate into elements which are ultimately the micrococcus form. The most instructive preparations were obtained by the use of methyl-violet B in very dilute aqueous solution, and mounting in Canada balsam or glycerin saturated with tincture of iodine. Identity of Bacterium fceetidum (Thin) with Soil Cocci.} — Mr. Spencer Le M. Moore gives details of experiments affording morpho- logical and chemical proof of the identity of Bacteriwm fotidum Thin (found on the soles of the feet) with the cocci of surface soil (‘corpuscles brillants” of Pasteur). Access of the ferment to the sole of the foot must take place by the penetration of fine dust containing ferment through the seams of boots; for not only is the ferment of universal occurrence in surface soil derived from deposits belonging to all the great geological horizons, but cocci are always to be found upon the feet even under the most cleanly conditions. Whether the ferment has any relation of causation to an abnormal escape of fluid from the soles is a very obscure problem. The soil ferment is possessed of greater chemical energy than is the bacterium. Artificial Attenuation of Bacillus anthracis.{—Drs. Koch, Gaffky, and Léffler made experiments, as a control of Pasteur’s observations, on the attenuation of the virulence of Bacillus anthracis, and on inoculation with the attenuated bacilli to confer artificial immunity against the virulent form of splenic fever. The thermostat of Arsonval was used as an incubator. Small pieces of virulent splenic fever material were introduced, with proper precautions, into Erlenmeyer’s tubes, and kept at a temperature of 42°-48° C. The alterations in virulence were tested by taking samples of the cultiva- tions, and introducing them directly, or after further cultivation in meat-jelly on glass slides, into mice, guinea-pigs, rabbits, and wethers. * Comptes Rendus, c. (1885) pp. 1252-3. + Journ. of Bot., xxiii. (1885) pp. 149-53. t MT. K. Gesundheitsamte, ii. (1884). ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 697 Spontaneous attenuation of virulence was only observed in a few eases. Pasteur used as his first vaccine, material which had been kept for 24 days, and as his second, material which had been kept for 12 days at 42°-43° C. The authors used as their first vaccine, material of 24 days, which did not kill rabbits or wethers, but killed mice regularly, and as their second, material which killed mice and guinea- pigs, but did not kill rabbits with certainty, and was quite inert on wethers. Further, a third and fourth vaccine were used. Still two out of five wethers died after inoculation with virulent material; rabbits and guinea-pigs could not, as a rule, be rendered proof against the disease. The authors have arrived at the conclusion that vaccination is only a very doubtful gain as a preventive measure. Cholera Bacillus.*—Dr. H. R. Bigelow mentions that out of six guinea-pigs inoculated in the duodenum by Babes, three presented the lesions of cholera; and pure cultivations of the bacillus of Koch were obtained from the intestinal contents. Koch has just introduced a new method of operation without the production of any external lesion, and he reports the cases as completely confirming the view of the pathogenic nature of the bacillus. The method of staining the bacillus in the tissues adopted by Babes consists in cutting thin sections in close proximity to a Peyer’s patch, placing them in an aqueous solution of fuchsin for 24 hours, washing in sublimate solution (1-1000), passing rapidly through alcohol and oil of cloves, well drying with blotting-paper, and mounting in Canada balsam. Curved Bacilli in Air and Water.j—In the present state of confusion which exists as to the exact réle which Koch’s comma bacillus plays in cholera, any information on the subject of curved bacilli is of interest. M. J. Hericourt finds that curved bacilli, some of the same type as the cholera bacillus, are present in all water, no matter what its source. The constant presence of these organisms can only be explained by supposing the existence of their germs in the air, in which they are present in the spore condition. Neutral bouillon and potatoes were sterilized and inoculated with dust from various places, and many curved bacilli developed in all the cultivations. They showed all the described forms, commas, curves, omega, §, spirals, &c. Intestinal dejecta in simple diarrhoea, dysentery, and typhoid fever, broncho-pulmonary secretions in all diseases of the lungs, pus exposed to the air, the saliva of healthy and sick persons, were all found to contain curved bacteria, often in much greater number than other forms of bacteria. Collected first on bouillon or cooked potato, and then cultivated on nutrient jelly, these curved bacilli form rounded colonies with serrated edges, composed of highly refractive granules. These colonies, kept at 20°-22° C., grow in the jelly and liquefy it, producing colonies of the shape of a gloved finger. * Science, v. (1885) pp. 454-5 (3 figs.). + Comptes Rendus, c. (1885) pp, 1027-9. 698 SUMMARY OF CURRENT RESEARCHES RELATING TO Woodhead and Hare’s ‘ Pathological Mycology.*—As in the case of the ‘ Practical Pathology’ of the first-named author, any success which may attend the publication of this work must depend in great measure upon the skill of the artist. ‘Those who visited the Bio- logical Laboratory at the Health Exhibition last year will at once recognize the accuracy of the coloured figures representing the mode of growth of bacteria, most of which were imported from Dr. Koch’s laboratory on nutrient jelly, potatoes, and bread-paste. The draw- ings made from microscopical preparations are artistically executed. In fig. 7 we notice that large numbers of micrococci with capsules stained by gentian violet are represented in sputum from a case of acute pneumonia. A description of the special method, if any, which was used in the staining of this specimen would be interesting as our Own experience coincides with that of Friedlander that, though the capsule can be easily demonstrated in the tissues, its presence can hardly be detected in sputum by staining methods. The description of the processes which are generally useful for staining bacteria is somewhat confused, and we cannot agree with the authors that “ Baumgarten’s method ” (by which the bacteria are ex- amined in an unstained condition) ‘is undoubtedly one of the most effective, and may be applied to any of the fluids.” It must be ad- mitted by any one who has practical experience in the microscopical examination of bacteria, that especially when present in small numbers, they are rendered much more conspicuous when properly stained than when merely treated with a solution of caustic potash. The subject _ of the cultivation of bacteria leaves much to be desired, as a descrip- tion of many useful methods of study is omitted. The important question of illumination is dismissed in less than a page. Neverthe- less, in spite of its shortcomings, the book will undoubtedly be found a useful guide by those who are unable to refer to foreign literature, and it is probably the best of the very few books on the subject in the English language, though it can hardly pretend to compare with the excellent practical and theoretical works by some of those, such as Hiippe and Pfliigge, who have worked under Dr. Koch’s guidance for a long time. * Woodhead, G.S., and A. W. Hare, ‘ Pathological Mycology. An inquiry into the Etiology of Infective Diseases.’ Sec. I. Methods. x.and 174 pp., 60 figs. 8vo, Edinburgh, 1885. ZOOLOGY AND BOTANY, MIOROSCOPY, ETO. 699 MICROSCOPY. a. Instruments, Accessories, &c.* Revolving Stage Microscope.—This instrument (fig. 136) appears to have anticipated those of Klénne and Miiller and of Mirand figured in this Journal, Vol. III. (1880) p. 144, and Vol. IIT. (1883) p. 897. No definite date can be assigned to it, but it bears the appearance of Fie, 136, having been made at least twenty-five years ago. It was apparently designed for some special purpose, as the rotating stage is only 4 in. in diameter, and is not adapted to take even the smallest-sized slides. The objects were placed in ten circular apertures (5/16 in. in diameter) * This subdivision is arranged in the following order :—(1) Stands; (2) Fye- pieces and Objectives; (3) Illuminating Apparatus; (4) Other Accessories ; (5) Photo-micrography; (6) Manipulation; (7) Microscopical Optics, Books, and Miscellaneous matters. 700 SUMMARY OF OURRENT RESEARCHES RELATING TO in the stage, the bottom of each being closed by a piece of glass. They were protected by a cover-glass, which was held in a pivoted frame, so that it could be turned away from the cell when desired. The instrument is of French workmanship. The arrangement for focusing is peculiar, the arm carrying the body being raised and lowered by es TET the milled head below the stage at Dp the back. Portable Microscopes. — The following forms complete, we be- lieve, the history of portable Micro- scopes, many of which have been already illustrated in the Journal. Nachet’s Pocket and Portable Microscopes —The original form of M. Nachet’s Pocket Microscope for powers up to 1/8 in., constructed in 1854, is shown in fig. 187. The metal box into which it is packed measures 33 x 25 x 13 in. In use the Microscope was screwed to the a box, as shown in the fig. The mirror is seen through the opening in front, which is closed by a disk of glass. It has a fine adjustment, and for oblique light it is suffi- cient to slide back the lid of the box as shown in the fig. Fig. 138. es To meet the demand for a portable Microscope of larger size, M. Nachet devised the newer model shown in fig. 138. This when closed ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 701 is 53 x 31 x 23 in. The Microscope is screwed to a metal plate which turns on a hinge joint at the side of the box. This plate forms the stage, and carries a mirror beneath. When the Microscope is removed and placed in the box the plate is turned back on the top of it. A rackwork coarse adjustment has since been added. The Microscope can be inclined, as shown in the figure, or used vertically. To prevent overbalancing, the bottom of the box is provided at each end with a flat brass slide, which can be extended 2 in. in front of the box. Collins’s Portable Microscope.—The peculiarity of Mr. C. Collins’s portable Microscope (fig. 139) is that it is permanently attached to the Fic. 159. lid of the box, so that no time is lost in screwing it to its support as in other cases. The lid itself is fixed to the box, and has a hinge joint at its lower end by which it can be inclined. A small clamp- screw acting on the brass support fixes the lid, and with it the body- tube, at any desired degree of inclination. To replace it in the box the mirror is pushed up to meet the stage, the body-tube racked down, and the inclined support with- drawn and allowed to fall into the box. The lid is turned a half-circle on @ pivot at the centre of its lower end, so that the Microscope now faces the inside of the box, into which it can then be dropped by means of the hinge on the lid. Box Microscope.—The instrument shown in fig. 140 was purchased in Paris, and was apparently made some twenty-five years ago. Like that of Mr. Collins, the Microscope is fixed to the lid, and when not 702 SUMMARY OF CURRENT RESEARCHES RELATING TO in use the body-tube is removed and divided, and the two pieces packed in the box, which can then be closed by the lid. It can only be used upright, as there is no provision for inclining it. Fic, 140, Pfaff’s Microgoniometer.* —Dr. F. Pfaff’s microgoniometer (fig. 141) is practically a theodolite in which the telescope is re- placed by a Microscope. A short pillar carries a large block to which the arc, graduated to 58°, is attached. The block has two sockets in faces at right angles to each other, so that the are can be set vertically, as in the fig., or horizontally. The alhidade can be clamped at any point of the are by a screw behind the latter, a slight movement being still capable of being imparted to the alhidade by the other milled head. The vernier reads to 4’. The lens is for reading the angles. The Microscope rests in the two frames attached to the alhidade, shown in the fig., and can be depressed or raised at the lower end by a spring screw (so that its axis coincides in direction with a radius of the arc), or moved nearer to or further from the centre of the cirele by loosening the side screws in the frames. For micro- scopic objects a stage (fig. 142) is provided, the bent arm of which * Pfaff, F., ‘Das Mikrogoniometer : ein neues Messinstrument, und die damit bestimmten Ausdehnungscoéfficienten der Metalle,’ 20 pp. and 1 pl. §8vo, Erlangen, 1872. ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 703 slides in the guides at the top of the block. The milled heads at the end of the feet are for levelling the instrument. The author claims that the instrument will measure to 1/ 100,000 of a millimetre, and gives a table showing the dimensions of an object Fic. 142. (at a distance of 1 mm, from the centre of the circle) for angles from 4” to 5°, Directions for use are also given, with remarks on the determination of the coefficients of expansion of the metals. Double-Drum Microscope. — In this form (fig. 143), the peculiarity is found of two drums, the one serving as the base of the Microscope, and the other as the support of the Fic. 143. 704 SUMMARY OF CURRENT RESEARCHES RELATING TO socket for the sliding body-tube. This latter application of the drum has no raison-@étre that we can discover, adding nothing to the con- venience or stability of the instrument. Theiler’s ‘“‘ Universal (Achromatic) Pocket Microscope.’—The commendations of Microscopes and microscopic apparatus by what we may term the “lay” press are often very wonderful, and after reading the following descriptions it was not perhaps surprising that we. should have become somewhat eager to possess the instrument. “ We have received from Messrs. Theiler and Sons a specimen of their Universal Pocket Microscope, which magnifies 50 diameters. It is a very admirable contrivance, and should Fic. 144. be in the hands of all young people.” — “This instrument is a virtual Micro- scope, giving beautifully well-defined images, and may be used either by the aid of day- i al! gge== or lamp-light. No one having any interest i] in microscopy should leave home unaccom- panied by such a small and so efficient an instrument. Its cost may be measured in the inverse ratio to its utility and value.” The instrument when received (from Messrs. M. Theiler and Sons, of London) turned out to be the familiar “ Taschen-Mikroskop” of the German opticians supplied for many years past. It is shown in fig. 144, The slide is inserted in the slit of the tube by pressing down the spring which keeps it in place.. The adjustment of focus is effected by screwing the lens in or out. Some of the German makers supply the instrument to take ordinary 3 x 1 slides. Eye-piece Micrometers.*—Mr. H. L. Tolman records that for - some months past he and Dr. M. D. Ewell, having been working at micrometry and the relative sdvantages of the eye-piece and cobweb micrometers, decided to make a series of independent measurements to see which method was superior. Two slides of fresh blood were prepared under the same circum- stances, as nearly as possible, the blood was dried about half an hour in the air of a well-warmed room, and then sealed in a cell, so that the degree of desiccation would be the same, and the measurements . were made the same evening, independently. Dr. Ewell used a 1/10 Spencer (homogeneous immersion, N.A. 1°35) with an amplifier and a 1 in. eye-piece, giving a power of about 2000, and Mr. Tolman a 1/10 Spencer (homogeneous immersion, N.A. 1:25) with a 3/4 in. eye-piece, power 1562. The former measured twenty-five corpuscles, the average being 1/3138 in., and the latter measured fifty with an average of 1/3139 in., the difference between the measurements being only 1/985,000, an amount far too little to measure. Mr. Tolman feels pretty well convinced, therefore, that the cobweb micrometer does not offer sufficient advantage in point of accuracy to compensate for its additional cumbersomeness and expensiveness. * Amer. Mon. Micr. Journ., vi. (1885) pp. 115-6. ZOOLOGY AND BOTANY, MIOROSCOPY, ETO. 705 In another report* of the measurements the matter is thus dealt with. “While of course these measurements have no tendency to prove the possibility of identifying blood by the diameter of the corpuscles, they are admissible to show that under exactly the same conditions there is an average diameter of the blood-corpuscles of an individual which varies within exceedingly narrow limits, and that this diameter may be measured with very great accuracy. The limits of error certainly fall within the 1/200,000 in., and probably within the 1/250,000. Whether this average diameter varies from time to time is a question not yet determined.” Boecker’s Holder for Analysing Prism and Goniometer.—This (fig. 145) serves not only to hold the analysing prism, but can also be used for a Leeson’s goniometer. Fic. 146. Te wn The apparatus is attached to the body-tube by the ring a b, over which is fixed the divided circle cd. Within the latter turns con- centrically the tube e f, with a bevelled plate on which is the index- mark. This tube receives either an analysing prism or the doubly- refracting achromatic quartz prism of Leeson’s goniometer (fig. 146). The rotation of the tube can be prevented when desired by the clamp screw r. “‘An Improvement in Objectives.’”{|—This is another paper by Mr. E. Gundlach, which we reproduce in its original form :— “Hight years ago I presented to the American Association for the Advancement of Science a description of a new quadruple objective for astronomical telescopes.{ The general acknowledgment with which the paper was received, and the high estimation of the theoretical principles of the invention by scientific authorities of this country as well as Europe, encourage me to present to this Society - a description of another improvement in objectives, which I expect will be of equal value for both the telescope and the Microscope. Although I have unfortunately not had sufficient opportunity for properly executing an objective of the above-mentioned description, and thus practically demonstrating its advantages, I must confess that during the time I have become conscious of a practical defect, * The Microscope, v. (1885) pp. 113-4, from ‘ Legal News.’ + Proc. 7th Aun. Meeting Amer. Soc. Microscopists, 1884, pp. 148-52, } Sce this Journal, ii. (1879) p. 75, 706 SUMMARY OF CURRENT RESEARCHES RELATING TO which is, the increased number of lenses. I am now of the opinion that any improvement of objectives which requires additional lenses will always be objectionable, however valuable the improvement may otherwise be. “The objective which I now wish to describe is free from this defect. It consists of two lenses only, one of crown and one of flint glass, like the ordinary objective. But the formula is based upon a new principle. In my description of the quadruple objective I have spoken of the so-called aberrations of higher order. Let me briefly review this for the better understanding of the following description. “We know that the flint glass lens of an objective acts merely as a corrector of both the spherical and chromatic aberrations of the crown glass lens; but, owing to this double action, the said correc- tion is, even in its best possible form, imperfect in so far as, when the part or zone lying about midway between the centre and the periphery is just right in correction, then the central part leaves a small remnant uncorrected, while the peripheric zone is already over- corrected. ‘These unremovable remnants or so-called aberrations of higher order are the only cause of those imperfections of the achro- matic objective which are dependent on the figure or curvature of the lens, and therefore the best formula for an objective will be that by which these aberrations are mostly reduced. Since the discovery of achromatism nothing has been spared to find by the aid of mathe- matics the best possible form for the flint glass lens for the correction of the aberrations of the crown glass lens; but for the finding of the proper form, or to better the proportion of curvatures of the crown glass lens itself, there never was a special rule adopted nor theoretical law found after which to obtain the most favorable result. But the calculations were based upon the principle that for any positive crown glass lens a negative flint glass lens can be found, combined with which it will form an achromatic objective in the common sense, and according to this principle no special pains were taken to find the proper form of the crown glass lens. “My object in this paper is to show that for the best possible construction of an achromatic objective the proper figure or proportion of curvatures of the crown glass lens is an important factor, submitted to a positive theoretical law, and that, as a consequence of the neglect of this law, the present objective is far from having the best possible form. The angular aperture, or, in other words, the proportion of aperture to focal distance of an objective, is limited by the spherical aberration of the crown glass lens, because the latter greatly increases with the increase of the angular aperture, and consequently the aberrations of the higher order are increased. But this limit can be extended, if the spherical aberration of the crown glass lens can be, without change of focal length and diameter, reduced by a mere change of curvature, because this reduction involves a corresponding reduction of the aberrations of higher order. According to this we can imagine two achromatic objectives which are equal in focal distance and aperture, but although the flint glass lens of both have the best possible form for correction of the aberrations of their ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 707 respective crown glass lens, one of the lenses is superior to the other in the correction of the aberrations of higher order, because the spherical aberration of the crown glass lens is less than that of the other. “ We now arrive at the question whether the spherical aberration of the crown glass lens of the present achromatic objective can be reduced by a mere change of proportion of curvature, and if so, what is the theoretical law after which this proportion must be found ? This law, which I have found by careful study, may be expressed as follows :—The spherical aberration of a lens for rays of given direc- tion will be a minimum if the proportion of the curvatures of the refracting surfaces is such by which the angle of refraction of the medium ray at the interior surface is equal to that at the emerging; or, in other words, by which the angle of the perpendicular inclina- tion of the medium ray at the entering surface is equal to that of the emerging surface. If the rays entering a lens are parallel or nearly so, as is the case with the telescope, then they will, after having passed through the lens, be changed by refraction to a converging direction toward the focal point of the lens, and to be equal in per- pendicular inclination upon their respective surfaces. The entering or first surface will certainly have to be of correspondingly shorter curvature than the emerging or second surface. For a lens of a relative focus and diameter, as the crown glass lens of the present telescope, the radius of the curvature of the inner surface will have to be about twice as long as that of the outer surface, to fulfil the condition of minimum spherical aberration. But we are familiar enough with the construction of our present objective to admit that just the contrary is the case, that is, the curvature of the outer surface of the crown glass lens is by far the longest. If the crown glass lens is reversed, so that the inner or shorter curved surface is brought outside, toward the parallel rays of the object, then the form of the lens would much nearer fulfil the conditions of minimum spherical aberration. But then, of course, the flint glass lens will no longer have the proper form as a correcting lens ; it would now over-correct the spherical aberration of the crown glass lens, and therefore a more flat long curved form of the same would be required. If the exact form or curvature of minimum aberration of the crown glass lens, as well as that of the correcting flint glass lens, as found by calculation, is compared with the present objective, it will be found that the aberrations of higher order in the new objective are reduced to about one-third of the old one, and a corresponding gain in the definition and reduction of colour, or otherwise an extension of the limit of aperture must be the result. Let me right here mention another idea as a further step for improvement of the objective in the same direction as described, that is, a further reduction of the aberrations of higher order. “T have in my foregoing description given the law after which a lens of minimum spherical aberration for rays of a given direction has to be constructed, and I will here complete this law by adding that: The absolute minimum of spherical aberration of a lens is 708 SUMMARY OF CURRENT RESEARCHES RELATING TO obtained, if the refracting surfaces of the same are equal in curvature, and the rays entering the lens are coming from a certain point of the optical axis, being in distance from the lens a little over twice that of its nominal focus, thus meeting at the other side at an equal distance and forming a cone equal to that at the entering side. Now there is a simple way to give the rays, coming from a distant point or object, before entering the crown glass lens of the telescope, a direction which will be nearly adequate to the first-mentioned condition, namely, if the flint glass lens is placed in front of the crown glass lens. The parallel direction of the rays will then, by the negative flint glass lens, be changed into such diverging direction as would correspond with a cone, being only a little shorter than that required for an equal-sided crown glass lens, and the latter will then for minimum spherical aberration have to be very near equal-sided, thus allowing the aberration of higher order to be in higher degree reduced than in the before described objective. But, however, as an objection to this arrangement, it may be mentioned that the flint glass lens will be directly exposed to the external air and liable to oxidation. “Tn my foregoing description I have, for the purpose of avoiding complications and giving a clearer understanding, referred to the telescope only; but as the construction of this instrument is sub- mitted to the same theoretical laws as that of the Microscope, little remains to be said about the application of the described new prin- ciple to the Microscope. Our present Microscope objectives are all achromatic in the common sense, but they differ widely in angular aperture, and accordingly in definition and resolving power. But the angular aperture is dependent on the correction of the aberrations of higher order; the latter again on the spherical aberrations of the crown glass lenses of the system. If the crown glass lenses are transformed according to the described principle and law of minimum spherical aberration, and then the flint glass lenses so changed as to properly correct the aberrations of the crown glass lenses, the same result will be obtained as with the telescope objective. ‘The extension of the limit of angular aperture will admit of giving the low power objective with long working distance a definition and quantity of light which at present are united only in considerably higher powers of short working distance.” Care and Use of Objectives.*—Mr. W. Wales uses only an old, soft, silk handkerchief, a small stick of soft wood, a phial of alcohol, anda watchmaker’s glass of two powers. A camel’s-hair brush can neither completely nor safely remove the film of dust with which the exposed surface of the back combination of an objective is sometimes found to be coated. Jt will make a series of rings on the surface of the lens, and it may, if grit be present, scratch the glass. Nor should the handkerchief, either wet or dry, be introduced into the tube of any but a low-power objective. The cells must first be unscrewed from their mountings, and then the cleaning can be done properly. * Journ, N. York Micr. Soc., i. (1885) pp. 113-6. ee | ’ q | q ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 709 Bat am objective ought never to be taken apart by any one but its maker. He has the lathe upon which it was made, and he alone, when the paris have been separated, can replace them in their original adjustment to the optical centre. Any other person will be likely to screw in the cells either too tightly or not tightly enough, and will thus throw the combinations out of their necessarily delicate relations to one another. Besides, unless skill and care be exercised in screwing the paris together, the front and the middle combinations will some- tames be brought im contact, and the flint glass, which is very thin at the centre, will be broken. The screw-thread of the cells is very delicate. Yet some persons, alter failing to catch it, apply force enough to break it. “A large angle oilimmersion lens gets out of order easily. If you find the defimition of such objective to have lost its sharpness, you may know that Fis. 147. the front lens is out of centre. It has come in contact with the slide. A very slight pressure is sufficient to work the mischief. This sus- weptibility to injury is unavoidable, as every optician willitell you. It is imcident to the The collar A (fig. 147) moves on a fine thread and forces down the bristle-holder B. A slit in prism rays from the posterior silvered surface and from the frout unsilvered surface prevent the light from being brought accurately to focus on the object on the stage. This belief is founded on the following 710 SUMMARY OF CURRENT RESEARCHES RELATING TO in the diaphragm of the condenser, and in an iris diaphragm fitted on to the lower portion of the condenser between it and the prism, a most exquisite image of the tree was seen. The definition of this was charming, every little twig and incipient bud being distinctly visible. Then, nothing else being altered, a plane mirror was sub- stituted for the prism. “ What achange! The larger branches were there indeed, but the slender twigs were involved in hopeless ‘ fuzz,’ which no amount of manipulation Herts. could eliminate.” The experi- ment was varied by forming the image of a net window-curtain about three yards distant from the Microscope. With the prism, the picture of the network and pattern was perfect, every detail tN! ZZ CT .E : pL ee being exquisitely shown. With i the plane mirror, the image was very markedly inferior, though less so than in the former ex- periment. Zentmayer’ss Abbe Con- denser.*—A simple and inexpen- sive mounting for the Abbe con- denser (shown in fig. 148) has been devised by Mr. Zentmayer, by means of which it can be used with any substage. The milled head, seen below on the right, moves the plate which carries the diaphragms. Topler’s Illuminating Apparatus.j—In the interior of micro- scopical objects many parts escape observation, not only on account of their small size, but also because very frequently their density differs too little from that of their surroundings, and consequently they influence but slightly the path of the rays. Dr. A. Topler drew special atten- tion to this subject in 1864, when he described an apparatus called by him “ Schlieren” (streaks) apparatus, on account of its use for the examination of streaks in glass. a (fig. 149) is a point of light sending rays to the lens pq; these will be refracted to b. To an eyed f, which receives all these rays, and is so accommodated that it clearly sees the lens, the latter will appear brightly illuminated. If, however, a diaphragm c h is moved towards the point b, then at the moment that it passes the point the rays will be entirely shut off and the lens will appear dark. If, however, there is a more strongly refracting point in any part of the lens, e.g. in gi, the rays, passing through this point, will not meet the axis at b, but nearer to or further from the lens, or will not meet it at all; these rays will then pass by the side of b. When the diaphragm is moved forward it will cut off part of the rays before the normal rays are affected, and the spot in question will * Amer. Mon. Micr. Journ., vi. (1885) p. 84 (1 fig.). + Zeitschr. f, Instrumentenk., ii. (1882) pp. 92-6 (8 figs.). { ‘Beob. nach einer neuen optischen Methode,’ Bonn, 1864. ZOOLOGY AND BOTANY, MICROSCOPY, ETC. (eal appear somewhat darker than the other portions of the lens; the difference, however, in the intensity of light is so slight, that it would not generally be remarked. At the instant, however, that the dia- phragm passes b and the lens becomes dark, only those rays remain which in the figure are seen to pass below 6, and g 7 will appear Fic. 149. brightly illuminated on a dark ground, If gz is not in the lens but in a medium before or behind it, as « y, the result is precisely similar, The same effect is produced if g 7 has a lower refracting power than the other part of the lens. Professor Tépler recently drew Herr W. Seibert’s attention to the fact that the same principle might be employed for Micro- Fie. 150. scopes, and the latter has accord- ingly constructed an apparatus which he says acts admirably with low powers. The semicircular diaphragm a, fig. 150 (the straight edge perpendicular to the plane of the paper), is so placed, that its inverted image appears in b, at which point a frame cc moves in a lateral slit in the nose-piece nn. This frame has at d a glass plate, unpolished on the under side, and at ea thin metal plate with a bevelled edge. The space between d and e is open, so that in placing the frame in position, as in the figure, all rays pro- ceeding from the object pass without hindrance. The screw g holds the frame in position ; if it be loosened, the latter can be moved by the hand. The final adjustment is effected (after g has been screwed up) by the fine screw h, Fig. 151 is a front view of the frame. In ordinary vision through the Microscope the field is brightly illuminated by the rays which, 3A 2 T12 SUMMARY OF CURRENT RESEARCHES RELATING TO passing the object f, reach the objective. All these rays must pass the point at b within the diaphragm image. Therefore, by pushing the frame from right to left, when the edge of the plate e approaches the axis, only a narrow strip of light from the diaphragm-image will remain, and this will also disappear by Fic. 151. a further movement of the frame. At the same instant, the field becomes dark, but the rays remain which deviate in the object towards the left—as in Fig. 150 the ray i—and the corresponding points appear bright. Spots in the object are thus easily recognized which would otherwise pass unnoticed in consequence of the brightncss of the field. Only those rays are effective which are deflected at right angles to the edge of the frame. The apparatus must therefore be so adjusted that the object can be turned round the optic axis, while all else remains immovable. The manipulation of the apparatus is as follows :—The frame c ¢ is placed in a central position so that the open space between d and eis in the optic axis, and the Microscope is accurately focused on the object. The latter is then pushed aside, so that there is now an open space in the stage under the objective, and the glass plate d is brought into the axis. The semicircular diaphragm is now so ad- justed that its image appears clearly on the glass, and the straight edge in this image exactly parallel with the edge of the plate e, but turned away from it, so that on moving the frame the convex side is first shut off, and finally only a narrow line of light remains. The adjustment of the diaphragm is effected by sliding it up and down. The position of the tube must not be altered, or else, if it is again adjusted to the object, the image of the diaphragm will no longer lie in a plane with e, which is an absolute necessity. The frame being now so adjusted that the rays can pass through it unhindered, the in- strument is ready for observation. The frame is moved slowly by the screw h till the edge e meets the optic axis and the direct rays are cut off. The field is now dark, but all points in the object which have a greater or less refractive power are brightly illuminated on the dark ground. If the frame be moved still more, these rays also dis- appear. The proper moment for observation is, therefore, when all direct light is shut off. This apparatus is only suitable for low powers ; with high powers | many inconveniences arise. The frame must of necessity be brought | quite close to the lenses, for if the whole is to be obscured at once, the frame must be exactly at the place where the image of the diaphragm is formed; if it is further away, only half of the field is effective. The nearer to the lens, however, the greater is the spherical aberration, because the objectives are properly corrected only for an image distance, equal to the length of the tube; the image of the diaphragm will not be very sharp, and the rays diverted in the object mingle with the indistinct margins of this image. A further incon- venience arises from the fact that in objectives having a focus of 3 mm., the distance between the object and the diaphragm must be so ZOOLOGY AND BOTANY, MICROSCOPY, ETC. vale; small, that an ordinary slide cannot be used ; and a cover-glass must be used instead. With still higher powers, particularly those with correction, where the frame cannot be brought so near to the lenses, the apparatus is unsuitable. This inconvenience might be avoided by causing a larger, brightly illuminated diaphragm to cast an image and from this to produce a second at ¢ c; the first image could then be brought nearer to the object if desired, and the action would be the same as if a real diaphragm were in the place of the image. The author, in order to use the apparatus for higher powers, also describes a modification by which the frame is placed above the eye-piece, where a second image of the diaphragm is formed ; but he adds that “this arrangement also is capable of improvement.” In observations with the apparatus, it was remarked that when the field of view was obscured, there was greater penetration. With a bright field, for instance, individual bacteria could only be seen when exactly in the plane of the focus; those in an inclined or perpendicular plane were only seen as points. When, however, the field was darkened by means of the frame, each individual could be followed in its movements. Bausch and Lomb Optical Company’s “Universal Accessory.” —This (fig. 152) is mainly intended as a remedy for the want of a substage. It consists of a brass base-plate to be laid on the stage, Fic. 152. having a central opening surrounded by a countersunk bed, which holds a polarizing prism shown in position in the figure. This can be rotated by the milled edge of its broad circular top. On removing the polariscope a hemispherical lens can be dropped into the opening in the plate, and serves as a condenser or, with a stop placed on it, as a paraboloid. An ingenious arrangement 16. 153. has been adopted to enable the lens to be retained in <= place. A disk of thin glass of slightly larger diameter than the plane face of the lens is cemented to it (fig. 153) so as to leave a projecting rim, This rim rests on the margin of the opening, and prevents the hemisphere passing through. Illumination.*—Mr. E. M. Nelson writes as follows:—The first step in studying the principles of illumination for the Microscope is to grasp thoroughly the various effects produced by a bull’s-eye. * Engl. Mech., xl. (1884) p. 68 (2 figs.); pp. 157-8 (3 figs.); p. 263 (6 figs.) ; p- 282 (6 figs.). 714 SUMMARY OF CURRENT RESEARCHES RELATING TO A (fig. 154) shows the effect produced by centering or placing the edge of a flame (from 1/2-in. paraffin wick) in the exact focus of a plano-convex bull’s-eye P. It is necessary to explain the meaning of the word “ effect,” for if a piece of card were held in Fie. 154. the rays proceeding from P, P the picture as shown at A would not be seen; but, in- a Stead of it, an enlarged and inverted image of the edge of the flame. Then, one will naturally ask, How do you get the picture A? By simply putting your eye in @): the rays and looking at the D bull’s-eye. As this is often disa- greeable, by reason of the strength of the light, a more < pleasant way of examining the picture is by placing in the rays a condensing lens (the field-glass of a 2-in. eye-piece) and focusing the image on a card. It should be noticed particularly that the diameter of the disk A depends on the diameter of the bull’s-eye P; but the intensity of the light in A on its focal length. The shorter the focus the more intense the light. In making these experiments the condensing lens is presumed to be at a fixed distance from the bull’s-eye P. B represents the picture when the edge of the flame E is centered, but within the focus of P. C the picture when E is centered, but without the focus of P. D the picture when E is focused, but not centered. Fig. 155 shows an error often perpetrated, viz. that of putting a Fic. 155. P ae "sea concave mirror C at the back of a bull’s-eye P, to increase its effect. The rays are brought to a focus and then scattered. The method of obtaining a critical image with transmitted light by objectives of 1/2-in. focus and less is shown at fig. 156, where E is the edge of the flame from a 1/2-in. paraffin wick, S substage condenser, and P the object. S is centered to, and the image E focused by S on, P. Fig. 157 shows the same thing with the addition Cc ZOOLOGY AND BOTANY, MICROSCOPY, ETC. ile only of the plane mirror m. Fig. 157 gives results as critical as fig. 156, it is, however, a little more troublesome to set up, and therefore fig. 156 will be found preferable where the instrument is sufficiently tucked up on its trunnions to permit of its being so used. Fig. 158 A shows a substage condenser S, and an objective O, focused on the same point; the con- denser being of an aperture equal to that of the objec- tive. On removing the eye- piece and looking at the back lens of the objective, it will be seen to be full of light as at C. Fig. 158 B shows the same thing, but with the aperture of the condenser cut down bya stop. Now only a portion of the back Frye. 157. lens of the objective is filled with light. (See D.) It does not follow that because the back lens of the objective is full of light, as at fig. 158 C, that there- _ fore the field ought to be Fic, 158. full of light. The field only c shows a bright image of the edge of the flame; but it is in the plane of that image where the picture is critical. If the condenser be racked either within or without the focus, the whole D field will become illumi- nated. At the same time, however, a far smaller por- tion of the objective will be utilized. On removing the eye-piece, and examining the back lens of the objective, a picture like fig. 154 C, p. 714, will be seen. Fig. 158 A shows the most severe test that can be applied to a Microscope objective, viz. to fill the whole of the objective with light, and so test the marginal and central portions at the same time. Few, indeed, are the objectives that will stand this ordeal. Some fog when half full of light; most when one-third full; and not one in one hundred will bear three-quarter filling. We now come to some very obvious points—so obvious, indeed, Fig. 156. 0B 716 SUMMARY OF CURRENT RESEARCHES RELATING TO that one would hesitate to mention them, unless frequently confronted with error. Fig. 159 shows the correct method of illuminating with diffused Fig, 159: ee i: Fic. 160. Fic. 162. a day-light, no substage con- denser being used. P the plane of the object. C the concave mirror. The mir- ror is placed at the distance of its principal focus from the object. Fig. 160 shows the rough and ready and, I am sorry to say, too often, the usual style. Fig. 161 shows the correct method of illumi- nating for dark ground, with substage condenser and stops. H, edge of flame; B, bull’s-eye; m, plane mirror; §, substage condenser. Fig. 162 is another_ correct method of doing the same thing by using the © concave mirror and no bull’s-eye. It is seldom used, as it is very difficult to set up. Fig. 163 shows the error of using the concave mirror with the bull’s-eye. Many do it, thinking that they get more light. Fig. 164 shows the error of not having the edge of the flame E in the prin- cipal focus of the bull’s-eye B. This teaches how im- portant it is to have the bull’s-eye fixed to the lamp, so that both may be moved together, and not indepen- dently. The author’s own bull’s-eye is so made that when it is pushed home in its slot, the lamp flame is in its principal focus. To set up fig. em correctly, with a bull’s-eye ZOOLOGY AND BOTANY, MICROSCOPY, ETC. TLa on a separate stand, would take an experienced microscopist a quarter of an hour or more, an inexperienced one an evening.* The following are a few hints on dark-ground illumination :— Let us, by way of example, take a definite object, thresh that out thoroughly, then after- wards show what alterations in the method will be re- quired for other objects. The necessary apparatus is an achromatic condenser, and a See = with a bull’s-eye fived ¢ a ; Fig. 163. S It is, in Mr. Nelson’s B opinion, most important Fic. 164. that the condenser should a be achromatic. It will be urged by many eminent microscopists that an achro- matic condenser is quite unnecessary. Also there are those who prefer a paraboloid, spot-lens, &e. B He does not, however, go into this question for fear of making his paper too long; the scope of it being a method of showing critical images on a dark ground by means of an achromatic condenser; the test of criticalness being the visibility of the dots in the hexagonal areolation of the larger Triceratia with a 2/3 of 0°21 N.A.(= 323° air angle). Let us, therefore, take this as our experimental object. We must first adjust our lamp and bull’s-eye as described on p- 714 and get the edge of the lamp expanded to a disk as in fig. 165. Place a small aperture in the condenser, and a Triceratium on the stage with the 2/3 in. objective on the nose-piece. The Microscope having been put in the proper position, the lamp should be placed on the left-hand side of it. The lamp should now be arranged as to height, so that the rays from the bull’s-eye may fall fairly on the plane mirror; the plane mirror being inclined to reflect the beam on the back of the substage condenser. Now, with any kind of light, focus and centre the Triceratium to the field, fig. 166. Then rack the condenser until the small aperture in its diaphragm comes in focus; centre this to the Triceratium, fig. 167. Rack the condenser closer up until the bull’s-eye is in focus, fig. 168 Here it happens that the bull’s-eye is not in centre, and is not uniformly filled with light as in fig. 165, but has instead two crescents of light. This is a case which often occurs; but, of course, it may be more or less filled with light, and may or may not be more nearly centered. Mm * Mr. Nelson thinks it would be a good plan if microscopists would always use the term “bull’s-eye” instead of “condenser,” to designate that piece of apparatus; leaving the term condenser for the substage condenser only. 718 SUMMARY OF CURRENT RESEARCHES RELATING TO We next have to centre the bull’s-eye to the Triceratium by moving the mirror, fig. 169. It will be noticed that centering the bull’s-eye does not put the light right. This must be done by moving the lamp with its attached bull’s-eye. This movement must be a kind of rotation of the lamp in azimuth round the wick as an ideal axis. The relative positions of the lamp and bull’s-eye must on no account be altered. It is taken for granted that the bull’s-eye is fixed to the lamp, and was adjusted at the first so that the picture, fig. 165, was obtained by direct inspection without any Microscope. Fic. 165. Fic. 166. Fig. 167, x Fig. 168. Fia. 169. Fic. 170. This adjustment being satisfactorily carried out at first, is not dis- turbed. By “moving the lamp round the wick as an axis,” is meant the moving of the whole thing as a solid mass. This is a very simple thing to demonstrate practically ; but it is not easy to describe even such a simple movement so as to preclude the possibility of error. A very slight movement in the right direction will produce the picture fig. 170. Any one having the necessary apparatus, by following out precisely this plan, will arrive with very little trouble at fig. 170. All that need now be done is to open the full aperture of the condenser, and put in the smallest opaque central stop; if this does not stop out all the light in the bull’s-eye, then a larger one must be tried. It is of the greatest importance that the stop be as small as possible; a very little difference in the size of the stop makes a great difference in the quality of the picture. Condensers ought, therefore, to be supplied with as many opaque central stops as open apertures. ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 719 On account of some residual spherical aberration, the condenser will probably have to be racked up a little to secure the greatest amount of light. In fig. 170 the expanded edge of the flame covers the Triceratium. When the whole aperture of the condenser is opened the size of that disk will not be altered. Its intensity only will be increased. When the central stop is placed at the back of the condenser, only in that part of the field represented by the disk of light will the objects be illuminated on a dark ground. But some will say: Suppose the disk does not cover the object; what is then to be done? Simply this: bring the lamp nearer the mirror. The size of the disk of light depends on three things. 1. The diameter of the bull’s-eye. 2. The length of the path of the rays from the bull’s-eye to the substage condenser. 3. The magnifying power of the condenser. If 1 and 3 are constant; the only way of varying the size of the dark field is by 2, as already stated. The intensity of the light in the disk depends also on three things. 1. The initial intensity of the illuminant. 2. The angular aperture of the bull’s-eye. 3. The angular aperture of the substage condenser. Mr. Nelson has elsewhere insisted that the power and aperture of the substage condenser should bear some proportion to the power and aperture of the objective used, and does not enlarge upon this, but merely alludes to it, as it does not legitimately come within the range of his paper. Finally, he says he prefers to make the disk of light no larger than necessary. If the whole field is required, he fills it; but if only a portion is wanted, then he reduces the size of the disk accordingly. Mr. A. C. Malley* strongly disputes Mr. Nelson’s recommendation of a bull’s-eye fixed to the lamp, and prefers one mounted on a sepa- rate stand, which is easier reached and moved, and by which tremor is avoided. The bull’s-eye should be placed about 34 in. from the centre of the flame, the lamp being surrounded by a tin shade haying a small plane mirror behind the flame, and an orifice the size of the bull’s-eye in front. The bull’s-eye is formed of two plano- convex lenses (34 in. focus) with their convex faces together. He also uses a cell of ammonio-sulphate of copper in front of the mirror. Hawkins’s Observatory Trough.{—Mr. R. Hawkins suggests an improvement on Dr. Giles’s Live-cell,t which he thinks will make the apparatus so simple, that any one can make half-a-dozen in an hour or less without extraneous aid. The arrangement consists in the use of clips, to keep the glass cover on, made of a piece of brass wire bent to fit the slide, and so as to have sufficient power to hold the cover well in position. * Engl. Mech., xl. (1884) p. 299. t mag eee 1885, p. 135 (1 fig.). ¢ See this Journal, ante, p. 135, 720 SUMMARY OF CURRENT RESEARCHES RELATING TO Pringsheim’s Gas Chambers.*—In order to make experiments with different gases, Professor N. Pringsheim had gas chambers con- structed by Schmidt and Hinsch, for use with his Photo-chemical Microscope, which differ from those hitherto used, and which combine great firmness and durability with easy management. As those of glass are very difficult to fix, besides having other disadvantages, the new ones (Figs. 171 and 172) are of metal, and very firm and secure. The base is of strong glass (or metal with an aperture closed with glass), the sides and cover d of metal. The latter has a circular Fig. 171. aperture in the centre, beneath which a glass cover is cemented for the reception of the hanging drops in which the object is placed. It can be firmly pressed down by the arm & (movable at 7) and the screw s. By a mixture of wax and vaseline at the joints and tightening the screws, the chambers can be made completely air- tight, and will even bear a considerable Fie. 172. pressure of gas. This is conducted through the tubes g. The base of the chamber is kept covered with a thin stratum of water. As the temperature of the drop, particularly in white light, may become higher than the object can endure without injury, it may be cooled by filling the chamber with ice, and by placing on it, instead of d (Fig. 171), the cover r (Fig. 172), which can then also be covered with ice. In the latter case, a quick conductor of heat from the drop to the ice can be obtained by means of the platinum cross p. Test for the Hand-Lens.—Mr. J. Deby points out that “while many tests exist for high- and medium-power objectives, none are on record for that most useful instrument to the naturalist, the hand- lens.” The best test he considers to be the elytron of Gyrinus marinus, a2 not very rare water-beetle. The lens must not only show the longitudinal rows of large dots, but also the fine intermediate punctations. None but a first-rate lens will show them. The male has finer punctations than the female, and is more difficult of resolution. * Zeitschr. f. Instrumentenk., i. (1881) pp. 332-3 (8 figs.). + See this Journal, ii. (1882) p. 395. ZOOLOGY AND BOTANY, MICROSCOPY, ETC. bau Aperture Puzzle.—A problem which much troubled the older generations in regard to aperture, was this :— “ Aperture” meaning essentially the “opening” of the objective, or its capacity for transmitting a greater or less amount of light, the following seemed to be paradoxical. In fig. 173 a dry objective is used, and the object can receive light from the whole hemisphere of 180°. If, for instance (as the matter was put with the view of bringing it within reach of the meanest capacity !), 180 candles were placed in a semicircle a b, light from every one of the candles would reach the object. Suppose now, that instead of a dry objective, whose aperture cannot exceed 180° or 1-0 N.A., an immersion objective is used with an aperture exceeding 1:0 N.A., a hemispherical lens being employed for the illuminator, as in fig. 174. It is suggested that in this case we have less light reaching the object, for, continuing the example of the candles, only those between Fic, 173. Fia. 174. 180? a' and b’ (or say 100 out of the 180) are effective, none of those between a and a’, or between b and 6’ illuminating the object, and they might as well not be lighted. The objective which has the smaller aperture, therefore, receives, it is suggested, the light of eighty more candles than the objective which has the larger aperture ! . The explanation of the seeming paradox is simply that the effect of the spherical surface in the second case has been disregarded, as was so constantly the case in the old aperture discussions. The action of the hemisphere in fig. 174 may be illustrated by fig. 175, which shows the course of the rays from a luminous surface OP to a definite surface element a b. Take the inner lines of the fig. as representing the pencil which, in air and without the interposition of the hemisphere, would reach the surface a b. If the hemisphere is interposed, the pencil, instead of continuing in a straight line as before, is compressed (refracted), and is now thrown on the smaller surface a 8. It is obvious that the two surfaces a b (in air) and a B (in glass) must each receive the same amount of light, for the pencils which reach them are identical in their origin. If now we take within the hemisphere a surface a b, which is larger than a , the former (a b in glass), will be illuminated, as the fig. shows, by a pencil which, in its origin, is larger than that illuminating the latter (a B in glass) ; and as a £ in glass is, as we have seen, identical in illumination with a b in air, a b in glass will receive a larger pencil than ab in air, the excess 722 SUMMARY OF CURRENT RESEARCHES RELATING TO being represented by the shaded space in the fig. In other words, the total quantity of light which in air is thrown upon the element a b, is by means of the hemisphere condensed upon the smaller element a B, so that the hemisphere will admit to the element ab, wider pencils from the points O P than are admitted to it in air. Though the Fig. 175. angle Oc P is the same in both cases, the quantity of light con- veyed within this angle to one and the same surface element is greater in glass than in air. As to the measure of the increase of light, it may be shown that iF = =; ic, ifn = 1-5 (the refractive index of glass), a or a b is half as large again as a 8. The increase of light is there- fore as 9: 4, or 2} times (n?). This is in agreement with the expres- sion for the numerical aperture in the cases of air and glass, which, for the same angles, are always as 2 : 3.* _ Discovery of Pseudoscopy.t— Under the title of the “ Discoverer of a Singular Optical Illusion,” Prof. Govi says, “ Of all optical illusions, that is certainly not one of the least remarkable by which, in looking at objects in slight relief or slightly depressed (as coins, seals, &e.) with a compound Microscope or a telescope which reverses the image, * See also on this subject this Journal, i. (1881) p. 329. ' ft Atti R. Accad, Lincei—Transunti, vii. (1883) pp. 183-8. ZOOLOGY AND BOTANY, MICROSCOPY, ETO. tae the parts in relief appear hollow, and that which is hollow assumes the appearance of perfect relief. It is indeed true that the illusion is not always, nor with all persons, equally successful, and that some- times the appearance is alternately that of hollow and of relief to the same eye and with the same object; but, in general, the inversion of form does not lead to deception, not being able to overcome either the knowledge of the object which the observer possesses nor that of the reversal of the image brought about by the instrument. Physicists admit that in this case the illusion proceeds from the observer’s knowing the direction from which the light comes, and seeing in the image the lights and shades of the prominences or cavities on the side opposite to that which, having regard to the direction of the light, they ought to occupy; so that, in the absence of any final test of the comparison to aid the judgment, one argues from the position of the lights and shades that what is really hollow is in relief, and vice versd. In fact, if every part of the object is illuminated, or if (as Brewster has suggested) a pin is placed upright by the side of it, and one observes the direction of the shadow which it throws on the object, the illusion suddenly vanishes and the object is seen as it really is, and not as one’s erroneous first impression had represented it. Almost all who have written upon the subject of vision, or the illusions of the senses, refer to this curious phenomenon, and attribute its discovery now to one, now to another person, according to the patience, erudition, and perhaps the nationality of the writer; for, with regard to the priority of discoveries, the factors on which the final judgment depends are numerous. Joblot, in 1718, believed himself to have observed it for the first time, not referring to any one who had preceded him. Gmelin does the same in 1745, in a paper on a kindred subject, printed in the ‘ Philosophical Transactions.’ I do not know the purport of Rittenhouse’s communication of 1786, because I have not hitherto succeeded in procuring the ‘ Trans- actions of the American Philosophical Society,’ which contains a work by that author on some such subject, but it is probable that, like Joblot and Gmelin, he too has believed himself to be the discoverer of the phenomenon. Muncke, in 1828, in the article “Gesicht,” in Gehler’s ‘ Dictionary of Natural Philosophy,’ attributed the discovery to Joblot (written Jablot by him). David Brewster, in publishing, in 1831, his ‘ Letters on Natural Magic,’ dedicated to Sir Walter Scott, alludes to an observation of this nature made by the members of the Royal Society of London in one of the first and earlier meetings of that society, and perhaps mentions it as well in an article in the ‘ Edinburgh Scientific Journal,’ which I have been unable to consult. In 1838, Charles Wheatstone, in the publication and description of his wonderful ‘ Stereoscope,’ alludes to the Royal Society of London as having first called attention to the strange phenomenon, without, however, giving the year or stating the manner in which it happened. Helmholtz, in his ‘ Physiological Optics, reproduces Muncke’s citations, and seems to adhere to Joblot as the discoverer of the illusion. Schréder, writing on the subject in 1858, stops at Gmelin, and attributes the discovery to him. 724 SUMMARY OF CURRENT RESEARCHES RELATING TO Although there is much disparity in the opinions, it is only the older observers who are really in competition for the honour of the discovery ; that is, Joblot and the Royal Society, but it does not appear clearly from the known records which of the two preceded the other. The ‘ Philosophical Transactions’ do not speak of any such obser- vation, but, consulting the ‘ History of the Royal Society, written by Birch, in which are found described with great care almost all the experiments, letters, communications, and discussions which the English savants did not think worthy to appear in the volumes of their ‘ Transactions, we may read there in the second volume the following passages :— Under the date of the 11th of February (Thursday), 1668 (count- ing ab incarnatione, and according to the Julian calendar): ‘The operator was ordered to speak to Mr. Hooke, that the great Microscope of Mr. Christopher Cock’s making be brought to the Society at the next meeting. And the 18th of February 1668 (Thursday), ‘Mr. Christopher Cock produced a Microscope which he said he had made for the Society if they liked it, with five glasses, of which the four eye-glasses were plano-convex, two and two so put together as to touch one another in a point of the convex surface. Various observa- tions being made therewith, it appeared to do very well, but there being a guinea put in it and looked upon, some of the members saw the image depressed, others embossed. The workman referred him- self to the Society for the price of this Microscope, and the Society referred it to the Council.’ Then the Council decides on the 22nd of February (Monday): ‘That the Treasurer pay to Mr. Christopher Cock 81. for a large Microscope made by him for the Society.’ It does not appear that the Society or any of its members made any further investigation after this into the singular illusion discovered on the 18th (28th ac- cording to Gregorian style) of February 1669, although the 202 Italian lire (8/.) paid for the Microscope which had demonstrated it attest the importance attributed to Mr. Christopher Cock’s instrument. The date of the first observation of the English academicians being thus established, Joblot’s priority disappears, unless it is wished to uphold it on the ground that the discovery remained unpublished in the records of the Royal Society until the time of its publication by Birch (1756). In any case, even recognizing the priority of the English, we are able justly to claim for an Italian countryman of ours the credit, not only of having anticipated the Royal Society in the discovery of the curious illusion, but of having forestalled those physicists who subsequently endeavoured to explain it. EHustachio Divini, of San Severino (the ancient Septempeda), on the frontier, was the most skilled manufacturer of lenses and glasses of all kinds of his time, and in the year 1649 had conceived the idea of placing in a telescope which he possessed, some fine threads crossed, substituting a convex ocular lens for the concave ocular used by Lippersheim and Galileo, in order to see the network and thus sketch with ease the image of the moon which, with all its markings, was depicted upon it, ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 725 thus anticipating the first micrometers of Gascoigne, Montanari, and Huyghens. Now this same Eustachio Divini, in a letter which has been printed, addressed to Count Carlo Antonio Marozini on the 15th of July, 1663, wrote thus :—‘ Now that we are upon the subject of telescopes fitted with the single lens, I ought to tell you of a remarkable matter; I have seen strange things. While looking at some object, such as a bas-relief or those arms carved in stone which are commonly put upon walls, their plane parts appeared depressed and level with the wall, while all the rest of the arms were devoid of relief. But the curious thing is, that the relievos which I have mentioned are seen as if hollowed out, whereas they are really raised up. When I discovered this, I showed it to other persons of enquiring disposition, and by looking several times at the same place, finally convinced myself that I had been deceived by the light which it received from the sun, for in the morning it appeared hollow, in the evening in relief, and in other parts in relief in the morning and hollow in the evening. The Microscopes with two glasses, which also show the objects to me reversed, usually do the same with a difference in the glasses, which I do not as yet understand. They magnify a thousand times, and by the conditions of this power cannot be applied to objects which are rather large; therefore I have sometimes added another lens with a curvature considerably greater than that of the small lens, taking away the latter and inserting the former, which does not magnify so much, but serves for rather large objects, and with them produces a most beautiful effect with the greatest clearness. With this apparatus I have looked at an old coin in order to see letters which could not be read. Sometimes I have seen the places in relief reversed and, changing their position (so to speak), stand on the right-hand side of the Microscope, and if I place myself on the left I see in relief that which when on the right I considered to be hollow. But what seemed to me altogether strange, and has happened to me more than once is, that when looking at another object in relief, I see it hollow, and on changing my position I still see even the part in relief hollow. However, I leave all this to distinguished intellects to speculate upon, and return to our telescope.’ The 15th of July (Gregorian notation), 1663, is earlier by 5 years 7 months and 15 days than the 18th of February (Julian notation), 1669; by this period, therefore, does Divini have precedence of the English academicians in the discovery of the pseudoscopy of reliefs, and by a still greater time is he beforehand in the endeavour to explain the phenomenon, for he attributes it to ‘deception of the light, and as his microscopical observations left him somewhat perplexed as to such a reason, he referred the matter to distinguished intellects, which, however, have not known how to find a better one, and repeat (only in a better form and somewhat aided by experi- ments) the same explanation which Divini had proposed two centuries ago,” * * A Bibliography of eleven of the books and papers referred to is apponded. Ser, 2.—Vow. VY. 3B 726 SUMMARY OF CURRENT RESEARCHES RELATING TO AxBBE, E.—UVeber optisches Glas. (On Optical Glass.) [Title only, with demonstration of Microscopes with lenses made of the new glass. | SB. Jenaisch. Gesell. f. Med. u. Naturwiss. for 1884 (1885) p. 32. Veber Object und Bild. (On Object and Image.) [Title only. ]- Ibid., p. 34, American Society of Microscopists.—Eichth Annual Meeting at Cleveland, O. [Circular issued by the Society. Also note by E. H. Griffith.] Amer, Mon. Micr. Journ., VI. (1885) p. 119. The Microscope, V. (1885) pp. 132-3, and 139. BecKkwitH, HE. F.—Resolution of Amphipleura. [‘‘On a slide prepared by H. H. Chase, with a refractive index of 2°42, I have succeeded in clearly resolving A. pellucida with a dry 1/5 in. of 135° air angle.’’] ” ” The Microscope, VY. (1885) pp. 131-2. Behrens, J. W.—The Microscope in Botany. A guide for the microscopical investigation of vegetable substances. Transl. and edited by A. B. Hervey and R. H. Ward. xvi. and 466 pp., 13 pls. and 152 figs., 8vo, Boston, 1885. Observation by Artificial Illumination. The Ocular Micrometer (and additions by R. H. Ward). Micr. Bulletin (Queen’s) II. (1885) pp. 20-1, from Zhe Microscope in Botany. ” 39 9 ” CARPENTER, W. B.—Wallich Condenser. [Remarks on the very great increase of focal depth withthe Binocular. “There was one very curious thing about the Binocular Microscope, that it did increase very greatly the focal depth. He had tried this under every condition, and had always found itto be so. It was to be explained to a certain extent by the binocular prism halving the aperture of the objective. That, however, did not explain it altogether; because having asked a friend to look through the binocular with one eye only, the prism being in its place, and to focus the objective for what he considered to be a medial distance, on then asking him to open the other eye, the differ- ence in the depth of focus had been at once observed ; indeed, it was considered that the increase amounted to at least five times. He had talked the matter over with his friend Sir Charles Wheatstone, but they could never come to any satisfactory conclusion.” ] Journ. Quek. Micr. Club, II. (1885) pp. 145-6. CHALON, J.—Note sur l’Objectif 1/16 de pouce de Powell et Lealand. (Note on the 1/16 in. objective of Powell and Lealand.) ' [Description of details of construction. ] Bull. Soc. Belg. de Micr., XI. (1885) pp. 196-8. Cuaney, L, W., jun.—Microscopical Exhibits at the New Orleans Exposition. Amer. Mon. Micr. Journ., VI. (1885) pp. 102-4 (2 figs.). Cuun, C.—Katechismus der Mikroskopie. (Catechism of Microscopy.) [Part I. Theory of the Microscope, pp. 3-81. Part IL. Use of the eee pp. 82-95. Part III. Methods of Investigation, pp. 96-138. vill. and 138 pp. and 97 figs., 8vo, Leipzig, 1885. ErEeRNOoD, A.—Des Illusions d’Optique dans les Observations au Microscope. (Optical illusions in microscopical observations.) 8 pp., 8vo, Geneve, 1885. FOULERTON, J.—Microphotography. (Demonstration to the Western Microscopical Club.] 4ingl, Mech,, XL1. (1885) pp. 320-1. ZOOLOGY AND BOTANY, MICROSOOPY, ETC. 727 GARTNER, G.—Ueber den Nachweis des Warmetonus der Blutgefasse mittels electrischer Beleuchtung. (On the detection of the influence of heat on the tonicity of the blood-vessels by electric illumination.) Allg. Wiener Med. Zty., 1884, p. 69. GrirritH, E. H.—See American Society of Microscopists. GuNDLACcH, E.—The Examination of Objectives. (Concld.) Micr, Bulletin (Queen's) II. (1885) pp. 18-9, from Amer, Journ, Micr. for 1867. Harpy, J. D.—Microscopical Delineation. [Abstract only.] 8th Ann. Report Hackney Micr. and Nat, Hist. Soc., 1885, pp. 28-9. Hawkins, R.—Observatory Trough. [Supra, p. 719.] Sct.-Gossip, 1885, p. 135 (1 fig.). Hervey, A. B.—See Behrens, J. W. {Hircucock, R.}]—Silvering Glass Reflectors. (Formula of Mr. J. Browning for silvering glass specula. ] Amer. Mon. Micr. Journ., VI. (1885) pp. 118-9. Houmes, E. A.—Polarized Light as applied to the Microscope. [Paper read before the Hackney Microscopical Society. ] 8 pp., 6 figs. Hunt, G.—The Right-angled Prism instead of a Plane Mirror in the Microscope. [Supra, p. 709.] Engl. Mech,, XLI. (1885) p. 414, Hunter’s (J. J.) New form of Graduating Iris Diaphragm. [Exhibition only. ‘Made to go close up under the object.” Journ. Quek. Micr, Club, IL. (1885) p. 161. JADANZA, N.—Sui punti cardinali di un sistema diottrico centrato e sul cannochiale anallattico. (On the cardinal points of a centered dioptric system, &e.) Atti R. Accad. Sei. Torino, XX. (1885) pp. 917-33 (8 figs.). Kuen, C.—Optische Studien am Leucit. (Optical studies on Leucite.) [Containsa description of a new Microscope devised by the author for minera- logical-petrological researches, pp. 436-43. Post.] Nachr. K. Gesell. Wiss, Géttingen, 1884, pp. 421-72 (1 pl.). Leprnay, M. pr.—Methode optique pour la mesure absolue des petites 1 ongueurs. (Optic method for the absolute measurement of small lengths.) [Post.] Comptes Rendus, C. (1885) pp. 1877-9. Lommet, E.—Bermerkungen zu dem Aufsatz: Ueber einige optische Methoden und Instrumente. (Remarks on the article “On some optical methods and instruments.’’) [Remarks as to the priority of Prof. Abbe and others in regard to the original paper ante, p. 532.] Zeitschr. f. Instrumentenk., V. (1885) p, 200. M.—Amateur Lens-making. (Directions for making lenses, with description and figures of tools. ] Engl, Mech., XI. (1885) pp. 424-5 (10 figs.), from Scientific American Supplement. M‘A.LuistTeEeR.—Slide showing Path of Electric Spark. [A slide, after being smoked over a small gas-jet, is placed centrally between the terminals of an induction coil, and at right angles to their direction. The terminals are held about 3/8 in. apart. A strong current is required. } Journ, N. York Micr. Soc., I. (1885) p. 104. MAYALL, J., jun.—Nobert’s Ruling Machine. (Concld.) Knowledge, VII. (1885) pp. 452-3, 504-5, 523-4, from Journ, Soc. Arts. Mituer, M. N.—Theory and Practice of Photomicrography. I., II. {Paper read before the Photographic Section of the American Institute. Describes apparatus and gives practical instructions. ] Engl. Mech., XL. (1885) pp. 298, 359-61, 3B 2 728 SUMMARY OF CURRENT RESEARCHES RELATING TO Monoyer, M. F—Zur Theorie der Fernrohre. Allgemeine Theorie centrirter dioptrischer Systeme. (On the theory of the telescope. General theory of centered dioptric systems.) (Jn part.) Centr.-Ztg. f. Optik u. Mech., VI. (1885) pp. 121-3, 153-6, abstracted by G. Fischer from Séances de la Soc. Frang. de Physique, 1883, pp. 148-75. Moors, A. Y.—The Microspectroscope. The Microscope, V. (1885) pp. 101-6 (3 figs. and 1 pl.). Neuson, E. M. [Reply to inquiry as to a condenser. Also statement that “the amount of flint in an object-glass depends entirely on the formula by which it is made, i.e. the idiosynerasy of the maker.’’] Engl. Mech., XUI. (1885) p. 283. “5 » Stop for an Abbe Achromatic Condenser. [Not described. ] Journ. Quek. Micr. Club., II. (1885) p. 148. 5 » Rotating Nose-piece Condenser. [Ante, p. 324 and p. 327.] Ibid., 11. (14885) pp. 153-4. QuEEN, J. W.—Remarks on using Oil-immersion Objectives. [General instructions sent out with his 1/15 in. objective. ] Micr. Bulletin (Queen’s) II. (1885) p. 22. Queen’s (J. W. & Co.) New Class Microscope. ([Post.] Proc. San Francisco Micr. Soc., 22nd April, 1885. “Ros. Crus.”—The Micro-objective. III., IV., V. Engl. Mech., XI. (1885) pp. 302 (8 figs.), 327-8, 413-4. ScHERRER, J.—Der Angehende Mikroskopiker, oder das Mikroskop im Dienste der Hohern Volks- und Mittelschule. (The young Microscopist, or the Micro- scope in the higher, primary and middle schools.) xy. and 206 pp., 134 figs. 8vo, Speicher, 1885. . Schoolroom, Microscope in the. [No person who has not made the trial can form an adequate conception of the mental quickening occasioned by an exhibition of selected micro- scopic objects to classes in the schoolroom. The scales on the butterfly’s wing, the hexagonal facets of the compound insect-eye, the transformation, as it were, of seemingly shapeless grains of sand into structure of exquisite beauty, the cyclosis of protoplasm in plant cells, and the movement of blood-corpuscles in the foot of the frog—reaching the mind through the eye, make and leave an impression, and give an understanding, which books and diagrams are powerless to produce. The Microscope, frequently and intelligently used, makes nature pellucid. There ought to be an excellent one under skilful manipulation in every school.”] Journ. N. York Mier. Soc., I. (1885) p. 110. ScuoTt.—eber optisches Glas. (On optical glass.) [Title only.] SB. Jenaisch. Gesell. f. Med. u. Naturwiss. for 1884 (1885) p. 32. Soutuas, W. J.—On the Physical Characters of Calcareous and Siliceous Sponge- spicules and other Structures. [Contains description of an arrangement for determining the density of minute objects under the Microscope. Post.] Scientif. Proc. R. Dublin Soc., 1885, pp. 374-92 (7 figs. and 1 pl.). Stokes—Watson Spark Apparatus. [Vol. IV. (1884) p. 964.] Nature, XXXII. (1885) p. 208. [Stowe.t, C. H. and L. R.|]—Long Papers v. Short Papers. [Advocates papers of not more than twenty minutes in length. ] The Microscope, V. (1885) p. 136. +6 53 See Walmsley, W. H. Textile Microscopical Association. [A National Textile Microscopical Association was formed last Saturday by members of the Corresponding Societies of Boston and New York.” ] Science, V. (1885) p. 472. ZOOLOGY AND BOTANY, MICROSCOPY, ETO. 729 Theiler and Son’s (M.) Demonstration Microscope. [Same as Waechter’s or Engell’s, Vol. IT. (1882) p. 398.] Knowledge, VI1. (1885) p. 491 (1 fig.), Nature, XXXII. (1885) p. 112, Universal Pocket Microscope. [Supra, p. 704.] Lbid., p. 491. Ibid., p. 112. Touman, H. L.—Eye-piece Micrometers. [Supra, p. 704.] Amer. Mon. Micr, Jovrn., VI. (1885) pp. 115-6. See also under “ Measurements of Blood-corpuscles,” The Microscope, V. (1885) pp. 113-4, from the Legal News, Van Brunt, C.—Diatoms mounted in Prof. Smith’s newest medium—Photo- graphs of same. Journ. N. York Micr. Soc., I. (1885) pp. 102-3. WaALeEs, W.—The proper care and use of Microscope Lenses. [Supra, p. 708.] Lbid., pp. 113-6 and 123. Warp, R. H.—Recent progress in the Improvement of the Microscope. from Annual Cyclopedia for 1884 (New York, 1885) pp. 499-522 (42 figs.). “s + See Behrens, J. W. Westien, H.—Apparat zur Vergleichung symmetrischer Stellen der Schwimm- haut des rechten und linken Fusses vom Frosche. (Apparatus for the comparison of symmetrical parts of the webs of the right and left feet of the frog. [ Post.] Zeitschr. f. Instrumentenk., V. (1885) p- 198 (1 fig.). ” ” 8. Collecting, Mounting and Examining Objects, &c. Preparing Embryos.*—The method of examination which Dr. L. Léwe employs is as follows:—The embryos are placed, according to their size, in a 1 per cent. to a saturated solution of bichromate of potash, which is frequently changed. They remain in this for several months orayear. After being thoroughly washed in water they are stained in a 1 per cent. solution of carmine, which is renewed as soon as its ammoniacal odour is lost, then again washed, soaked in glycerin- jelly in an incubator (1-4 weeks), and hardened in alcohol. Sections are then cut with a microtome. Methods of Investigating Animal Cells.t—The methods of exa- mining living animals, e. g. Amebe, Infusoria, &c., under the Micro- scope, are first described by Dr. A. Brass. When they have been studied in their natural state, various reagents are applied to the living object; e.g. a mixture of chromic acid, 1; platinum chloride, 1; con- centrated acetic acid, 1; water, 400-1000; hyperosmic acid, picro- sulphuric acid, or concentrated solution of corrosive sublimate. Brass believes, however, that better results are obtained by studying protozoa without reagents or staining. The free cells of the animal body are examined in the living state on a warm stage in lymph fluid, vitreous humour, iodized serum, or 0°6-0°7 per cent. salt solution. The ova of mammalia are examined on a warm stage in lymph, to which a trace of sodium carbonate has been added. Animal tissues are examined in the fresh state in 0°6-0:7 per cent. salt solution, iodized serum, or lymph fluid. The application of water is to be avoided, as it alters the cells. Tissues, of which the internal structure is to be examined, are washed, after treatment with * Zeitschr. f. Wiss. Mikr., i, (1884) pp. 585-6. + Ibid., pp. 39-51. 730 SUMMARY OF CURRENT RESEARCHES RELATING TO reagents, in water, to which alcohol or a few drops of acid have been added. Small animals, and embryos of higher animals, especially those which have not a strong external skeleton, are put alive into a 1/8-1/2 per cent. solution of chromic acid till they are dead, then treated with several drops of concentrated chromic acid, and finally washed, first in 30 per cent. alcohol, and then in gradually increasing strength up to absolute. As staining reagents, borax-carmine, ammonia-carmine, and log- wood are used. By starving or exposing to a low temperature the lower animals, insects, worms, &c., Brass has discovered that the granular substance inside the cells is dissolved and reabsorbed, and that finally the nuclear corpuscles disappear by degrees. To study this process in the higher Vertebrata—parrots, mice, rabbits, &c.—they were infected with tuberculosis. The chromatic substance of the cells disappeared more or less, especially in those of the ovum, in which the changes were very marked, as ascertained from sections of the ovary. Demonstrating the Nuclei in Blood-corpuscles.**— Herr M. Ladowsky recommends for the demonstration of the nuclei in white blood-corpuscles treatment with solutions of osmic acid (1 per cent.), or weak solutions of picric or chromic acid, and subsequent staining with rosanilin, safiranin, or better methylen-green. The latter is also useful for demonstrating the stroma and nucleus of red corpuscles. The author shows that the white corpuscles are not sticky by inject- ing watery solutions of indigo-blue, eosin, or even distilled water into the blood, which make the plasma cells aggregate in heaps, whereas the white corpuscles circulate unchanged. Demonstration of Karyokinesis in Epithelial Tissues.}—Signor Tizzoni employs the method of fixing the tissue with Miiller’s fluid, hardening, preserving in ordinary alcohol, and staining with alum- carmine, which differentiates the chromatic figures of cell-nuclei ina state of division with the same distinctness as logwood and safiranin ; the resting nuclei assume a violet colour, those which are dividing a ruby-red colour. This difference of staining points to a difference in chemical composition. The alum-carmine which the author uses is made by adding to Grenacher’s formula a trace of sodium sulphate, which increases its staining power. Investigating the Structure of the Central Nervous Organs.t— Dr. J. Stilling recommends that pieces of brain hardened in chromium salts should be placed, after washing, in red or rectified pyroxylic acid or artificial pyroxylic acid (glac. acet. ac. 100 ¢.; ordinary water 800 g.; kreasote 30 minims). The connective ‘tissue swells, and is quite macerated, so that the nerve-fibres, which remain intact, can be prepared under water with needles and forceps. The specimens can afterwards be stained with picro-carmine. * Virchow’s Arch. f. Path. Anat., xevi. (1884) pp. 60-100. + Bull. Sci. Med. Bologna, 1884, p. 259. t Zeitschr. f. Wiss. Mikr.. i. (1884) pp. 586-7. ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 731 Application of Borax-methylen-blue in the Examination of the Central Nervous System.*—Dr. H. Sahli recommends the following formula: Distilled water 40, saturated watery solution of methylen- blue 24, borax solution (5 per cent.) 16. Mix, leave for 24 hours, and then filter. Sections are stained in this solution for 10 minutes to several hours, and then washed in water or alcohol, until the grey substance is clearly distinguished from the deeply blue-stained white substance, dehydrated, clarified in cedar oil, and mounted in balsam, either pure or mixed with cedar oil. The ganglion cells appear pale greenish, and are clearly differentiated from the blue-stained nuclei of the neuroglia. The most delicate nerve-fibres are stained. The author obtains better results with this solution than with the ordinary alkaline methylen-blue in the examination of the central nervous system for the presence of micro-organisms. Preserving Sections of the Nervous System Treated with Bichromate of Potash and Nitrate of Silver,t—To obviate the difficulty of preserving preparations, Signor C. Golgi places a drop of dammar varnish on the section, and allows it to dry in an even layer. He uses slides which have a square hole in the centre, which is closed below with a cover-glass. The section covered with dammar is placed on this, and when the varnish is dry the specimen can be examined on both sides. Study of Fat Absorption in the Small Intestine.{—Herr Th. Zawarykin makes use of the following method :—A piece of intestine is treated with hyperosmice acid, washed in water, and placed in spirit for 24 hours. A small portion is then cut between two pieces of elder-pith, in which it is placed in such a way that the villi are turned towards one half and the serous coat towards the other half of the pith. The razor should be wetted with alcohol. The sections can be stained with picro-carmine. Preparing the Cloacal Epithelium of Scyllium Canicula.s— To isolate the goblet-cells, Herr J. H. List uses Miiller’s fluid and alcohol. The preparations are then imbedded in celloidin, cut, and stained with eosin and methylen-green, The epithelial cells are in this way stained rose-red, the goblet-cells green. Preparing Embryos of Amarecium proliferum,||—MM. C. Maurice and A. Schulgin employ the following methods:—The whole, or better pieces, of the Ascidian are laid in water with an equal quantity of picro-sulphuric acid. After half-an-hour they are placed in alcohol, the strength of which is gradually increased. ‘They can be stained whole with alum-carmine, or treated as follows:—The isolated ova or embryos are stained with borax-carmine for 15-18 hours, treated with hydrochloric acid, washed in 70 per cent. alcohol, and transferred to a very weak solution of Lyons blue for 15-20 * Zeitschr. f. Wiss. Mikr., ii. (1885) pp. 49-51. + Arch. per le Scienze Mediche, viii. (1884) p. 53. t Arch. f. d. Gesammt. Physiol. (Pfliiger) xxxy. (1884) pp. 145-57. § SB. K. Akad, Wiss. Wien, xc. (1884). || Ann. Sei. Nat,—Zool., xvii. (1884). Tw, SUMMARY OF CURRENT RESEARCHES RELATING TO hours. They are then quickly imbedded in paraffin, to which ceresin is added. They are cleared with oil of bergamot or cloves. A long stay in alcohol abstracts the colour. By this method the nuclei are stained red, the plasma blue. The three layers of the embryo are clearly differentiated. 'The ectoderm is a darker blue than the endo- derm. 'The mesoderm shows the least blue staining, as its cells possess a large (red-stained) nucleus, against which the blue plasma stands out in contrast. Mounting Insects without Pressure.*—Mr. R. Gillo describes the process which he uses for this object, and which is a selection and combination of somewhat well-known methods. “ Let us suppose that the object to be mounted is an ordinary ground-beetle, perhaps 1/2 in. long. The first thing to be done is to steep it in liquor potasse (full strength), and for this purpose I use a test-tube. When the solution becomes dark-coloured, it must be poured away and fresh added. After being in this for ten days or a fortnight, the insect must be transferred to water in a tea-saucer (dis- tilled or soft water should be used), and whilst holding it steady with a camel’s-hair brush, gently squeeze the body with another, giving the brush at the same time a kind of rolling motion, thus driving the contents of the abdomen towards the anus, from which it will presently be discharged. The beetle should now be removed to clean water, and left for an hour or so, when the squeezing pro- cess with the two brushes must be repeated as before, when more of the abdominal contents will be ejected. Again place the insect in clean water, and in this way, by several soakings and squeezings, the whole of the contents of the viscera will be removed without the least injury to any of the internal organs. Throughout this process, however, the insect will be seen to be as opaque as it was at first. It is, therefore, necessary to bleach it; and to effect this it must be placed, until sufficiently transparent, which may take a week or more, in the following solution :—A saturated solution of chlorate of potash, to which is added ten or twenty drops or more of strong hydrochloric acid to each ounce of solution. A shallow but large-mouthed corked bottle is best for this purpose. The chlorine, which is slowly liberated in the solu- tion, attacks the chitine, and thus gradually bleaches it and renders it transparent, It is now necessary to wash all this solution out of the insect, which is best accomplished by placing it in a small pomatum pot filled with distilled water, and after an hour or so to change the water, repeating the process four or five times.” “For the next part of the process, a nest of china saucers or alettes, such as are used by water-colour artists (these fit sufficiently accurately one on the other to hold spirit for a day or two without its evaporating), will be required. In an empty palette place the insect on its back, and arrange its legs in the positions they are intended to retain when finished. Now gently pour methylated spirit over it, * Journ. of Microscopy, iv. (1885) pp. 151-4. ZOOLOGY AND BOTANY, MICROSCOPY, ETC. Too so as completely to cover it, noticing that the legs are not displaced, for if they are right during this part of the process, they will naturally assume the same position in the final stage of the mounting. After several hours, or next day, change the spirit for fresh, and again, after several hours, pass the insect into ether, but as this is such a volatile fluid, it should be used in a test-tube tightly corked. There need be no anxiety about the position of the legs in this stage, as they have been already stiffened by the spirit, and if displaced now will spring back again into their original position. After soak- ing some hours in ether, pass into turpentine, in which it may be ' allowed to remain any length of time.” Directions for mounting in a cell with balsam in benzole follow, and for cementing, and it is pointed out that among other advantages insects thus mounted polarize brilliantly, probably owing to the action of the bleaching solution on the different tissues. Mounting the Proboscis of the Blow-fly in Biniodide of Mer- eury.—Mr. H. Sharp describes his method as follows:—The appa- ratus necessary consists of two pieces cut from a glass slip, 1 in. by 15 in., a weak spring clip, and a wide-mouthed bottle containing methylated spirit. Kill the fly by dropping it into boiling water, cut off the head, place it on one of the pieces of glass, and squeeze it with the finger until the tongue protrudes and the lobes expand. Then gently nip it with the other piece of glass, and put on a weak clip to hold it in position. Place the whole inthe methylated spirit, and leave it there for an hour or more. On releasing the proboscis from the glasses the lobes will remain expanded ; cut off the proboscis and place it in spirit till all the air is removed. Then put it in water for half-an-hour, and then in weak solution of biniodide of mercury (half water and half saturated solution) for two or three hours; then in the full strength solution for 12 hours. When the proboscis is put in the weak mercury solution the lobes will most likely curl up, to prevent which place it on a slide when taken from the water, and put on a cover with a weak clip to hold it in position, and then run the weak solution of mercury under the cover. Do the same when transferring from the weak to the full strength solution. Mount in a shellac cell, and use shellac for securing the cover. Mr. Sharp finds it safe to use for the final mounting a solution of the biniodide of mercury slightly weaker than saturation, as if of full strength crystals will develope in very cold weather. Preparing Luciola italica.*—To investigate the seat of oxida- tion which produces the light, Dr. C. Emery kills the living animal in a solution of osmic acid, which stains the luminous plates of the still living and light-developing animals brown. The parts which are to be further examined are macerated for a long time in water, the development of fungi in which is prevented by the addition of * Zeitschr. f, Wiss. Zool., xl. (1884) pp. 338-54, HO SUMMARY OF CURRENT RESEARCHES RELATING TO erystals of thymol. The osmie acid is especially reduced at the bifurcations of the blind ending tracheal capillaries within the luminous plates, and in the tracheal branches before the bifurcation. Another method of preservation consists in injecting corrosive sublimate solution into the animal, and subsequent treatment with alcohol. Preparing Embryo of Peripatus Edwardsii and P. torquatus.* —To obtain the embryos uninjured, Prof. J. v. Kennel removes them with the uterus from the chloroformed mother-animal, and places them, partly in concentrated solution of corrosive sublimate, partly in 1 per cent. osmic acid solution, and subsequently hardens them in alcohol. Alcohol alone, chromic, picric, or picro-sulphuric acid cannot be used for hardening, as they alter the object. The uterus is rendered transparent by turpentine, and cut with its contents, or the embryo is taken out and cut alone. Preparing Diatoms from the Stomachs of Mollusca and Crus- tacea.{— Mr. H. S. Courroux recommends that in the case of mussels and cockles, the stomach should be cut out and steeped, or even boiled, in nitric acid until it is dissolved, and the resultant deposit washed and cleaned after one of the methods recommended in the text-books. A little special care, however, in the treatment of shrimps’ stomachs will not be thrown away. On removing the shelly skin at the back of the head, the stomach will be seen as a small, dark-coloured body, the size of a small pea. Its position may gene- rally be detected in the perfect shrimp from the dark appearance at the back of the head. The stomachs may be detached with the point of a knife, and when some 12 or 20 or more (as the deposit obtained from them is small) have been collected, they should (taking care that the skin of each stomach is cut or broken) be boiled for a few seconds in a weak solution of washing-soda or ammonia, and then immediately be thrown into a beaker of cold water. By these means we get rid of grease, &c., and render the subsequent treatment by acids more easy. The empty skins of the stomachs will float, and may be picked out of the solution. The residue which collects after the solution has stood for some time should first be washed free from alkali, and then treated with acids in the usual manner. The method of separating deposits into different densities is very useful here as with many other gatherings of diatoms, inasmuch as the large forms are then more easily isolated. The often advised whirling in a large evaporating dish in order to separate the diatoms from sand and débris may be frequently practised with success. In the washings of all diatoms, the author has found it of the utmost advantage to perform the later rinsings in distilled water. The diatoms are thus more effectually cleaned from salt, &c., and present less attraction to moisture in the case of dry mounts. * Arbeit. Zool.-Zoot. Inst. Wirzburg, vii. (1884) pp. 1-222. + Journ. of Microscopy, iv. (1885) pp. 19b-8. ZOOLOGY AND BOTANY, MICROSCOPY, ETC. fop The operator may be reminded that the material, even from a con- siderable number of stomachs, is of course very small in quantity, and must be handled carefully, and, as the most beautiful forms are often the lightest, it is of the utmost importance to let the deposit settle thoroughly in the washings of the lighter portions of the gatherings. The water holding the diatoms in suspension should be allowed to stand at least half-an-hour for every inch of its depth, and hence time will be saved by using watch-glasses and shallow dishes for the purpose. Bayberry Tallow for Imbedding.*—This substance is obtained from the ordinary bayberry-bush, and is used by furniture manu- facturers for oiling the sliding surfaces of bureau-drawers, &c. It is claimed for the bayberry-tallow that it is cheaper and better than celloidin, and far superior to parafiin and other kinds of wax hereto- fore used. A special feature claimed for it is non-solubility in alcohol, except when warmed to about the temperature of the body or a little above it, and hence the specimens may be kept indefinitely in alcohol at ordinary temperatures. Another point to the credit of the tallow is that tissues injected with it or imbedded in it can be shaved in thinner sections than those allowed by other materials, and that on account of its firmness it allows of amore even cut. After making a section the tallow may be removed from the specimen by simply placing it for a few minutes in a bath of warm alcohol. Imbedding and Examining Trematodes. — Dr. P. M. Fischer + recommends soap, fifteen parts dissolved in 17°5 parts of alcohol (96 per cent.) as a good imbedding medium for Opisthotrema cochleare. Glycerin is used in the examination of the sections. The whole animal can be hardened in absolute alcohol, stained with picro-carmine, logwood, or ammonia-carmine, clarified in oil of cloves, and mounted in Canada balsam in chloroform. For the investigation of the embryonic sheath of living Cercarie in snails, Dr. J. Biehringer { employs the blood-fluid of the snail it- self, Many facts, e.g. the origin of the accessory membrane of the sporocyst, can only be brought to light in this way. Hatfield’s Rotary Section-cutter.§— Rev. J. J. B. Hatfield’s section-cutter is rotary in all its moving parts except the specimen- carrier in its approach to the knife, and the horizontal frame Brice Ba.” JOURNAL OF THE ROYAL _ MICROSCOPICAL SOCIETY: CONTAINING ITS TRANSACTIONS AND PROCEEDINGS, AND A SUMMARY OF CURRENT RESEARCHES RELATING TO ZOOLVCGYT AND BOTAN YDT (principally Invertebrata and Cryptogamia), MICROSCOPY, &£c. Edited by FRANK CRISP, LL.B., B. ee One of the Secretaries of the Society and a Vice-President and Treasurer of the Linnean Society of Liles ; Ne ee: WITH THE ASSISTANCE OF THE PUBLICATION COMMITTEE AND _ AW. BENNETT, M.A., B.8c., F.L.S., F, JEFFREY BELL, M.A, F.Z.8., | Lecturer on Botany at St. Thomas's Hospital, Professor of Comparative A natomy in King’s College, _ JOHN MAYALL, Jox., F.Z8., FRANK E, BEDDARD, M.A., F.Z.8., AND B. B. WOODWARD, F.GS., Librarian, British Museum (Natural History), FELLOWS OF THE SOCIETY, WILLIAMS & NORGATE, LONDON AND EDINBURGH. 3 1 BY WM. CLOWKS AMD SONS, LIMITED.) , ‘ (STAMFORD STREET AND CHARING CROSS, CONTENTS. TRANSAOTIONS OF THE SocireTY— XIV.—New Barrish Micro-Funer. By G. Massee, FRMS. (Plate XIII.) Pea et Was Pie MA teeta Nae a eae NS: XV.—On Erosion or THE SuRFAOE OF GLASS, WHEN EXPOSED TO. Tae Joint Action or CARBONATE oF Lime anp Contos. By William M. Ord, M.D., F.R.MS., F.LS. 6 ee oe XVI.—On a Septic Miorosz From A- Hien Atitupr. Tae Nizsen Bactiius. By G. F. Dowdeswell, M.A., F.RMS., OS Bike ie g ci eee aa pei (haat Pom ti ee AC Ua Aaah eae XVII.—On THE USE OF THE Asidouauiae MANDIBLE IN THE DETER- — MINATION OF THE CuiLosTomatous Bryozoa. By Arthur = Wm. Waters, F.R.MS., F.L.S. (Plate XIV.)..0 1.0 a SUMMARY OF CURRENT RESEARCHES. ZOOLOGY. . A. GENERAL, including Embryology and Histology x of the Vertebrata. Doukn, A.— Primitive History of the Vertebrate Body =... se oo ewe Minot, C. §.—Formative Force of Organisms». we se ae newt ww Fou, H.—Tazl of Human Embryo en Lavianre—Nature of the Placental Neoformation and ihe Unity of Composition of, ya the Placenta ~°.. Ab ERE Ro re OO ai et Ce DENIEER, J.—Letus of Gibbon "and “its Placenta HNC MDA ME Nr Rrh aucey een Brown, H. H.—Spermatogenesis in the Rat .. Bi Gerace, L.—Hatching of Birds’ Eggs after Resin of the Shell Sia: daa k Peete Sprnozr, W. BaLpwin—Larly Development of Rana temporaria .. +» cc ve Broox, G.—Development of Motella mustela ., +. +0 ee «6 ee os 90 ae Ryper, J. A.—Development of the Salmon...” Sgr eG Lae la Raa BWWART, CossaRr, & G. Brooxk—Spawning of the Cod eo oe ee oe ee oo oe RertTERER— Development of Vascular Glands is Seti Hes ghige ni MeEtiann, B.—Simplified View of Histology of Striped "“Muscle- fibre .. adits eon pat lana Hows, G. B.—Atlas of Practical Elementary Biology .. «. os 08 20 we B. INVERTEBRATA DN ae Conn, H. W.—Marine Larve and their Relation to Adults... GAR eee i ae a Ransom, W. B.—Cardiac Rhythm of Invertebrates .. da \ oa tele cre | Wanieny, H. pe—Physiology of the Unstriated Muscles of Fnerterata db ar pei) Sse hicte Prenzev, J.—Temperature Maxima for Marine Animals oo), we) lee, een) eal he Mollusca, ae so ee ee metaent J —Mid-gut Gland (Liver) of the Mollusca... o« c+ 0 cae Sioa eee HALLER,- ’B. —Renal Organ of Prosobranchiata .. BEC RM BRE Pole meri Bouvigr, E. L.—Nervous System of Buccinide and Purpuride Wldeeiy tees ‘ee Bourne, A. G.—Communication of the Vascular System with’ the Exterior im Plewrobranchus > .. Wah Pacis HUN S GTR Gua @: Beira a Se iene Grrespach, H.—Inception of Water among Mollusca Ae Scutiiur, P.—Relations of Cavernous Spaces in the Connective ' Tissue oF Anodonta je to the Blood-vascular System...» to aie tee Gairrirus, A. B., & H. FrnLows—Organs of Bojanus in Anodonta hha cfewes oF 7 5 Oszorn, H. L.—Mimicry among Marine Mollusca =. 4 a oe ee ee oe TOD e3 z Molluscoida. @, Tunicata. Benepen, E. van, & O.\Jc0L1n—Postembryonal Sigh ca sneer ee 795 4 Jounpay, 8.—The Synascidian Diplosomide .. .. B. Polyzoa. = LANKESTER, E. Ray—Polyzoa oe ee * oe ae Ostrovmorr, A.— Metamorphosis of Cyphonautes.. hee ae Sas Arthropoda, a. Insecta. Beavrecarp, H.—Natural Development of Cantharis.. + «. WIELOWIEFSEI, H. v.— Formation of Ova in Pyrrhocoris APs _ Korornerr, A.—Development of Gryllotalpa «ss ss VIALLANES, H.— Optic Ganglion of Aeschna .. .. _ Povutoy. E, B.—Nature of the Colouring of Phytophagous "Larvz 3 Dewrrz, H.—How Insects adhere to flat vertical surfaces .. .. = y. Prototracheata. _ SEnewrcr, A— Development of Peripatus capensia .. «+ ve = 3. Arachnida. _ Dau, F.—Season Dimorphism in Spiders... ++ ee ae te Trovessakt, E, L.—Sarcoptide se oe oe oe oe oe oe 2 «, Crustacea. _ Oxavs, C.—Morphology of Crustacea 41 +0 nn te tee Scum«ewirscu, W.—Development of Astacus .. oe z ‘Gairritus, A. se —Extraction of Urie Acid eetals from the Green Gland of Astacua oe oe oe oe - Sanvr-Lovp, B_-Pasisties ‘of Mena vulgaris Eon eee PELSENEER, a P.—Nervous System of Apus A Baa _ Pacxarp, = 8. Fert hig Be 5 Limulus polyphemus a a fear . ‘Dyzowss!, B —Crustacea of La Baikal lee oe oe oe ae - errs, SIDNEY I—New SN toy or oe se oe oe a) 2 Vermes. 5 Samr-Love, & lg read acre as ne id bewesla See 4 in evelopment of t ead of Poly ae , femme 9 of Nematodes... i ye hep. ee - Tnvorasr, R —Dexelop mee Spherularia bombi Lewy, J.—New Bothesooep A. C.—Circulatory and Nephridial Apparatus of the Nemertea ~ Ovpemans, _ Savensxy, "W.— Development evelopment of M VIVEPATA 20 40 ~ Beppaxp, "¥. E—Nephridia of Acanthodrilus sp. ART cere Zacuanias, O- ee ridia of Microstoma lVineare., «+ 1+ + : BDour.essis-Govuret, G.—Fresh-water Monotide .. .. + «+ _ Perroncito, E.— Action of Sodium Chloride on cglens ee Sak ~ Grarr, L. v.—New Species Boole By yzostoma 4. Sige _ ur, 0. E—Pdagic and resh-water Rotatoria 4. 5 ws Echinodermata. P. Henpent—Vaseular System of Echinoids .. .. | Pesrier, E.—Ambulacra of Echinoderms.» +s un ts _ Provno— Anatom matory o Dorocidaris * - - ad * ~ Dencan, 2 gh M. =, 2 0 Celopleurus ‘Maillardi “- “* ” ee. P. H.—New of Metacrinus 4. ss) we os be nll bee Coelenterata. 4 Bavuot—Adamsia palliata * * aad * ” - - * me Porifera. ida , A.— Development of Spongilla .. « Sores E.—New Fresh-water Sponge .. + a y ee Se a Sd ae ‘ PAGE 796 797 798 ( 4 ) Protozoa. Lanxester, EH. Ray—Protozoa * HAiBueron, W. D:— Chemical Composition of. Zoocytium. of Oplerydinm ‘versatile. Mésrvs, K.—Freia Ampulla O. F. Mill., the Flask-animaleule .. oi sane ee Basiant, H. G., & A. Scunemer—Anoplophrya CU CWLANE- . Angle of Aperture (= 2 w). Theoretical Ae Back Lenses of various 3 Tilumi- | — “Resolving Pene- Dry and Immersion . | Numerical Water- | Homogeneous-| nating Power, in. _| ‘tating Objectives of the same | Aperture. ry Immersion| Immersion | Power. | Lines toan Inch,| POWe? Power (3 in.) (msinu=a.)| Objectives. | Opiectives.| Objectives. | (a2) | (A=0°5269 u () from 0°50 to 1°52 N. A. @=1) {nm =1-33)) @=1"52.) =lineE.) | \a7 1°52 ee e- -} 180° 0’ | 2°310} 146,528 "658° 1°50 . a's af 161° 23’ | 2:250)} 144,600 “667 1-48 os oe 153° 39’ | 2190} 142,672 "676 1°46 ae “a 147° 42' |2-132| 140,744 | +685 — p 1°44 = we 142° 40’ | 2:°074)| 138,816 “694 1:42 “6 oe 138° 12’: | 2°016} ~136,888 "704 - - 1-40 oe fs 134°. 10’. | 1-960] ~ 134,960 |. °714 — 1:38 a be 130°-26’ | 1°904|- 133, 032 “725 1-36 x és 126° 57’ |1°850} 131,104 | *735 ~~ 1:34 a 123° 40’ |1°796| 129,176 +746 1°33 xD 180° 0’; 122° 6’ |1°770|° 128,212 | *752" - 1°32 oe -1165° 56’| 120° 33 |1:742| -127,248 iy 5): ae 1:30 a 155° 38’| 117° 34’ |1°690| 125,320 Be (2 ons 1°28 es 148° 28’| 114° 44’ |1:°638} 123,392 | *781 ; 1-26 ae 142°. 39'|- 111° 59’ | 1-588) 121,464 “794 1:24 Ze 187° 86'| 109° 20' | 1-538} 119,536 | +806 — 1-22 = 133° 4"| 106° 45’ |1°488} 117,608 { +820 — 1°20 ee | 128° 55’) 104° 15’ | 1°440) 115,680 | -833 1:18 a 125° 3’) 101° 50’ | 1°392} 113,752 |. *847— : 1-16 SS 1° 111,824 - | >* 1°14 re zi 109,896 ~ 1-12 as 1 107,968 | *893 1-10 a 1 106,040. | = : 2 1:08 os 1 104,112» 5 1:06 s 1 102,184 | +9 1:04 3 1 “100,256 =| > : 1-02 oa 1 98,328 ] 1:00 180° 0! 1 96,400 “0 0-98 157° 2! 94,472: - | 1: 0:96 147° 29' 92,544 | 15 0°94 140° 6’ 90,616 | 0:92 133° 51’ 88,688 | 1 0-90 128° 19° 86,760 | 1°: : 0-88 123° 17’ 84,832 |” es 0:86 118° 38’ 82,904 | 0°84 114° 17’ - 80,976 | | 0°82 110° 10! 79,048 > : 0:80 106° 16’ - 77,120. =| 1*28 0:78 102° 31’ 975,192 4 : 0:76 98° 56! 73,264 | ; 0:74 95° 28! 71,336 | 0:72 92° 6’ 69,408 |] : a4. 379 0°70 88° 51’ 67,480 | 17429 — 0:68 85°. 41’ ~. 65,552. 4 1*47b = 0:66 82° 36’ 63,624 | 1°515 © 0°64 Oe 95" 61,696 | 1°562 0°62. 76° 38’ ‘59,768 | 1-613 | 0:60. 73° 44! 57,840 | 1°6 0°58 70° 54’ 55,912 | 1°72 Pas te 0°56 68° 6! 58,984 | 1-786 0:54 65° 22! » $2,056 ‘ 0°52 62° 40’ “<§0,128 |.1°925 | *90 0:50 60° 0’ 48,200. | 2-000 — EXAMPLE.—The apertures of four objectives, two of which are dry, one water-immersion, and one oil-immers © would be compared on the angular aperture view as follows;—106° (air), 157° (air), 142° (water), 130° (oil). Their actual apertures are, however, as *30 "98 "1°26 1°38 ort numerical apertures. ¢ Boyes v Pe II. Conversion of British and Metric Measures. aa 1.) Linnat. Seale showing Micromillimetres, §c., into Inches, §c. Inches, &c., into Se “ ins. mm. ins. mm. ins, Mier eae: ’ ¢,, to Inches. z p0ohey : -039370 ps ae ga aun. *00007 “078741 047262 | __2 =. 8 -000118| 3 -118111|° 58. =. 2086683] 772°? Manes cm. ins. 4 -000157| 4 157482 | 54 2°126003 | 2°2°" 4.693378 a! ' 5 -000197| 65 196852 | 55 2°165374 | =°3°" 9.539977 TIE 6 -000236| 6 ‘236223 | 56 2°204744 | 23°" 9.899107 7 -000276| 7 1275593 | 5'7 2-244115 | 2°P° - 3.474979 8 -000315| 8 +314963| 58 2283485 | 52°° 3.¢98539 9 -000354| 9 -354334 | 59 2392855 | 7° 4.933995 : 10 -000394| 10 (1em.) :393704| 60 (6cm.) 2°362226] “1 5-079954 11 -000433} 11 -4383075| 61 2°401596 | aoso 6°349943 12 +000472| 12 472445 | 62 2°440967 | sooo _8° 466591 | JE 18 :000512| 18 ‘511816 | 63 2:480337 | alsa 12°699886 SAL 14 +000551| 14 551186 | 64 2-519708 | iba 29°399772 | a 15 +000591| 15 590556 | 65 2+559078 : mm. 16 ~-000630| 16 “629927 | 66 2:598149| soo (028222 17 -000669| 17 “669297 | 67 2+637819 | soo (081750 18 -000709| 18 -*708668 | 68 2:677189 | ros — '036285 19 -000748 | 19 748038 | 69 2°716560] som *042333 20 -+000787| 20 (2cem.) *787409| 70 (7em.) 2°755930] B90 Seve 21 -000827| 21 "826779 | ‘71 2:795301 | 23° -963499 = 22 -000866| 22 *866150 | ‘72 2-834671! 23° 979571 E 23 -000906| 23 -905520| 73 2°874042| 23° — .oga666 = 24 -+000945 | 24 944890 | 74 2°913412| 38° .401599 [= 25 -000984 25 -984261| '75 2:952782| 23° —-ya6999 [= 26° +001024 | 26 1:023631| 76 2:992153} 23° 169332 = 27 -001063| 27 1:063002| "77 3°031523 | 23° «953998 is 28 -001102) 28 1°102372| 78 3070894} “2° «507995 E 29. -001142| 29 1°141743| '79 3-110264} 2’ 1-015991 = 30 -001181| 30 (Sem) 1:181113| 80(8em.) 3:149635] 2 1-269989 l= 81. -001220| 381 1°220483| 81 3°189005} va — 1°987486 I= 82 -001260| 32 1:259854 | 82 3:228375| ws 1°693318 33 -001299| 33 1°299224 | -88 3°267746 | “xs 2°116648 84 -001339| 34 1°338595 | 84 3°307116| vo 2°989977 85 :001378| 35 1°377965 | 85 8° 346487 % © 8174972 86 -001417| 86 1°417336 | 86 3° 385857 x £°233299 87 -001457| 37 1:456706| 87 3425298] vs #° 762457 88 -001496| 88 1:496076| 88 - ~ 8464598 % 5079954 89 °001535| 39 1°535447| 89 3503968 2 6349943 40 -001575| 40 (4em.)1-574817| 90 (9 em.) 3°543339| is 7987420 41 -001614| 41 1-614188| 91 g-5e270g | . 9'PeRNS 42 -001654| 42 1:653558| 92 3622080} - 2 1111240 43 +001693 | 43 1692929 | 938 3°661450 % -1:269989 44 -001782)| 44 1°732299 | 94 3*700820 |g: 17428787 45 -:001772| 45 1°771669 | 95 3740191 7 g 1 -587486 46 -:001811| 46 1°811040| 96 8°779561 | 3% 1+746234 47 -001850) 47 1°850410| 97 3°818932| 1:904983 48 *001890) 48 1°889781| 98 8° 858302 22 2063782 : 49 -001929 17929151} 99 3897678} 4% —-2+222480 = 50 -001969 | 50 (5 cm.) 1'968522 | 100 (10 em.=1 decim.)} 4% 2°381229 : 60 -002362 E 1. 2°539977 Waa | | 2 Sits] Pg 5 Et HS -0031 P : E 90 “008543 2 7874086 asim. aE 100 -008937 3 11°811130 Oi se Ree TE 200 007874 4 15°748173 GE Mtr TE 400 *015748 6 933622959 ta a < 1g 5OO -019685 : 97° 559302 8 2°081982 “ 2 600 023622 8 31496346 9 2°285979 700 «027559 9 35°483389 aK Se emeate 800 °031496 10 (1 metre) 39°370432 HEN Rag ot ont ; = 3°280869 ft. geapenee: 5 = 1-°098628 yds. lyd.= ‘914392 (10). CHARLES COPPOCK, MANUFACTURER OF SCIENTIFIC LATE’ PARTNER WITH R. &d. BECK, PATHOLOGICAL aia AND a Microscopes PHYSIOLOGICAL ae PREPARATIONS, stidunke and STAINING FLUIDS Aa AND ALL ee ACCESSORIES a /LLUSTRATED FOR STUDENTS’ CATALOGUE, USE. 28e3 Ie —100,NEW BOND STREET, : LONDON, W. a N.B. SPECTACLES !! ~ QCULISTS’ PRESCRIPTIONS RECEIVE PERSONAL. ATTENTION, AGENT for W. H. BULLOCH, CHICAGO, ILLS., U.S.A, R. H. SPENCER & CO., N.Y., U.S.A. JAMES L. PEASE, MASS., U.S.A. " M. PRAZMOWSKI, PARIS. - M. A. NACHET PARIS. i a yo pS a ke j EEE rt —— a Sart. 9 CEL EB Riel Ne ae be ates eres incerta SRS a re ee ee as ee) DMP LPs Gn ees Gs ea INSTRUMENTS, -—————— ve et sip Pik h Fie ad aa ae " X ae 2 + rT, PRN; ee ——-———~ i is oe Fas laa L® in ile GA 3 Ace a ae ae Cet Siero JOURN.R.MICR.SOC.SER.ILVOL WIP IL, 200 West, Newman & Co lith, G.Massee del.adnat. New British Micro-fungi. JOURNAL OF THE ROYAL MICROSCOPICAL SOCIETY. OCTOBER 1885. TRANSACTIONS OF THE SOCIETY. XIV.—New British Micro-Fungi. By G. Masszs, F.R.M.S. (Read 10th June, 1885.) Puate XIII. Didymium hypnophilum n. sp. (Plate XIII. figs. 8-12). Spor- angia sessile on a broad base, hemispherical or elongated, sub- depressed, powdered with white amorphous granules of lime; columella hemispherical, large, white ; capillitium of violet-coloured threads which are attached to each other at intervals in a fascicu- late manner, thus forming a loose irregular net, furnished sparingly with slender fusiform thickenings, which sometimes contain a few yellowish granules of lime; spores globose, large, spinulose, dull violet. On moss, Scarborough. EXPLANATION OF PLATE XIII. Fig. 1.—Stilbum flecuosum, nat. size. » la—Same x 30. » 2.—Same, section of head x 350. ; 8—Same, portion of head with conidia x 500. » 4.—Helminthosporium pumilum, parasitic upon Stilbum fleruosum, x 30, » 0—Same x 500. , 6.—Arthrobotrys rosea, nat, size. , 6a—Same x 350. » 7-—Same, conidium x 500. » 8.—Didymium hypnophilum, nat. size. » 9.—Same x 30. » 10.—Same, section of plant x 50. », 11.—Same, portion of capillitium attached to wall of sporangium, x 500, » 12.—Same, spores x 500. », 13.—Corepthoris paradoxa, nat. size. » 14.—Same x 350. » 15.—Same, conidia x 500. »» 16.—Corepthoris epimyces, nat. size. » 17.—Same x 350. ,, 18.—Same, conidia x 500. » 19.—Sporidesmium atrum, spore * 500, Ser. 2,—Vo1, V. 3 D 758 Transactions of the Society. This species agrees with D. confluens in the large spinulose spores and fasciculate capillitium, but differs in the sporangia not being confluent and the white columella. The spores of Lycogala epidendrum Bux. are not smooth as | described in Cooke’s ‘ Myxomycetes of Great Britain, but distinctly warted ; the same remark is also true of Prototrichia flagellifer B. and Br. Sporidesmmum atrum Link. (fig. 19). “ Tufts scattered, black, pulverulent, true stroma absent ; spores oblong, attenuated at both ends, transversely 3-4 septate, 4-5 celled, slightly constricted at the septa, epispore smooth, brown, pedicel white, diaphanous.” While examining some sections of Hutypa scabrosa F'ckl., a few spores were observed which resembled those of some Phragmidium, but the habitat—on bark of sycamore—did not favour this idea; and on further examination, they were found to agree in every particular with Corda’s figure and description of Sporidesmiwm atrum Link. as given in his ‘ Icones Fungorum,’ vol. vi. t.1.f 14. As detached spores only were seen, Corda’s description of the species is given. New to Britain. Stilbum flecuosum n. sp. (figs. 1-3). Gregarious; black ; head clavate, then globose, smooth ; stem long, filiform, often flexuous or geniculate, a little thickened at the base; conidia colourless, sub- globose. On rotten wood, Scarborough. About a line high, head viscid, so that when placed in water the conidia disperse very slowly. Septate threads of stem bright brown by transmitted light. Allied to S. rigidum P., but differmg in the flexuous stem and black head. Helnvinthosporium pumilum n. sp. (figs. 4 and 5). Fasciculate or scattered; stem simple, subulate, straight, with about four septa, base dark brown, opaque, becoming paler and pellucid towards the apex; conidia broadly obovate, at first pale, then pitch brown, opaque, shining, without septa. Parasitic on all parts of Stilbum flexuosum. Scarborough. Very minute, head shining like a black glass bead. Ftelated to H. obovatum Berk., but readily distinguished by its habitat and eseptate conidia. I have seen what appears to be the same, or a very closely allied species, parasitic on a new and very remarkable Hepatic (Mytilopsis albifrons Spruce), collected by Dr. Spruce in the Peruvian Andes. Helnusporium stemphylioides Corda. ‘This species was found some years ago near Scarborough and determined by Mr. Phillips, but owing to some oversight, has not up to the present been recorded as British. Arthrobotrys rosea nu. sp. (figs. 6 and 7). Tufted; pale rose colour ; fertile flocci erect, sparingly septate, with from three to five swollen nodes at equal distances, each node bearing a globose New British Micro-Fungi. By G. Massee. 759 head of conidia; conidia broadly obovate, uniseptate, slightly con- stricted at the septum, apical segment largest, base apiculate. On damp decaying branches, Scarborough. The nodes are covered with minute spicules arranged in a spiral, to which the conidia are attached. The conidia readily germinate within a few hours when placed in water; usually one filament springs from the apical segment close to the septum, this elongates for some distance, when the contents of the conidium pass into it and it developes into a much branched, septate, procumbent, floccose tuft. At this stage growth was arrested owing to desiccation, but from an examination of the fully developed plant, the fertile flocci appear to originate as erect lateral branches from the procumbent vegetative mycelium. Very distinct from A. superba Corda, which is pure white with oblong conidia divided into two equal parts by the septum. Corda’s two genera Arthrobotrys and Gonatobotrys would appear to be too closely related; the most important point of dis- tinction consists in the latter having unilocular conidia, and in Gonatobotrys simplex Corda, which is not uncommon in this dis- trict, I have occasionally met with uniseptate conidia along with the normal eseptate ones. Corepthoris paradoaa Corda (figs. 13-15). Gregarious ; stem erect, yellowish -olive, clavate, composed of numerous slender flocci ; apical portion barren, the remainder with numerous septate compound branches, some of which bear heads of simple elliptical conidia ; branches and conidia brownish olive. On an old shoe in a damp ditch, growing along with Ascobolus saccharinus B, and C. Agreeing with Corda’s figure of this species given in ‘ Prachtflora,’ except that the stem has a brighter yellow tinge. Corepthoris epimyces n. sp. (figs. 16-18). Gregarious; pure white; stem conical, composed of a bundle of flocci; branches simple or compound, springing from every part, except the expanded base, septate, patent, some supporting subglobose heads of conidia ; conidia colourless, hyaline, linear-oblong, obliquely apiculate. On decaying Agaricus (Mycena) purus P. along with Mucor Susiger Link. Scarborough. This plant, on account of its conical stem and colourless conidia, does not quite agree with Corda’s generic character, as given in ‘ Prachtflora,’ yet as the two plants in all important pints are so closely allied, an emendation of the genus seems ieterabile to the establishment of a new one. The following is Corda’s definition of the genus, and if the bracketed portions are omitted, it would include both species :—*“ Corepthoris. Stroma erectum, primum simplex, [subclavatum|, dein supra multifidum, e fibris longissimis, simplicibus, intricatis constipatum, infra ramulis fertilibus hetero- 3D 2 760 Transactions of the Society. geneis obsitum. Ramulis fertiles septati, cornei ramosi, bi- vel trifidi, apice ramuli subverticillatis, et sporis simplicibus heterogeneis in capitula conglobatis ornati. Spore acrogenz, heterogene, simplices, (uniloculares) ; | episporio simplici diaphano, intus nucleo et guttulis oleos's repleto |.” When young the stem is quite smooth ; soon the fibres of which - it is composed separate more or less and become patent; some remain short and simple, resembling hairs; others increase in length, become branched, and bear at their apices the heads of conidia. CF WGESS) XV.—On Erosion of the Surface of Glass, when exposed to the Joint Action of Carbonate of Lime and Colloids. By Wit M. Onp, M.D., F.R.MS, FLS. (Read 11th March, 1885.) More than a year ago there appeared in ‘ Nature’ a letter from Surgeon-Major Bidie, now Sanitary Commissioner, Madras, describing a sort of etching of some glass vessels at points on which white-ant mud had been deposited. There was much in this letter to arouse my interest. The story made it probable that the deposit of ant-mud had somehow eaten away the polish of the glass. The first explanation of the erosion was found, plausibly, in the hypothesis of the presence in the ant-mud of an acid capable of dissolving glass after the fashion of hydrofluoric acid. But no organic acids are known to possess such a property, and the presumable presence of some colloidal organic matter in the ant-mud led me to seek an explanation of a very different kind. The observations and reasonings of my distinguished teacher, the late Mr. George Rainey, had been always fresh in my mind. I knew that in some of his experiments he had, incidentally, noted an erosion of glass surfaces wherein no free acid or alkali was concerned. At the risk of wearying the members of this Society by the repetition of a story already well known to them, I will briefly recapitulate the observations to which I refer. Mr. Rainey was engaged in investigating the causes leading to the assumption by carbonate of lime of a spherical form in various solutions. In some of his experiments he allowed two solutions of gum, one containing carbonate of potash, the other containing carbonate of calcium, to mix slowly; the one being superimposed upon the other. Next he introduced glass slides of the kind ordinarily used for microscopic purposes, into the apposed solutions, with the: expectation, confirmed by the result, that a deposit of carbonate of lime would be presently formed on their surfaces. After pro- longed immersion under conditions which precluded the occurrence of evaporation, the glass slides were found to have become covered with adherent spherules of carbonate of lime. The adhesion was of considerable firmness. The spheres remained attached after washing with water ; and where their complete removal was sought, the use of diluted hydrochloric acid was necessary. It was then observed that the surface of the glass was no longer smooth and transparent. Mr. Rainey took casts of the surface with collodion, and was able to show from examination of the casts that the loss of transparency was brought about by the formation of shallow 7162 Transactions of the Society. depressions of a rounded form, corresponding severally to the points of contact of the spherules. Mr. Rainey had already shown the great probability—I might perhaps indeed say the certainty— that the exquisite spherules which he had produced by his ex- perimental method were built up first by the agglomeration of small granules into small spherules, next by the agglomeration of small spherules into larger spherules. More minutely considered, the actual process appeared to be not a simple one of agglomeration of granules into spherules, and of smaller spherules into larger spherules; but, throughout, of re- adjustment of the molecules constituting the several contingent spherules. In the process of deposit, the first-formed spherules were surrounded by others till groups were formed, comprehending several spherules in contact with each other. Presently, their con- stituent molecules, hitherto held in each independent sphere around its centre by virtue of their mutual attraction, were disturbed by the attraction of surrounding spheres, and were impelled to arrange themselves round a new centre of mutual attraction placed some- where in the midst of the group of spheres. In the end the small spheres and granules vanished, having been incorporated into one large sphere. Touching the erosion of the glass surface, Mr. Rainey argued that when such a spherule was formed on a glass surface with the surrounding colloid gum sticking to the glass surface, and actually entering also into the composition of the sphere, the same attractive power which had determined the incorporation into one sphere of a number of spherules in contact with one another would determine also the incorporation of adjoining molecules of the glass into the incumbent sphere. The result would be the excavation of a pit in the glass opposite each sphere in contact therewith. With these things already in my mind, on reading Surgeon- Major Bidie’s letter I wrote to him to suggest that the etching of glass which he had observed, might be explained on the hypothesis that “ white-ant mud” consisted of a mixture of some colloid with earthy matter. Dr. Bidie wrote to me afterwards a very courteous letter telling me that, to his great regret, he could not provide me with white-ant mud, but that he had sent some of the earth in which the white ants worked. This I duly received. I made only two experiments with the earth, which were inconclusive, and I regret to be obliged to confess that the misplaced zeal of a house- maid put an end to my opportunities of making further experi- ments. It was, however, open to me to institute experiments bearing upon the erosion of glass by carbonate and phosphate of lime in the presence of colloids. So far, I have only used the carbonate. The following experiments were set in action. In the first, strong On Erosion of the Surface of Glass, &e. By Dr. W. M. Ord. 763 solutions of gum containing respectively carbonate of potash and chloride of calcium were superimposed one upon the other after Mr. Rainey’s plan. Glass slides were coated with solid paraffin ; the letters of the word ANT were inscribed on them, with a piece of matchwood which easily removed the paraffin without injuring the surface of the glass. The slides were then placed in the gum solution as in Rainey’s method. In a second experiment, albumen was used in a similar way. In a third, glycerin was used in a similar way. In a fourth, a slide coated with paraffin and subse- quently marked with the letters A N T was laid horizontally. Over the exposed surface a mixture of egg-albumen and glycerin was smeared to the depth of 1/10 of an inch; then a few drops of a strong solution of chloride of calcium were placed in contact with one end of the islet of glycerin and albumen, and a few drops of a solution of carbonate of potash in contact with the other end, so that the two solutions would diffuse through the mixture of glycerin and albumen, would meet therein, and produce, by mutual decomposition, carbonate of lime. Glycerin was added to diminish evaporation and to aid the contact of the colloid with the exposed surface of the glass. Hvaporation was further opposed by placing the preparation in a moist chamber. Lastly, a controlling experiment was made by placing a glass slide, similarly coated and inscribed, in a mixture of pure glycerin and carbonate of potash. In parallel experiments, slides of mother-of-pearl, and of ivory, coated with paraffin and marked like the others, took the place of the glass slides. In all the experiments large stoppered bottles were used, so that no evaporation was possible. It was not till the end of a twelyemonth that the bottles were opened and the slides examined, Inspection showed that the paraffin had not been an effective insulating substance in the case of the glass slides. It had peeled off from them in flakes, and had floated away, so that their whole surface was encrusted, in all the experiments except the last, with a deposit of carbonate of lime. The carbonate of lime was found to have assumed the form of small spherules closely aggre- gated in dense masses and much deformed by mutual reaction. Mr. Rainey in his experiments had used exceedingly dilute solutions in order to obtain his beautiful spherules. To imitate the ant-mud I had used much stronger solutions. But the result was that I obtained a very much more complete etching of the glass, and had, as I suppose, fairly imitated what Surgeon-Major Bidie had seen. The slides which I show to-night are, I think you will say, deeply etched. ‘They pe oman the etching effected by carbonate of lime in the presence of gum, of albumen, and of albumen and glycerin together. I may note in passing, that pure glycerin in combina- tion with carbonate of potash produced no etching. Under the Microscope the etched surface of the glass shows 764 Transactions of the Society. erosions of various kinds. In the first place there are a number of scattered erosions of circular form varying in size from fine points as seen under a 1/4 in. objective up to cavities three or four times the diameter of a blood-corpuscle. Secondly, the surface of the glass is marked by a number of Imes taking various directions, which must correspond either to original scratches on the surface of the glass, or to lines of detachment of the paraffin. Erosion has occurred along these lines in a beaded fashion, the size of the beads corresponding with the size of the spherules of carbonate of lime deposited. Thirdly, over considerable areze the entire surface of the glass has gone. ‘The floor of these depressed areze is marked with closely approximated circular and dumbbell-shaped depressions, in many of which an inner circle or concentric circles may be seen. At first sight these inner circles appeared to indicate projections in the centre of depressions ; but so far as I can make out by careful focusing they are, in fact, deeper excavations marking a deeper extension of the process of molecular disintegration of the glass. It is hardly necessary to point out that the last experiment— with glycerin and carbonate of potash—was made in order to determine the possibility of a solution of glass by carbonate of potash, the occurrence of which would have introduced a different element of a chemical kind. This, having evoked no response, enables us, I think, fairly to fall back on Mr. Rainey’s explanation of the phenomena occurring in his own observations. I have mentioned that in addition to es slides I have used slips of mother-of-pearl and of ivory. dere the paraffin kept the firm hold which I had hoped it would maintain on the glass surface; and I am able to show slips of this kind in which, after removal of the paraffin, the word ANT is clearly seen etched on the surface. ‘The etching here occurred in all the experiments, even in that where glycerin was used with the carbonate of potash, a point of some interest when viewed in certain aspects of these experiments. I wish to draw the following inferences from the experiments I have related. First, that without the use of the acids or the alkalies which are known to be capable of dissolving glass, a glass surface may be eroded almost to opacity when placed in contact with carbonate of lime and a colloid. Secondly, that the erosion so effected may be explained on the basis of Mr. Rainey’s observations on molecular coalescence. Thirdly, that, in contact with glycerin and carbonate of potash, ivory and mother-of-pearl may be eroded, although as far as can be seen, no spherules of carbonate of lime are deposited. The first part of these conclusions is applicable to Dr. Bidie’s observations ; the third part has a different, and, as I think, a wider application. Mr. Rainey’s chapter on what he called “ Molecular Disintegra- On Erosion of the Surface of Glass, dc. By Dr. W.M. Ord. 765 tion” has always seemed to me to have an importance as great as that of his chapters on “ Molecular Coalescence.” The two together presented a beautiful correlation, enabling one to follow the build- ing up of skeletal formations in the first place, and their adapta- tion to altered conditions of growth and repair in the second. In bone, for example, we could see, in principle, how the struc- ture of the first Haversian systems was determined by the law of molecular coalescence ; how the earthy matters deposited in colloid ground-substance ceased to show crystalline form and were moulded into laminz wherein the organic and inorganic matters were intimately mingled and distributed. We could see in it by the light of the principle of molecular disintegration the formation of Haversian spaces, as a part of remoulding and repair. May I for a moment step aside to remind you of what Mr. Rainey meant by this expression, “molecular disintegration”? He meant this— that when spheres of carbonate of lime, or spheres of mixed carbonate and phosphate, had been formed in a matrix of gum, and were afterwards transferred to a fresh solution of gum of the same kind as that first used, they lost their sharp outline, became visibly fibrous in their structure, and gradually faded away. The advent of a new colloid, differing ever so little from the first, determined a complete disorganization of the attractions which held the molecules together. They—the molecules—were reft asunder for a time, and were afterwards gathered into new spherical combinations. In applying the principle deducible from these observations to the explanation of the formation of the tubular erosion-spaces in bone which have been called Haversian spaces, a seeming difficulty arises. We have indeed no reason to assume that the quality of the circulating and acceding colloids varies in such a way as to bring about such a difference between the sphere and the surrounding matter as was present in the experiment. The seeming difficulty rests upon the assumption that the colloid matter entering into the herical combination remains unchanged. If we can be convinced that the colloid is changed by reason of its prolonged contact with the crystalloid matter, we can understand how the afflux of fresh a of the original colloid may determine the breaking-up of spherical combinations wherein the original colloid has undergone chemical and physical change. It can be shown most clearly that the colloid matrix of spheres, whether of collagenous or of albu- minous nature, is altered after no very long time. It takes on chemical reactions approaching those belonging to ripe epithelial structures and chitine. Such a change, if occurring in bone, may be conceived to be a part of senescence. The transformation of an active into an inactive colloid must presently call for complete reorganization. The altered balance of colloids will constitute an enabling condition. Wach part of a bone as it grows old is swept 766 Transactions of the Society. away by the dynamic influence of fresh nutritive matter, knowing, so to speak, nothing of the past. The post is vacated by the superannuated colloid, which first yields up its crystalloid associate and then disappears, leaving the ground free for fresh organization. It may be observed that the parts which are thus swept away are in the outcome, though possibly not in the beginning, the circumferential portions of Haversian systems; and that they are removed in such a way as to include portions of two or three adjacent systems. ‘These are, of course, the oldest or first-formed parts, of the several systems. The form assumed by the nutritive matter which is presumably active in determining the breaking- down of the old tissue is most interesting. At the points where the bone is being broken down we find lodged in cup-shaped recesses of eroded bone little masses of protoplasmic matter with ill- defined surface but well-marked nuclei, which, to all appearance, are the agents of the change. These are the so-called osteoclasts. Their surface ig ill-defined because, on the one hand, it merges into the colloid of the vanishing bone, showing at the point of junction a curious striate marking, suggestive of the existence of currents running between the protoplasm and the old bone; and on the other, it is connected by processes with the protoplasmic material filling the gradually increasing cavity, of which protoplasm it is in fact an extension. It appears to me that we have here, before our eyes, the direct application of a new and active colloid to an old product of molecular coalescence, with the sequence of molecular disintegration. I cannot resist the temptation of referring to one or two other processes in which both molecular coalescence and molecular dis- integration play a part. Mr. Rainey has shown that the first—molecular coalescence— is an essential part of the building-up of the shells of the Mollusca. The second—molecular disintegration—appears to me to come into action in the later stages of the growth of molluscous shells. For instance, in the whorled shells of the Gasteropods, apical parts of the interior which have been occupied by the young mollusc are removed as the growth of the animal and its shell proceeds, so as to economize the space available in the whole shell. I have no know- ledge of the existence of anything like osteoclasts in this case ; but the contact of the tissues of a rapidly-growing mollusc with the old coalescence formation will, I think, be sufficient to account for the solution of hard structures now superannuated. Mr. George Busk, F.R.S., after seeing my letter in ‘ Nature’ on this subject, was good enough to tell me that he saw in the prin- ciples which I sought to establish an explanation of a phenomenon which had puzzled him, namely the excavation of shell surfaces to which Polyzoa had been attached. He has lent me for ex- On Erosion of the Surface of Glass,&c. By Dr. W. M. Ord. 767 amination a piece of smooth shell—the internal surface of a pinna—ovyer which a colony of Lepralia punctata has been spread. In this genus, as Mr. Busk has demonstrated to me, the ectocyst of the under or attached surface of the ccencecium is not continuous, but leaves oval spaces corresponding to the middle portions of polypides, through which the soft tissues of the polypide come into direct contact with the surface of the shell. When the ccencecium is detached from the shell, its under surface is therefore seen to be regularly fenestrated. And in the specimen of which I am speak- ing, the surface of the shell from which the ccencecium has been removed presents regular markings exactly corresponding to the fenestre. These markings turn out, on microscopical examination, to be depressions in the surface of the shell, produced by erosion. It can be plainly seen that their floor is totally different from the surface proper, both in colour and texture. The surface of the shell is smooth, and reddish in colour; the excavations present a granular white floor. In another specimen, stained while the animal matter was yet in its place, the points which would after removal of the ccencecium have been occupied by the shallow pits, have attached to every one a strongly adherent piece of dried stained animal matter. Mr. Busk’s observation is in fact an illustration of my experiments, which shows what was sought better than did the experiments themselves. Through the windows in the framework of the coencecium the organic matter of the polypides has, so to speak, stencilled the structure upon the surface of the shell, as I had tried to engrave letters on the surface of the glass. I cannot resist the temptation of expressing the gratitude which I feel to so great an authority as Mr. Busk for his kindness in giving attention to my letter in ‘ Nature, and in letting me have the opportunity of seeing his specimens under his own demonstration. Another illustration of this kind of action was, as I think, adduced by Professor Charles Stewart in the admirable course of lectures on the Hydrozoa delivered by him recently at the Royal College of Surgeons. Professor Stewart showed dried specimens of a species of Hydractinia investing shells of Gasteropods. The shell had been completely covered by the fleshy expansion of the Hydractinia, and had been deprived thereby of all its earthy material. I have long believed that the action of the little sponges which bore into molluscous shells, particularly those of Lamellibranchs, was molecular. It is of course conceivable that the action might be chemical; that an acid might be excreted having the power of dissolving carbonate oflime. It is also conceivable that the action might be mechanical. The boring sponges contain siliceous spicules, which, moved by the contractions of the protoplasmic material, might grind away the softer shell matter. I have tested fresh sec- 768 Transactions of the Soccety. tions without detecting the presence of an acid, and Professor Stewart has given me the opportunity of examining, under the Microscope, sections of the cavities produced by the boring sponge. The posi- tion occupied in these sections by the siliceous spicules makes it certain that they cannot be the agents of erosion, at least in a mechanical way. In the sections we can see everywhere small hemispherical excavations of the shell oceupied by extensions of the protoplasm of the sponge. Yet, at many points, long attenuated conical cavities are seen invading the substance of the shell ; always filled with the protoplasm, often containing one or two siliceous spicules, which from their length and position must have been totally incapable of exerting any mechanical action. As it seems to me, we have here a transposition of the conditions which in the experiments related at the beginning of the paper brought about the breaking-up of the glass surface. There we had a colloid con- taining carbonate of lime applied to a glass surface ; here we havea colloid containing silica applied to a surface of carbonate of lime mixed with another colloid. I venture to believe that in the case of the boring sponges, the action upon the shell is of compound nature ; consisting partly in the contact of a new colloid, partly in the addition of the presence of a different crystalloid. Examining carefully the sections which Professor Stewart has lent me, I am able to recognize in the substance of the protoplasm adjoining the excava- tions, delicate spherules having all the appearance of carbonate of lime re-arranged in a new matrix. I have cited here but a few illustrations of the possible application of Mr. Rainey’s observations to explain the formation, and still more, the removal or absorption of shells and shell-like substances. I venture to hope that the attention of this Society will be more and more drawn to the contemplation of these subtle non-chemical agencies as factors in the process of building and repair in the hard, and, very probably, in the soft-structures of animal bodies. : ( 769 ) XVI.—On a Septie Microbe from a high altitude. The Niesen Bacillus. By G. F. Dowpsswett, M.A., F.R.MS., F.LS., &e. (Read 8th April, 1885.) Art the present time, when the functions of micro-organisms in all the provinces of nature, more especially in relation to disease, are exciting such general interest, their occurrence in the atmosphere has engaged renewed attention. The systematic study of the particulate constituents of the atmosphere commenced with Ehrenberg, though in the previous century Leeuwenhoek had made the first recorded observations upon Bacteria, and shown their occurrence in rain-water. Ehren- berg examined dust from various situations in extensive series of observations, and particularly with reference to the outbreak of cholera in 1848, though with negative results, but found that numerous forms of organic life, both vegetable and animal, as he regarded them, were present in dust of the most varied situations ; he recognized the occurrence of bacteria, which he termed infusoria, in rain-water that was allowed to stand, but could not detect any in the fresh drops, in dew, or in the atmosphere. After that time the subject was pursued by numerous observers, till towards the year 1859 the promulgation of the vital, or “ germ,” theory of fermentation and putrefaction by Pasteur, aroused the controversy respecting spontaneous generation, so fertile in results, in the French Academy, and this induced the first systematic observations of Pouchet, the foremost of the Abiogenetists, and those of Pasteur himself, upon atmospheric germs, followed by a constant succession of observers, amongst whom, however, the most diverse views as to the occurrence of organic germs in the air have prevailed till quite recently, when the question has been finally set at rest, firstly by the systematic observations of Dr. Miflet, of Kiew, made in the Botanical Institute of Breslau in conjunction with Professor F. Cohn,* with the object of determining whether the microbes that produce fermentation and putrefaction are veritably contained in the atmosphere, or whether they are not derived exclusively from water or contact with contaminated surfaces, as previous experiments, by Prof. Cohn himself and others, seemed to indicate, The result of these observations was to show clearly that by aspirating the air of different localities through cultivating fluids of suitable constitution, various species of bacteria or their germs were introduced, and developed he placed in the incubator at the * Beitr. Biol. Pflanz., i. (1879) p. 1438. 770 Transactions of the Society. requisite temperature. Thus were explamed the previous failures to recognize the presence of organisms in the atmosphere, by the circumstance that the cultivating fluids then employed had generally been solutions of mineral salts—the so-termed Pasteur’s or Cohn’s fluids—and which are here shown to be unsuitable for the develop- ment of most species of these organisms. More recently has appeared “the remarkable work* carried out during some years past by Dr. Miquel at the Observatory of Montsouris, near Paris, some of the results of which have recently been brought to the notice of this Society by one of our Fellows, himself amongst the earliest investigators im this direction. As a branch of this subject, the examination of the air at different altitudes has not been neglected: the purity of the atmo- sphere in these situations has ever been a matter of common observation ; and the different experiments that have been made at various heights, have all, with one exception, tended to show the extreme rarity of organic germs in it. Recently, M. Freudenreich, of Bern, a former pupil of Dr. Miquel, under his auspices and following his exact methods, has made several series of systematic observations upon this point, far exceeding in scope anything previously attempted; this he has done by aspirating large measured quantities of air on different mountains at various elevations, with the general result that the rarity of micro-organisms it contains is proportionate to the altitude, for whilst at Bern, at an elevation of 1900 feet 300 to 400 of these bodies occurred in a cubic metre of air, which is less than a tenth part of their numbers in Paris, at higher elevations they became proportionately rarer,{ and above 7000 feet were generally altogether absent; but in one series of these observations on the summit of Mount Niesen in the Bernese Alps, at an elevation of 7900 feet, close on the line of perpetual snow, together with three bacteria and one of the moulds, a form of bacillus hitherto unde- scribed occurred in 500 litres of air aspirated; preparations from the cultivation of this organism which I lately received from M. Freudenrich through Dr. Maddox, are here shown to-night. This microbe, in Cohn’s drag Foihon a bacillus, in form is very similar to the common hay bacillus, B. subtilis, but is readily dis- tinguished from it by not forming a pellicle on the surface of the * ¢Les Organismes vivants de l’Atmosphere,’ Paris, 1883. + As shown in the following table (‘ Annuaire de Observatoire de Mont- souris, 1883, p. 538). Number on bacteria contained in 10 cubic metres of air in different situa- tions :— 1. At altitudes from 6000 to 12,000 ft. .. .. .. 0:0 2. On Lake Thun, 18,000 ft. eee tats 8:0 3. On land, in the vicinity ofthe samelake .. .. 25°0 4. In the park at Montsouris .. OOOO 5, In the streetsiotyearish: ue a eesiene a ee OOL000"0 On a Septic Microbe, de. By G. F. Dowdeswell. 771 cultivating fluid; it is, too, generally less active, whilst it differs from the B. anthracis by the segments, of which the longer rods and filaments are composed, being more rounded at the ends—less rectangular—than the almost cubical cells which compose the latter ; it is, too, a little larger in width than either of the two other microbes; though somewhat variable in the same medium, it _ averages fully 1 micromillimetre (0°001 mm.) in breadth. It fre- quently forms spores at one or both ends of the short rods in an early stage of development ; the cells themselves develop to long sinuous leptothrix filaments, the segmentation of which is obscure, unless demonstrated by special reagents. It forms, as already men- tioned, no zoogloea nor pellicle on the surface of the nutrient fluid, and this character again distinguishes it at once from the hay bacillus; it grows diffusely through the liquid, rendering it uniformly turbid, not forming the clouds or flecks which characterize the anthrax bacillus. It forms numerous spores, as may be observed in the preparation under the Microscope. These at maturity are set free, the plasma of the segments which contain them degenerating and disappearing, having been used up in the reproductive process— sporulation—the other segments remaining unchanged for a time, till ultimately their life cycle ends in the same manner. ‘This is the significance of the numerous shadowy forms apparent in preparations of this organism ; the wall of the cell alone remains, the living plasma, or “protoplasm,” has died and disappeared. This form of degeneration in the cell was first, 1 believe, figured and described by Dr. Klein,* in the case of B. anthracis, the appearances it offers, which are conspicuous in the preparation here shown, having sometimes been misunderstood by previous observers. The spores when set free appear to germinate in the same nutrient medium in which they were developed, as is not the case with some other species; they develop regularly in the direction of their longer axis, never, as far as I have observed in innumerable instances, in the excentric manner described by Brefeld t in the case of B. subtilis, and copied by so many subsequent observers from him, in that case also, | may mention, quite contrary to my own observations.t There is a peculiarity in the spores of this organism at once apparent in the preparation under the Microscope ; it is, that they * Rep. Med. Off. Loc. Goyt. Bd., 1883, and Quart. Journ. Micr. Sci., 1883. + Bot. Untersuch. iiber Schimmelpilze (Leipzig, 1872) p. 46, &e. t As, however, there are at least three or four distinct species of hay bacilli, all of which are more or Jess resistent to heat, and it is difficult accurately to diagnose Colin’s species of 2. subtilis, it is possible that the spores of some one of these species may germinate in the excentric manner described, though this has not been the case with any of those that I have hitherto obtained, in very numerous experiments, by the usual methods of boiling, &e. 772 Transactions of the Society. are more circular—less elongated—than those of either of the other organisms ; they stain, too, readily with the usual dyes, which the others do not; and thus the microbe may generally be distinguished at a glance from either of its prototypes. Cultivated in nutrient gelatin it liquefies the medium regularly from the point or line of inoculation, forming clouds or flecks in it, but no pellicle; in aga-aga bouillon or pepton it forms a creamy- white scum on the surface, but does not liquefy the jelly. It might have been supposed that an organism, the habitat of which is on the confines of perpetual snow, would have been more at home at a low temperature; it, however, developes more readily at about 100° F. than at 50° or 60°, though the difference pro- duces no appreciable variation in its form or habit. It does not develop in hay infusion, neutral or alkaline, this character again at once distinguishing it from both the microbes which it resembles in form; neither does it germinate in solutions of mineral salts, It will not develop in cultivating fluids that are slightly acid; 0°1 per cent. of free hydrochloric acid in solutions of pepton, or bouillon and pepton, entirely prevents its germination. It is not pathogenic when inoculated or injected in considerable quantities into the tissues of rodents, and must be considered a septic organism; it occasions, however, no very marked fetor in the fluids in which it developes. It bears a general resemblance to the widely diffused bacilli that occur so generally in putrid matter. The characters of these, which’ are probably of many different species and varieties, have never been particularly described. They are sometimes termed blood bacilli, from their occurrence in putrid blood, but have been more appropriately named collectively by Klein * Bacillus septecus. They, however, usually, or as far as 1 have yet observed, invariably, form a pellicle in cultivating fluids, which the Niesen bacillus does not. The labour and difficulty of such observations as those here referred to, in which the microbe now described was obtained, is obvious, involving the transport of the requisite apparatus and instru- ments to such inaccessible places, and the obstacles to be overcome in making experiments with the requisite precautions in these situations. This, however, does not apply to the examination of air at more moderate and accessible elevations, such for instance as the hills and mountains of our own country, or even on high buildings, where, as far as I know, no observations whatever have as yet been recorded, though one of our own countrymen, as is well known, has examined the air of the Alps. As an instance of how even comparatively slight elevations * ¢Micro-organisms and Disease,’ 1884, p. 78. On a Septic Microbe, de. By G. F. Dowdeswell. 773 affect the purity of the air, it may be mentioned that Dr. Miquel (Op. cit., p. 240) found micro-organisms twenty times more numerous in the streets of Paris four feet above the ground than at the summit of the Pantheon at an elevation of 330 feet. Important as is the microscopical examination of air, and immeasurably as the subject has been advanced and illustrated by the magnificent work of M. Miquel—certainly by far the most extensive and important as yet made in any branch of micrology—there is as yet one void in it, and that is the want of a clear diagnosis of the specitic characters of the various microbes that occur in different conditions, seasons, and localities. In a general way no doubt the salubrity of any given portion of air corresponds with the paucity of micro-organisms which it contains, but in spite of the innumerable observations and the laborious statistics that have been given, it has not yet been shown that there is any direct connection between their number and the prevalence of infectious or epidemic diseases. The reason of this appears obviously to be that we are not as yet generally able, from the mere inspection of the outward characters of any micro- organisms, to say that such an one is fatally infective—the bacillus of tubercle—the microcoecus of pneumonia or diphtheria—that another is merely saprophytic or zymotic, harmless to the animal organism.* When we are able to do this, then will it be possible from the mere microscopical examination of a sufficiently large sample of the air of any locality to connect it certainly with the prevalence of infectious diseases. The same considerations apply equally strongly to the examination of drinking water, and now that the chemical analysis of this has lately been shown to be practically useless,{ if not even misleading, it appears that microscopical examination must be relied on in future. With this object the study of and familiarity with the specific characters of these organisms is one of the most important subjects that can occupy the microscopist. In this view I have brought to notice to-night the diagnostic characters of the microbe now shown, remarkable from the situation where it occurred. A comparison of the preparations under the Microscopes will show that it is not impossible to discriminate by their form alone two microbes somewhat similar, and which to a cursory view might appear identical. * The habit of growth of the lower fungi in solid cultivations, which has been so much dwelt upon of late, is very unreliable and much over-rated as a means of specific diagnosis, being only ut most of very secondary utility, as I shall endeavour to demonstrate shortly. + Rep. Med, Off. Loc. Govt. Bd., 1882-3. Ser, 2.—Vox. Y. bE 774 Transactions of the Society. XVII.—On the use of the Avicularian Mandible in the determination of the Chilostomatous Bryozoa. By Artour Wm. Waters, F.R.MS., F.LS. (Read 10th June, 1885.) Piate XIV. In a paper “ On the Use of the Opercula in the Determination of the Chilostomatous Bryozoa”* I pointed out the value of these chitinous organs, and figured those of thirty-six species, of which thirty-five were from the Mediterranean. This was really to be looked upon as a supplement to my papers on the Bryozoa from the Bay of Naples,} and in these latter I referred individually to the figures of the opercula. It was almost self-evident that the EXPLANATION OF PLATE XIV. Fig. 1.—Avicularian mandible of Flustra truncata L., Naples. ea: es 5 F, armata Busk, Cape of Good Hope. Sy penee x 4 F. foliacea L., Brighton. tee. e : Diachoris magellanica Busk, Naples. 5. D. hirtissima Hell., Naples. ” 29 6.—Operculum of Flustra truncata L., Naples. Gf. 5s F. armata B., Cape. 8.—Avicularian mandible of Schizoporella linearis Hass., Naples. 9.—Lateral avicularian mandible of Caberea Boryi Aud., Rapallo, Italy. x 250 & 85. 10.—Anterior 5 “0 3 5 11.—Avicularian mandible of Cellaria sinuosa Hass., Roscoft. 12.—Operculum of C. sinuwosa Hass., Roscoff. 5; Ls! 9 C. fistulosa L., Roscoff. 14.—Avicularian mandible of C. fistulosa L., Roscoff. 15.—Operculum of Caberea Boryi Aud., Rapallo. 16.—Avicularian mandible of Smittia Landsborovii Johnst. x 250 & 85. 99 Naples. » 17.—Avicularian mandible of Retepora Couchii Hincks. x 250&85. Naples. oneal lish * oe Porella cervicornis K. and Sol., Naples. cos Umbonula verrucosa Wsp., Capri. 20.—Opereulum of Cellaria Joknsoni Busk, Naples. 21.—Avicularian mandible of Cellaria Johnsoni Busk., Naples. wees ay 3s Schizoporella unicornis Johnst., Naples. 20s a5 A Smittia, Rapallo. sy 24: is a Smittia nitida var. ophidiana W., Naples. enzo: rf i Mucronelta coccinea Abild., Naples. » 26. x 7 Schizoporella arrogata Waters, Naples. 5 as i * Diporula verrucosa Peach, Naples. op eh 55 5 Cellepora pumicosa Busk. (non. L.). x 250 & 85. Naples. 5 29.—Mandible of (small) avicularium of C. c:ronopus Wood, Naples. OU: 5 large (onychocellaria) avicularium of C. coronopus Wood, Naples. * Proc. Manchester Lit. and Phil. Soc., xviii. (1878) p. 8. “Bryozoa of the Bay of Naples,” Ann. and Mag. Nat. Hist., ser. 5, iii. (1879) pp. 28, 114, 192, and 267. JOURN.R.MICR.SOC.SER ILVOLYV. PL. XIV. EX ¢- Fig 41 ft \ r/\] Fig.42. * a Whecers hth Avicularian. Mandibles &, of Bryozoa. er ut inet ' On the Determination of Bryozoa. By A. W. Waters. 775 mandibles of the avicularia should also be taken into consideration, but as I had only examined and made preparations of a limited number I did not feel justified in publishing anything about them, but called the attention of many of my friends who were working at the Bryozoa to the use they were likely to be, and showed them drawings. Since then I have been engaged in the examination of fossil Bryozoa, in which of course the chitinous organs are not preserved, but the careful examination of the oral aperture, from which con- clusions as to the shape of the operculum can be drawn, has been the basis of my work with the Australian fossils, and I have pre- pared the opercula of a large number of Catenicelle and other genera represented by fossil allies, so that although we may never find the chitinous organs fossil, yet the study of them may be of the greatest value paleontologically. Mr. Busk, when working at the ‘Challenger’ material, in consequence of my short paper, took up the examination of the chitinous organs, and to him we must give the credit of first applying the form of the mandible in specific determination, the results being especially valuable in the genus Cellepora; and Professor MacGillivray has also shown their value in the genera Cellaria and Retepora.* The most important feature of Mr. Busk’s report on the ‘Challenger’ Bryozoa is undoubtedly the use he makes of the chitinous organs, but as some of his generalizations are evidently based upon incomplete series, I take the opportunity of adding to Fig. 31.—Avicularian mandible of Cellepora costata MacG. = retusa var. caminata Waters, Naples. meee a re C. avicularis Hincks, Naples. eros o “ C. sardonica Waters. x 250 & 85. Naples. 34. Cribrilina radiata var., Naples. 9 ” 35.—Spatulate avicularian mandible of Schizoporella auriculata Hass., Naples. 36.+—Oral ” ” ” » 87.—Avicularian mandible of Cellepora verruculata Sm., Naples. Z 38. oe - C. digitata Waters, Capri. Bs dae * fe C. sardonica Waters, Naples » 40. a os Membranipora curvirostris Hincks, Naples. g 41. es s, M. tenuirostris Hincks, Naples. ec ae Be a M. angulosa Rss., Naples. » 43. z 5 M. Flemingii Busk. x 250 & 85. Durham. » 44. a ‘g Adeonella polystomella Rss. x 250 & 85. Naples. b, operculum of ditto, All are shown magnified 85 times, being the same as that adopted in my paper “On the Use of the Opercula,” &¢., but as some avicularia are too small to show detail this size, they are given as fig. a magnified 85 times, and also figured increased to 250 times. All were examined with a power magnifying 500 times. * “Description of New or Little Known Polyzoa,” Trans. Roy. Soc. Victoria, xx. (1883) pp. 103, pls. 1 and 2; also in vol. xxii. (from advance copies). 3 EE 2 716 Transactions of the Society. the number of described mandibles by giving the figures of some in my collection, and as these are mostly from Mediterranean species, this must be considered as another supplement to the description of species from the Bay of Naples. In the communication referred to, I said, when speaking of the Celleporidee, that “I believe the opercula may assist very much to bring this family out of its present confusion,” and Mr. Busk has now made a good start towards making this a fact. ‘There is, however, one point connected with the Cellepora mandibles which requires further notice, as Mr. Busk describes a slender process rising from the middle of the base of the avicularian mandible in the holostomatous division of the genus Cellepora, but finds it only in this division, and further only in those from the southern hemi- sphere. In a paper read before the Geological Society I have shortly pointed out that this is by no means the case, but that it can be found in species from the northern hemisphere, not only in both divisions of this genus, but apparently in other genera. Mr. Busk seems to have looked for it in vain in Cellepora sardonica Waters, from the Mediterranean, but this species has two forms of avicularia, one triangular and acute (fig. 39), in which I do not find any process, whereas in the small round avicularium (fig. 33) this process is very distinct, so that perhaps Mr. Busk only ex- amined the one form. Besides occurring in this species of Cellepora it is found in Cellepora coronopus Woods (fig. 29) and C. costata MacG. (fig. 31).* Ina similar position there is in many species a process arising from the calcareous bar which divides the aperture of the avicularium. This I figured six years ago in C. sardonica (loc. cit. plate XIV. fig. 5), also in Schizoporella biaperta (id. plete XI. fig. 1). Smitt also figured it in the avicularia of Lepralia edax (Floridan Bry., plate XI. fig. 222), and it is a character which can frequently be distinguished in well-preserved fossils (see fig. Retepora marsupiata var., Q. J. Geol.S., vol. xxxix. plate XII. fig. 21). It occurs in Schizoporella auriculata, Porella cervi- cornis, Retepora Couchii, a New Zealand Smitiia, &e. The process in the chitinous mandible Mr. Busk calls a columella, and says that it is covered with “short hairs,” but these upon comparison with other mandibles turn out only to be the remains of the attachment of the muscular threads. In the ‘ Challenger’ report a genus Adeonella was made, and includes species having a pore opening into the body of the zocecia * The mandible of Diachoris magellanica B, (fig. 4) has a double “ columella,” and since the paper was written the examination of D. bilaminata Hincks, shows that the mandibles of both are identical in size and detail structure, and the similarity of other specific minute characters is most close, proving that the two species are most closely allied, although the mode of growth produces a very different general appearance. On the Determination of Bryozoa. By A. W. Waters. TIT below the oral aperture, and having the proximal edge of the aperture straight; while other species have a pore which is peristomial and the aperture has a broad sinus, that is to say, the two most important characters are different, and I think atten- tion having been called to this, that it will be seen that they must be kept distinct. Mr. Busk, however, points out that “in the entire group” (speaking of the family Adeonez) “ the avicularian mandibles, both large and small, always exhibit a projecting point or articular process at each end of the base.” This is certainly a curious fact, but in order to see what value must be attached to it we must examine whether it is only in this group that this process obtains, and when we have found it in various genera it is only reasonable to conclude that we must not attach generic importance to this when other characters are widely divergent. In Cribrilina radiata (fig. 34) this process is pronounced, and it is also seen in the mandibles of Flustra armata (fig. 2) and F. foliacea (fig. 3), and the structure of several Membraniporx where the basal portion is thicker in the centre than at the corners, is only a modi- fication of the more distinct process of the Adeonee. This is shown in M. curvirostris (fig. 40) and M. Flemingii (fig. 48), and oceurs very distinctly in mandibles of a Membranipora allied to M. dentata d’Orb.* These processes in the mandibles of Cellepora and Adeona lead us to the consideration of the importance of such modifications. They indicate differences in the muscular attachments, and both here and in the opercula it is really the muscular system which has the greatest classificatory value; but this is best studied by means of the variations in the chitinous parts. This Mr. Busk does not seem to have fully appreciated ; for the muscular attach- ments or projections for the purpose are not figured by him, where preparations in my possession show such characters very clearly. ‘The pattern of the mandibles, if we may thus call it, depends upon there being either two chitinous layers in places, or upon a thicken- ing of the chitin. In some cases this may be directly for the at- tachment of the muscles, but more frequently it seems to be rather a thickening to give support to the point of muscular attachment. There are a few cases of very thin mandibles, some of which may be stained, instead of showing up yellow against the coloured tissue. As examples, see the mandibles of Mucronella coccinea (fig. 25), es arrogata (fig. 26), and the large mandible of Letepora ouchii. * Under Adconella I should include A. polymorpha B., A. platalea B., A. intricaria B., A. atlantica B., A. pectinata B. (?), A. polystomella Rss. (2schara Pallasii Hell); but Microporella distoma B., M. coscinopora Kss., M. lichenoides M. Ed., and M. fissa Hincks, I should not place in this genus. 178 Transactions of the Society. Although it is convenient to commence this study with the separated opercula and mandibles, this should only be considered as an introduction to a complete investigation of the muscular systems of both zocecia and avicularia. Our information with regard to the avicularia is also not complete unless the shape of the openings covered by the mandibles is given; and this can usually be seen without preparation, but sometimes it is necessary to incinerate * a specimen for the purpose. I would lay great stress upon the examination of this character, as it may be of great value in the determination of fossils, and is one which, a reference to my papers on the Australian Bryozoa will show, can frequently be used ; though fossils being as a rule less well preserved than recent material, such work should be based upon the examination of recent specimens. Turning to the mandibles figured, those of three Membrani- pore deserve especial attention. One of these is M. Plemingiu (fig. 43), from Britain, and great variation having been assigned to this species I was misled into calling a species from Naples M. Flemingii, and another M. Flemingi var., but the former is M. curvirostris of Hincks (fig. 40), and the latter M. tenwirostris Hincks (fig. 41). The mandibles will be found characteristic in each case, but upon examination the same structures are found throughout, the only difference being in the shape. The mandibles of Cellaria sinuosa (fig. 11), fistulosa (fig. 14), and Johnsoni (fig. 21), though showing considerable characteristic differences in shape and size, present great similarity in the different parts; and this is the case with other Cellarie. In Cellepora sardonica (the sub-oral avicularia) (fig. 39), C. digitata (fig. 88), and C. verruculata (fig. 37), the avicularia could scarcely be distinguished except by size. The similarity of the small oral avicularia of Smittia Lands- borovie (fig. 16), Porella cervicornis (fig. 18), and Umbonula verrucosa (fig. 19) must at once strike any one. On each side of the large mandible of Membranipora angulosa (fig. 42) there is a separate thick lunate chitimous mass in the front of the avicularian chamber, and to this the lower corners of the mandible are attached in the position shown. It will be m- teresting to know whether similar structures are the rule where the mandible is very large and powerful. In the whole of the Membraniporide the opercula are very similar, having a considerable lateral projection for the muscular attachments. Mr. Busk’s figures of the opercula of Vineularia gothica (loc. cit., p. 72, fig. 2) and V. labiata (p. 78, fig. 3) may * A convenient way of doing this is to plave the specimen upon a piece of platinum foil and hold it in the flame ofa spirit-lamp until all the organic portion is removed. On the Determination of Bryozoa. By A. W. Waters. 779 be taken as typical Membraniporidan opereula. The opercula of Selenaria are also of this form, and those of Cellaria approach to this type, having a downward projection (figs. 12, 18, 20). The opercula of a Lepralia from New Zealand, which I at present think may be called a variety of L. adpressa, has a lateral strengthening bar, and the same is the case in a Microporella allied to M. decorata Rss. The operculum of Monoporella crassatina Waters, from New Zealand, has a somewhat similar projection, looking like that of Flustra armata (fig. 7). Although the small oral avicularia of Schizoporella auriculata (fig. 36) is very different in size and shape from the larger spatulate avicularia (fig. 35), yet the structure of the mandibles is almost identical. The chitinous organ (fig. 8) of Schizoporella linearis I call an avicularian mandible. It closes a cell which Mr. Hincks (Brit. Mar. Poly., p. 251) calls an ocecial cell, and if Mr. Hincks really finds them containing ova, then there can be no doubt about their function. My specimens are all dried ones, and do not enable me to settle this point; but I have never found such a chamber con- nected with a true ovicell, although there is usually an inflation above it which might easily be mistaken for one. This is shown in my plate IX. fig. Z, “ Bryozoa of Naples.” * * Some of the species alluded to were not mentioned in my paper on the Naples Bryozoa, but since that was written I have collected material from a somewhat wider range, and have also found some fresh species among the material collected in Naples, and as soon as I have finished work on hand hope to be able to write a supplementary paper about doubling the number previously given. The following is, however, a provisional list of some additions to be made to the Bay of Naples fauna :— Bicellaria ciliata L.; Notamia (Gemellaria) avicularis Pieper; Cellaria Johnsoni Busk; Membranipora flustroides Hincks, Capri; UM. Dumerilii Aud. ; M. Lacroixit Aud. ; Memraniporella nitid: Johnst., Capri; Mastigophora Dutertrei Aud., Capri; Micropora coriacea Esper., Capri; M. hippocrepis Goldf., Capri; Cribrilina figularis Johnst., Capri; Microporella distoma Busk., Capri; VII. Radiolaria. Zhalassicolla, Acanthometra. Grade B. Corticata. Lipostoma .. .. + I. Sporozoa. Gregarina, Coccidium. 5, IL. Flagellata. Monas, Euglena, Volvom. » II. Dinoflagellata. Prorocentrum, Ceratium. Stomatophora .. » LV. Rhynchoflagellata. Noctiluca, » V. Ciliata. Vorticella, Stentor. » WI. Acinetaria. Acineta, Dendrosoma. Chemical Composition of Zoocytium of Ophrydium versatile.* Dr W. D. Halliburton has investigated the chemical nature of the jelly, mucilaginous investing matrix, or zoocytium which is exuded by the colonial ciliated protozoon O. versatile. ‘The lumps of jelly were about an inch in diameter, firm, colourless, and transparent. On the surface were green patches due to chlorophyll. The substance resembles vegetable celiulose in its general pro- perties, and only differs by being less easily converted into sugar; herein it resembles tunicin, or the substance of which the test of the Tunicatais formed. Dr. Halliburton directs attention to the fact that we have here an animal in which chlorophyll and cellulose coexist. Freia Ampulla 0. F. Mull, the Flask-animalcule.{—Prof. K. Mobius, after a description of the infusorian, says that in many capsules there is, at the side of the hind-body of a perfectly developed in- dividual, a young animal without funnel-lobes, nearly uniformly rounded off anteriorly and posteriorly, and produced by fission from the body of the parent animal. This, when it is still connected with its parent only by a slender cord, stretches the fore part of the body out of the capsule, tears itself free, and swims away, carried along by fine cilia which cover the whole body in close longitudinal series. At the anterior extremity rudiments of pectinelle already show themselves, and a slight notch is the beginning of the formation of the funnel- lobes. After the young animal has swum about freely for a time, it attaches itself to some firm support and secretes the material of the capsule as a transparent mass, thicker behind than before, where it is not yet turned out as in mature individuals. Anoplophrya circulans.;—A new parasitic infusorian allied to Opalina is described under the above name, by Prof. E. G. Balbiani, * Quart. Journ. Micr. Sci., xxv. (1885) pp. 445-7. + Schriften Naturw. Ver. Schleswig-Holstein, vi. (1885), See Ann. and Mag. Nat. Hist., xvi. (1885) pp. 154-5. { Recueil Zool. Suisse, ii. (1885) pp. 277-305 (1 pl.). ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 819 from the blood of Asellus aquaticus; it is the first example of a ciliated infusorian living in the blood of its host, and circulating with the blood. The parasite does not, however, spend its entire existence within the body of its host; in the water containing Aselli infected with the parasite, a number of infusoria were observed which appeared to be identical with the individuals contained in the blood of their host ; the liberation of these is certainly due on occasions to the rupture of the terminal portion of the antenne, and possibly always so; these organs being long and delicate are more liable to such fractures than any other part of the body; it is interesting to note that the parasites make use of an accidental lesion as a natural way to leave the body of their host. The majority of the thus liberated parasites die, but a good many survive; these become encysted on a filament of Conferva or similar locality ; even the body of an Asellus is occasionally fixed upon. It is not, however, certain how the parasites regain the body of their host. M. A. Schneider also describes* this infusorian, more especially in regard to its method of reproduction. Conjugation takes place between the small ovoid individuals which, instead of simply coupling, unite by temporary fusion of the protoplasm. Before this fusion or at the moment that it takes place, the nucleus and nucleolus, with which each is provided, undergo modifications. The nucleus of the one elongates and extends for half its length into the protoplasm of the other, which in its turn also sends a portion of its nucleus to its neighbour. The two nuclei form, at this moment, two parallel transverse bands, proceeding without solution of continuity from the centre of one individual to that of the other. The nucleoli are divided, and each individual has four. The author is unable to say whether any exchange of these nucleoli takes place. At the close of the conjugation each individual hag six globules, two large and four small: the former representing two halves of the nucleus, of different origin; the latter are the nucleoli. The two large globules amalgamate and constitute the new nucleus, and one of the small ones persists as nucleolus; the other three are reabsorbed. New Vorticella.t—Dr. A. C. Stokes describes a new species of Vorticella found in the cedar swamps of New Jersey. V. limnetis n. sp. is remarkable for the peculiar twisted appearance of the sheath of the pedicle, a characteristic which it has in common with V. octava Stokes; but apart from its smooth. cuticular surface, it is easily dis- tinguished from that species by the much smaller body, and the greater abundance of the spirals and the consequent shortness of their curves. Difflugia cratera. {—Several species of animals belonging to marine genera have lately been discovered in the deep waters of certain fresh-water lakes in Switzerland. Among Infusoria, Tintin- * Comptes Rendus, c. (1885) pp. 1552-3. + The Microscope, v. (1885) pp. 145-6 (1 fig.). ¢ Zool, Anzeig., viii. (1885) pp. 293-4, 820 SUMMARY OF CURRENT RESEARCHES RELATING TO nidium fluviatile and T. semiciliatum and Tintinnus subulatus are at present the only examples known of such a change of habitat—no doubt produced by geological changes. Dr. O. E. Imhof records a fourth Tintinnodea from the lake of Zurich, which is apparently identical with Leidy’s Difflugia cratera, and which ke names Codonella cratera. New Type of Sarcosporidia.*—-M. R. Blanchard has found in a Macropus penicillatus small white spots in the large intestine; these were seen to be cysts, each of which was bounded by a delicate membrane, the rupture of which allowed the escape of reniform cor- puscles, altogether similar to what are ordinarily called psorosperms ; they are granular, and often have at their ends a bright spot, but no nucleus could be detected. The author does not doubt that they are the equivalents of the falciform corpuscles of coccidia, and like them they exhibit amceboid movements. The numerous vesicles found in the cysts of the Sarcosporidia correspond, therefore, to the spores or pseudonavicellz of coccidia, and they appear to be most nearly like those of Klossia, from which they differ only in secondary points, such as size and habitat. The smallest spores were found in the centre, and the largest at the periphery of the cyst, and the latter were found to be the more mature ; they are from 9°8 to 12 » long and 4 to 5°5 p broad. EE BOTANY. A. GENERAL, including the Anatomy and Physiology of the Phanerogamia. a Anatomy.t Protoplasm in the Intercellular Spaces.t—From an examination of over 100 different species of plants, Prof. E. Russow concludes that air-containing intercellular spaces of schizogenous origin are always closed by a thin layer of protoplasm which can be revealed by treatment with iodine and sulphuric acid. He believes it must have some important function, perhaps for the absorption and condensa- tion of certain gases in the intercellular spaces. He shows also that - Schaarschmidt’s statement § of the occasional presence of chlorophyll- grains in the intercellular spaces rests on erroneous observation. Forms of Cells.||—Prof. J.O. Hennum has made a series of ex- periments on the forms resulting when balls of moist clay are rolled * Comptes Rendus, c. (1885) pp. 1599-1601. + This subdivision contains (1) Cell-structure and Protoplasm (including the Nucleus and Cell-division) ; (2) Other Cell-contents (including the Cell-sap and Chlorophyll); (8) Secretions; (4) Structure of Tissues; and (5) Structure of Organs. *, SB. Dorpat. Naturf. Gesell., vii. (1884) 15 pp. See Bot. Centralbl., xxii. (1885) p. 15. Cf. this Journal, iv. (1884) p. 404. § See this Journal, ante, p. 84. || Arch. Math. og Naturvid., Krigstiania, ix. (1884) pp. 301-404 (7 pls.). See Biol. Centralbl., ix. (1885) p. 199. ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 821 up in lycopodium-powder, either side by side or one over another, and then subjected to pressure in various directions. The forms resulting are described from a mathematical point of view in regard both to their surfaces and to their contents, and the laws thus obtained are then applied to account for the various forms of cells found in the animal and vegetable kingdoms. Structure of the Nucleolus.*— Dr. E. Zacharias has carefully examined the structure, properties, and functions of the nucleolus, taking as his chief illustration, on account of their size, the nucleoli from the inner layers of the wall of the ovary of the snowdrop. In uninjured cells in which the currents of protoplasm are still kept up, the nucleolus appears under water perfectly homogeneous, in contrast to the fine granulation of the rest of the nucleus. When, on the contrary, the cells have been ruptured, the entire mass of the nucleus except the nucleolus swells up, the latter forming a shining sharply defined body, which is usually soon expelled from the ruptured nucleus. In the nucleolus itself may be detected two substances of different appearance, a central mass of stronger refringency and vesicular character, surrounded by a homogeneous ground-substance. The same differentiation is produced by absolute alcohol. Carmine stains chiefly the central mass. Treated with ferrocyanide of potas- sium and chloride of iron, the nucleolus is coloured blue, and contracts, leaving a space between it and the ground-substance of the nucleus ; the diameters of nucleolus, cavity, and nucleus, are about in the proportion of 3,4,and 10. The nucleolus has the appearance under these circumstances of a fine-meshed framework with coloured strands. In artificially prepared gastric juice, the nucleolus becomes pale and swells up, while brightly shining granules of nuclein appear in the rest of the nucleus. Longer immersion causes the nucleus apparently to disappear, but it is again coloured blue by ferrocyanide of potassium and chloride of iron, though reduced to about one-third of its original size. Carmine does not stain it in this condition, and even a 10 per cent. solution of chloride of sodium causes no change. Pieces of tissue heated for some days with 10 per cent. solution of chloride of sodium and then examined in alcohol, rendered the nuclei very pale, and showed that a large portion of their substance was removed. A solution of carmine in very dilute ammonia stains the nucleoli very rapidly and strongly; while in a strongly acid solution of carmine in acetic acid the nuclein body is very strongly stained, the nucleolus remaining quite uncoloured, pale, and swollen ; after a time it takes some colour, but remains lighter than the rest of the nucleus. All these reactions show that the nucleolus consists mainly of albuminoids in addition to plastin, but that it contains no nuclein. The same properties were found in the nucleoli of many other plants, such as those of the bast-cells of Cucurbita Pepo, of the filaments of Spirogyra, and of the nuclei in the asci of Peziza cinerea and vesiculosa. The nucleoli resemble the pyrenoids in consisting of albuminoids * Bot. Zty., xliii. (1885) pp. 257-65, 273-83, 289-96. Ser. 2.—Vo.. V. 3H 822 SUMMARY OF CURRENT RESEARCHES RELATING TO without any nuclein; but it is improbable that the latter contain plastin. They have a still closer affinity with the starch-generators in the epidermal cells of flowering plants, plastin being certainly present in these also. But the albuminoids of the starch-generators display different reactions from those of the nucleoli, deliquescing in water. The nucleoli always disappear when the nucleus is about to divide ; their disappearance and reappearance in the daughter-cells can be peculiarly well watched in living cells of Chara, especially in the growing apices of the rhizoids. In one instance the whole process of the division of a nucleus, and that of its daughter-nuclei was followed in the course of twenty-four hours. The nucleolus of the living nucleus is not homogeneous, but contains vacuoles varying in number and size; and the different parts also display different degrees of refringency, When the nucleus is about to divide, the nucleolus loses its sharpness, and undergoes slow and finally amceboid changes of form, at length entirely disappearing. Ata later period several fresh nuclei are to be seen in the daughter-nuclei ; and these almost immediately coalesce into one. During the coalescence these new nucleoli lose their sharpness, which they again rapidly regain later. The author has been unable definitely to determine what becomes of the substance of the nucleolus after its disappearance, and its re- lationship to the elements of the nuclear plate and to the spindle- fibres. Possibly the albuminoid substance only disappears, the frame- work of plastin remaining and passing into the daughter-nuclei, where it again takes up albuminoids. Zacharias regards the statements of Strasburger and others as to the appearance of so-called “ paranucleoli,” and their expulsion from the nucleus, as resting on error, resulting partly from the exclusive use of hardened material. The behaviour of the nucleoli is somewhat different in male and female sexual cells. While they are invariably present in the latter, they may disappear from the former before their complete develop- ment. ‘This difference was displayed in Chara, Marchantia, and in several ferns. ‘In the oosphere of flowering plants a nucleolus appears never to be wanting; while in the nucleus of the pollen-cell it is not to be detected immediately before impregnation. In the nucleus of vegetative cells it is always present. No general statement can be made with regard to changes in the nucleolus as the cell becomes older; it seems sometimes to increase, sometimes to decrease in size; in some cases it undergoes alteration in form, while in other cases no change is apparent. The author is unable to assign at present any physiological function to the nucleolus. At the same time he dissents from the view of Strasburger, Carnoy, and Pfitzner, that it is not the living substance of the nucleus, and can only be regarded as a reserve- substance. Chlorophyll and its Combinations.* — Some investigations of M. Guignet seem to show that chlorophyll is contained in envelopes * Comptes Rendus, c. (1885) pp. 434-7. ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 823 which are insoluble in petroleum ether, but soluble in alcohol. In pouring a solution in concentrated alcohol upon water, the chloro- phyll is gradually precipitated by diffusion, but it takes the form of brown flakes, which appear completely changed. On replacing the water by alcohol at 50° the chlorophyll is precipitated in deep green flakes without any evidence of crystallization; but the product thus obtained is very impure. Chlorophyll is very stable in the presence of bases, behaving like a true acid and giving compounds which appear to be very well defined. In order to obtain in the crystalline state the combination of chlorophyll and soda, alcohol may be added to the aqueous solution of that compound. On evaporating over lime under a bell-glass, the lime absorbs aqueous vapour, and the alcohol becomes more and more concentrated until it deposits needles of a very deep green, which appear almost black; they are very soluble in water, and present all the characters of a perfectly definite compound. Crystals in the Leaves of Leguminose.*—Prof. J. P. Borodin has examined the distribution of the crystals of calcium oxalate in €60 species of Leguminose. In the Mimosez their occurrence is very constant, in the form of solitary crystals disposed parallel to the veins. In the Cesalpiniee the distribution is the same, but in addition there are clusters of crystals scattered through the paren- chyma of the leaf. These occur again in the Rosacex, but not in the Papilionacew. In the Papilionacee there are three principal types :— (1) Crystals altogether wanting :—the Genistee, many Galegee, as Astragalus and Colutea, and some genera in other groups. (2) Clino- rhombic crystals along the veins:—the Viciex and Trifoliee ; some Phaseolew and Galegex have clinorhombic crystals scattered through the parenchyma. (3) Clinorhombic crystals in groups in the epider- mis :—Dioclea and Canavalia ; in Stylosanthes the crystals lie in the membrane of the epidermis. When crystals are wanting in the leaves, they are deficient also in the stem. Secreting Canals of Plants.}—In pursuance of previous investi- gations on the same subject,t M. P. van Tieghem gives details as to the nature and arrangement of the secreting canals in a large number of natural orders of Dicotyledons. In the Labiatiflore (suborder of Composite), when secreting canals occur, their structure and arrangement correspond to that in the suborders Radiiflore and Tubuliflore. In the Composite taken altogether, the secreting apparatus occupies two different regions according to its nature ; when composed of oleiferous canals it belongs to the endoderm ; when composed of laticiferous cells, whether isolated or forming a network, it belongs to the liber in the root, to the pericycle in the stem and leaves. The Dipsacacesw resemble the Tubuliflorea in the presence and the position of the lacticiferous cells, but differ from all Composite in * SB. Internat. Congress f. Bot. u. Gartenbau, St. Petersburg, May 1884. See Bot. Centralbl., xxi. (1885) pp. 222 and 351, + Ann. Sci. Nat.—Bot., i. (1885) pp. 5-96. t See this Journal, iv. (1884) pp. 767, 770. 824 SUMMARY OF CURRENT RESEARCHES RELATING TO the nature of the pericycle of the stem and leaf, which is always reduced to a single layer of thin-walled cells. The Umbellifere and Araliacee are characterized by the invariable presence of a secreting system of canals in the pericycle, frequently superposed on a second system situated in the parenchyma. If this character is adopted, the genera Mastixia, Helwingia, and Curtisia must be excluded from Araliacee. These two orders, together with the Pittosporex, constitute a group distinguished from the whole of the rest of the vegetable kingdom by the arrangement of the secreting canals in the root, and the displacement which this causes in the insertion of the secondary roots; the Pittosporez differmg from the other two orders in their superior ovary. In this respect, however, Ancistrocladus furnishes a connecting link. In the Clusiacez the embryo is abundantly provided with secret- ing canals, affording a remarkable example of a secretion produced abundantly in the embryonal condition. The Ternstrcemiacez are, as a rule, destitute of these structures, though the rule is not without exception. The Hypericacee are characterized by the presence of narrow oleiferous canals in the pericycle, whenever this remains parenchymatous, i.e. always in the root, as well as in the stem in the typical herbaceous species. In other respects this order shows close affinity to the Clusiacee. The resiniferous cavities of the Myrsinacez are localized in the stem and leaf, never occurring in the roots. The Dipterocarpez are distinguished by the presence of oleiferous canals, and by the exclusive localization of these canals in the primary and secondary wood. Details are given with respect to the structure and arrangement of the secreting canals in some other less important natural orders, making 18 in all; and the results given in previous papers are again included. Peculiar Structures in the Flesh of the Date.*—Prof. W. A. Tichomirow describes structures in the flesh of the date, the nature of which he is not able to determine, similar to those found by Flickiger in the fruit of Rhamnus cathartica. They are insoluble in water, not doubly refractive, coloured yellow by iodine and sulphuric acid, cobalt-blue by chloride of iron, green or olive-green by Millon’s reagent, olive-green by ammoniacal cupric oxide, blue-violet or red- violet by caustic potash. ; Anatomy of Euphorbiacee.|—Herr F.. Pax discusses this subject in relation to the classification of the genera in the order. Bicollateral vascular bundles are found in all the Crotonezx ; occasionally in all the rest of the groups except the Stenolobee, Phyllanther, and Brideliee. The Euphorbiacee may be divided into four groups according to the degree of development of the latex-vessels, viz. (1) Latex-vessels entirely wanting; the secretion being distributed * SB. Internat. Congress f. Bot. u. Gartenbau, St. Petersburg, May 1884. See Bot. Centralbl., xxi. (1885) p. 222. + Engler’s Bot. Jahrb., v. pp. 384-421 (2 pls.). See Bot. Centralbl., xxi. (1885) p. 326. ZOOLOGY AND BOTANY, MICROSCOPY, ETO. 825 through all the cells of the parenchymatous tissue; (2) Latex-tubes segmented, and the segments of equal length; (3) Latex-tubes seg- mented, with the segments of unequal length; and (4) Latex-tubes unsegmented ; in the true Euphorbiex. Anatomical Structure and Development of Ceratophyllum.* — _ This is described in detail by Herr J. E. F. af Klercker, the point of chief interest determined being that the dermatogen always divides only by anticlinals, and, in young apices of stems, appears to possess only a three or four-edged initial, in older apices apparently several. Asarule the periblem and plerome have distinct initials, the latter in young stages only one, in older stages several. In exceptional cases a single group of initials gives birth to both periblem and plerome. Lenticels.t—Dr. A. Zahlbruckner has examined the structure of the lenticels in leaves, with the view especially of determining the question whether they are completely closed in winter. For this pur- ~ pose Stahl’s apparatus was employed, and applied to the leaves of Aisculus Hippocastanum and Ulmus effusa, and with the result of showing that they are not completely closed, although their structure in this respect may be different from what it isin summer. In Sam- bucus, Gleditschia, and the lilac, the lenticels did not permit a greater quantity of air to pass through them when they had just emerged from the bud than in winter. Owing to the power of swelling of the substance which fills up the cells of the lenticels, they allow less water to pass through them when saturated with water than when dry. The author was able to establish fully the connection between the lenticels and the air-passages, not only of the bark, but of the wood, in consequence of which a complete circulation of air is kept up through the plant. In branches destitute of lenticels other means of aeration are present. The special anatomical construction is described of the lenticels of Rhus Coriaria and Euonymus verrucosus, the former belonging to the type in which the cells are all densely filled with a corky sub- stance ; the latter to the type in which, in addition to the cells filled with corky substance, are others of a sclerenchymatous character with lignified walls, perforated by simple pores which connect them with the adjacent cells. Anatomy ofthe Wood of Conifers.t—Dr. P. Pfurtscheller describes the appearance of certain tracheids in the wood of Abies eacelsa, Picea vulgaris, Larix europea, Abies Douglasii, and other coniferous trees, almost wanting in Abies pectinata. This was a projection in the membrane in the form of a spiral thickening, erroneously described by some observers as a striation, with which it has in fact nothing to do. In some cases the author observed a striation on the same tracheid, and satisfied himself that the two structures were entirely unconnected with one another. This tendency to the formation of a “ SB. Bot. Sallsk. Stockholm, May 12, 1884. See Bot. Centralbl., xxi. (1885) p. 157. + Verh. K. K. Zool.-Bot. Gesell. Wien, xxxiv. (1885) pp. 107-16. t Ibid., pp. 535-42 (2 pls.). 826 SUMMARY OF CURRENT RESEARCHES RELATING TO spiral thickening of the wall is not confined to the tracheids, but ex- tends also to the outer cells of the medullary rays of the first-formed annual ring. Here they are especially conspicuous on the horizontal walls, and therefore distinct on transverse section; and are found also in the later annual rings where there is no trace of spirally thickened tracheids. The spiral thickening was found most distinct in the tracheids of the yew and of Abies Douglasit. Comparative Anatomy of the Tissue of the Medullary Rays and - Annual Zones of Growth in Conifers.*—Herr H. Fischer has made a careful study of this subject in the stem, root, and branches of Pinus Abies. Notwithstanding contrary statements of previous observers, he states that no absolute universal character by which the wood of the stem, root, and branch can be distinguished from one another is to be obtained from the relationship between the mean number and height of the medullary rays in the successive annual rings and the age of the ring. The stem and branch can, however, be distinguished by the different structure of their broad annual rings. In the stem these consist, as a rule, chiefly of summer-wood, in the branch chiefly of autumn-wood. In narrow annual rings in both stem and branch, the autumn-wood constitutes at least half the breadth, in the branch usually more. The stem, root, and branch are to be distinguished by the anatomical structure of their annual rings, according as they are wide or narrow. In narrow rings in the root, the summer-wood usually prevails; wide rings contain as a rule more summer-wood than rings in the stem of the same width. A prevalence of autumn- wood is sometimes seen in very young and narrow rings of older roots. There is only a gradual passage between the character of the wood in primary and secondary roots. The annual rings are usually well marked in the stem, root, and branches, the chief exceptions being furnished by the root. Behaviour of the Leaf-trace-bundles of Evergreen Plants as the stem increases in thickness.t—Dr. O. Markfeldt has investigated the question, What becomes of the leaf-trace—the common bundles of vascular plants which, within the stem, represent the discernible trace of the leaves to which they belong—when a new annual ring is formed in each recurring vegetative period, in the case of those trees and shrubs which retain their leaves through the winter? His observa tions were chiefly directed to Gymnosperms and Dicotyledons, and with the following general results :— All the Gymnosperms examined have a portion of the leaf-trace which runs through the cortex, parallel to the main axis of the stem or branch, and surrounded on its lower side by cambium. The portion of the leaf-trace which runs into the wood stands vertically to the axis, or nearly so, and is closely inclosed on its upper and inner sides by the wood. ‘The annual increase in thickness of the stem or branch causes a rupture of the leaf-trace in the neighbourhood of the cambium, while at the same time new vascular elements are formed * Flora, Ixvili. (1885) pp. 263-294, 302-9, 313-24 (1 pl.). + Ibid., pp. 33-9, 81-90, 99-113 (1 pl.). ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 827 from the leaf-trace cambium, which again unite together the two ruptured parts of the leaf-trace. This gives the appearance as if the rupture took place on the upper side only of the leaf-trace, while in fact it extends to the whole bundle formed during a period of vegetation. The space left vacant by the rupture of the leaf-trace is probably filled up by the cambium, perhaps with the assistance of the woody parenchyma which surrounds the leaf-trace. The cells thus formed, after their cell-walls have become thickened, constitute the companion-cells (Begleitzellen) which arise at a greater depth in the wood. After the fall of the leaf the leaf-trace is completely ruptured, except in the case of the Araucariew, where the leaf-trace does not appear to be completely torn through, even in the oldest internodes of the main stem. All the evergreen Dicotyledons examined, with the exception of Aralia quinquefolia and Prunus Laurocerasus, have a thin-walled tissue above the leaf-trace which separates it from the upper woody portion of the branch or stem. This tissue is in immediate connection with the pith, and consists of similar cells, The leaf-trace is in all eases curved outwards. In Ilea Aquifolium the leaf-trace is ruptured in the third year. In this case the space left vacant by the rupture is filled up by cells which resemble those of the pith-like tissue lying above the leaf-trace. In all Dicotyledons which have a long portion of the leaf-trace running through the cortex, a rupture of the cambium takes place after the fall of the leaf. In Camellia japonica the leaf-scar arises so deep in the feebly developed cortex that there can hardly be said to be a cortical portion of the leaf-trace. Hence the whole of it is in this case concealed. The same is true of the leaf-trace in deciduous as in evergreen Dicotyledons; after the fall of the leaf a rupture of the leaf-trace takes place at the cambium in those cases where it has a cortical portion. Gum-canals of the Sterculiacee.*—M. P. van Tieghem points out that the more or less abundant production of gum or mucilage is a@ common character of the Malvacex, Tiliacew, and Sterculiacea, which ought, he considers, to be treated rather as three tribes of one order than as distinct orders. But the mode of formation of the gum differs in the three groups. In the Malvacee and Tiliaceew it is secreted in large isolated cells which sometimes coalesce; in the Sterculiacez in large schizogenous secreting canals. The cells which border these canals do not usually differ in any respect from the surrounding parenchyma, and may contain starch or calcium oxalate; sometimes they are smaller than the ordinary parenchy- matous cells. These canals occur in the stem and leaves only, being entirely absent from the root. In the stem they are usually developed simultancously in the cortex and in the pith; the rest of the stem being as a rule destitute of them. In the cortex they are arranged in * Bull. Soc. Bot. France, xxxii, (1885) pp. 11-14. 828 SUMMARY OF CURRENT RESEARCHES RELATING TO a single circle in the median zone, their number amounting to 20, 40, or even 60; those of the pith are also most often in a single circle in the peripheral zone, and are always separated by some rows of medullary cells from the primary xylem of the vascular bundles; sometimes they form two concentric circles. In some genera the cortical canals are wanting. Those genera which have canals in both the cortex and the pith possess them besides in the external and internal paren- chyma of the leaf-stalk; but when the cortex of the stem is destitute of these canals, so also is the external parenchyma of the leaf-stalk. The large starchy cotyledons of Cola and Heritieria contain no gum- canals; and in some genera of Sterculiacez they are entirely wanting even in the leaves and stem. Striated Woody Tissue.*—Herr F. v. Hohnel describes a pecu- liarity of the wood of a certain number of exotic trees belonging principally to the natural orders Leguminose, Bignoniaces, Sima- rubex, and Ebenacex, a striated appearance on longitudinal section due to the presence of horizontal rays. This results from the regular disposition of the medullary rays, which form so many parallel hori- zontal bands. In addition the tracheids, which constitute the greater part of the wood, are swollen in their middle and taper off at their two extremities ; the median swellings which alone are punctated, are arranged in parallel lines, which further contributes to give the wood its striated appearance. Structure of Stem of Strychnos.;—M. J. Hérail has investi- gated the peculiar structure of the stem of Strychnos, in the three species S. triplinerve, brasiliense, and nua-vomica, in which the ring of wood is traversed by light-coloured plates sometimes arranged regularly in a circle, sometimes irregularly in the woody mass, com- posed of sieve-tubes surrounded by parenchyma. M. Hérail shows that this structure is not due, as has been supposed, to an abnormal power of the cambium of producing both xylem and phloém on one side; but that it, in the usual way, produces xylem only on one side and phloém only on the other side. The peculiar appearance results from the cambium ceasing to produce xylem at the points where it produces phloém; and this peculiarity persisting for an indefinite time, the result is that the xylem formed in all the other parts advances more and more upon the phloém, which it appears ultimately to surround. Mechanical Tisssue-system.{— Dr. A. Tschirch proposes the following terminology for the various developments of this system. By the term sclereid he understands all thick-walled elements which cannot be included under specific mechanical cells, viz. bast-fibres, libriform, and collenchyma; hence all the célls formerly classed as sclerenchyma, except the stereids, collenchyma, and libriform cells. The sclereids must aiso be regarded as specifically mechanical cells, * SB. K. Akad. Wiss. Wien, Ixxxix. (1884) pp. 30-47. See Bull. Soc. Bot. France, xxxii. (1885) Rev. Bibl., p. 9. + Bull. Soc. Bot. France, xxxii. (1885) pp. 92-5. { Ber. Deutsch. Bot. Gesell., iii. (1885) pp. 73-5. ZOOLOGY AND BOTANY, MICROSCOPY, ETO. 829 and may be divided into Osteosclereids (bone-cells of Hakea, &c.), Astrosclereids (ophiure-cells of Jénsson), and Brachysclereids (stone- cells). Except in actual reserve-receptacles, as in seeds, the thickening of the wall is never effected by the storing-up of reserve-cellulose. Sclereids are often employed in constructions for producing radial pressure, as the osteosclereids of the Proteacex, Restiacer, and Thea, and the brachysclereids in the palisade-layer of the testa of seeds. The mechanical contrivances in the bark of dicotyledonous trees are very various ; and the sclereids here often perform a secondary func- tion in protecting the sieve-structures. The “mixed ring ” of Quercus, Cinnamomum, Betula, &c., is produced by thin- or thick-walled ele- ments of the cortex becoming intercalated in cavities formed during the early years in the mechanical ring of the primary group of sclereids. The author is unable to explain the function of isolated sclereids or groups of them not connected with bast-cells. In the fruit of the Pomaces they may be the remains of walls previously continuous, though this will not explain the isolated clusters of stone- cells in older cortex, and the isolated sclereids in the pith of many plants. Structure and Function of the Aril in certain Leguminosxz.*— Herr E. Bachmann describes the appendage to the seeds known as the aril in Sarothamnus scoparius and some other Leguminose. Its purpose appears to be to cause in the ripe seed a detachment from the funicle, by means of a very large intercellular cavity, and thus to promote the dissemination of the seeds. A similar purpose is served by a totally different structure in the aril of species of Vicia and Lathyrus ; the separation being caused here by a difference of tension between the cells of the aril and those of the seed itself. Leaves of Statice monopetala.t—Dr. M. Woronin describes the structure of the leaves of this plant, in which the most noteworthy points are the following :—Among the otherwise very regular layers of palisade-cells immediately beneath the epidermis of the upper and under surfaces, are large much-branched sclerenchymatous cells, containing a colourless finely granular protoplasm, and sometimes a distinct nucleus. The leaves display a strong calcareous incrustation partly in the form of a thick and regular layer, partly in the form of separate scales of roundish outline, which, when violently removed, reveal beneath them remarkable glands consisting always of eight cells, by which the calcium carbonate appears to be separated. Absorbing Organs of Albuminous Seedg.{—Dr. M. Ebeling has investigated the process by which, in germinating seeds which have their food-material stored up in endosperm, the embryo obtains this food-material from the embryo. He finds that the various modes may be classified under the following types :— In Cycadew and Monocotyledons the cotyledons remain perma- nently in the seed, and are destined for no purpose except the absorp- * Ber. Deutsch. Bot. Gesell., iii. (1885) pp. 25-9 (1 pl.). + Bot. Ztg., xliii. (1885) pp. 177-85 (1 pl.). t Flora, Ixviii. (1885) pp. 179-202 (1 pl.). 830 SUMMARY OF CURRENT RESEARCHES RELATING TO tion of the endosperm, perishing after this is completed. In Liliaceae, Juncaginee, Iridew, Amaryllidee, and doubtfully in Cycadex, the cotyledon remains anatomically unchanged during germination, absorbing the endosperm through the ordinary epidermal cells which differ in no way from those of the young leaves. In Graminex, Palme, Commelynaceex, Cyperacez, and Juncacee, the cotyledon developes special organs or haustoria for the absorption of the endosperm. In grasses this is the scutellum, a shield-like organ, clothed with an epithelium composed of elongated thin-walled absorp- _ tive cells at right angles to the surface, from four to ten times as long as broad, and projecting into the endosperm like sacs. In Palms and Commelynacez, on the other hand, the absorptive organ is of the same shape as the seed, its periphery consisting of elongated thin-walled cells placed vertically to the surface, and from two to six times as long as broad. In Cyperacez and Luzula (Juncacez) the organ in question is of a filiform-cylindrical shape, continually renewing itself at the apex. The entire haustorium consists of elongated thin-walled cells, from four to six times as long as broad, and having their longer.axis parallel to that of the organ. In Juncus the haustorium is pear- shaped ; both the inner and the epidermal cells are elongated in a direction parallel to its longitudinal axis; the terminal cells at its apex being elongated radially and club-shaped. A second type occurs in Dicotyledons and Conifer. The coty- ledons remain only for a time in the seed, consuming the endosperm, after which they rupture the testa, emerge above the soil, and perform the function of assimilating organs, with the characters of ordinary leaves. Their epidermis consists of thin-walled cells, not specially elongated, but with the ordinary forms of young epidermal cells. The main point of difference is that in Monocotyledons the coty- ledon serves only for the absorption of the endosperm, and may deve- lope into a special haustorium; while in Dicotyledons and Conifers the cotyledons serve in the first place for the absorption of the endo- sperm and afterwards for assimilation, when they assume the form of ordinary leaves. Embryo-sac of Santalum and Daphne.*—Prof. E. Strasburger has made further observations on the structure of the embryo-sac of Santalum album from Madras. In contrast to previous statements, he finds that the *‘ egg-apparatus ” follows the ordinary rule of possessing only a single ovum-cell and two synergide. A fallacious appearance is presented by the synergid-caps (or filiform apparatus) being strongly separated from the synergide themselves, and a ridge springing out from the wall of the embryo-sac between them. The pollen-tube forces its way between the two synergid-caps to the point of insertion of the ovum-cell, after which the egg-apparatus exhibits its ordinary changes. The formation of endosperm is commenced by the division of the secondary nucleus of the embryo-sac, and a transverse division of the embryo-sac itself beneath the swollen spot. With regard to the embryo-sac of Daphne, Strasburger admits the * Ber. Deutsch. Bot. Gesell., iii. (1885) pp. 105-13 (1 pl.). ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 831 force of the objection taken by Prohaska to his previous interpreta- tion of the peculiar structures found in it by this observer. He now considers that they are neither disorganized cells of the nucellus, endosperm-nuclei, nor cell-nuclei; and details observations made on D. Blagayana, Mezereum, and Laureola, which establish that they are yacuoles filled with a strongly refractive substance which is fixed by alcohol, corresponding to similar structures found in the ovum-cells of conifers. Morphology of the Receptacle.*—Sig. F. Baccarini infers, from an examination of the course of the fibrovascular bundles, that in the case of the inferior ovary of perigynous flowers, of which the Rosez may be taken as the type, the cup-shaped receptacle is an axial organ, as is shown by the formation on its margin of the outer whorls of floral organs. When, in an inferior ovary, the placentation is axile, as in Pomacee and Myrtacex, the whole structure is of a compound character, consisting of two parts closely united to one another in growth, the outer of which is the widened receptacle, while the inner part is formed of the carpids, formed at the bottom of the axial cup. In the Cactacez the course of the fibrovascular bundles seems to show that the carpids, like the other appendicular organs of the flower, are inserted on the margin of the axial cup, but that the placentz are formed in the hollow of this cup along the descending leaf-trace- bundles. Spur of Cucurbitacee.}— In many germinating Cucurbitacee a kind of spur is formed on the tigellum which appears to have for its function the freeing of the seedling from the testa of theseed. Sig. A. Baldini has examined the structure of this organ, and finds that if its forma- tion is prevented, the seeds germinate imperfectly and abnormally. The spur itself varies in form, but is always seated at the spot where the tigellum forms an angle with the root, on the side facing the sub- stratum. In the course of its development it undergoes several changes of position ; its apex finally bending and pressing against the testa, so that the seedling is at length forced out from its confinement within the latter. In addition to its mechanical function, the author ascribes to this organ another connected with the life of the seedling. On the side of the spur which faces the root, when it is pressed closely against the testa, are a number of hairs altogether resembling in their nature root-hairs, which appear to absorb nutriment from the inner integu- ment of the seed, and later from the soil; so that it may be regarded as an organ of nutrition. Morphologically he regards the spur as belonging to the tigellum rather than to the root. _ Anatomy of the Fruit of Ranunculacee.{—Dr. E. Adlerz finds in the fruit of Ranunculaces two kinds of mechanical and supporting * Ann. R. Ist. Bot. Roma, i. (1884) pp. 66-85 (5 pls.). See Bot. Centralbl., Xxi. (1885) p. 229. t Ann. R. Ist. Bot. Roma, i. (1884) pp. 49-65, See Bot. Centralbl., xxi. (1885) p. 229. Adlerz, E., ‘ Bid, till fruktvaggens anat. hos Ranunculaces,’ 42 pp. (4 pls.), Orebro, 1884. See Bot. Centralbl., xxi. (1885) p. 330. 832 SUMMARY OF CURRENT RESEARCHES RELATING TO tissue :—(1) the sclerenchymatous strings which accompany the vascular bundles; (2) tissues of various kinds distinct from the vascular bundles. Some of these form the hardening layer, while others do not. The venation or distribution of the finer vascular bundles in the fruit of Ranunculacee also shows a number of varia- tions. Anatomy of the Female Inflorescence of Dioon edule.*—Sig. G. Cugini furnishes a useful contribution to our knowledge of the repro- ductive organs of Gymnosperms. The axis of the female inflorescence of Dioon edule is composed of a nearly homogeneous parenchyma through which run the numerous gum-canals characteristic of the Cycadez, in a longitudinal direction, apparently without any order, and branching and anastomosing abundantly. Like the vascular bundles they curve to enter the ovuliferous leaves. They are full of a yellow gum which dries on exposure to the air, and is completely soluble in potash. The fibrovascular bundles are arranged in a central cylinder sur- rounded by a circle of smaller bundles; the xylem and phloém are side by side; between them is a woody parenchyma. The lamina of the ovuliferous leaves has an epidermis composed of tabular cells, the lower surface alone being furnished with a few stomata. Beneath the epidermis is a hypoderma composed of two or three irregular layers of cells, and beneath this a thickish sclerenchy- matous layer. ‘The mesophyll is composed of large cells containing abundance’ of starch, and is penetrated by gum-canals and fibro- vascular bundles. Each leaf bears two horizontal or pendulous ovules, with a single integument prolonged into a micropylar canal; the nucellus, con- sisting of a single sac, was examined only in an unfertilized condition. From the arrangement of the fibrovascular bundles, the author con- cludes that the ovules are equivalents of lobes of leaves. Influence of the Medium on the Structure of Roots.j—As the result of a series of experiments, M. J. Costantin has arrived at the conclusion that when a root developes in the air instead of the soil, the cortex is diminished in mass, while the pith is increased ; the fibrovascular system, both cortical and central, is increased, together with the number of lignified vessels; and the endoderm-cells are rendered harder and less permeable. When, on the contrary, a root developes in water, the number of air-cavities is increased, both in the cortex and the pith, the latter is diminished in quantity, while the fibrovascular system is reduced. The changes effected by a change of medium of the root are in fact similar to those produced in the stem. Structure and Dehiscence of Anthers.t—M. Leclere du Sablon repeats in further detail, giving a large number of illustrations, the * Nuoy. Giorn. Bot. Ital., xvii. (1885) pp. 29-48 (4 pls.). + Ann. Sci. Nat.—Bot., i. (1885) pp. 135-82 (4 pls.). t Ibid., pp. 97-134 (4 pls.). ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 833 results at which he has arrived * respecting the speciality in the structure of anthers which causes their dehiscence in different ways in different cases. Vegetative Organs of Urtica dioica.t—Dr. A. Gravis takes the anatomy of the vegetative organs of the common nettle as a basis for a general and comparative study of the Urticacee. The minute structure of the stem, root, and leaf is worked out and exemplified under all modifications attendant upon age and biological conditions, and the importance of recognizing these conditions and states is insisted on. This treatise would be an excellent vade-mecum and guide for any student who wished to undertake serious work in vegetable histology. The style of exposition is as clear as are the illustrative figures. Anatomy of Peduncles compared with that of the Primary Axes and of Petioles.§—M. EH. Laborie is led to conclude from numerous researches that the organization of the floral axes differs very frequently from that of other portions of the plant. Of the differences observable, the ones that may be termed essential are always found when the structure of the peduncles is not identical with that of the stem; the others, accessory in some sort, vary with the species. The former affect the constitution itself of the tissues or systems of tissue occurring in all the axes, and their relative im- portance. The latter are due to either the absence in the peduncle of some tissue which exists in the stem, or the presence of some elements which the stem does not possess. Thus as regards A. Essential Characters.—There is generally observable in the peduncles (1) a great development of the bark (Hibiscus syriacus, Antirrhinum majus, &c.) ; (2) An organization of fibrovascular bundles, characterized (a) in its external portion by a frequent augmentation of the diameter of the fibres, independently of their number, which may be diminished (Cornus sanguinea, Catalpa bignonioides); or increased (Lathyrus sylvestris); (b) in its interior portion, by a very marked reduction of the number and size of the large vessels (Dolichos sinensis, Vitis vinifera, &c.). (3) Lastly the small size of the pith (Aquilegia vulgaris, Gratiola officinalis, Quercus pedunculata, &c.). B. Accessory Characters.—Various tissues, constant elements of the stem, do not always recur in the peduncles. For instance, the disappearance in it is noticed of cork (Lonicera alpigena, Ribes mal- vaceum), of chlorophyll-cells (Aristolochia sipho), of the woody part of the vascular bundles (Citrus Aurantium, Pastinaca pratensis Jord. ; Maclura aurantiaca, &c.), of sclerenchymatous cells which are often mixed with woody fibres (Styphnolobium japonicum). At times, lastly, the number of certain supplementary parts is diminished (reversed bundles of Calycanthus macrophyllus.) On the other hand, the peduncles of various species possess tissues or elements which are * See this Journal, ante, p. 91. + Gravis, A.,‘ Recherches Anatomiques sur les Organes Végétatifs de l’Urtica dioica,’ 4to, Bruxelles, 1885, 256 pp. and 23 pls. t See Amer. Journ. Sci., xxx. (1885) pp. 84-5. § Comptes Rendus, xcix. (1884) pp. 1086-8, 834 SUMMARY OF CURRENT RESEARCHES RELATING TO wanting in the stem; e.g. woody fibres (Thymus vulgaris) ; the special reticulate cells (Acacia cultriformis). These modifications sometimes correspond to the size of the floral organs, or to the size or con- sistency of the fruit; but most frequently they can only be connected with the function of those organs. In fact, on comparing the peduncles with the petioles, it is seen that the most marked and constant difference which distinguishes them is in the number and size of the large vessels of the wood; few and small in the former, numerous and large in the latter. From the point of view of sexuality, the influence of the flower on the organization of the peduncles sometimes expresses itself in well- defined characters. Thus the peduncles of the female flowers of certain moncecious species always possess a thicker bark, and a better organized woody ring furnished with larger if not more numerous vessels, than the peduncles of the male flowers (Castanea vulgaris, Juglans regia, &c.) In short, the floral axes present modifications, more or less marked, which express in some sort the influence which the production of flowers exercises, and gives us, so to speak, the measure of its value. This influence may be nothing or at least may appear to be such. Often it does not extend beyond the immediate supports of the flower, or at least of the various members of the inflo- rescence (Pavia rubra, Vitis vinifera, &c.). And lastly, in some plants it makes itself felt as far as the branches which give rise to the floral axes, so as to provoke in them either a partial modification (Ribes mulvaceum), or a complete differentiation (fruit-bearing branches of the pear and apple, of Salisburia, &c.). Wolffia microscopica.*—Herr F. Hegelmaier describes the struc- ture and anatomy of this previously little-known species, the smallest of flowering plants, from India. Its most striking external peculiarity is the rhizoid or “radicula” of Griffith, a comparatively large conical protuberance from the lower surface of the plant, somewhat nearer to the base than the apex of the shoot, the purpose of which appears to be to enable the plant to float in a horizontal position. The author suggests that in the allied genus Wolffella we may have a true example of apogamy, hitherto unknown in flowering plants, a con- tinual non-sexual reproduction from generation to generation, with- out seeds being ever produced. 8. Physiology.+ Fertilization of Asclepias Cornuti.;—Mr. T. H. Corry describes in great detail the structure and development of the gynostemium and the mode of fertilization in this plant. Pollination takes place entirely by the agency of insects, and only in fine weather ; and the author states that, as far as his observation goes, the flowers are absolutely sterile when pollinated artificially from pollinia extracted either from the same flower or from another of the sameage. This is * Bot. Ztg., xliii. (1885) pp. 241-9. + This subdivision contains (1) Reproduction (including the formation of the Embryo and accompanying processes) ; (2) Germination ; (3) Growth; (4) Respira- tion; (5) Movement; and (6) Chemical processes (including Fermentation), { Trans. Linn. Soc, Lond.—Bot., ii. (1884) pp. 173-207 (3 pls.). ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 835 the case even though the pollinium may produce a skein of pollen- tubes which penetrate down into the interior of the style; and even when the tubes enter the ovary this is insufficient to ensure the production of an embryo. Blooming of Arum italicum.*—Herr G. Kraus describes the struc- ture of the club-shaped appendage to the inflorescence of Arum italicum, and the remarkable changes which take place in its chemical constitu- tion during blooming. In the course of a few hours this structure loses, on an average, about 74 per cent. of its dry weight, chiefly by the consumption of carbohydrates. Before blooming, about 66 per cent. of its dry substance consists of starch, which entirely disappears, as well as the sugar. These substances are not used up by the plant, but oxidized and exhaled. In five inflorescences an average tempera- ture of 51°3° C. was observed during blossoming, or 35° 9° above that of the surrounding air. Arum maculatum displays a similar elevation of temperature ; Calla ethiopica, on the other hand, none at all. Influence of Electricity on the Growth of Plants.t—Dr. A. Bronold finds that electricity has a threefold influence upon the growth of plants—as an illuminant; as decomposing the constituents of the soil; and as ozonizing the air. By the joint application of this triple agency to certain ornamental plants and to strawberries, he effected growth, strength, and health, exceeding by two or three times that obtained under natural cultivation; larger size and better development of flowers and fruits, without loss of flavour and odour ; larger seeds, possessing greater germinative power; more complete assimilation of the plant-food in the soil, and freedom from vermin. Prof. Holdefleiss { has observed that beet seed, sown in a flower- pot so placed that the soil was exposed to the electric light, germinated two days earlier than similar seeds without the action of the electric light. i Herr Schdller § also testifies to the exceptional luxuriance of beets, in a plot of about two square metres, which had been struck by lightning. Respiration of Plants.||-MM. G. Bonnier and L. Mangin point out that hitherto the amount of oxygen given out by plants to the air has been supposed to represent the total result of the fixation of carbon. They show that this is not the case, but that at the same time that the carbon is assimilated by the chlorophyll, the protoplasm absorbs oxygen and emits carbonic acid. An analysis of the gas emitted by a plant, therefore, only represents the difference between the amount of oxygen disengaged by assimilation of carbon and the amount absorbed by respiration, and on the other hand, between the carbonic acid decomposed by assimilation and the carbonic acid produced by respiration. * Abh. Naturf. Gesell. Halle, xvi. (1884) 102 pp. (3 pls.). See Bot, Centralbl., xxii. (1885) p. 163. + Zeitschr. Land. Vereins in Bayern. See Journ. of Sci., vii. (1885) p. 248. t ced Landwirth. See Journ. of Sci., vii. (1885) p. 248. 1d, ; Comptes Rendus, ec. (1885) p. 1303, 836 SUMMARY OF CURRENT RESEARCHES RELATING TO Three methods are given for separating the result of the action of chlorophyll from that of respiration. One is by calculating the difference between the whole amount of gas emitted and absorbed by plants exposed to light, and the volume which they emit by respira- tion alone in the same light. A second method consists in suppress- ing assimilation by the use of chloroform or ether without altering the respiration. In the third method, two plants, of which the physiological identity has previously been ascertained, are exposed, the one to ordinary air, and the other under similar conditions except that a concentrated solution of barium hydrate is placed in the con- taining apparatus to absorb the carbonic acid formed. Under these circumstances an excess of oxygen is found in the apparatus without baryta, while in the apparatus containing it the carbonic acid when set free by hydrochloric acid is found to be in excess of that in the other vessel. The conclusion arrived at by the authors from these experiments is that the volume of oxygen disengaged by assimilation is greater than that contained in the carbonic acid decomposed.* Respiration of Plants at different seasons.;— MM. G. Bonnier and L. Mangin give the following experimental results on this subject :—In any given stage of development, the proportion between the volume of carbonic acid given out and that of oxygen absorbed, is constant, whatever the temperature. This proportion remains also constant if the pressure of oxygen is diminished, and that of carbonic acid increased. Galvanotropism of Roots.t—Herr J. Brunchorst describes under this name the curvature in roots growing free in water caused by a galvanic current. Weaker currents cause curvatures which are con- cave on the side of the negative electrode; these he calls negative curvatures; while stronger currents cause curvatures which are concave on the side of the positive electrode; and these he calls positive curvatures. The point of passage from negative to positive curvatures varies greatly with different plants. Decapitated roots exhibited only positive curvatures. Movement of Water in Plants.§—In support of Godlewski’s view as to the cause of the ascent of water in plants,|| Herr J. M. Janse describes the following experiment. The central portions of long branches with abundance of leaves at their summit were placed in a water-bath without separating them from the plant. The portion im- mersed in water, from 15 to 20 cm. long, was heated for an hour to a temperature of 70°C. The result was that in Fuchsia globosa the leaves above the heated part began to wither the next day, and after five days were completely dried up. Syringa vulgaris held out some- what longer, its leaves did not begin to wither till the fifth day, and were all dead in seventeen days. He concludes that the co-operation of the living elements of the wocd is essential for the ascent of water * See Bull. Torrey Bot. Club, xii. (1885) pp. 63-4. + Bull. Soc. Bot. France, vii. (1885) pp. 175-80. See this Journal, ante, p. 679. t Ber. Deutsch. Bot. Geseil., ii. (1884) pp. 204-19. § Maandbl. vy. Natuurwet., 1885, pp. 11-24. See Bot. Ztg., xliii. (1885) p. 302. || See this Journal, ante, p. 490. © ZOOLOGY AND BOTANY, MICROSCOPY, ETO. 837 in trees; and that the medullary rays are especially adapted for driving up water to the highest branches. “‘Bleeding’’ of Parenchymatous Tissues.*—Dr. C. Kraus states that “bleeding” takes place from all parenchymatous tissues as the result of osmotic forces when the turgidity is sufficiently high, when there is no mechanical resistance, and when the parenchyma is in the right condition. The composition of the sap thus excreted varies, and is often different from that of the cell-sap. While the cell-sap is usually decidedly acid, the excreted fluid may be neutral or very slightly acid or even strongly alkaline; sometimes it is even more acid than the cell-sap. The bleeding is not brought about by trans- verse sections alone, but also by tangential and radial wounds. Bleeding often takes place from the leaves of cut branches, but usually only when the leaves are young; also from the surface of the epidermis of young roots; and acid drops have been observed to exude from the apex of root-hairs. The reaction of the parenchy- matous sap appears to vary in the same plant. Physiological and Pathological Effect of Camphor on Plants.t;— Dr. A. Burgerstein has determined, from a large series of experi- ments, that when cut and withered shoots of various plants are placed in camphor-water, they recover more rapidly, and again become turgid sooner, than if placed in distilled water. At the same time camphor- water increases the transpiration from the shoot. If, however, the absorption of camphor-water is continued for a longer period, from two to five days, the plant is injured and at length killed. If made to swell in camphor-water, seeds will absorb water more rapidly and in greater quantity than if placed in distilled water. Chemical and Physiological Action of Light on Chlorophyll.t{— M. C. Timiriazeff, in order to avoid errors due to the unequal dis- persion of a prism, adopted the method of decomposing portions of the previously dispersed light. By means of the cylindrical lens and prism of small angle used in experiments on complementary colours, two images, complementary in colour, were thrown at the same time either on two test-tubes containing a 30 per cent. solution of carbonic anhydride in which was placed a small branch of Hlodea, or on a plate coated with collodion containing a small quantity of chlorophyll. When the spectrum was divided into two equal parts with respect to the normal spectrum, the two images were of course respectively yellow and blue. The maximum chemical and physiological effect was exerted by the yellow, whilst the effect of the blue rays was scarcely appreciable. The blue-violet portion of the spectrum being cut off by a screen, the less refrangible portion was divided into two equal parts, red and greenish yellow. The maximum chemical and * Bot. Centralbl., xxi. (1885) pp. 212-7, 245-9, 274-8, and 373; also Wollny’s Fortschr. a. d. Geb. d. Agriculturphys., vii. (1884) pp. 136-71. See this Journal, iv. (1884) pp. 591, 777. t Verh. K, K. Zool.-Bot. Gesell. Wien, xxxiv. (1885) pp. 543-62, + Comptes Rendus, ec. (1885) pp. 851-4. Ser. 2—Von. V. i 838 SUMMARY OF OURRENT RESEARCHES RELATING TO physiological effect was exerted by the red. By placing the prism in the greenish-yellow part of the spectrum, a greenish-yellow and a violet image were obtained. The latter contained all the rays ab- sorbed by chlorophyll, whilst the former contained only the green which is reflected by vegetation. In this case the maximum effects were exerted by the violet. It follows from these results that chlorophyll acts as a true sensitizer, undergoing decomposition itself, and promoting the de- composition of carbonic anhydride in those parts of the spectrum _ which it absorbs. The different rays absorbed by chlorophyll produce decomposition in very different degrees, the maximum decomposition coinciding in a remarkable manner with the maximum energy in the normal spectrum as measured by Langley and Abney. It would seem, therefore, that it is the amplitude rather than the period of the vibrations which brings about that disturbance of the carbonic anhydride molecule which finally results in its dissociation. The chemical action of light on the photographic plate seems to be strictly analogous to its physiological action on the living plant, provided that, as in the case of chlorophyll, the absorption phenomena are identical in both cases. B. CRYPTOGAMIA. Cell-wall-thickenings and Cellulin-grains in Chara and Vau- cheria.*—Prof. G. Schaarschmidt has observed these structures in Chara hispida and Vaucheria sessilis. They are especially abundant on plants grown inaroom. ‘They are of various forms, cylindrical, conical, or ribbon-shaped, occasionally branched or united in groups, or of larger size and undulating, or very rarely empty and vesicular. They make their first appearance as small elevations on the inside of the cell-wall, often very closely packed; developing then into a cylindrical-conical form, manifesting a distinct lamination, and with either a “nucleus ” or crevice near the base. The undulating thick- enings are found especially in the antheridia and oogonia, on septa formed as the result of injury. The protoplasm collects in large quantities at the spots where these thickenings are taking place; it contains but a small number of chlorophyll-grains, and finally dis- appears with the exception of a very thin layer, which shows very beautifully the hyaloplasmatic membrane of the chlorophyll-grains. In Vaucheria and many other fresh-water algz the cell-wall is im- pregnated with various incrusting substances of unknown composition. These thickenings are regarded by the author as pathological products, and are often accompanied by abnormal structures such as, in Vaucheria, the septation of the filaments. The portions of proto- plasm separated by transverse thickenings develope into gemme, or into a multicellular or branched septated form, the “conferva” and “cladophora”’ condition respectively. These forms are in no way connected with the Gongrosira-condition. * Magy. Novén. Lapok., viii. pp. 1-13 (1 pl.). See Bot. Centralbl., xxii. (1885) p. 1. ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 839 Cellulin-grains were observed by the author in Vaucheria sessilis and geminata, but not with certainty in the living cells; best in preparations treated with hyperosmic acid, and then mounted in glycerin, after the cells have lain for a long time in alcohol. They vary in size from 4 to 14 p, and are of a compressed roundish form. The inner spongy mass of the young grains takes up pigments greedily, while the outer part is scarcely or not at all stained ; nigrosin and rosanilin stain them most strongly. The inner portion is, however, coloured by an aqueous solution of eosin. They are remarkably insoluble in chlor-iodide of zinc, and in sulphuric acid unless very concentrated. Cryptogamia Vascularia. Apical Growth of the Root of Todea.*—M. P. Lachmann finds in the roots of Todea barbara a group of four initial cells, each with the form of a prism or of a four-sided truncated pyramid. The secondary roots proceed from a single cell of the endoderm of the adventitious roots, but in these also there is formed at an early period a group of four initials lying in a cross. The author regards this as establishing an additional point of union between the Osmundacea and Marattiacez. Prothallium of Lycopodium.t—Dr. H. Bruchmann points out a remarkable difference between the prothallium of Lycopodium anno- tinum, observed by Fankhauser and himself, and that of LD. cernuum, described by Treub. The latter is an erect cylindrical body growing above the surface of the soil and containing chlorophyll, with a leaf- like rim, beneath which are the archegonia and antheridia. The former is a prostrate underground tuber, entirely destitute of chloro- phyll, and bearing antheridia and archegonia on the surface of special cushions inclosed by the margin of the prothallium. Neither form appears to be in any way abnormal, and the explanation suggested is that the European club-mosses have one type of prothallium, the tropical species another. Another peculiarity of the prothallium of Lycopodium, as observed both by Treub and by Bruchmann, is the constant presence in its cells of an endophytic fungus, apparently an undescribed species of Pythium, resembling that described by Sadebeck in the prothallium of Equisetum. It appears to exercise very little injurious influence on the tissues. Bodies which were probably oogonia were detected by Bruchmann in some of the cells. Spores of Lycopodium.t— Mr. D. H. Galloway has made some measurements of the spores of Lycopodium, with the following results : He made careful measurements of 50 spores and found their average diameters to be 7/6000 in., the largest having a diameter of 8/6000 in., and the smallest 6/6000 in. It would therefore take 857 of them * Bull. Mens. Soc Bot. Lyons, 1884, pp. 42-4. See Bot. Centralbl., xxi. (1885) p. 354. + Bot. Centralbl., xxi. (1885) pp. 309-13. See this Journal, ante, p, 277. ¢ Bull. Torrey Bot. Club, xii. (1885) pp. 55-6, from ‘ Western Druggist.’ 312 840 SUMMARY OF CURRENT RESEARCHES RELATING TO laid side by side to make an inch in length; to cover a square inch 734,449 would be required; and to fill the space of a cubic inch 629,422,793. Or in terms of the metric system, a row 1 em. in length would contain 343 spores; a sq. cm. 117,649, and a c.cm. 40,353,607. On measuring the capacity of one of Powers and Weightman’s dram morphine bottles he found that it was almost exactly 40 c¢.cm., there- fore one of the bottles would contain 1,614,144,280 of these spores. The same bottle will hold 10,600 flax seeds, 350 cubeb berries, 250 grains of allspice, 66 Cocculus Indicus seeds, 20 nux vomica seeds, 200 canary seeds, 8400 dill seeds, 2900 grains of paradise, 1250 hemp seeds, 500 black pepper berries, 661 white pepper berries, 8250 stramonium seeds, and 100 pumpkin seeds. It will thus be seen that one hemp seed equals in size 1,291,315 lycopodium spores. Node of Equisetum.*—Mr. A. A. Crozier describes the structure of the node of Equisetum arvense. If a section is made lengthwise through a node of a fertile stem, each vascular bundle is seen to divide into two parts, each part uniting with a corresponding part of an adjacent bundle to form one of the bundles of the next internode. If the section be made radially through one of the teeth of the sheath or rudimentary leaves, a bundle is seen to pass down and unite in the node with one of the bundles of the stem. The bundle of the leaf is derived not by a simple separation of a portion of the outer phloém, part of the bundle in the stem, but originates where that bundle begins to divide, and in such a manner that its vessels are continuous with the xylem of the divided bundle. Each bundle of the stem, therefore, divides at the node into three parts—two lateral portions, each with xylem and phloém, which by rearrangement continue the bundles of the stem, and a central part which bends outward into the leaf. Muscines. Development of the Sporangium of Frullania. j— M. Leclere du Sablon describes the development of this organ in the case of F. dilatata. In an early stage the organ is composed of cells more or less square and arranged regularly in two different directions. The upper part consists of two layers of cells forming a somewhat hemispherical surface, beneath which is the essential part of the sporangium, viz. a somewhat fusiform row of eight cells, distin- guished by larger nuclei, and by their protoplasm being denser and _ taking a darker stain from hematoxylin. These are the source of both the spores and the elaters. Hach of these cells divides into four by two vertical walls; the subsequent divisions being in a transverse direction. Ata later period the nucleus is seen to divide in some of these cells, but not in others; and in such a way thata cell of each kind in one row alternates regularly with cells of the other kind in the adjacent rows; both kinds at the same time increasing in length. Those which do not divide are the mother-cells of the elaters; those - * Amer. Naturalist, xix. (1885) pp. 502-3 (2 figs ). + Bull. Soc. Bot. France, vil. (1885) pp. 187-91. ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 841 which do divide give birth to the mother-cells of the spores. In the formation of the latter no cell-wall is formed between the daughter-cells, which are separated only by mucilage; and this process is repeated many times; this gelatinous substance surrounding the mother-cells like a true membrane. Finally the spores surround themselves by a thick membrane. The elaters are also at an early stage surrounded by a thin gelatinous membrane like that of the spores; their proto- plasmic contents gradually diminish, and are at least partly con- sumed in the formation of the spiral, the development of which resembles that of spiral vessels as described by Strasburger. By the time this spiral is completely developed, the protoplasm in the interior of the elater has entirely disappeared. Trochobryum, a new genus of Mosses.*—Herren J. Breidler and G. Beck give the following diagnosis of this new genus of Seligeri- acez :—Dwarf plants, with the nearest affinity to the genus Seligeria. Leaves loosely areolated from a short base, subulate, with a long projecting mid-rib. Capsule seated on a thick seta, sub-spherical, thick-walled, with a short indistinct neck, depressed when dry ; sub- disciform or of a shallow funnel-shape when the operculum is removed. Peristome-teeth 16, equidistant, hygroscopic, rather broad, without any dividing line. Operculum adnate to the columella, apiculate. Calyptra hooded. The only species, T. carniolicum, is from calcareous rocks in Carniola. Alge. Physiological Anatomy of Alge.j—Herr N. Wille has made observations on the elasticity of the tissue of the larger marine alge, by means of which they are able to resist the traction and other distorting forces of large waves. The faculty of stretching he found to be very considerable in the larger Floridew, and still greater in the Laminariex, varying from 25 per cent. in Porphyra vulgaris to 48 per cent. in Laminaria flexicaulis. 'The “leaves” of seaweeds are almost invariably flexible ; while on the other hand, the “stem” may have considerable firmness; and this firmness may be imparted in three different ways, viz. :—(1) by the whole of the interior being occupied by strongly thickened cells, as in Ahnfeltia plicata ; (2) by incrusta- tion, as in Corallina officinalis; (3) by columnar haptera, as in the Laminariew, where the walls of the outer cells are more strongly thickened than those of the central cells. Contrivances to prevent traction are very common. The cell-walls towards the base of the stem are thicker in Chorda filum, while this organ itself is stouter in Polysiphonia. Rhizines are formed for the same purpose outside the membrane of the mother-plant, consisting of single rows of cells in Cladophora ophiophila, of plates of cells in Monostroma orbiculatum ; or within the mother-plant, of rows of cells in Cladophora rupestris and Bangia, of plates of cells in Porphyra * Verh. K. K. Zool.-Bot. Gesell. Wien, xxxiv. (1885) pp. 105-6 (1 pl.). + SB. Bot. Sallsk. Stockholm, Nov. 19, 1884, Sce Bot, Centralbl., xxi, (1885) pp. 282 and 315, 842 SUMMARY OF CURRENT RESEARCHES RELATING TO vulgaris. ‘‘ Hyphe” for a similar purpose occur in the stem and mid-rib of the leaf in Fucacew. Strongly thickened mechanical cells are found in the centre of the organ in Odonthalia dentata, or forming a ring round the conducting tissue in Cystoclonium purpurascens. The vegetative branches are matted together into a felt-like structure in Ectocarpus tomentosus. Finally certain branches develope into a kind of tendril embracing other alge, as in Cystoclonium purpurascens var. cirrhosa. The same purpose is served in other ways by the whole thallus being expanded flat or united into a cushion, mucilaginous in Calothrix scopulorum, incrustaceous in Melobesia, or enveloped in a mucilaginous envelope in Nemaleon multifidum. The stem creeps and is fixed by haptera in Polysiphonia rhizoides; or the alga grows up among other more resistant species, by which it is protected, as for example Ascophyllum bulbosum. The assimilating cells are distributed over the surface of the organ ; but are sometimes, as in Chordaria flagelliformis, arranged in radial rows. The conducting system consists largely of long and narrow hyphe, the transverse walls of which are swollen quite after the manner of sieve-tubes and perforated by extremely fine orifices; and these conducting hyphs are in communication throughout the plant. New Epiphytic Floridea.*— Herr M. Mobius describes a minute epiphytic alga found on preserved specimens of Centroceras clavulatum (Ag. MS.) from Western Australia. It occurs on speci- mens from this locality only, and only on the tetrasporangia, in the form of a large central cell enclosed in a small-celled tissue. In the latter are found not only male and female organs, but also tetraspores, all on different individuals, but closely packed together on the same host. For this epiphyte the author proposes the name Episporium Centroceratis. ‘The tetraspores are formed from simple swollen ter- minal cells, and are dispersed in large numbers among the superficial vegetative cells. They arise by tetrahedral division, and form a body of about 0:016 mm. diameter. The female specimens put out nume- rous trichogynes, but the development of the carpogenous cells and cystocarps is difficult to follow. The trichogyne is often of con- siderable length, and is seated on a trichophore composed of two or three smaller cells, which appear to arise from some larger carpo- genous cells. The male individuals are densely covered on their surface by minute cells, about -003 mm. in diameter, the antheridia, which spring singly or in pairs at the apex of a terminal cell of the thallus. While the form of the male and female organs of Hpisporium resembles in its general features that of other Floridex, the structure of the thallus differs so widely from any hitherto known that it must be regarded as the type of a new section. Conjugation of Rhabdonema arcuatum.{—Mr. T. H. Buffham describes the phenomena noticed in the process of conjugation of * Ber. Deutsch. Bot. Gesell., ili. (1885) pp. 77-80 (1 pl.). + Journ. Quekett Micr. Club, ii. (1885) pp. 131-7 (2 pls.). ZOOLOGY AND BOTANY, MICROSCOPY, ETO. 843 Rhabdonema arcuatum. The following are the salient features :— (1) The male frustules are the smaller in size, have the more definite arrangement of endochrome, and are the more readily detached. (2) The female frustules have slightly longer valves, more numerous annuli, and have always a wide band near the middle. (8) Conjuga- tion is always polyandrous, and is effected by the male frustules attaching themselves indifferently to any part of the annuli of the female frustule. (4) The result of such conjugation is the production of one sporangial or zygospore-frustule if only the basal half of a female frustule persist; but if both halves persist, each will produce a sporangium—the two sporangia being in close apposition. (5) The sporangial or zygospore-frustule consists of two valves, without annuli, which have a length about thrice that of the valves of the female. With regard to the inducing causes of conjugation, it would appear that self-division, which gradually reduces the size of the bounding valves, has gone on so long that a new generation becomes necessary to maintain the size. Sections of Diatoms from the Jutland “ Cementstein.” *—M. W. Prinz criticizes at some length the opinions expressed in recent papers by MM. Grunow, Deby, Cox, and Fldégel, calling in question the results of the researches undertaken by M. Van Ermengem and him- self concerning the structure of the valves of diatoms. He also describes from both a geological and a petrological point of view the Jutland “‘ Cementstein,’ and the mode of occurrence in it of the diatoms as well as their state of preservation, which he maintains is one of absolutely perfect integrity. The question of illusory images and the visibility of the perforations of diatoms in the sections is discussed, with some observations on perforated and imperforated diatoms found in the rock. He also draws attention to a singular imperforate organism which, according to Dr. Van Heurck, is probably not a diatom, though, like certain diatoms, it is composed of two unequal valves fitting into each other. Phytophagous Fishes as Disseminators of Algx.t—Sig. A. Piccone finds in the digestive organs of Box Salpa, portions of as many as eighteen species of seaweed, some of them in a fruiting condition, the spores or conceptacles of which are evacuated with the feces ; and he concludes that this is of great importance in the dissemination of the species concerned. Lichenes. Formation of Thalli on the Apothecia of Peltidea aphthosa.t— Dr. M. Finfstiick describes specimens of this lichen from various localities in which the apothecia, when they had attained a certain stage of development, were covered on their back by small, wrinkled thallus-scales. A transverse section through an apothecium in which these scales had not yet made their appearance, reveals, in the medul- * Bull. Soc. Belge Mier., xi. (1885) pp. 147-93 (4 pls.). + Nuov. Giorn. Bot. Ital., xvii. (1885) pp. 150-8. } Ber. Deutsch. Bot. Gesell., ii. (1884) pp. 447-52 (1 pl.). _ B44 SUMMARY OF CURRENT RESEARCHES RELATING TO lary tissue beneath the fructification, scattered groups of gonidia which are larger and of lighter colour than the normal gonidia of the thallus, and which might easily be mistaken for cephalodia. They are, in fact, derived from the normal gonidial layer, and, under favour- able conditions, become gradually transformed into the scales in question. They should strictly be regarded as a part of the fructi- fication. In Peltidea aphthosa the apothecia have a different origin from that in the nearly related genus Peltigera, viz. from immediately beneath the gonidial layer. The endogenous origin of this peculiar thallus-formation can be proved by following it out from the first isolation of the gonidia to their complete differentiation into cortical, gonidial, and medullary layers. No similar formation was observed in Peltidea venosa. Fungi, Thermotropism of the Roots of Athalium septicum.* — Dr. J. Wortmann has further investigated this phenomenon, first observed by Stahl, and finds the optimum temperature for its manifestation to lie between 35° and 40° C. With exposure to unequal temperature above 86°, he finds the plasmodia to be negatively, while below this limit they are positively thermotropic; both kinds being thus capable of being induced on the same plasmodium. This phenomenon he com- pares to that of Phycomyces, the fructification of which is negatively, while the mycelium is positively geotropic. The thermotropic pheno- mena of plasmodia are closely analogous to those of roots. Plasmodiophora Alni.j—Dr. H. Moller has further investigated the peculiar swellings caused by this parasitic fungus (Schinzia Alm Wor.) on the roots of the alder, which he finds on almost every specimen examined of both Alnus glutinosa and incana. The proto- plasm of the parasite is imbedded in a sac of the protoplasm of the host, and this protoplasmic envelope is connected by several strings with the parietal protoplasm. The protoplasm of the host remains comparatively unaffected; and hence the small amount of damage done by the parasite. Both in this and other points, the physiological processes present a great resemblance to those of Plasmodiophora Brassice. Nutrition of Trees by means of Underground Fungi.j—Herr B. Frank has made the remarkable discovery that the roots of certain trees are unable to derive nutriment directly from the soil, but do this entirely by means of a mass of fungus-hyphe which entirely invests the root, and to which he gives the name Mycorhiza. If the absorbing organs of our native oaks, beeches, hornbeams, chest- nuts, or hazels are examined, they are found to consist of a nucleus, the true root, and a cortex organically associated with it in growth, composed entirely of fungus-hyphz, completely enveloping the whole * Ber. Deutsch. Bot. Gesell., iii. (1885) pp. 117-20. + Ibid., pp. 102-5 (4 figs.). See also pp. 177-8. t Ibid., pp. 128-45 (1 pl.). ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 845 of the root, even the growing point. The structure of this latter is that of a sclerotium ; it is composed of a dense mass of hyphe varying in diameter from 0-0024 to 0-01 mm., usually in several layers, from which other endophytic hyphe penetrate into the root between the epidermal cells, which are still slenderer than those of the envelope. By this structure the formation of root-hairs by the tree is entirely prevented, and it is through it alone that it is able to absorb nutri- ment out of the soil. It makes its appearance first on the lateral roots of very young seedlings, and is constantly being replaced by fresh formations on older roots. Dr. Frank found this structure invariably on every root examined on every tree belonging to the Cupulifere, also occasionally on Salicacez and Conifers, but never on woody plants belonging to other natural orders, or on any herbaceous plants. It is quite independent of the nature of the soil, and its specific character has not been deter- mined. He regards the phenomenon as an example of symbiosis comparable in all essential points to that of lichens, the mycorhiza corresponding to the fungal element in the lichen, the tree itself to the algal gonidia. Dr. M. Woronin * confirms these statements in relation to Conifera, Salicinew, and some other trees. He regards the phenomenon rather as an instance of parasitism than of symbiosis, and thinks it probable that the parasitic fungus is a Boletus. He claims the priority of this observation for F, Kamienski. Composition and Spore-cultivation of Merulius lacrymans.j— Prof. Poleck has investigated the mode of operation of the mycelium of this fungus, which, known as dry-rot, is so destructive to timber, especially that of Conifers. The proportion of water varies from 48 to 68-4 per cenit. The amount of ash is large, varying from 6°33 to 9°66 per cent. The composition of this ash varies within rather wide limits; but there was always found a large proportion of phosphates. As an average it may be stated that of the dry weight about 4°9 per cent. is nitrogen, and 13 per cent. oil; there are also several acids and traces of an alkaloid. The author states that the action of the mycelium on the wood consists in removing its mineral constituents, thus destroying its solidity, and rendering it liable to the attacks of other agents. The richer the wood in phosphoric acid and salts of potash, the more energetically is it liable to be attacked by the fungus. When once desiccated the mycelium has no power of resuscitation. Mycelial filaments have been measured from 5 to 6 metres in length. Prof. Poleck has been the first to succeed in inducing the spores of Merulius lacrymans to germinate on their natural substratum, and to follow out their development, which is described in detail. Germination of the Spores of Merulius lacrymans.t—Prof. R. Hartig has been able to effect this in gelatin moistened with the * Ber. Deutsch. Bot. Gesell, iii. (1885) pp. 205-6. + Bot. Centralbl., xxii. (1885) pp. 151-6, 182-6, 213-7 (2 figs.). _ Bot. Ver. Miinchen, Dec, 10, 1884. See Bot. Centralbl., xxi. (1885) p. 155. 846 SUMMARY OF CURRENT RESEARCHES RELATING TO juice of fruit with addition of urine or of ammonia and potassium carbonate. He notes also the absorption of the mineral constituents of the walls of the wood-cells when in immediate contact with the hyphee of the fungus, while the organic constituents are dissolved only by the ferment excreted. New Chytridiacese.*—Since publishing his monograph of the Chytridiacez,} Dr. C. Fisch has observed two new forms, one of which deviates in several particulars from the typical structure of Chytridium. It was found as a parasite on Mesocarpus, in the form of small flask- shaped brownish receptacles, in length about half the diameter of the Mesocarpus-filament. 'These are zoosporangia, with brownish thick wall, not coloured by iodine. From the point of attachment to the host proceeds an extremely fine mycelial filament, which penetrates the Mesocarpus-cell, usually only reaching about its centre. The contents of the zoosporangium consist of rather coarse-grained proto- plasm, in which no nucleus was detected. The formation of the zoo- spores is preceded by various changes in this protoplasm. 'The zoo- spores are rarely more than eight in number, and agree in their structure with those of Reessia. They are rather large, composed of finely granular protoplasm, imbedded in which is an evident nucleus or nuclear structure. A single cilium springs from the somewhat narrower anterior end. These zoospores move about rapidly in the sporangium before the latter suddenly bursts by the separation of a circular lid. After moving about rapidly for a considerable time in the water, a pair of zoospores approach one another by their ciliated ends, and coalesce completely. The resulting zygote contains at first two nuclei, which soon coalesce into one. It then surrounds itsclf with a cell-wall, and attuches itself to a Mesocarpus-filament. By means of a small appendage which pierces the wall of the host-cell, the zygote empties its contents into the latter, and rapidly grows to a large cell with membrane in two layers, the typical resting-spore of Chytridium. These germinate after a short period of repose, and again produce ZOOSPores. The second new species is a Reessia, near to R. ameboides, and parasitic on a large Cladophora. The three genera Reessia, Chytridium, Rhizidium, present a series in which the first species here described, perhaps the type of a new genus, presents a connecting link. It is a typical Huchytridium, in which the sexual function has not been lost. In the form and be- haviour of the zoospores it is closely allied to Reessia ; while in the structure and germination of the resting-spores, and in the develop- ment of the zoosporangium and of the mycelial appendage, it is a typical Chytridiwm. Nowakowskia, a new Genus of Chytridiacee.t —Sig. A. Borzi finds a parasitic fungus on Hormotheca, a new genus of alge, in such * SB. Phys.-med. Soc. Erlangen, xvi. (1884) p. 101 et seg. See Bot. Centralbl., xxi. (1885) p. 167. + See this Journal, iv. (1884) p. 938. t Bot. Centralbl., xxii. (1885) pp. 23-6 (1 pl.). ZOOLOGY AND BOTANY, MICROSCOPY, ETO. 847 quantities as completely to destroy it, and proposes for it the name Nowakowskia Hormothecee. It lives on the germinating zoospores of its host, the contents of which it appropriates by means of very slender rhizoid-like appendages, usually 3-5 in number, attached to its peri- phery. It grows free in the surrounding medium in the form of a small ball of greyish protoplasm, inclosed in a delicate membrane which is coloured blue by tincture of iodine. The protoplasm is of a very finely granular structure, is stained yellow by picric acid, and contains minute strongly refractive corpuscles. ‘The size of these bodies varies considerably, from 4 to 6. The rhizoid-like append- ages are extremely delicate, and only visible under a high power, and appear to be composed of dense, homogeneous, strongly refractive protoplasm, extremely receptive to pigments, without, as far as could be detected, any membrane. The development of Nowakowskia is extremely simple, and closely resembles that of Polyphagus Euglene. After absorbing a sufficient amount of food-material by means of its appendages, and attaining its full size, it transforms itself directly and completely into a zoospor- angium ; the zoospores being formed by the appearance of a number of shining spherical particles, round which the whole of the proto- plasm collects and breaks up into as many minute portions. As soon as the zoospores begin to be formed, the wall of the zoospor- angium begins to be absorbed and become indistinguishable, finally disappearing altogether, and the mass of zoospores then swarms in the fluid, without the individuals at first separating from one another, the motion resembling that of a colony of Volvox. The zoospores, which do not exceed 1 » in their longest diameter, finally separate ; their form is then somewhat hourglass-shaped, rounded at both ends and somewhat constricted in the middle. In the anterior end, which terminates in a single very long and extremely slender cilium, is a drop of oil. After moving about very actively for a few minutes, the zoospores come to rest. They germinate free in the water, and only reach their host by putting out in its direction the very fine rhizoid- like appendages. ‘The entire transformation into a zoosporangium occupies from four to six hours. No sexual reproduction could be detected with certainty. Borzi considers Nowakowskia as most nearly related to Obelidium and Rhizidiwm on the one hand, to Polyphagus on the other hand. New Fungus-parasite on the Rose.*—Herr J. Eriksson describes a disease to which Rosa rubrifolia is subject in the neighbourhood of Stockholm, due to the ecidial form of Phragmidiwm subcorticum, which attacks the leaves, leaf-stalks, and flower-stalks of both first and second year's shoots, The mycelium appears to hibernate in the stem. Mycological Monstrosities.t—M. E. Heckel describes two cases of monstrosity in fungi. In the first case, a specimen of Lactarius delicioeus, the margin of the pileus was non-adherent to the stem at * SB. Bot. Sallsk. Stockholm, Sept. 27, 1884. See Bot. Oentralbl., xxi. (1885) p. 221. + Comptes Rendus, xcix. (1884) pp. 1088-90. 848 SUMMARY OF CURRENT RESEARCHES RELATING TO only one point of the periphery ; throughout the rest of its circum- ference it formed one substance with the stem. The normal hymenial lamellz were entirely suppressed, while the hyphe of the pileus bore the lamelle united into a compact mass by their free margins and by several points of their parallel faces ; thus leaving between them free spaces, few in number, in which the terminations of the hyphz were crowned by perfectly normal spores. The cavities being closed-in, dissemination of the spores was absolutely impossible. The second instance was Polyporus betulinus. Composed of two parts dissimilar in appearance and specifically distinct, although juxta- posed on the same plane and united at their margins, the monstrosity is formed by a single pileus whose substance has been constricted at one point. Whilst the second part is perfectly normal, the first presents a singular teratological alteration. Both the surfaces are covered with spores. On the upper surface the tubes are long and inclined, with denticulated and torn edges. On the lower surface, they are vertical and short; both bear normal spores. The former disposition of the tubes evidently has for its object a more éfficacious protection of the spores which are more exposed to exterior agencies. This monstrosity is of double interest: first, it testifies to the experi- mental value of researches into the abnormal formation of spores; second, it shows that fungi, even of the higher orders, are endowed with great plasticity of form, receiving promptly the impression of the plexus of surrounding forces. Some Remarkable Moulds.*— Dr. M. C. Cooke gives full de- scriptions of some remarkable moulds, brief diagnoses of which have been previously published,} viz.:—Basidiella sphxrocarpa Cooke; Sterigmatocystis ferruginea Cooke, and Aspergillus nigricans Cooke. He also describes Polyactis depredans Cooke MS8., that grows on the leaves of Acer pseudo-platanus, and Polyactis truncata Cooke,{ likewise previously described. Pneumonomycosis of Birds.§—Hearing that near Berlin many geese were dying of a disease the duration of which was short and the cause unknown, Dr. Schiitz requested the owner of the birds to send a body for examination. This disclosed a pneumonomycosis. Its specific nature was determined by breeding at temperature of 30° C. on bread-paste. The usual precautions were taken, and in 24 hours a layer of Aspergillus fumigatus was formed. In the subsequent inoculation process it had to be borne in mind that at the post-mortem examination the crop was found to be in direct communication with a cavity in the right lung, hence the original infection focus could only be determined by experiment. The fungi were bred in agar-agar and in bread-paste at a temperature of 30°. The usual sterilizing pre- cautions were taken, and in four days a luxuriant fungous growth * Journ. Quekett Micr. Club, ii. (1885) pp. 138-43 (2 pls.). + Grevillea, vi. pp. 118 and 127, viii. p. 95. + Bommer’s ‘ Champignons de Bruxelles,’ p. 137. § MT. Reichsgesundheitsamte, ii. (1884) p. 208. ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 849 appeared. The fungi thus obtained were mixed with (a) soft bread and with (6) dry oats. The bread was given to pigeons, the oats to geese. The pigeons were fed by stuffing a piece of the bread mixed with fungus down their throats for six consecutive days. The geese were allowed to dispose of as many infected oats as they pleased. The first goose died on the sixteenth day, and as no result was evident on post-mortem examination, recourse was had to infection by inhala- tion. The Aspergillus fumigatus grown in the flasks was dried under a bell-jar and then placed in a glass vessel inside which a pigeon could stand easily. The glass jar was shaken several times in order to raise a cloud of the fungi. The pigeon died on the third day. From the diseased parts of the lungs of this pigeon bread-paste was inoculated and Aspergillus fumigatus appeared. The remaining parts of the lungs were hardened, and on microscopical examination an extraordinary quantity of the fungus was found. In further experi- ments only a few spores were introduced into the glass jar and the pigeon was only allowed to remain five minutes. Under these con- ditions the animal did not die so soon, and the fungi spread from the lungs to other organs. Exactly the same results ensued when small birds were used. Aspergillus niger gave similar results, A. glaucus only acted as a foreign body in the lung. Protophyta. Ferments.*—Dr. E. C. Hansen publishes a few further observations on the development of Saccharomyces. Under certain conditions structures arise consisting of a gelatinous network in the spaces of which the Saccharomyces-cells are found ; but they are sometimes taken up into the network itself, which is not coloured blue by iodine. This occurs not only in both forms of S. cerevisiz, but also in species belonging to the groups Pastorianus and ellipsoideus. 'The yeast used for the observation of this structure was obtained from pure cultures in sterilized nutrient solutions, beer-wort, ora mixture of saccharose and yeast-water; but it occurs also in practice in breweries. When the spores in a Saccharomyces-cell are preparing for ger- mination, they swell up strongly. In certain species, when cultivated on blocks of gypsum, structures arise which present the appearance of septa. These are caused by the pressure which the swollen spores exercise on one another ; the walls being brought into close combina- tion with one another at the surfaces of contact. S. apiculatus, although a ferment of alcoholic fermentation, is destitute of invertin, and cannot therefore ferment saccharose. Its ordinary habitat in summer is ripe fruits, and it is the only ferment that ir found in nature. It appears to perish in less than twenty-four hours vhen removed from its nutrient substratum. Microphytes of Normal Human Epidermis.|—Prof. G. Bizzozero describes various methods for observing the microphytes of the human * Bot. Centralbl., xxi. (1885) pp. 181-4. + Arch, Ital. de Biol., vi, (1884) pp. 194-206 (1 pL). 850 SUMMARY OF CURRENT RESEARCHES RELATING TO - epidermis, and gives an illustrated account of such parasites as he has observed. The parts of the body covered with hair are the most favourable localities for the growth of these organisms, of which three different kinds were noted. (1) Round cells, composed of a thick membrane, enclosing a homogeneous non-nucleated mass, which closely resembles a Saccharomyces, and may be termed S. sphezrica. 2) Oval cells, smaller and paler than the preceding, which are named S. ovalis. (8) Micrococci and Bacteria ; these latter abound in all parts of the body, and characteristic forms are found in different regions, being associated with local pathological conditions. Systematic Position of the Bacteria.*—In a review of recent works on Bacteria, Dr. C. Fisch shows that the assignment of the Schizomycetes to the Fungi does not rest on a sound morphological basis, the physiological resemblance in the absence of chlorophyll not being sufficient of itself to show a genetic affinity. The history of development furnishes conclusive evidence against the Schizomycetes being connected with the Fungi phylogenetically, either as an early form of development or as the result of retrogression. The nearest affinity of the Bacteria lies unquestionably with certain green organisms, Nostoc, Oscillaria, &c., included under the Schizophyces or Cyanophyceex ; and these form together a natural group of Schizo- phyta, with no close affinity to any group of Fungi. According to our present state of knowledge the Schizophyta must be regarded as displaying the nearest genetic affinity with the Flagellata. Influence of Oxygen on Fermentation by Schizomycetes.;— Herr EH. Buchner has experimented on the effect produced by free oxygen on the energy of the fermentation caused by the so-called “ slycerin-ethyl-bacterium,” Bacterium Fitz, distinguished by its very energetic fermentation of glycerin, chiefly into ethyl-alcohol, together with volatile and stable acids, carbon dioxide, and hydrogen. Three cultures of this ferment were prepared, one of which was retained asa control experiment, while through the other two streams of oxygen and hydrogen respectively were passed. After twenty-nine hours the fluid through which the oxygen had been passed was considerably more turbid than the two others. Microscopical examination showed the following results. The multiplication of Bacterium Fitz is pro- moted to an extraordinary degree by the presence of free oxygen. In cultures of the same extent and in the same time, the quantity of glycerin fermented is increased. Whether oxygen or hydrogen is passed through the culture, the formation of carbon dioxide given off remains nearly the same in proportion to the amount of glycerin fer- mented. The fermenting power of the individual Schizomycete is diminished by the presence of free oxygen. Cholera Bacillus——Mr. W. W. Cheyne gives{ the results of his investigations at Paris during the epidemic of cholera, and afterwards * Biol. Centralbl., v. (1885) pp. 97-102. + SB. Bot. Ver. Miinchen, Jan. 14, 1885. See Bot. Centralbl., xxi. (1885) pp. 348 and 385. ; + Brit. Med, Journ., 1885, April 25-May 23. ZOOLOGY AND BOTANY, MICROSCOPY, ETO. 851 at his own laboratory. His conclusions are, that the comma bacillus was present, and generally in large numbers, in all the cases of cholera which were examined ; that he has never met with the comma bacillus except in cholera, and that the other curved bacilli described (Finkler and Prior’s, Lewis’s, and Denike’s or Fliigge’s), differ from it in important particulars. Mr. Cheyne also combats Klein’s arguments against the specific nature of the comma bacillus. Dr. E. Van Ermengem has also published an elaborate report * to the Belgian Minister of the Interior, which is the most exhaustive that has yet appeared. He supports Koch’s assertions. Etiology of Tuberculosis.;—Dr. R. Koch sums up the results on this subject obtained by himself and others, adding some new observations. The best mode of detecting the bacillus of tuberculosis is by the staining reaction with anilin according to the methods of Ehrlich and Rindfleisch. There is no other kind of bacterium with which it agrees in this respect except the lepra-bacilli, and from them it is distinguished by not taking up Weigert’s nuclear-staining. The variability in the behaviour of this bacillus with staining reagents Dr. Koch believes to result from its being surrounded by a very thin envelope. The separate individuals of the bacillus of tuberculosis are long very narrow rods, with no segmentation of any kind, but often with slight angles and curvings, and a tendency to spiral twisting, by which they are distinguished from many other bacilli otherwise resembling them in form, such as those of the septicemia of mice. They occur within the cells of the tubercular nodules; only in small numbers in the cheesy substance. The formation of spores is very frequent. When spores are about to be formed, the bacillus does not break up into separate segments, but from two to six ovate spores are formed in each, distinguished by their high refractive wer. a Dr. Koch found the bacillus in the bodies after death of patients who had suffered from every kind of tubercular disease; and in especially large numbers in the sputum, where the formation of spores is particularly abundant, and where it retains its vitality for an extraordinary period. It occurs also in the excreta both of men and animals suffering from tubercular disease. The culture of the bacillus of tuberculosis was carried out success- fully on the solidified serum of the blood of oxen at a temperature of 37° ©. The following are mentioned as special characters under cultivation :—(1) It does not cause the serum to deliquesce; (2) it spreads itself over the surface, lying loose upon it ; (3) the individuals attach themselves to one another in large masses, which fall to the * Ermengem, E. van, ‘ Recherches sur le Microbe du Choléra Asiatique,’ Mém. Soc. Belge Micr., x. (1884) pp. 1-342 (13 pls.). t MT. K. Reichsgesundheitsamte, Berlin, ii, (1884) pp. 1-88 (10 pls.). See aaa xxi, (1885) p. 235. Cf. this Journal, ii. (1882) p. 385; iv. (1884) Pp. . 852 SUMMARY OF CURRENT RESEARCHES RELATING TO bottom; (4) the nutrient fluid always remains clear; (5) under low - powers the young culture appears S-shaped and strongly swollen in the middle. It grows on all kinds of serum, but not on the white of egg. Dr. Koch regards the bacillus of tuberculosis as a true parasite, in contrast to other pathogenous bacteria. It goes through its whole course of development, up to the production of spores within the body. He believes it has no genetic connection with any other form of bacterium. Development and Pathogenous Properties of a Bacterium.*— Herr G. Hauser describes a pathogenous bacterium obtained from the putrefaction of a calf’s heart at 30° C. under ordinary conditions. An infusion after eight days showed a great quantity of bacteria, which, however, when cultivated in the ordinary way, did not exhibit any great power of causing deliquescence of the substratum. After exposure for another eight days to the ordinary temperature of a room there appeared in the infusion a bacterium which grew with extraordinary rapidity, causing rapid deliquescence of the gelatin on which it was cultivated. After cultivation on gelatin for twelve hours, a great quantity of small oval bacteria were to be seen floating on the substratum, often linked together in pairs; the whole of the rest of the surface being completely covered by colonies of irregular form consisting of a single layer of well-developed rods and short filaments. These colonies were in continual rapid motion, some of the rods constantly leaving them in the form of an elongated well-defined group, which glided rapidly over the free surface of the gelatin, then joining with others or with another colony. Hach of these groups consists of from three to five parallel rows of spindle-shaped rods. Their movements are very peculiar, resembling those of individual bacteria, and are in no way due to motions in the substratum. Other groups again did not become separated, but reunited themselves with the colony from which they had partially detached themselves. The deliquescence of the gelatin by these bacteria took place very rapidly, being completed in from twelve to twenty-four hours, with the formation of a whitish sediment. In this condition it contained a number of minute bacteria endowed with a dancing movement, and closely resembling Bacterium Termo. When cultivated on gelatin, these developed gradually from shorter to longer rods and filaments, which swarmed over the entire surface of the nutrient gelatin, causing it to deliquesce. From these swarming colonies were developed longer filaments endowed with rapid motion, which gradually divided into shorter elements, and finally came to rest, passing then into an hour- glass-like form, from which were developed the peculiar colonies already described. This peculiar bacterium causes very rapid decomposition in the flesh of animals, accompanied by the development of stinking gases ; the products of decomposition appearing to have poisonous properties. * SB. Phys.-med. Soc. Erlangen, 1884, pp. 156-71. See Biol. Centralbl., v. (1885) p. 36. ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 853 Cornil and Babes’ “ Bacteria.’”’**— With the object of presenting all the researches upon the bacteria in their proper light, the authors have produced a profusely illustrated book, containing all that is known in regard to Bacteria at the present time. The work begins with an introduction to the study of the pathogenic Bacteria, and a rapid summary of the beginning and progress of discovery in this direction is given. This is of special value to the student because of the copious references to original monographs that are made. The development of the Microscope for work of this kind, the discussions as to the specific nature of infectious disease, and the criticisms which bacteriology has undergone, are reviewed, and this is followed by the first part of the book proper. This is devoted to a consideration of the Schizomycetes in general. The various forms of the organisms are given and illustrated, and their methods of growth are treated at length. A full account of all the instruments and materials necessary for work in the observation of Bacteria, with the methods of employ- ment, renders this part of the subject plain, while the discussion of the anilin colours conveys information not easy for the student to obtain elsewhere. The methods of culture are given in full. . The classifications of Cohn, Van Tieghem, and Rabenhorst are spoken of as the latest and best; and a complete list of all the patho- genic Bacteria, with their main characteristics, follows. The bone of contention, “‘ the attenuation of virus,” finds a place, and the various organisms with which experiments approaching success have been made are allowed to tell their story. Then the lesions occurring with the presence of pathogenic Bacteria occupy the authors’ attention ; and the modes of entrance, and disturbances of circulation and nutri- tion produced by them, are all placed before the reader in the plainest way. A discussion of the “ experimental maladies ” of Koch and others closes the first part of the work, which is followed by a complete bibliography of the important works upon Bacteria in general. The second portion of the book is devoted to the special infectious diseases. Beginning with chicken-cholera and ending with leprosy, the results of all the investigations upon any disease suspected to be due to a micro-organism are dealt with in the most impartial manner. This includes not only the diseases of man, but also those of animals concerning which any evidence of their bacterial origin has been offered. * Cornil, A. V., and Babes, V., “Les Bactéries et leur réle dans l’anatomie, et Vhistologie pathologique des maladies infectieuses, viii. and 696 pp., 27 pls. and figs., 8vo, Paris, 1885. t Cf. Science, vi. (1885) pp. 77-8. Ber. 2.—Vou. V. 3 854 SUMMARY OF CURRENT RESEARCHES RELATING TO MICROSCOPY. a. Instruments, Accessories, &c.* Deby’s Twin Microscope.— Mr. J. Deby, C.E., sends us the following description of a new selecting and mounting Microscope devised by him :— “ Being myself in the position of many other lovers of the Micro- scope in regard to the few occasional hours I can find time to spare for its enjoyable employment, I hope I may be rendering a service to some of my fellow-workers by publishing the description of a labour-saving selecting and mounting instrument which I recently designed for the purpose of making the most of my time, and which has been most carefully constructed for me by Messrs. Beck. The Microscope, which I propose to call the “Twin Microscope,” consists of the following parts (fig. 180) :— 1. Two independent parallel tubes attached to the same stage ; the axis of each of the tubes corresponding to the centre of one of the eyes of the observer. Hach tube has its independent rack motion by a milled head. 2. Two mirrors, one for each tube, with swinging bars and usual motions. 3. A fixed stage of large size, with necessary clamps for holding two parallel glass slides, one under each of the tubes. 4, A movable substage, placed immediately below the upper stage, having a considerable range of rectangular mechanical motions by means of two milled heads. 5. A mechanical finger attached anteriorly to the movable sub- stage. This finger is provided with universal motions by a ball-and- socket arrangement. It is suited for carrying a bristle-holder, needle-holder, or small scalpel. A small milled head permits of the rotation of these holders independently of the ball and socket which holds them. 6. Eye-pieces and objectives, either similar or dissimilar, for both the tubes. The directions for the use of the instrument may be summed up as follows :— a. Clamp a slide with the material to be operated upon under. one of the tubes, and clamp another clean slide under the other tube. b. Dissect or pick-up the desired object from slide No. 1 by using one eye only, that over tube No. 1. c. Close this eye and open the other, looking down the tube No. 2. d. Swing the object rapidly round by means of the mechanical finger till it appears under the other eye. * This subdivision is arranged in the following order :—(1) Stands; (2) Eye- pieces and Objectives; (3) Illuminating Apparatus; (4) Other Accessories : (5) Photo-micrography; (6) Manipulation; (7) Microscopical Optics, Books, and Miscellaneous matters. ZOOLOGY AND BOTANY, MICROSCOPY, ETC. Fic. 180. i il Degy’s Twin Microscorr. a eo 855 856 SUMMARY OF CURRENT RESEARCHES RELATING TO e. Lower the object till it nearly touches the slide, and by means of the mechanical motions of the substage place it exactly where it is wanted, when a slight touch at the lever-end of the bristle-holder will deposit it permanently. d. Return the point of the bristle-holder to the first slide, and re- commence the above operations as long as may be desired. Objects may be searched for and selected under a low power, such as a1 in., a 1/2 in., or a 2/3 in., and if very small may be deposited under the other tube under a 4/10 in., a 1/4 in., ora 1/5 in. Those who cannot use their eyes alternately, may shift one eye from one tube to the other with insignificant loss of time. The principal advantages of the instrument consist in the rapidity with which it becomes possible to pick up and put down small objects, and in the great precision of the manipulations. By employing duplicate slides of a same material, one being placed under each of the tubes, it becomes easy to use the Microscope for comparative observations in polariscopy and spectroscopy by adapting the micro- polariscope or the micro-spectroscope to one tube alone, leaving the other to be used as an ordinary monocular Microscope. Many com- parative and biological researches may also be conducted under the Microscope without the need of the frequent changes of lenses and shifting of the slides so irksome in many cases to the working naturalist. For the dissection of minute animals or plants, for histological researches in general, in the hunt for nematodes or other minute forms of life, for the picking-up of desmids, diatoms, protophytes, &c., and for the grouping of these objects easily, rapidly, safely, and elegantly, I believe that the twin Microscope remains as yet unrivalled. I sincerely hope that others may derive as much satisfaction from the use of the instrument as I have myself, and that it may lead to increased results both in useful and in beautiful work.” Klein’s Mineralogical and Petrological Microscopes.*—Prof. C. Klein in the instrument shown in fig. 181, has combined all the most valuable of the recent suggestions for this class of Micro- scope. The body-tube has the arrangement of M. Bertrand’s stand for introducing above the objective a quartz plate, a quarter undulation plate, a Nicol prism, Bertrand lens, &c. The objective can be centered by two screws at the nose-piece. The stand can be inclined, and has both coarse and fine adjustments, the latter reading to 1/500 mm. The graduated stage can be moved in rectangular directions, and the amount of movement read to 1/100 mm. It can be rotated by rack- work or by the hand. The polarizer fits in a tube beneath the stage, and can be adjusted by rack and pinion. Two smaller forms are shown in figs. 182 and 183. * Nachr. K. Gesell. Wiss. Gottingen, 1884, pp. 436-43. The Microscopes are made by Messrs. Voigt and Hochgesang, of Gottingen. + See this Journal, iii. (1883) p. 413, ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 857 Fie. 181. KLEtw’s MINERALOGICAL AND PrrRoLoGIcAL Mioroscorn. 858 SUMMARY OF CURRENT RESEARCHES RELATING TO Fie. 182. Fig. 183. | | | HI | Z ZT vada) CCC EAR TMD NUNIT Wit a CTT i KCNA AMAA) TN i Reichert's Mineralogical-Geological Microscope.—This, fig. 184, in its general features resembles some of the forms already recorded, especially that of Dr. Zeiss. It differs from the latter, however, in the mode in which the quartz plate is inserted above the objective, and in the two millimetre graduations of the stage intersecting in the centre at right angles. The polarizer is on a movable arm so that it can be rapidly turned away. Hach 90° of rotation of the analyser is marked by a spring catch. ZOOLOGY AND BOTANY, MICROSCOPY, ETO. 859 Fic. 184. Reicuentr’s MINEKALOGICAL-GEOLOGICAL MICROSCOPE, 860 SUMMARY OF CURRENT RESEARCHES RELATING TO Watson-Wale Microscope.—Fig. 185 shows a modification of G. Wale’s *“* Working Microscope,” * devised by Messrs. Watson and Sons. Instead of the limb sliding between jaws, as in the original form, the new instrument has a slot cut through the limb, which slides on Fig. 185. the axis of inclination, a clamp-screw fixing it at the required position. The limb may also revolve on the inclining axis without sliding upward or downward, but in this case the instrument is less stable. The “Zentmayer” system of fine adjustment is applied. The stage rotates completely and has a glass surface on which Tighl- * See this Journal, iii, (1880) p. 1045. ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 861 mann’s friction-stage works, and a rotating disk of diaphragms is fitted within the thickness of the stage. A substage-tube is applied beneath by means of a horizontal bayonet-joint. Schieck’s Microscope with Screw Stage-Micrometer.—The micrometer attached to this instrument (fig. 186) differs somewhat from English models in having a rotating plate* for the object, and a Fig. 186. second movement from back to front, actuated by a screw at right angles to the motion of the micrometer-screw. The position of the object to be measured can thus be readily centered when the Microscope has no mecha- nical movements to the stage. The | micrometer-screw registers 1/5 mm. to each revolution of the drum-head, the whole turns being read on an engraved scale on the edge of the moving plate, whilst the drum-head is graduated in 100 divisions, and by means of a fixed vernier tenths of these divisions can be read. (In the fig. one of the clips is shown turned back away from the stage.) Microtome-Microscope. | — “ Mr. “©, P. Hart described [to the Section \Y “of Histology and Microscopy of the . “ American Association for the Ad- “vancement of Science] a clever “manner of making a Microscope into “a microtome, by using the tube to “carry the imbedded object, and the “movable stage to carry the razor; the object to be cut is moved by “the fine adjustment.” Duboscq’s Projection Microscope.{—MM. T. and A. Duboscq describe their apparatus as follows : — “This apparatus consists of a system of lenses, or condenser, to converge the illuminating rays and cause them to pass through an achromatic objective serving to project the images on a screen. The novelty of our apparatus consists in the addition which we have made to the condenser for the projection of microscopic objects. There is a stage furnished with a lens which shortens the focus of the condenser and concentrates the greatest amount of light on the object. * Zeiss’s stage-micrometer (see this Journal, iii. (1883) p. 573) has a rotating plate, and we have seen a similar arrangement to the above on a Microscope con- structed forty years ago by Plossl; we are informed, however, that the plan was originally devised by Schieck. t Science, vi. (1885) p. 228. t+ Comptes Rendus, ci. (1885) pp. 476-7. 862 SUMMARY OF CURRENT RESEARCHES RELATING TO Hitherto, projection Microscopes have given a relatively large magnifying power, but with a definition insufficient for the wants of science. This arises from the quality of the objectives which are employed, and also from the way in which the illumination is obtained. We have recognized that according to the dimensions of the micro- scopic objects to be projected and the magnification desired, it is necessary to vary the form of the convergent pencil which illuminates the object, consequently the focus of the additional lens must be modified. The apparatus is therefore provided with lenses of different foci to be used with the condenser, according to circumstances. We have, morever, arranged to employ the objectives used for ordinary Microscopes. 'Thanks to these and to the perfection of our condensing system we are able to project microscopic objects with high powers and with a clearness as perfect as that obtained with the ordinary Microscope.” Polarizing prisms can be used, also a rotating stage, so that sections of rocks and crystals can be projected. “Twin” Simple Microscope.—Fig. 187 shows a peculiar arrange- ment of two simple Microscopes mounted side by side on one plate. One of them is fitted with a power of about 1 in., and Fic.187. the other about 1/4 inch, and both have Lieberkiihns. The object is held by forceps pivoted beneath the lens- carrier, so that it can be readily examined by either power without having to alter the lenses, as is ordinarily the case. The instrument must have been made a considerable time, for we have seen an exactly similar one in the “(Cabinet de Physique” of the University of Louvain, where we were informed it had been for upwards of 30 years. The workmanship suggests a French origin. Laurent’s Apparatus for registering the Curva- ture and Refraction of Lenses.*—M. L. Laurent’s apparatus consists of a vertical frame B (fig. 188), in which slides a rectangular carrier S controlled by a chain; the position of the carrier is shown by a vernier, and the lenses to be tested are placed on a plate rotating horizontally on the carrier. On the top of the frame is an eye-piece having a diaphragm (shown in front view at D, fig. 189) divided in two parts: the right half is covered by an illuminating prism; its horizontal face is silvered, and squares are ruled on the silver, which are viewed either by refraction or re- flection; the image of the squares is seen in the plane of the diaphragm. A plane plate of glass T is put on the carrier 8, and the vernier is adjusted to zero at the point p where the plane is seen to touch the squares. The lens L is placed on the plane; the light emerging * Comptes Rendus, ec. (1885) pp. 902-5 (4 figs.). ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 863 from the squares traverses the lens, is reflected on the plane and directed upwards again and focused in the plane of the diaphragm. The carrier is moved until the image is seen sharp in the eye-piece, and the focal plane Fic. 188. of the lens L coincides with the plane of the diaphragm; the reading of the vernier is taken, allowance being made for the shape of the lens, its thickness, &e. The image, consisting of luminous lines on a black ground, is easily seen ; the light traverses the lens twice, and doubles its defects. The focus is very precise, so that by covering up portions with small screens, the variations in the curves can be estimated by the differences in their acuteness, and the sharpness will indicate the quality of the lens tested. White or monochromatic light is used for illumination. Reflected light enables each surface to be tested separately, while the estimation of the combination of surfaces Fic, 189, and media is effected by means of the re- fracted image. Instructions are also given for using the apparatus for concave mirrors, diverging lenses, convex surfaces, spheres and cylin- drical surfaces. The author claims that the apparatus is an accurate focimeter, of general application to all curved surfaces; the precision may be carried to a high degree where necessary, and in ordinary cases it provides ready means of seeing at a glance and without preparation the quality of an optical system. Gundlach’s Improved Objectives.* — The Gundlach Optical Company are now making objectives “after the new principle dis- covered by Mr. Gundlach.”f “The water-immersion objectives have a very long working dis- tance and the aberrations of higher order are corrected to a much higher degree than was heretofore possible in a water-immersion objective ; hence, these objectives have a definition and resolving power found in oil-immersion objectives only. This series of objectives may there- fore be regarded as a new improvement in the field of microscopic apparatus, a water-immersion objective of highest optical quality having also a long working distance.” Series of Objectives.—Mr. J. C. Stodder sends us the following note of the late R. B. Tolles’s views of the best series of four or five objectives, to cover as far as possible the whole range of “ general microscopy.” “For four only—3 in., 1 in. (30°), 4/10 in. (110° dry), 1/10 in. * Amer. Mon. Micr. Journ., vi. (1885) pp. 130-1. t See this Journal, ante, p. 705. 864 SUMMARY OF CURRENT RESEARCHES RELATING TO oil-glycerin-water immersion which will work through 1/100 in. covers, and with a balsam angle of not much less than 120° for best results. An excellent and useful lens to add to the above series would be a 1/5 in. (110° or 120° dry).” Right-angled Prism instead of a Plane Mirror.*—Mr. E. M. Nelson replies to Mr. G. Hunt’s remarks { as follows:—“I can see no possible advantage in going to the expense of a right-angled prism, as in the commonest Microscopes I find the mirrors quite good enough. One mirror I have gave me four or five images of the flame, which would, of course, be fatal to good definition. This, however, was corrected by turning the mirror round in its cell until a point was found where all the images overlapped. Another mirror I have is a concave, of about 10 ft. focus. I find no difference for ordinary work. Any concavity in a plane mirror is bad, and ought to be avoided, because it shortens the focus of the condenser, which will be quite short enough, if it has any angle in it, without any further shortening. I cannot say I can mention any definite object or object-glass in which I could perceive any difference with mirror or lamp direct. If any one is doing very special work, and fancies some error due to the mirror, then turn it aside, and use the lamp flame direct. I cannot see any advantage in a prism, which cannot possibly be so good as nothing at all. One special advantage in using the lamp flame direct is that one is not so liable to get the light out of centre. Whena mirror or prism is used, a slight touch, or shake of the table even, is apt to throw it out of centre.” Hélot-Trouvé apparatus for Electrical Illumination.t—Dr. H. Van Heurck observes that the electric illumination of the Microscope, hitherto little used, has just entered upon a new phase through the new and thoroughly practical Trouvé apparatus, which realizes all that can be desired for the most difficult investigations in microscopy and photo-microscopy. The battery consists of a small ebonite box, fig. 190, 15 em. x 10 cm. x 18 em., the inside of which is divided for two-thirds of its height into six compartments, communicating at the bottom by a small aperture between each. The elements, each consisting of two rods of amalgamated zinc placed between three carbon rods, are attached to the cover, being coupled in tension, and may be let down into the liquid (potassium bichromate, sulphuric acid, and water) or withdrawn therefrom, or more or less immersed according to the power required at the time. The illuminating apparatus (fig. 191 in section), attached to the front of the battery (fig. 190), or made to slide with universal joint on a standard (fig. 192), soas to throw its light in any direction desired, is the Hélot-Trouvé photophore, originally devised for surgical operations and the examination of the cavities of the body. The * Engl. Mech., xli. (1885) p. 523. + See this Journal, ante, p. 709. { Heurck, H. Van, ‘Synopsis des Diatomées de Belgique,’ Texte, 1885, pp. 219-22 (3 figs.). See also Journ. Soc. Arts, xxxiii. (1885) p. 1005, ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 865 photophore consists of a nickelized brass tube, in which the incan- descent lamp, of special form with a straight filament, occupies the Fic. 190. i Bree 1925 middle. At the back is a reflecting mirror, and at the front a con- densing lens in an adjustable sliding tube, by which converging, diverging, or parallel rays may be obtained. As the light from the reflector might be objectionable in very delicate observations, a small blackened disk is added for covering the reflector, and a diaphragm may be placed on one or other side of the lens for intercepting the light from its margin. The battery is capable of maintaining the lamp for two hours, producing a light which may be utilized in certain cases of photo- micrography, but which is much too intense for ordinary microscopic research. By a slight modification of the battery, however, suggested by Dr. Van Heurck, by which only 4 or 5 of the elements are coupled, and the rest added as the battery becomes exhausted, or by employing a lamp of less power, the exact degree of light required may be obtained. ‘The battery evolves no fumes, and the expense of mainten- ance is very slight, that is to say 1d. per hour, including loss of zine, or less than a halfpenny an hour if the small Stearn lamp be used. Dr. Van Heurck concludes as follows :—“ It is seen then that the 866 SUMMARY OF CURRENT RESEARCHES RELATING TO electric light is really now brought to every one’s door, and we cannot too strongly advise microscopists, especially diatomists, to whom the electric light is indispensable, to provide themselves with one of these apparatuses, the price of which is very moderate. An experience of more than three years has shown us that when the electric light has been once tried and the really marvellous facility noted with which it resolves at the very outset the most difficult details of structure, it cannot be given up again, and the expensive lamps with which we were so recently content are thrown aside.” Illumination for Projection Microscopes.*—M. d’Arsonval de- scribes an improvement in the illumination of projection apparatus by the employment of a petroleum lamp with three burners, of which the middle one heated by the two lateral ones “allows of an enormous intensity of light, augmented moreover by a reflector at the back.” In addition to the fact that this apparatus gives an illumination nearly equal to that of the largest projection apparatus, it is much less costly. The use of napthalin increases still more the light and favourably modifies its nature. MM. Malassez and Hénocque lay stress on “the enormous advantage to be obtained from naphthalin, which gives a white light, very useful for microscopical or spectroscopical examinations.” Lantern Transparencies.,—Mr. C. M. Vorce says that where a considerable number of lantern slides are desired, as for distribution among co-workers, they can be made considerably cheaper by the use of the carbon process than by using dry plates. The process’ is very cheap and not difficult of application; for the author’s description of it the original must be referred to. Lantern transparencies when prepared to show microscopic objects very highly magnified are best made from camera enlargements of a less highly magnified negative, as follows:—Prepare a negative showing the desired points by means of an objective of as low power as will clearly show all the desired details. This negative will be smaller than is required, but will be a better one than one made of the desired size by a higher power, because the penetration of the objective will give sharper projection than if a higher power were used, Place the negative in a copying camera and enlarge it to the desired size if possible; if not, a second enlargement would be re- quired, but is seldom if ever necessary. The second plate, that is, the enlargement of the first negative, is a positive, and if well done may be mounted as a lantern slide; but first a negative is made from this by contact printing, and from this negative not only paper prints but other lantern positives may be made at will. It should be noted that if any retouching in the original negative is required it must be done with care and skill, as any errors would be exaggerated by the enlargement, but the enlarged positive may be freely retouched before being used for contact printing, and thus letters, figures, names, &c., * Journ. Soc. Scientifiques, i. (1885) p. 140. (Soe. de Biologie, 1885, March 21st.) + Amer. Mon. Micr. Journ., vi. (1885) pp. 84-5. ZOOLOGY AND BOTANY, MICROSCOPY, ETO. 867 may be introduced into the lantern slides prepared from the last negative, which also may be retouched if necessary like any other negative. The superiority of such enlargements over negatives made originally of the same size is often very marked. Microscopical Electrical Apparatus.—It appears to be but very rarely that in this country any use is made of the electric current in microscopical examinations. We have never seen any apparatus for the purpose in the hands of any English microscopist, and our text- books on the Microscope make no reference to the subject. Nearly all the standard German treatises, however, contain drawings of appa- ratus intended specially for use with the Microscope for observations on the influence of the electric current on blood, living tissues, micro- scopical organisms, &c., and from these and from English text-books on Physiology we have compiled the following summary of the various forms that have been devised. In regard to the utility of such investigations, Dr. Dippel says,* “The use of electric currents is not less important for many microscopical objects than the appli- cation of high temperatures. This physical reagent has in modern times acquired a high (if here and there exaggerated) importance, and scarcely any microscopist who concerns himself with the minute anatomy of plants and animals can afford to neglect its use.” The simplest apparatus} consists of two needles which can be readily joined to the wires of a battery and with which any given parts of the object can be touched. They can be hooked to be more readily attached. Pléssl’s Discharger t (fig. 193) is simply the ordinary discharger reduced to microscopical dimensions. The conducting wires are con- Fic. 193. TOUT ST nected with the two platinum wires shown in the figure, the latter being insulated by being inclosed in capillary glass tubes which slide through sprung brass tubes attached to the upright supports by hinge joints, which can be rotated or set at different inclinations. The object is placed on the glass plate in the centre. The apparatus cannot, however, be conveniently made available for covered objects on account of the inclination at which the wires must be set, or for * Dippel, L., ‘Das Mikroskop und seine Anwendung,’ 1882, p. 656. + Robin, C., ‘ Traité du Microscope,’ 1877, p. 679. See also Robin’s remarks on the effect of electricity on the circulation of the blood, &c., ibid., pp. 680-1. } Chevalier, A., ‘L’Etudiant Micrographe,’ 1865, pp. 141-2 (1 fig.). Dippel, op. cit., p. 656 (1 fig.). Harting, P., ‘Das Mikroskop,’ 1866, ii. p. 145, iii. p. 404, 868 SUMMARY OF CURRENT RESEARCHES RELATING TO high powers, and its use is practically therefore limited to large uncovered objects, such as the larger Infusoria, Rotatoria, &e. Schacht’s * plan was simply to cement two platinum wires to the slide extending beneath the cover-glass. Jendrassik and Mezey’s + (fig. 194) is now used in the Buda-Pest physiological laboratory. It consists of a slide which has two Fig. 194. z = parallel grooves about 3-5 mm. apart. At both ends of these small holes are bored, through which thin platinum wire is passed, so as to fill the grooves and be in contact beneath with two metal plates attached to the stage of the Microscope; these plates are connected with the poles of a battery. The designers used this apparatus for the microscopical examination of the contraction of muscle-fibre. Another plant} is to take a piece of silvered looking-glass and remove the quicksilver in the centre, leaving two narrow strips. Fig. 195. Kiihne § attached to the slide pieces of platinum foil of the form shown in fig. 195, placing upon them small leaden blocks which were connected by wires with the battery. * Dippel, op. cit., pp. 656-7. + Thanhoffer, L. v., ‘Das Mikroskop und seine Anwendung, 1880, pp. 91-2 (1 fig.). Dippel, op. cit., pp. 658-9 (1 fig.). { Dippel, op. cit., p. 657. § Ibid., p. 657 (1 fig.). ZOOLOGY AND BOTANY, MICROSCOPY, ETO. 869 Thanhoffer’s * (fig. 196) was formerly much used in the laboratory of the Buda-Pest University, and has been somewhat modified to answer Prof. L. v. Thanhoffer’s purpose. Two T-shaped strips of platinum are fixed to a small piece of glass by Canada balsam. To prevent their coming off, they are bent back and fastened to the other side of the glass. The slide thus prepared is placed in a wooden or Fia. 196. hard indiarubber frame. At one side of the frame two copper plates with copper screws are fixed. These plates, which are somewhat curved, lie upon the platinum strips. The poles of the battery are connected with the screws. Briicke’s + (fig. 197) consists of a plate of wood A with an opening in the centre, on either side of which copper bands B Bare let in and Fic. 197. are connected with the poles of a battery. The slide C lies on these bands, and is covered at both ends, above and below, with tin-foil. * Thanhoffer, op. cit., p. 91 (1 fig.). The name of the original designer is not given. + Thanhoffer, op. cit., pp. 90-1(1 fig.). Dippel, op. cit., p. 657 (1 fig.). Stricker’s ‘Manual of Human and Comparative Histology.’ Transl. by Power, 1870, pp. xx.-xxii. (1 fig.). Ser. 2.—Vou. V. 84 870 SUMMARY OF CURRENT RESEARCHES RELATING TO The tin-foil on the upper surface ends in blunt points above the opening in the plate at a distance apart of about 5mm. The object is laid on these points and covered with a cover-glass. Strobelt’s * apparatus is described by him as follows:—Cut two pieces of tin-foil, b b, fig. 198, of about 20 mm. in breadth and 35 mm. in length, and place them upon the ends of a slide A so that their longest side is parallel with the shortest side of the slide, the ends being doubled underneath. If the tin-foil is not too thin it will adhere to the slide of itself; under these can be inserted other strips Fic. 198. of tin-foil with pointed ends aa, the distance of which from each other can be varied according to desire. The slide is placed upon a larger glass plate B, on which two strips of tin-foil c ¢ are cemented, the latter being connected with the battery by the conducting wires d d. The advantage claimed for this apparatus over the older forms, in which the strips of tin-foil 6 b and a a are formed of one piece cemented upon the slide, consists in the fact that (1) the space between the pointed ends a a—the positive and the negative poles—can be in- creased or diminished at pleasure ; (2) tin-foil with blunter or sharper ends can be easily inserted; (3) the apparatus can be fixed on the same slide on which the object has been first examined, so that the frequently tiresome work of transferring it is avoided ; and (4) when the influence of the electricity has been observed, the further treat- ment of the object and in many cases the mounting also can be dene upon the same slide, after the tin-foil has been removed. Stricker describes | his apparatus as follows:—“It is not prac- ticable to carry out the examination of tissues under the influence of electrical currents with the same elegance of detail as can be accomplished when a simple slide only is employed. The single circumstance that the tin-foil in adhering to the glass makes the surface irregular and uneven renders it necessary that the sections of the preparation should be thicker, and proportionately interferes with the investigation by means of high powers. I endeavour therefore to combine my researches with electrical currents with those conducted in the gas-cell (made by forming a ring of putty on a slide with two tubes passing through it). By this means I am * Zeitschr. f. Instrumentenk., ii. (1882) pp. 274-5 (1 fig.). Dippel, op. cit., p- 660 (1 fiz.). + Op. cit., p. xxiii. ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 87] able to avoid the inconvenience alluded to; for it is quite possible to place the electrodes in close proximity with the preparation which is on the inner side of the cover, and to examine it in consequence with high powers. I attach to each side of the slide a strip of tin-foill which passes over the putty and reaches its inner side (s s, fig. 199). Fie. 199. Cemented to the cover are also two small strips of tin-foil s’ s’, which running in the axis of the cover, leave between them a space of a few millimetres in diameter. The object is placed at this spot, and the cover is so disposed on the wall of putty that the metallic strips of the cover lie on the strips covering the putty, and the cover is then firmly pressed down on the soft putty. The cell being now complete, the electric current is conducted by the strips of metal to the object, through which it passes at the same time; this lies immediately beneath the cover, and can therefore be examined with the highest powers. It is, moreover, no small advantage to combine the appli- cation of electricity with researches on the influence of gas, because we can neutralize or aid the effects of the current by the introduction of different gases.” Harting’s * (fig. 200) is a glass slip a b ¢ d, about 100 or 120 mm. long and 30 mm. wide, to which are attached by starch paste two pieces of somewhat narrower tin-foil A and B, with a space between them of about 25 or 30 mm. The tin-foil projects beyond the ends of the slip as shown in the figure. Over the tin-foil two thick cover- Fic. 200. glasses d e fg and hiklare cemented by marine glue or a mixture of pitch or rosin for the stage clips to rest upon. The platinum wires n and p are loose, and are bent in the form shown at C. The part mrs rests on the tin-foil and the other curved portion m tv dips into the fluid in the cell D. They can be brought close together if required. If they are to be used for covered objects they must be bent so as to lie horizontally and be as thin as possible: the * Harting, op. cit., ii, pp. 145-6 (1 fig.). Dippel, op. cit., pp. 657-8 (1 fig.). Frey, H., ‘Das Mikroskop,’ &e. Transl. by Cutter, 1880, p. 102 s ig L 872 SUMMARY OF CURRENT RESEARCHES RELATING TO projecting ends of the tin-foil are connected with the wires of a battery. For researches on blood-corpuscles Rollett * used a modification of this apparatus made by bringing the strips of tin-foil nearly to meet in the centre. The blood-corpuscles were placed between them and spread out so as to touch the margins. Dippel’s { (fig. 201) was devised to obviate the inconveniences of Harting’s, attendant upon its length, and upon the fact that the connection with the battery wires is very loose, and that the bent wires are liable to be easily disturbed by the hands. It consists of a not too thin glass plate a b c d, of the same size as the stage, on each side of which is fixed a small coil of covered copper wire (mand n), the wire being wound on glass tubes. The inner end of this wire is (to obtain greater facility of movement) bent at right angles in a horizontal plane, and the end either hammered Fie, 201. tify Z a b flat or soldered to a piece of platinum so as to allow it to lie easily under a cover-glass, and not to raise the latter so much that high powers cannot be used. In order to prevent the ends of the wires from shifting, and to enable them to be adjusted to the object, they are carried under two small strips of glass so that they cannot be easily moved. The free ends of the wires are attached to a holder which also receives the wire from the battery, both wires being fixed by screws. The apparatus can either be held on the stage of the Microscope by the stage clamps, in which case it will be more or less movable, or it can be dropped into a brass frame having two pins beneath fitting into the holes for the spring clamps. Schafer’s { (figs. 202-4) does not differ essentially from some of those already described. The glass slide (fig. 202) has two strips * SB. K. Akad. Wiss. Wien, 1. (1865) p. 178. + Dippel, op. cit., pp. 659-60 (1 fig.). t Schafer, E. A., ‘A Course of Practical Histology,’ 1877, pp. 37-9 (2 figs.). ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 873 of gold-leaf or tin-foil attached to it by shellac varnish, with pointed ends which almost meet in the middle of the slide. One strip passes Fic, 202. Fic. 203. round to the under surface, where it rests on the brass stage of the Microscope, and the other is isolated from the stage and may be con- nected with the outer coating of a Leyden jar, the charge of which is made to pass between the points by connecting the knob of 874 SUMMARY OF CURRENT RESEARCHES RELATING TO the jar with the brasswork of the Microscope. On the right a small piece of the foil is fixed to the under surface of the slide, so that this end shall be level with the other. Fig. 203 shows a combination of the apparatus with a moist chamber for the examination of blood. In this case the cover-glass has two strips of tin-foil cemented to its under surface, and the drop of blood being spread out in a thin layer between the points is quickly inverted over the ring of the cell. The tin-foil slips are kept isolated by the glass slide from the brasswork of the Microscope, and their free ends are clamped to isolated metal supports as shown in fig. 204, and can be connected with a Leyden jar or an induction coil. The ends of the wires or slips can also be made to dip into cups of mercury placed on the table, into which the terminal battery wires can also be led. Engelmann* also devised an arrangement for electricity (figs. 205 and 206) in connection with his gas-chamber. The glass top is Fic. 205. pierced with two apertures at x a, through which is inserted clay steeped in 1 per cent. salt solution, so as to fill the space between the top and the glass plates gg and hh Fie. 206. (which form a channel for it) and to Le. extend to the sides of the drop sus- if: ————7_ pended from the under surface of the See 1S 5 75 cover-glass, which closes the aperture in the chamber. The points of the Du Bois non-polarizable electrodes are placed on @ a. According to Rollett f it is advisable in using electrical discharges, that the tin-foil points should be 6 mm. apart. The Leyden jar should have a surface 500 sq. cm. and give a spark 1 mm. long. Stricker also points out ¢ that the distance of the lamine of tin-foil from one another is of importance in regard to the transmission of the current. As a general rule, they should not be separated from one another toa greater extent than a few millimetres. He prefers to see the two electrodes at the sides of the field, because then the position of the object in regard to them and to the middle line is simul- taneously visible. It is a matter of very great moment to observe and distinguish between the effects of the current in the immediate neighbourhood of the poles and at some distance from them; for the effects of electrolysis are produced on breaking the current in the vicinity of the electrodes, and the tissues become altered, as * Jenaisch. Zeitschr. f. Naturwiss., iv. (1868) pp 331-3, 385 et seq. + Klein, Burdon-Sanderson, Foster, and Brunton, ‘Handbook for the Physio- Icgical Laboratory,’ 1873, p. 17. + Op. cit., p. XX1. ~ ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 875 they would be were they subjected to the action of weak acids or alkalies. At parts more remote from the electrodes changes also occur which, however, are not so remarkable as those which are induced by the chemical processes above alluded to. The effects, which may be trusted as being really due to electricity, should occur quickly after the passage of the current, and not be limited to the part in the immediate neighbourhood of the electrodes. If the current be allowed to pass for some time, that is to say, for more than a few seconds, through the tissue, the products of electrolysis first extend over the whole surface lying between the electrodes, and then the intensity of the current becomes extraordinarily reduced, frequently indeed to zero, on account of the pole becoming covered with bubbles of gas. On this account the employment of constant currents for microscopic investigation is scarcely to be recommended, for with the closure of even very weak currents so violent a development of gas occurs, that but little confidence can be placed in the results that are observed to follow their passage. The amount of electrolysis that occurs with induction currents is much smallér, and they have therefore been most generally employed. The arrangement in which there is a single shock on opening and closing of the current is particularly advantageous. The shocks obtained from a Leyden jar are infinitely superior to the constant currents, because the instantaneity of the shock causes the disturbing influence of the evolution of gas bubbles to be altogether abolished. With regard to induction currents, he also points out that on breaking the current, heat is developed in the tissue. If an un- covered drop of blood is under examination with strong ordinary lenses, these become dimmed at the instant of the passage of the current, but after a short period they again become clear. The preparation, however, very soon dries up. It is requisite in such cases to determine what are the effects of the sudden elevation of temperature, and what are those of the electric current alone. Stricker’s electrodes * are shown in fig. 207. The slide (covered with tin-foil as previously described) is held in position by the electrodes, each of which is insulated by being screwed into an ivory knob let into the stage-plate of the Microscope. The electrodes are connected (with the interposition of a key) with the secondary coil of a Du Bois Reymond induction apparatus. In the woodcut the key is re- presented open. Mr. R. T. Lewis states} that when investigating the disruptive effects of the electric spark—more especially with regard to the peculiar shape of the perforations made by it through various materials —many experiments were carried on upon the stage of the Microscope, and he found that a very simple and convenient method of holding and insulating the terminal wires was to pass each through a small glass tube held by a brass spring-clip, mounted upon a jointed pillar * Klein, Burdon-Sanderson, Foster, and Brunton, ‘Handbook for the Physio- logical Laboratory, 1873, p. 17 (1 fig.). ¢ Engl. Mech., xlii, (1885) p. 19. 876 SUMMARY OF CURRENT RESEARCHES RELATING TO at the corner of the stage in the same manner as the stage forceps. The pointed end of a glass dipping-tube answered the purpose admirably. When it was desired to pass sparks vertically through Fic. 207. an object in focus, a glass stage-plate was used. This consisted simply of two pieces of glass, about an inch longer than the brass stage, cemented together with a wire between them, the point of which turned up at right angles in the centre of a hole drilled through the upper plate. The other terminal, mounted as above, could then be adjusted over it in any required position. A small induction coil was used for the purpose, giving about a 1/2 in. spark with a single bichromate cell. If a Leyden jar was placed in the circuit, discharge sparks of much greater size and brilliancy were obtained, giving beautiful effects when viewed through the micro-spectroscope. “ Cau- tion is desirable in conducting experiments of this kind, since manipulation, duriug observations which engage the attention closely, is apt occasionally to produce very startling results.” Apparatus for watching the phenomena that animals subjected to great pressure present.*—As previously recorded,{} Dr. P. Regnard has experimented on the conditions of life at high pressure. With apparatus designed by M. Cailletet, he has subjected aquatic animals to enormous pressure, such as prevails in the depths of the ocean, and has examined the results when those inhabiting the surface are suddenly placed at great depths. * Comptes Rendus, c. (1885) pp. 1243-4 (1 fig.). Nature, xxxii. (1885) pp. 399-400 (2 figs.), from ‘ La Nature.’ t See this Journal, iv. 1884) p. 362. ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 877 Since his first experiments Dr. Regnard has invented an inge- nious method by which he can see, notwithstanding the great pressure, what goes on inside the apparatus. Hitherto the operator simply placed the animals on which he experimented in the iron block of the Cailletet pump, and subjected them to the pressure corresponding to a given depth; he then released them, sometimes very slowly (after several days), sometimes rapidly and even instantly, and examined, physiologically and microscopically, the effects produced. But all the intermediate stages between the introduction of the animals and the time they were taken out escaped the observer. Now, however, the apparatus shown in figs. 208 and 209 allows him to follow each minute the effects. Two holes are pierced through the lower part of the Cailletet block M (fig. 208). In these are inserted two tubes at r and 7’, These are hollow, and in each of them is solidly fixed a cone of quartz B, the end of which comes as far as the edges of the hole which is pierced in the screw-nut. A ray of light thrown in at the orifice r will thus traverse the apparatus and emerge at 7’. Experiments have shown that the apparatus will resist easily a pressure of 650 atmo- spheres, which represents that of the greatest depths that have been dredged—about 6500 metres. Through one of the quartz cones are sent the concentrated rays of an electric lamp. These rays cross the block (full of water), and emerge on the opposite side, where they are received by an achromatic object-glass which projects them on a screen. The observer therefore works at a distance from the appa- ratus, where he is sheltered from all danger. The arrangement has an- Fic. 208. other advantage. The orifice pierced at r is hardly"half a centimetre in diameter, and small organisms can be experimented with in the vessel immersed in the block M, which are invisible to the naked eye. By pro- jecting them with a lens they are so enlarged, and appear with such transparency, that we can follow on the screen the movements of their branchia, and even of their heart, during the experiment. In the ex- periment represented in fig. 209, one of the operators is occupied in regulating the electric lamp and in setting the Projection Micro- scope, while the other applies the pressure. Dr. Regnard is pursuing his studies on life under high pressures. He showed last year that the unequal compressibility of the liquids and solids of the organisms caused the latter, after a long pressure, to be soaked with water, become turgid, and consequently lose their functions. But with the apparatus here described, he has been able to follow the phenomena which precede this. At the pressure of 1000 metres (about 200 atmospheres) the object shows inquietude; at 2000 metres it falls to the bottom of the vessel struggling; towards SUMMARY OF CURRENT RESEARCHES RELATING LO 878 ‘SQLVUVddY S.GUVNOTY ‘Yq FO MHIA IVYANAYH)—'60Z “YI ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 879 4000 it remains inert and benumbed. When its normal pressure returns it recommences moving, unless the pressure has been pro- longed and its tissues are soaked. This seems to show that the effect is a compression of the nervous system. Westien’s apparatus for comparing symmetrical parts of the webs of the right and left feet of a frog.*—The apparatus of Herr H. Westien (fig. 210) consists of a glass plate holder C, the stand P, and the Microscope A (upper part omitted). The ring m, movable on the upright n, is fastened by the screw w and carries the bar o, to which the clampS is attached. The glass plate K is clamped into this, and on it the frog is laid, and its extremities and toes fixed with threads which are fastened in holes bored in the glass plate. Fic. 210, The plate K rests on the glass-plate G, on which it can be easily and quickly pushed in a horizontal plane up to the clamps cc which are fastened on the upper border of the glass plate G. By proper adjust- ment of the glass plate K on a certain spot, e.g. a small artery of the left foot, the corresponding spot of the right foot can be placed in the field by pushing the plate up to the clamp c. The apparatus for pro- ducing stimuli a is attached to the glass plate K by the clamp R. Apparatus for Determining the Specific Gravity of Minute Objects under the Microscope.t—Prof. W. J. Sollas found the diffi- culty of determining the specific gravity of calcareous sponge spicules by the method of weighing insuperable, as they are so small and so difficult to free completely trom air, even with an air-pump. Sonstadt’s solution appeared to offer the best chance of success ; but here again the small size of the spicules was a difficulty. This, however, was overcome by adapting the Sonstadt method for use with the Microscope. An ordinary collecting tube (fig. 211, T), about 2 in. long and 8/8 in. in diameter, was cemented with plenty of Canada balsam to a glass slideG. The object of using excess of balsam was to destroy * Zeitschr. f. Instrumentenkunde, v. (1885) p. 198 (1 fig.) + Scientif. Proc. R. Dublin Soc., 1885, pp. 374-92 (7 figs. and 1 pl.). 880 SUMMARY OF CURRENT RESEARCHES RELATING TO optically the curvature of the side of the bottle. As the refractive indices of Sonstadt’s solution and balsam are not very different, this plan succeeded admirably. A thin cover-glass was similarly cemented to the opposite side (front face) Fic, 211. of the bottle, which was thus optically flattened front and back. Some, Sonstadt’s solu- tion (sp. gr. 2:77) being introduced, a fragment of aragonite (sp. gr. 2°9) was dropped in; it at once, of course, sank to the bottom. Next a piece of calcite (sp. gr. 2:7) was added ; it floated on the surface. The spicules lying in water, were freed as far as possible from air by boiling, and with the air- pump. With a dipping-tube the water and spicules to- gether were taken up and added to the top of the Sonstadt’s solution, where they floated. The tube was then left to stand in order that diffusion might take place. After some hours the water and Sonstadt’s solution had become gradually mixed, giving a column of fluid with a specific gravity of about 2°4 at the top and 2°77 at the bottom. The calcite and the spicules floated at different levels (the spicules being above) in layers of fluid having respectively the same specific gravity as themselves. A fragment of pure quartz (sp. gr. 2°65), and another of adularia felspar (sp. gr. 2°58) were next added ; the quartz sank to a level below the spicules, the felspar remained above. As the contents of the tube could be easily examined under the Microscope with a 1 in. or even a 1/2 in. lens (Zeiss’s C), one could make certain of the absence of air-bubbles, vacuoles, or other troubles; and as the spicules could be seen individually, it was possible to determine the specific gravity of a single one. The spicules did not all lie at exactly the same level, but formed a zone thickest towards the middle, and thinning off above and below; a few stragglers were seen at some distance on either side, but this was ~ owing either to adhesion to the side of the tube, or attached im- purities. The specific gravity could now be exactly determined. Two rectangular axes are ruled, fig. 212; on one distances are taken to represent the densities of the calcite, quartz, and felspar; on the other the exact distances between the middle line of each fragment as it floats in the tube are measured off. These distances were obtained by gumming two scales divided into millimetres on the stage of the Microscope at right angles to the glass slide carrying the experimental tube, i.e. parallel to this tube (fig. 211, Sc, and Sc,). The calcite was brought into focus, and the position of one edge of the glass slide read off on the scales; the ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 881 slide was then moved down till the quartz came into view, and the position of the slide again read off on the scales. The object of Fia. 212. Z- Adularia . ee ‘An occasional spicule oe Middle of zone of calcareous poll ss Beginning of same zone cs Quartz and perforate oe rn eo Perforate foraminifera Ce. tae examples) . . Calcite and Milliola Lowest lying Milliola ..--+“----- 2°72 2:7 2°67 2°65 2°63 2°62 2°58 a. Axis of distances, b. Axis of specific gravities. having two scales is obviously to ensure parallelism in the movements of the glass slide. The specific gravities and distances being indicated on the rect- angular axes, one constructs a curve which gives the change in density from one mineral to another in the tube. The height of the zone of spicules being now indicated on the axis of distances, a line is drawn parallel to the other axis through it; from the point where it cuts the curve a perpendicular is let fall on the axis of specific gravities, and the point where it meets the axis gives the specific gravity. In this way the specific gravity of the spicules was determined to be from 2°61 to 2°63. They are plainly, therefore, not aragonite, and, arguing from the specific gravity alone, probably consist of calcite. The slight difference between it and them in specific gravity is no doubt due to the presence of organic matter ; for within, a minute canal, filled with some kind of organic material, possibly spongin, occurs in the axis of the spicules; and without they are surrounded by a thin sheath of a probably similar material. Prof. Sollas finds by calculation that allowing for the organic matter a specific gravity of 1°5, it would require to be present to the extent of 62 per cent. to reduce the total specific gravity of the spicules from 2°7 (supposing them to consist chiefly ‘of calcite) to 2°62, the density found. Keeping both Eyes open in Observation.*—Mr. E. M. Nelson considers that the unused eye should be shut when the weaker light is in the Microscope, both eyes being kept open only when the object is in the stronger light. ‘Thus by diffused daylight the light in the instrument is the weaker, and the other eye must be shut. By artificial light in a dark room both eyes can be kept open. “One hour of steady hard work with the Microscope by diffused daylight * Engl. Mech., xli. (1885) p. 523. 882 SUMMARY OF CURRENT RESEARCHES RELATING TO will tire you more than a whole day’s work in a dark room by lamp- light.” Aperture Puzzles.—Another puzzle turns on the statement some- times made that it is not necessary to have an objective of 1:0 N.A. (180° air) to resolve 96,000 lines to the inch as shown by the Aperture Table; that it can be effected by a dry objective of say 0°50 N.A. (60° air). The way in which this feat is supposed to be accomplished is by attaching a truncated cone A to the cover-glass as shown in fig. 213, the connection being made by balsam, oil, &c. Here the first diffrac- Fig. 213. Fig. 214. ‘C-gl. Ap. tion spectrum and the dioptric beam which leave the object (Amphi- pleura pellucida) at an angle of 82° in glass emerge from the cone at an angle of only say 60° in air, and are therefore collected by a dry objective of approximately that aperture. The explanation simply is that by connecting the cone with the cover-glass we have an immersion objective, with the difference that (1) instead of using a hemispherical piece of glass to cause a pencil of 82° in the glass to emerge as one of moderate air angle, to be taken up by a dry objective above it, a conical one has been substi- tuted, and that (2) in place of attaching the extra piece of glass once for all to the rest of the optical combination, as in an ordinary im- mersion objective, it has to be attached to each slide examined, at a great sacrifice of convenience! The cone has, moreover, the disad- vantage, as compared with the hemisphere, that whilst the latter will readily collect to a focus the whole pencil of 82°, and thus allows of the real delineation of all kinds of objects, the cone will only collect two very narrow partial pencils of equal and opposite obliquities and will not bring these toa proper focus. ‘The problem is in fact only an- other mode of stating the old mare’s-nest of the “ hemisphere puzzle,” disguised by the substitution of a truncated cone for the hemisphere. The same effect, though with more dispersion, can be obtained by refraction (instead of reflection) through a truncated prism of isosceles section and suitable inclination of the refracting faces (fig. 214), and whatever form is employed the only essential conditions are that two infinitely narrow beams (the incident beam and the first diffraction pencil) shall have equal and opposite inclinations u to the axis within the front medium, and that they should be deflected, by ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 883 refraction or reflection, in such a way that they emerge into air under equal and opposite inclinations u’, smaller than the semi-angle of aperture of the dry objective above, which is focused to the point o’ of vertical intersection of the two beams. Every device which con- forms to these conditions will act as an immersion front-lens in regard to the particular pair of beams in question. The conical or prismatic front will, moreover, like the hemisphere, increase the power of the optical combination. This power may be determined by the formula N = a where n is the index of the glass front, uw the internal angle of obliquity, and wu’ the angle of obliquity after emergence into air. In the ratio of the quotient N to unity the power of the objective will be increased (or its focal length diminished) in regard to the delineation of the particular set of lines from which the two opposite pencils originate. For any other set, of different closeness, wu and wu’ will require different values, and the power of the same cone or prism will be different. The ‘Times’ on the Microscope.—The following leading article appeared in the ‘Times’ of the 26th August :— “We publish this morning an article descriptive of some of the progress which has been made during late years in the construction and cheapening of Microscopes and of their accessory apparatus—a progress so marked that it has become time for all who are engaged in the work of instruction to consider carefully to what extent the improved instruments of the present day can be employed for the furtherance of the general work of teaching. If we may adopt Paley’s definition of education, as ‘comprising every preparation that is made in our youth for the sequel of our lives,’ we shall be prone to admit that few of these preparations can be of greater importance, or of greater ultimate utility, than the training of the eye to observe natural phenomena, and the training of the mind to appreciate the meaning of these phenomena and their relations to one another. It was a great day during the childhood of many who have now passed the meridian of life when the lecturer with an oxy- hydrogen Microscope was announced as being about to exhibit and to discourse at the town hall; and the huge transparency in which the insect life of a drop of water was displayed in full activity became a wellspring of new thoughts and of increased mental activity to nearly all of those who gazed in wonder at the presentment of rapid movement, of abounding life, and of continual destruction. The sight which was then to be seen only on rare occasions, and as a sort of entertainment, is now at the daily command of every school- master, or of every parent who can spare only a small amount of money, and who possesses sufficient intelligence and manual dexterity to learn the use of the instrument which, more than any other, has led to increased knowledge of the structure of man and animals, and to modern improvements in the healing art. The powers now at the disposal of the savant far surpass any which were attainable only a few years ago; but the use of these high powers requires the devotion 884 SUMMARY OF CURRENT RESEARCHES RELATING TO of much of a lifetime to the study of learning how to see, and how to interpret what is seen. No persons are more certain to fall into gross errors than the untrained possessors_of powerful Microscopes ; and the conduct of actual research, of the business of carrying know- ledge a step in advance of its former boundaries, must always be limited to the few. When, in 1854, the late Dr. William Budd announced that cholera was dependent upon the presence of a minute intestinal fungus, there were probably not three observers in England who were capable of pronouncing a trustworthy opinion as to whether a given speck was a microscopic fungus or not; and there was little doubt that the so-called ‘fungi’ of many persons were nothing more than fine particles of chalk, derived from medicine which had been administered to the patient. Since that time vast strides have been made in the methods of conducting such investigations, together with corresponding improvements in the instruments by which they are conducted ; and almost every beginner now thinks himself qualified to prattle about microbes. In the case, unfortunately, of those who may be presumed to be the most skilled observers, talk and observa- tion do not always seem to be conducive to agreement. It is not, however, for the sake of prosecuting original inquiry, but for the sake of making known to the young what has already been established, that the Microscope should commend itself to edu- cationists. It reveals and displays plainly to the sense of sight two great facts—the fact of the wonderful complexity and beauty of the structure of the smallest and apparently the most insignificant crea- tures, and the fact that all living things of appreciable magnitude, whether they be plants or animals, are built up by the aggregation of myriads of minute organisms or cells, each of which possesses inde- pendent life, and each of which fulfils a purpose in the corporate body by its own inherent and independent activity. If a Microscope is given to children as a toy, and if all that is done for them is to permit them to look through it at something the nature of which they do not understand, it will do them no more good than seeing a conjuring trick, perhaps hardly so much; but if children are encouraged to examine first the more simple vegetable structures, making their own sections and proceeding gradually from low powers to higher ones, from coarse to minute and complex structure, they can hardly fail, if ‘ capable of enlightenment at all, to obtain such new notions of the universe in which they live as will never wholly cease to influence their minds. The lore actually gained may perhaps be comparatively small; but the true gain will be in the power to think about occur- rences, to discover real resemblances between things which are externally different, and to perform that wonderful work of ratiocina- tion through which two ideas, similar or contrasted, become the parents of a third. It is difficult to believe that a child who was not only permitted to work with a Microscope, but who was assisted to do so in a rational way, encouraged to collect his own objects, to examine them in his own fashion, to try to overcome his own diffi- culties and doubts, would ever grow up into an entirely stupid man or woman. There are but few who are gifted with the infinite patience ZOOLOGY AND BOTANY, MICROSCOPY, ETO. 885 and the love of truth for its own sake which form the raw material, so to speak, of the philosopher; but the instances are at least equally few in which the lessons in observation and reflection, which even a small Microscope is calculated to afford, would not serve to raise the mind of the user to a higher level, and to develop a higher degree of intelligence than could have been obtained without such help. In a few very good schools, chiefly for the children of the more wealthy classes, natural history teaching by the aid of Microscopes is systematically conducted, the classes collecting their own specimens, and being expected to give the best account they can of them before being assisted towards a better one by the teacher. Our argument is that all this should be done much more widely and generally ; educa- tion, in fact, being made to advance along a road which is rendered comparatively smooth by the perfection of modern appliances. The tasks of school, in too many cases, appeal to the memory rather than to the understanding, and cultivate stupidity rather than intelligence. Ii is impossible to doubt that much which is taught, say in Board schools, might be relinquished without any appreciable loss to the intellectual development of the scholars, and that by such relinquish- ment time might be gained for instruction of a more fruitful kind. As for the material, even in towns, it is present in immeasurable abundance. There is a legend that an ardent naturalist once de- termined to write a complete account of the plants and animals which he found in the garden of Lincoln’s-inn-fields, but that the magnitude of the task was such as to place insuperable obstacles in the way of its accomplishment. An attempted history of the insect life alone was abandoned for the same reason; and a second Gilbert White might have found ample occupation in observing and recording the habits of the various denizens of the narrow space. It is, perhaps, too much to hope that the officials of a public department will ever so far emancipate themselves from the trammels of routine as to take the initiative in the promotion of better nature teaching; but it is not impossible that they might learn to follow if they were clearly shown the way. The parochial clergy in old times were the pioneers of improvement on all educational questions; and there is no reason why they should not seck to regain something of the leadership which has to so great an extent slipped away from their grasp. Could they not, especially in rural districts and in country towns, do something towards the promotion of a reform which would render the younger members of their congregations more observant, more thoughtful, more careful of animal life, less ready to be over sure about problems the solutions of which are not yet known to mankind, but on which so many people are prone to be dogmatic in precise proportion to their ignorance? The mcdern Microscope might form one of many levers by which the minds of future generations might be guided towards the attainment of knowledge and the cultivation of modesty and charity.” The article referred to was as follows (under the head of “ Recent Microscopical Science”) :— “A glance at the Journal of the Royal Microscopical Society, Ser. 2.—Vou. V. 3M 886 SUMMARY OF CURRENT RESEARCHES RELATING TO which is edited by Mr. Frank Crisp, with the assistance of several Fellows of the Society, shows that activity in microscopic science is incessant. Last year the Journal included 1008 pages of matter, most of it consisting of summaries giving the essential features of all important papers bearing on microscopical science published throughout the world. This year 756 pages of the Journal have already been issued, and students who use the Microscope are thus better off than the devotees of most other departments of science. It is to be noted as to the Microscope itself, that improvement is not now rapid as regards fundamental principles and their application to the less powerful lenses with which the average student is chiefly concerned, but that considerable advances have been made in the last few years in the theory and practice of the construction of lenses of high powers. Thus under the eye of a skilled observer an excellent objective of 1/10 in. focal length will now accomplish as much as or more than an objective of 1/25 in. not many years ago; while those now made of the very high power signified by 1/50 in. focal length, and capable of magnifying from 2000 to 10,000 diameters, according to the eye-piece used, greatly surpass in all important qualities lenses of the same power sold by the best makers less than five years ago. Moreover, for some kinds of work the adoption of the principle of immersing the surface of the objective in distilled water or in very pure oil has proved of great value. Thus many delicate points of detailed structure, formerly discoverable only by the most persistent efforts and careful manipulation, can now be demonstrated with comparative readiness. It is obvious that if the educative influence of microscopical study is to be very widely diffused, much depends upon the cheapening of good apparatus. This is especially the case if schools are to employ to any considerable extent recent biological methods. Cheap forms of Microscope have hitherto been more or less unsatisfactory. Hither they were cumbrous to work, they readily got out of order, they became unsteady, or they did not long continue to magnify clearly or without introducing inopportune colours into the field of view. All the leading makers, however, have recently brought out cheap in- struments of improved construction. Among others, Messrs. Beck, whose name stands high for finish and reliability of workmanship, have recently brought out a so-called ‘Star’ Microscope, which combines solidity and steadiness with good magnifying powers (1 in. and 1/4 in. in focal length respectively), suitable for average students and for research within limits. The tube can be inclined at any angle, there is a fine adjustment, the stand is solid and firm, and a diaphragm with apertures of various diameters under the stage can be rotated so as to regulate the admission of light. Marked improvements continue to be made in the lantern Micro- scopes used for magnifying objects for public lectures and demonstra- tions. Mr. Lewis Wright has brought to great perfection a lantern Microscope which throws large-sized and exceedingly clear views of minute objects on to a screen free from distortion or colour. Struc- tures so complex as the minute anatomy of the human tongue, the ZOOLOGY AND BOTANY, MICROSCOPY, ETO. 887 wood of an elm tree, and even the circulation of the blood in the web - of a living frog can be exhibited with perfect sharpness of definition up to the very margin of the illuminated field of view. The import- ance of this for scientific lecturing is evident. In no department of microscopic work has more ingenuity recently been applied than in the construction of microtomes. These are instruments for cutting numerous very thin sections of substances parallel to one another, either for distribution to large classes or for obtaining successive adjacent portions of a structure, so as fo secure an exhaustive examination of it. The somewhat complex instrument devised a couple of years ago by Messrs. Caldwell and Threlfall, of Caius College, Cambridge, and manufactured by the Cambridge Scien- tific Instrument Company, was made to deliver its thin sections in a continuous riband at the rate of 100 per minute, or even twice as many when a water motor was used. They were delivered in conse- cutive order and with the same side upwards. Uniform thinness could also be obtained by an ingenious screw. The great novelty of the instrument consisted in the use of an endless band to receive the sec- tions as they came from the razor. When imbedded in suitable material the sections adhered to one another and came off the razor in a continuous riband. As soon as a sufficient length was cut, the end was picked up by a needle or scalpel and placed on the band, which was adjusted so as to be moved forward, at each throw of the object-carrier, through a distance equal to the breadth of the surface which was being cut. Many persons were soon at work to improve and simplify this method and to reduce its cost. This object seems to have been best accomplished by the Cambridge Instrument Company itself. Its improved instrument is called the rocking microtome, a rotary instead of a sliding motion of parts having been employed. Its cost is less than one-sixth of that of the original instrument, and instead of being lifted on to a continuous silk band, the riband of sections falls by its own weight directly from the razor on to a sheet of paper, or on to the glass slide on which the sections are to be finally mounted. Sections as thin as the 1/40,000 of an inch are said to be obtained by this plan. It is much easier to work, is less liable to get out of order, easily packed, and very portable. One result of the increased facility of instruction and study in microscopical science appears to be the rapid multiplication of memoirs and papers dealing with isolated portions of subjects. We do not note in this country that the number of men of real power who devote themselves to these studies and patiently elaborate systems and build up sure edifices of enlightenment increases very greatly. Rather there is a multiplication of men of the second or third rank, who catch the jargon of the reigning school, make respectable re- searches on a few points, and become absorbed in teaching or in other money-carning pursuits. There is a fashion in microscopy as in other things, and it is the fashion to study bacteria and bacilli, just as it formerly was the thing to pore delightedly over test-slides of diatoms. The bacteria will yield a more fruitful harvest, certainly, 3m 2 888 SUMMARY OF CURRENT RESEARCHES RELATING TO in the hands of scientific workers, but the path is toilsome and the goal distant. There is reason in this devotion. When we know the very little, how it lives and moves, and what it can do, we shall be much more ready to comprehend how similarly minute elements com- bined work in larger organisms.” AGEN, F. D’.—Microscopical. [As to air-bubbles in the back combinations of objectives. Also as to the resolution of A. pellucida by a dry 1/5 in..of 135°. (Cf. ante, p. 726.)] Engl. Mech., XLII. (1885) p. 37. American Association for the Advancement of Science. [Remarks on the abolition of the Section of Histology and Microscopy. “This anomalous Section finding its end near, proceeded with dignity to request the Association to kill it: the request has been granted.” “This change has been urged for some time by those who do not think a special science of Microscopy exists, but that the Microscope is a tool used by scientific men in various branches.” “It is to be hoped that Dr. Minot’s suggestion of forming a Microscopical Club within the Association will be carried out, to insure the cultivation of technique among the members interested.””] The Microscope, V. (1885) pp. 181-2. See also Amer. Mon. Micr. Journ., VI. (1885) p. 175. American Society of Microscopists—Our Highth Annual Meeting. [Urging that papers, speeches, and sessions should be short. “ We must insist upon being relieved and upon relieving our fellow-sufferers from the lengthy uninteresting papers read by parties who have become monomaniacs on their pet subjects.”’] The Microscope, V. (1885) pp. 180 and 181. See also Amer. Mon. Micr. Journ., VI. (1885) p. 157, and Micr. Bulletin (Queen’s), II. (1885) p. 25. Report of Cleveland Meeting. (Jn part.) Amer. Mon. Micr. Journ., V1. (1885) pp. 165-7, 175. Amyot, T. E.—Direct Vision Microscopes. [Post.] Sci.- Gossip, 1885, pp. 201-2 (1 fig.). ARSONVAL, D’.—Simplification des Appareils a projection. (Simplification of projection apparatus.) [Supra, p. 866.] Journ. Soc. Scientifiques, I. (1885) p. 140. (Soc. de Biologie, 21st March.) Banks, C. W.—Electric spark under the Microscope. [Mr. Banks showed, under the Microscope, the electric spark in its passage between the terminals of a 1/4 in. spark induction-coil attached to a Grenet bichromate solution battery. Two vulcanite slides had been prepared, on which were fastened adjustable platinum strips connected with the battery wires and terminating in brushes of platinum wires of extreme tenuity. The electric fluid, in its passage from one terminal to the other, formed a very attractive object under the Microscope. One of the slides was used to show the effect on the electric spark of interposing films of soot of different thicknesses. In its passage through these the current was deflected into meandering lines, around which scintillated showers of sparks. The particles of soot could be seen arranging themselves in symmetrical groupings around the terminals. ] Proc. San Francisco Micr. Soc., June 10th, 1885. See Micr. Bulletin (Queen’s), IT. (1885) p. 30. Bavscu, H.—Manipulation of the Microscope. [Contains chapters on Simple Microscopes, The Compound Microscope, Ob- jectives and Eye-pieces, Requisites for work, How to work, Advanced Manipulation, Substage Illumination, Care of a Microscope, and Con- iderations in testing Objectives. ] 96 pp. and 27 figs., 8vo, Rochester, N.Y., 1885. ”? ” 7 ZOOLOGY AND BOTANY, MIOROSCOPY, ETO. 889 BrEEcHING, S.—Amateur Lens-grinding. Engl. Mech., XLI. (1885) pp. 498-9 (1 fig.). Buss, E. J.—Opaque Illumination. [Mainly an historical summary of the various appliances. ] Trans. and Ann. Rep. Manchester Micr. Soc., 1884-5, pp. 23-6. BurRRiv1, T. J.—Photographs of Amphipleura pellucida.—New Heliostat. [Good photographs obtained by Dr. H. J. Detmers with a common coal-oil lamp.—Note of the construction of a new Heliostat of simple mechanism for photo-micrography. ] Science, VI. (1885) p. 228. C., L. P. pu.—Le Microscope grande modéle de Hartnack et Prazmowski. (The large model Microscope of Hartnack and Prazmowski.) [Description of it, with the modifications introduced by their successors Bézu, Hausser & Co.—principally an excentric diaphragm in place of a sliding one, and an adapter for changing objectives. ] Journ. de Microgr., 1X. (1885) pp. 262-3, CapLatzi, A.—See “ Orderic Vital” and “ Rector.” Coorrr, W. A.—Daylight v. Lamplight for microscopical observation. [Quotation of Dr. Carpenter’s views in favour of daylight as against Mr. Nelson’s. ] Engl. Mech., XU1. (1885) p. 564. Dusosca, T. and A.—Nouvel appareil de grandissement pour la projection, soit des tableaux de grandes dimensions, soit des objets microscopiques. (New magnifying apparatus for the projection of large pictures or microscopic objects.) [Supra, p. 861.] Comptes Rendus, Cl. (1885) pp. 476-7. Dup.tey, P. H.—Triceratium Davyanum. (3 photo-micrographs x 408, representing the diatom when viewed in 3 different focal planes. ] Journ. N. York Micr. Soc., 1. (1885) pp. 145-6, and p. 157 (3 photographs). DvRanp, W. F.—A practical method of finding the optical centre of an objective and its focal length. [Post.] Amer, Mon. Micr. Journ., VI. (1885) pp. 141-5 (1 fig.). Dynamo-electric Machines. (Exhibition of two small machines, one operated by the foot and the other by hand. “For microscopical illustration fa dynamo} can be used with great advantage, especially in photography.”] Journ. N. York Micr. Soc., I. (1885) p. 156. Fasoldt’s (C.) Detaching Nose-piece. (See this Journal, IV. (1884) p. 959.] Amer. Mon. Mier, Journ,, VI. (1885) pp. 149-50 (1 fig.), Grant, F.—Microscopical. [Whether daylight or lamplight is the better for illumination “can be settled only by experience.””— Measuring amplifying power of the Microscope and angle of aperture of objectives—Advantages and dis- advantages of large apertures.—Explanation of numerical aperture. ] Engl. Mech., XLII. (1885) pp. 57-8, Gray’s (S.) Water Microscopes. {Claim by “the ghost of Stephen Gray” that Hippisley’s Pocket Field - Microscope infra is an inferior form of Gray’s Water Microscope.] Ling!. Mech., XLI. (1885) p. 520. Gundlach’s Improved Microscope Objectives. [Supra, p. 863.] Amer, Mon. Micr. Journ., VI. (1885) pp. 130-1. Han, OC. P.—Making a Microscope into a Microtome. [Supra, p. 861.] Science, VI. (1885) p. 228, Hastincs, C. S.—On the Colour Correction of double Objectives. Lng!. Mech., XL. (1885) pp. 559-60; XLIT. (1885) pp. 8-9; from Amer. Journ, Sci., XXIII. (1882). Hinocgure.—Appareils destines 4 Vexamen du sang. (Apparatus for the examination of blood.) [ Post. Journ. Soc. Scientifiques, 1, (1885) p. 24, (Soc. de Biologic, 11th Jan.) 890 SUMMARY OF CURRENT RESEARCHES RELATING TO Hevrck, H. Van.—Eclairage artificiel: Eclairage électrique par incandescence. (Artificial illumination: Incandescent electrical illumination.) [Supra, p. 864.] Synopsis des Diatomeées de Belgique. Texte. 1885, pp. 219-22 (8 figs.). Cf. Jeurn. Soc. Arts, XX XIII. (1885) p. 1005. HiIppisLey, J.—A pocket field Microscope. [“ Magnifying 100 diameters, useful in the search for infusoria, &., and which may be constructed, lens and all, in a few minutes. Bend a slip of thin metal 5 in. or 6 in. long and 1/2 in. wide into the form of the letter V, make two circular holes 1/10 in., one in each arm, opposite each other, so that when the arms are sprung together by pressure the holes shall meet exactly. Place a drop of water in one hole, taking care not to wet more than its interior circumference. The water will assume the form of a perfect double convex lens, of focal length varying from 1/8 to 1/10 in. according to the quantity of water introduced. Such lens, though by evaporation its focal length is gradually increased, maintains its efficiency for a time quite sufficient for the examination of a drop of water or other substance in the opposite hole. The end of one arm of the V is bent inward so as to form a “stop,” which when they are pressed towards each other to effect the focal adjustment, prevents a contact which would destroy the lenticular form. The definition of these water-lenses is excellent, and their magnifying power is from 80 to 100 diameters, according to the quantity of water in the lenticular drop.” Engl. Mech., XL. (1885) p. 502. » Microscopic. It is very easy to make glass globules for microscopic use of ordinary glass. The difficulty is in using them as Microscopes. Besides the instrumental difficulty of focal adjustment for such small lenses, the light of so small a pencil of rays is quite inadequate, except with “violent” illumination. “But lenses by melting glass may be made to much better purpose of more useful focal lengths—not globular— but double-convex lenses, in the following manner, which, I believe, is new, or was so when I first made them, say 30 or 40 years ago. Take a bit of fine binding wire, iron (not brass or copper), make, by twisting it round a taper wire for mandrel, a nicely circular loop; flatten it so that the loop is all in one true plane. The loop may vary in diameter from any desired smallness up to 1/4 in. (which is nearly the largest size my glass-melting apparatus will conveniently manage). Place a square piece of glass—thicker or thinner, according as it is desired to have a lens of more or less convexity, but large enough to completely cover the loop. Then, holding it in a suitable blowpipe flame (which should be a vertical, not a horizontal one), the glass assumes in melting a doubly- convex lenticular form. A form, moreover, in which the spherical aberration of a globule tends to be corrected, and a larger proportion of the field is flatter than it is with an ordinary double-convex lens.” “Such lenses are made in a few minutes, and perform most admirably when a suitable instrumental apparatus is used.” | Engl. Mech., XLI. (1885) pp. 540-1. Hitoxucockt, R.—Optical arrangements for Photo-micrography and remarks on Magnification. [Post.] Amer. Mon. Mier. Journ., VI. (1885) pp. 168-70. [Hircxucock, R.]|—The Postal Club. [Comments on its position.] Amer. Mon, Micr. Journ., VI. (1885) pp. 1384-5. —Testing Objectives. [Recommendation of the Abbe test-plate.] Amer. Mon. Micr. Journ., VI. (1885) pp. 177-8. International Inventions Exhibition. XII. Philosophical Instruments and Apparatus. [Includes Microscopes and Apparatus. ] Engl. Mech., XLI. (1885) pp. 444-5. James, IF’, L.—American v. Foreign Microscopes. The Microscope, V. (1885) pp. 164-5, from the National Druggist. Kuz1n, C.—[Horizontales Erhitzungsmikroskop.] (Horizontal heating Micro- scope.) [Posé.] Nachr. K. Gesell. Wiss. Gottingen, 1884, pp. 133-4. ZOOLOGY AND BOTANY, MICROSCOPY, ETO. 891 Lacaze-Duruiers, H. pr.—Note accompagnant la presentation d’Appareils d@éclairage électrique pour les travaux des naturalistes, chimistes, micro- graphes, &c., construits par M. G. Trouvé. (Electrical illuminating apparatus for naturalists, chemists, microscopists, &c., constructed by G. Trouvé.) [1. Glass jar with a silvered glass bottom and a silvered parabolic reflector over the mouth, having in the centre an incandescent lamp illuminating the interior of the jar. 2. Modified apparatus for fermentations. 3. Modified Hélot and Trouvé electric photophore. } Comptes Rendus, CI. (1885) pp. 405-7 (1 fig.). Lewis, R. T.—Electricity in the Microscope. [Supra, p. 875.] Engl. Mech., XLII. (1885) p. 19. Matcotm.—On Binocular Glasses adjustable to eyes having unequal focal lengths. [ Post. ] Proc. Phys. Soc. Lond., VII. (1885) pp. 80-1. M‘ConneEL, J. C.—Notes on the use of Nicol’s Prism. [1. On the error in the measurement of a rotation of the plane of polarization caused by the axis, about which the Nicol turns, not being parallel to the incident light. 2. On a new method of obtaining the zero-reading of a Nicol circle.] Proc. Phys. Soc. Lond., VII. (1885) pp. 22-39 (7 figs.). Netson, E. M.—Microscopical. [Supra, p. 864.] Engl. Mech., XLI. (1885) p. 523. Nicol Prism, repairing. [Nicol prisms which have become scratched and dull may be restored by cementing a thin cover-glass over the ends with clarified gum-damar. The prisms should first be carefully cleaned with a very soft brush and soap, to which may be added a little precipitated chalk. They should then be rinsed with distilled water and carefully dried, pains being’ taken to remove every particle of dust and dirt from within the scratches. The cover-glass, which should be thin and perfectly clean, should then be applied in the usual way, exactly as in making a balsam mount. When carefully done, not a vestige of the scratches can afterwards be detected. ] : The Microscope, V. (1885) pp. 188-9. “OrpDERIC VITAL.”—New Optical Glass. [Feil’s “ extra dense flint, No. 1738.” Also remarks by A. Caplatzi.] Engl. Mech., XI, (1885) p. 519; XLII. (1885) p. 15. Perfect Laboratory Microscope. [Four questions for “ Professors and others who have had large experience in microscopical work ” to answer, as to the model of Microscope generally preferred by educational institutions. ] Micr, Bulletin (Queen’s), II. (1885) p. 25. Queen’s (J. W. & Co.) Resistance Coil. [Designed especially for use with micro-clectric lamps. | Micr, Bulletin (Queen’s), II. (1885) p. 30 (1 fig.). “Rector, F.R.A.S.”—The Optical Lantern. (Queries as to improvements. (Four wick lamps burning best kerosene oil give as much light as can possibly be obtained from that medium.) Also facetious reply by A. Caplatzi, mainly as to the excessive heat of such lamps. : Engl. Mech., XLII. (1885) pp. 62 and 84-5. “Ros. Crvus.”—The Micro-objective. [On mounting the lenses of eye-pieces and objectives. } Engl. Mech., XLI. (1885) pp. 563-4 (2 figs.). See also p. 526. Rocuer, B. pv.—De la Mégaloscopie. (On Megaloscopy.) [ost. ] Comptes Rendus, Cl. (1885) pp. 329-30. Royal Society of South Australia, Postal Microscopical Section of. (‘A box of microscopical objects has been received from Victoria and duly circulated among the members of this section, and a box of South Australian objects has been made up in this colony and forwarded to Victoria and New South Wales.”} Trans. and Proc. and Rep. R. Soc. 8. Australia, VII. (for 1883-4), 1885, p. 130. 892 SUMMARY OF CURRENT RESEARCHES RELATING TO Stoxes, G. G.—On Light as a means of Investigation. Burnett Lectures. Second Course. 114 pp., 8vo, London, 1885. The “Times” on the Microscope. [Supra, p. 883.] Times, 1885, August 26th. Cf. also February 16th. VERRALL, G. H.—Micro-photography for illustrating the neuration of trans- parent winged insects. [Note of successful experiments. | Proc. Entomol. Soc. Lond., 1885, p. iv Walmsley’s (W. H.) Photo-micrograph of Rinnbach’s arranged Diatoms. [Cf. ante, p. 580.] The Microscope, V. (1885) p. 181. Warp, R. H.—The Binocular. [ Post.] Micr. Bulletin (Queen’s), II. (1885) pp. 28-9 (1 fig.) from The Microscope in Botany (Behrens). B. Collecting, Mounting and Examining Objects, &c, Method for Observing Protoplasmic Continuity.*—M. L. Olivier recalls that three years ago he pointed out that photography applied to the study of minute objects revealed details of structure which made no impression on the retina, and that in support of this he instanced a photograph which showed on the walls of the cells markings and perforations invisible under the Microscope. He now further illustrates the matter by reference to the canals which traverse the cell-walls of plants. The existence of these canals escapes the ordinary processes of investigation, but can be shown by the employment of photography. Thin transverse sections are made of living tissues whose growth is complete. A direct photograph is taken of the sections, with an amplification of 300 to 700. On these negatives, examined with a lens, the cell-membranes seem to be in a very surprising state of com- plication: perforated in various ways, with canals, some transverse, others longitudinal, that establish a communication between the contents of the cells. It seems impossible to explain by a pheno- menon of diffraction this appearance of canals on the photographic lates. After having made out this structure on the negatives, the author endeayoured to see them by direct vision and examined the prepara- tions under an amplification of 700-900, in a dark chamber into which the Microscope was introduced, in such a way that the eye received no other impression than that of the light coming from the instrument. Under these conditions he succeeded in sen seeing the interruptions of the cell-walls in many plants. Direct observation is, however, in most cases quite insufficient, and the author obtained a better result by staining, either the cell- membranes of his preparations, or the protoplasmic elements after fixing, turgescence or contraction by means of appropriate reagents. In the first case the septa presented here and there colourless lacunz, at least in certain species of plants. In the second case the walls of the cells were white against the coloured ground; the canals which traverse the septa are then visible, since they are coloured like * Comptes Rendus, ec. (1885) pp. 1168-71. ZOOLOGY AND BOTANY, MICROSCOPY, ETO. 893 the protoplasm itself. M. Olivier also attempted to cause a fluid, capable of colouring the protoplasm, to penetrate under gentle pressure into the organs; transverse sections were then made. The injection rarely succeeded ; but when it took place in a fairly regular manner, this process led to a result identical with the preceding. Eau de Javelle as a Medium for Clarifying and Dissolving Plasma.*—Dr. F. Noll finds that eau de Javelle (an alkaline hypo- chlorite solution) destroys and then dissolves the whole of the plasma of the cells in preparations which have been preserved in alcohol. A similar, but more or less imperfect solution of the plasma-contents occurs in tissues which have been treated with glycerin, Miiller’s fluid, picric or chromic acid. It is not necessary that alcohol should be present during the operation of the reagent ; if a drop of the water is placed on a section made through young cells rich in plasma, this is soon dissolved, with development of small bubbles of gas. If the action takes place in the open air, a soft pellicle quickly forms on the drop, consisting of calcium carbonate, which can be readily dissolved in acetic acid. The formation of this pellicle can be prevented by placing a cover-glass over the drop, under which the process can be studied step by step. In a very short time, usually 3-4 minutes, the plasma is converted into a clear fluid. When the section is suf- ficiently clear, it is washed in water, so as to remove the bubbles of gas. The superfluous granules of calcium carbonate are removed by acetic acid, and the section is then ready to be placed in glycerin. The water acts on cuticular membranes in the same way as Schultze’s macerating fluid, but only slightly and after some time (1 hour or more). Calcified membranes should be first treated with acetic acid to dissolve the mineral constituents, washed, and treated with the water in the usual way. Starch-granules swell in the water, so as to become invisible. Cocaine for Mounting Small Animals.|—Prof. J. Richard de- scribes a new way of fixing Hydroids, Bryozoa, &c., in an expanded condition, which is as follows. A number of the animals are placed in a watch-glass with 5 c.cm.of water when they are fully expanded. A 1/2 per cent. solution of chlorhydrate of cocaine is added drop by drop till it forms a fifth part of the entire fluid. Half a c.cm. of the drug is then added, and the animals become.so completely fixed that it is necessary to touch them very roughly with a needle in order to induce them to contract; ten minutes after, they are quite dead, and can be mounted in the ordinary way. This reagent is superior to all others, because it requires no delicate manipulation; it is not certain yet whether its effect upon marine animals is equally strong in all cases. Preparing Tissues to show Cell-division.t—Dr. C. Rabl objects to Flemming’s chrom-osmic-acetic acid mixture, on the ground that the preparations soon become darkened; and to the 1/2 or 1/3 per cent. solution gold chloride, that in summer reduction takes place and the * Bot. Centralbl., xxi. (1885) pp. 377-80. + Zool. Anzeig., viii. (1885) pp. 332-3. t Morphol. Jahrb., x. (1884) pp. 214-330 (6 pls.). See this Journal, ante, p. 217. 894 SUMMARY OF CURRENT RESEAROHES RELATING TO cell-substance is coloured violet. The best results are obtained from solutions of chromo-formic acid and platinum chloride. Formula for chromo-formic acid :—1/2 per cent. solution chromic acid, 200 grm.; concentrated formic acid, 4-5 drops. The mixture is always to be freshly prepared for use. Small pieces of fresh specimens are to be used. After 12 to 24 hours, wash in water and then transfer to 60 or 70 per cent. alcohol, and after 24 or 36 hours more to absolute alcohol. A 1/3 per cent. solution platinum chloride has the same effect as gold chloride, and this without being reduced by light or heat. Specimens should remain in this solution 24 hours, they are then washed and treated as before. The one method supplements the other, as chromo-formic acid causes certain fibres to swell, while platinum chloride has a somewhat shrivelling effect. Method for showing the Distribution and Termination of Nerves in the Human Lungs.*—Dr. H. F. Beckwith, aware of the futility of hoping to obtain good results from any known manner of preparation and staining of the nerves of the lungs, sought a new method, and the following modification of a process lately promulgated in Germany for staining brain-tissues was found to answer. Harden fresh lung for about ten days in the following solution :— Bichromate of potash 2°5 per cent., to which is added sulphate of copper C. P. to the amount of 0°5 per cent. The tissue is then frozen and suitable sections made, which are treated with gold chloride 0°5 per cent., 2-10 minutes in the dark. Washed with distilled water. Sodium hydrate 1-5, until cleared up. Potassium carbonate 10 per cent., 30-60 minutes. Dried with absorbent paper. Potassium iodide 10 per cent., 15 minutes, when gold will be nicely reduced. The nerves and ganglia in sections thus prepared are of a deep red or violet colour, occasionally shading off into a blueish green, the other tissue being red. The differentiation in colour is sharp, so that nerve-tissue may be recognized by its colour alone whenever seen. The above method differs very little from the German process, with the exception of the potassium carbonate, which the author believes essential to success, as the unmodified process failed to give good results, when used on lung tissue. A great advantage of the method consists in the fact that the reduction of gold always takes place in a uniformly even manner; and with little practice, perfect staining can be accomplished with every section. Unfortunately, as in other gold preparations, the specimens spoil in a short time unless preserved in the dark in 40 per cent. alcohol, and when examined should be temporarily mounted in glycerin. Preparing Tail of Puppy.j—Mr. A. C. Cole’s method of prepara- tion is to first harden the tail in methylated spirit for a week, then soak in water, then place in a considerable quantity of a 1/6 per cent. solution of chromic acid, to every ounce of which five drops of nitric acid are added. This mixture should be frequently changed. * The Microscope, v. (1885) pp. 148-52 (3 figs.). + Cole’s Studies in Micr. Sci., iii. (1885) Sec. 4, p. 24. ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 895 When the bone is softened, the tail is to be soaked in water to remove the acid and reharden in spirit. Transverse sections are cut from the tail and stained in the ordinary borax-carmine solution; when sufficiently stained they are transferred to methylated spirit, and then placed in a mixture of five parts spirit and one part hydrochloric acid ; from this they must be removed as soon as they attain a brilliant scarlet tint, and be again placed in spirit until no trace of acid remains. The sections are then to be stained in sulph-indigotate of soda—two drops of a saturated aqueous solution of which are added to one ounce of spirit—and in this the sections should remain for from four to six hours. They are then to be finally and carefully washed in spirit, cleared in oil of cloves, and mounted in Canada balsam. Demonstrating Spindle-shaped Bodies in the Yolk of Frog’s Ova.*—Dr. O. Hertwig states the best method is to place the ovary for two or three minutes in a mixture of 0°3 per cent. osmic acid and 0-1 per cent. acetic acid, and then in order to prevent over-blackening transfer to iodized serum or bichromate. Osmic acid causes ova to coagulate homogeneously, so that they are transparent. Very dilute acetic acid on the other hand clearly shows up the contours of germinal vesicle and nucleoli. Excessive blackening by osmic acid may be removed by peroxide of hydrogen. Thus treated, ova retain all their details after six months. Only teasing out is required. Microscopical Technique of the Eye.t—Dr. R. Warlomont describes the method of preparing specimens of eyes for microscopical examination which is used at the Moorfields Ophthalmic Hospital. The whole eye is placed in Miiller’s fluid for 3-4 weeks, and then cut with a sharp knife into two symmetrical parts, which are washed in water to remove the yellow colour. The decoloration is hastened by placing them for several minutes in a 1 per cent. solution of chloral. They are then placed for a day in ordinary alcohol, and transferred to absolute alcohol for 24 hours. They are next placed for 24 hours in celloidin dissolved in equal parts of sul- phuriec ether and absolute alcohol, and laid in a paper box, which is filled with the celloidin solution. When this has become changed into a gelatinous elastic mass, it is placed in ordinary alcohol (70-80), in which it acquires the necessary hardness, and in which it can be preserved indefinitely. The sections are cut with Katsch’s microtome beneath alcohol, stained with Ehrlich’s logwood or other solution, washed in water and alcohol, clarified in oil of bergamot, and mounted in balsam. Preparing Eyes of Gasteropods.t—Concentrated solution of per- chloride of mercury is found by Dr. C. Hilger to keep the rods in good condition for hardening in Miiller’s fluid. Picric acid or alcohol may be used. The best stain is hematoxylin. First overstain, then decolo- * Morphol. Jahrb., x. (1884) pp. 837-43 (1 pl.). + Bull. Soc. Belg. Micr., xi. (1885) pp. 201-8. $+ Morphol. Jahrb., x. (1884) pp. 351-71 (2 pls.). 896 SUMMARY OF CURRENT RESEARCHES RELATING TO rize with weak alum solution for a period of several hours to some days. Nucleiand cell boundaries are wellshown. Cutin paraffin. For macerating, a 2 or 3 per cent. solution of chromate of potash, or it may be concentrated and diluted with a weak oxalic acid solution or Muller’s fluid. Fresh material is ready in a few hours; hardened material in a few weeks. It is recommended to dissociate the macerated and stained specimen when in section, and to separate its elements by tapping on the cover-glass. Method of Softening Chitin.*—Dr. Looss describes a new method of dissolving the chitinous skeletons of Arthropoda, &c. The reagents used are hypochloride of potassium and sodium; the latter can be purchased in chemists’ shops under the name of Eau de Laberraque. The percentage of the solution has not been definitely settled. The chitinous skeletons of insects are rendered completely transparent, and the nerves and muscles uninjured by the use of the reagent diluted 4—6 times with water. Demonstrating Nerve-end Organs in the Antenne of Myrio- pods.t—In order to demonstrate the origin and the articulation of the olfactory bulb in the antenne of Chilognatha, Dr. B.Sazepin first washes the antenne in alcohol, and then, in order to remove the pigment from the chitinous tissues, immerses in chloroform to which one drop of strong nitric acid has been added. After being placed in absolute alcohol they are treated with 1/2 per cent. solution of osmic acid. The nervous tissue becomes brown in about 20 hours. The processes previous to cutting are to place the antenne in absolute alcohol and next in picric acid for a day. After washing frequently in 75 per cent. spirit, transfer to absolute alcohol and stain with Grenacher’s alum-carmine. Wash for a whole day in water; for another in 75 per cent. spirit; then absolute alcohol, chloroform, paraftiin, and cut. Sources of Error in the Examination of Fresh Tissues.{—Dr. Heller draws attention to two sources of error in the examination of fresh tissues, each of which can, however, be obviated by adopting proper precautions. 1st. The red blood-corpuscles are in a great many cases destroyed by the cold temperature when the sections are cut with a freezing microtome. This can, however, be prevented by placing the pieces of tissue, before cutting, for a short time in a weak solution of bichromate of potash. 2nd. When a large number of sections have to be examined, a development of micro-organisms may occur before there is time to carry out the examination. This, too, can be prevented by placing the sections in salt solution (3/4 per cent.) to which 1 per cent. chloral hydrate has been added. An addition of 1/2 per cent. chloral * Zool. Anzeig., viii. (1885) pp. 333-4. + Mém. Acad. Imp. Sci. St. Petersbourg, xxxii. (1884), 20 pp. and 3 pls. { Zeitschr. f, Wiss. Mikr., ii. (1885) pp. 47-8. ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 897 prevents the development of the Schizomycetes, but not of the moulds. A solution stronger than 2 per cent. acts unfavourably on many tissues. Mounting Media for Nematodes.*—The following is recom- mended by Dr. M. Braun as a medium in which unstained prepara- tions of small nematodes may be mounted :—Gelatin 20, glycerin 100, water 120, carbolic acid 2. The preparations are treated beneath the cover-glass (after previous treatment with Miiller’s fluid and distilled water) with weak alcohol (first 25 per cent. and then 40 per cent.). This is removed by placing at the edge of the cover- glass glycerin diluted with an equal part of water; by the evapora- tion of the water pure glycerin remains. The cover-glass is then lifted up, and the gelatin, rendered fluid by warming, applied. A sealing varnish is not necessary. Preparing Myzostoma.j—As preserved specimens did not give favourable results, their development was chiefly studied by Mr. J. Beard on the living animal. If plenty of naturally impregnated Comatula with adult Myzostoma glabrum can be obtained, the arms are cut off by the calyx and placed in a vessel filled with sea water. On the following day the Comatula are removed, and at the bottom of the glass the ova or larva of Myzostoma will be found. They can be kept alive from 4-5 days. But as only a few ova can be obtained, and the Comatula die in a few days, ova artificially impregnated are used. A number of adult Myzostoma are removed from their host and placed in a watch-glass containing 2-3 teaspoonfuls of freshly filtered sea water. They are then torn with needles and left for two or three hours. The pieces of Myzostoma are then fished out; the ova which remain at the bottom of the vessel are supplied with fresh sea water every other day and also with air by means of Andres’ apparatus. Most larvae die in about six days. For the later stages of development the Comatula are placed in a vessel containing a mixture of sea water with 10 per cent. of alcohol. By this they are slowly killed. On shaking the vessel Myzostoma glabrum and cirri- ferwm fall to the bottom. Alcohol is then gradually added until it reaches 90 per cent. In this they are preserved. Sensitive Tests for Wood-fibre and Cellulose.{—Dr. A. Ihl finds that besides the well-known reagent phloroglucin, other phenols stain lignin in a characteristic way. An alcoholic solution of orcin acidulated with hydrochloric acid stains woody fibre a beautiful dark red. Cellu- lose remains unchanged. Resorcin with alcohol and hydrochloric acid gives a blue violet stain. JResorcin with alcohol and sulphuric acid (1 part C,H,O to 1/3 part H,SO,) gives a dark blue violet stain. To cellulose a reddish hue. a-naphthol, alcohol, and hydrochloric acid produce a greenish hue: a-naphthol, alcohol (1 part), sulphuric acid (1 part), impart a dark-green colour to wood, to cellulose a red-violet * Braun, M., ‘Die thierischen Parasiten des Menschen nebst einer Anlei- » heigl praktischen Beschaftigung mit der Helminthologie, fiir Studirende und erZte. + Zeitschr. f. Wiss. Mikr., ii. (1885) p. 231. t Chem. Ztg., 1885, p. 266. 898 SUMMARY OF CURRENT RESEARCHES RELATING TO colour. Pyrogallic acid, alcohol, and hydrochloric acid give, with heat, a blue-green stain. Carbolic acid, alcohol, and hydrochloric acid a yellowish green. Modification of Semper’s Method of making Dry Preparations.* —Prof. O. P. Hay, finding that preparations made according to Sem- per’s method often present a dingy, weatherbeaten aspect, recommends that the method should be completed by saturating the preparation with a solid that fills up the pores and binds the parts together. The solid which he employs is a mixture of Canada balsam, paraffin, and vaseline, but it is probable that a soft paraffin will in most cases do quite well. It is necessary that the mixture shall melt at about 46° C. Freeing Objects from Air.;—D. 8. W. recommends the follow- ing plan for mounting objects containing a considerable quantity of “Take, for example, a collection of Isthmia, or some other diatom. The valves enclose so much air as to cause them to float upon water, and it must be extracted, for until they sink it is impossible to wash them. Drive from water all the air you can by a good boiling for about five minutes, allow the water to cool so as to be in condition to absorb air, and without delay drop in the diatoms. The water will extract the air from them and they will go to the bottom. Then add to the water a little dissolved chloride of soda, and with an occasional shake up, you will find the material pretty well cleaned and bleached in one hour. Wash thoroughly in several changes of water. Take a drachm of redistilled alcohol and add thereto two drops of dissolved gum arabic. With a sharpened stick place a small quantity on the centre of a cleaned slide. It will spread out and the alcohol will quickly evaporate, leaving a very thin film of the gum. On this gummed spot place a drop of your cleaned diatoms, and see that they are thoroughly dried by time or heat. Of course, they are now filled with air, and are firmly enough attached to the slide, and can be covered in a cell if a dry mount is desired. To mount in balsam, however, the air must be again extracted, and at this stage the boiled water prescription cannot be administered. Have Canada balsam made quite tough by age or heat, and then dissolved in benzole. Put around the objects which have been dried on the slide a few fragments of cover-glass, and on them, as legs to a stool, place a clean cover-glass. A drop of the pure benzole will quickly run under the cover-glass, and very promptly take the place of the air in the diatoms; anda drop of the balsam at one edge of the cover, and a corner of blotting-paper at the other, will quickly substitute the balsam for the benzole. Time or gentle heat will harden the cement, and the specimen is safe.” Cleaning and Preparing Diatom Material—Mounting Diatoms.— Herr E. Debes, in an article of 17 pages, { describes the necessary * Amer. Natural., xix. (1885) p. 526. + Amer. Mon. Mier. Journ., v. (1884) p. 18. { Hedwigia, xxiv. (1885) pp. 49-66. ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 899 processes both in the case of recent and fossil forms. In a later article of 16 pages * Herr Debes describes the various mounting media, and gives directions for mounting diatoms. The articles cannot be usefully abstracted. Gowen’s Microtome.t—Mr. F. H. Gowen, considering that the use of paraffin for imbedding is attended with difficulties on account of its becoming loose in the microtome, has made a microtome in which the difficulties are overcome. A hole is turned about half-way through the table of a microtome, and into this a tube is screwed, forming the well. The hole through the remainder of the table, forming the mouth of the well, is turned with sufficient “ gather,” or taper, to take up the shrinkage of the parafiin. On the upper side of the piston a dovetailed groove is turned. The column of paraffin receives no support from the tube, but is securely held by the piston at one end and by the contracted mouth of the well-hole at the other. (Diameter at the top, 0°9 in., tapering from diameter of 0°92 in. Length of taper, 0°15 in.) Jacobs’s Freezing Microtome.{—Dr. F. O. Jacobs has devised the freezing: microtome shown in figs, 215 and 216. It consists of a copper rod A, 2 in. or more in diameter, and 6 in. high, inclosed by Fia. 215. Fic. 216. SONS MOA SSS SSS ‘ an inner zinc and an outer brass tank. Above is the table D, work- ing on a fine screw. Through the centre of the table passes a narrower portion of the copper rod p. When the inner tank is filled with a mixture of salt, ice, and water, the temperature of the copper rod is so reduced as to freeze any object F placed on its upper end. The size of the rod is such that its temperature will remain very steady for from four to six hours, without any further care on the part of the operator. * Hedwigia, xxiv. (1885) pp. 151-66. + Amer. Mon. Micr. Journ., vi. (1885) p. 156. ¢ Amer. Natural., xix. (1885) pp. 734-6 (2 figs.). 900 SUMMARY OF CURRENT RESEARCHES RELATING TO By this arrangement objects can be easily frozen, and without any slop. The imbedding medium is composed of:—gum arabic, 5 parts; gum tragacanth, 1 part; gelatin, 1 part. The mixture is dissolved in enough warm water to give it the consistency of thin jelly when cold. A little glycerin (1:6) is added to the water. Eternod’s Microtome with Triple Pincers.*—The instrument of Dr. A. Eternod consists of a brass cylinder terminating above in a polished nickel-plated platform, on which the razor is directed. The cylinder is composed of two drums screwed one over the other so that the lower drum being fixed, if the upper drum is turned round its axis it is gradually raised. The edges of the upper drum are divided into 100 parts. Each entire revolution of the drum raises or lowers the platform 1 mm.; if it is moved through only one division, the platform is displaced to the extent of 1/100 mm. The object is fixed in the axis of the microtome by a triple pincer consisting of three pieces of brass set on the base-cylinder, which can be separated or approximated by means of a screw beneath the in- strument. If the screw is turned from right to left, the three pieces are separated and the specimen can be interposed, imbedded in cork, elder-pith, &c. If the screw is now turned from left to right, the pieces are approximated, and the specimen can be firmly fixed. It is easy With this microtome to cut sections 1/200-1/400 mm. thick. Dr. A. Eternod, in writing ¢ to claim to be the originator of the microtome, points out several advantages not noticed in the above description. It can be filled with alcohol or Fie, 217. other liquid, so that the object to be cut can be preserved for some time. Objects 4 cm. long can be cut. Gannett’s Dripping Apparatus.t—Dr. C. 8. Minot recommends Dr. W. W. Gannett’s drip- ping apparatus for cutting under alcohol (fig. 217). A litre bottle is convenient in size, and the height of the stand should be such as to bring the end of the i) dripping-tube about lin. above the blade of the knife, on which the alcohol is allowed to fall continuously. To regulate the flow an 1/8 in. globe-valve is found to be the most convenient. ; Staining for Microscopical Purposes.$—In further continuation of his excellent articles, Dr. H. Gierke deals with (1) the treatment * Journ. de Microgr., ix. (1885) pp. 171-4. t+ Ibid., pp. 264-7, + Amer. Natural., xix. (1885) p. 916 (1 fig.). . § Zeitschr. f. Wiss. Mikr., i. (1884) pp. 497-557, and ii. (1885) pp. 13-36. ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 901 of specimens with various metal salts, such as chloride of palladium, oxide of iron, &c. (2) Staining methods in which carmine is com- bined with other reagents, e. g. picric acid, indigo-carmine, and metal salts. (3) Methods in which logwood is used in combination with various other reagents. (4) The combination of anilin dyes with each other and with metal salts. (5) The combination of the gold and silver methods. Not the least important and interesting part of the articles is the historical description of the development of the employment of anilin dyes in staining technique, commencing with mauvein and fuchsin in 1856. The author well observes that those who are engaged in histological research with the aid of staining materials should be thoroughly acquainted with the chemistry of the dyes with which they work, and a description is given of the source, manufacture and properties of the anilin dyes as well as alizarin, logwood, indigo, carmine, and others. In his concluding article,* Dr. H. Gierke has drawn up elaborate tables respecting the anilin pigments. The first table gives the ordinary nomenclature, chemical formule, remarks on the solubility, reactions, and preparation of the various anilin stains. The second table, arranged according to colour, gives the solubility in water or alcohol and the behaviour with acid and alkalis. The rest of the paper is chiefly occupied with a discussion as to whether, when a preparation becomes coloured, the colour is due to imbibition of pigment, or is the result of chemical changes effected in the tissue by the pigment. The author maintains that though histo- logical staining depends for the most part on the physical processes of diffusion and imbibition, the occurrence of chemical combination in staining cannot be denied. On the contrary, such combinations are of frequent occurrence and, as micro-chemical reactions, are of the greatest importance. The histological stain, so far as it impartsa permanent dye, depends on the physical process of surface attraction. Chemical processes should be suspected when a pigment is discharged or changes to a different shade. Wemay, therefore, speak of chemical processes when one and the same pigment stains different tissue elements of a preparation in different ways. Double staining by the simultaneous or consecutive use of several dyes only in part depends on chemical processes. In greater measure they are effected by the unequally developed attraction-force of various tissues. It is also shown by the fact that one pigment is able to remove another from certain tissue elements, but not altogether from the same preparation. Ifa section of any organ, rich in various tissues, be laid in a mixture of several pigments, each histological element is stained by that for which it possesses the greatest attraction. If a certain part have for two or more dyes an exactly similar attraction, it then takes up both or all, and a mixed colour is the result. Examples of staining by chemical processes are, among others, the various reactions on amyloid substance. When Curshmann employed methyl-green for staining amyloid-degenerated nerves, all the normal parts were coloured green, the hyaline cylinder light blue, and the amyloid substances * Zeitschr. f. Wiss. Mikr., ii, (1885) pp. 164-221. Ser. 2.—Vou. V. 3.°N 902 SUMMARY OF CURRENT RESEARCHES RELATING TO violet. The latter, therefore, entered into chemical union with the pigment, the new body only showing a colour differing from that of the dye. Thus, too, the rose-orange staining of red blood-corpuscles by eosin may be regarded as the result of a chemical reaction. The author concludes by expressing the opinion that the staining problem of the future will be solved by the aid of chemical reaction. Staining Methods.*—Dr. J. H. List discusses some double stains which he has used for a long time with excellent effect, especially on gland and epithelium. 1. Bismarck-brown and methyl-green stain is prepared acoordine to Weigert’s method, i.e. 5 grm. of pigment to 100 c.c. aq. destil. The sections are left in the brown solution for from two to fifteen minutes. They are then washed and removed to the green stain, where they remain until they have assumed a dark-green colour. They are again washed and placed in absolute alcohol. Experience is the only guide as to when they should be taken out of alcohol, but as soon as a sap-green hue appears the sections may be withdrawn and placed in bergamot, xylol, &c., to clarify. The advantage of this method is that Bismarck-brown gives with methyl-green a beauti- fully distinct sap-green colour, while for goblet-cells and mucous membrane it is especially valuable, because the intracellular network is coloured brownish green or dark brown, and stands out with a sharpness as in no other staining combination. 2. Bismarck-brown and anilin-green may be used in an exactly similar manner. 3. Hosin and methyl-green were first used by Calberla, who dis- solved a mixture of 1 part eosin and 60 parts methyl-green in 30 per cent. warm alcohol. The author uses the stains separately. The sections are first placed in an alcoholic solution of eosin made by mixing 5 ¢.c. of a watery solution of eosin (0°5 grm. to 100 c.c. aq. dest.) with about 15 c.c. absolute alcohol. Two to five minutes suffice to stain deeply. Wash again and transfer to absolute alcohol, from which it is usual to remove the sections when the eosin is perceptible. They are then placed in the clarifying medium. This method of staining may be recommended for epithelium, mucous membrane, and cartilage. 4. Eosin and anilin-green. Schiefferdecker was the first to employ this method of double staining. The following modification may be employed with excellent results for cartilage and glands. An alcoholic solution of eosin is prepared as in No. 3. After remaining in this ~ solution for fifteen minutes or so, the sections are washed in alcohol, and are then transferred to an alcoholic solution of anilin-green. After remaining in this for fifteen minutes, they are removed to absolute alcohol, where they remain until the eosin stain begins to show itself. 5. Hematoxylin-glycerin and eosin. Renaut’s method { of double staining, somewhat modified, produces splendid preparations. Three or four drops of Renaut’s hematoxylin. glycerin are mixed with 1/4 * Zeitschr. f. Wiss. Mikr., ii. (1885) pp. 145-50. + Comptes Rendus, Ixxxviii. (1879) p. 1039. See this Journal, ii. (1879) p. 763. ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 903 litre of aq. dest. In this the sections are left for 24 hours. Then wash and transfer to an alcoholic solution of eosin (as in No. 4) for several minutes. Wash in alcohol, and clarify. This method pro- duces a beautiful nuclear stain, the nuclei are coloured deep violet, the rest of the tissue a beautiful rose red. 6. Hematoxylin-glycerin and rosanilin nitrate. The sections are placed in the dilute hematoxylin-glycerin (No. 5) for 24 hours; then for ten minutes in a solution of rosanilin nitrate ; after washing in water, dehydrate and clarify. 7. Methyl-green and rosanilin nitrate. The sections are left in the No. 1 solution of methyl-green for ten minutes, then after washing are placed in solution of rosanilin nitrate for fifteen minutes; wash again, dehydrate, clarify. The first three methods may be modified by using very dilute solutions and staining for 24 hours. For hardening, the author always employed absolute alcohol ; and Miiller’s fluid or chromic acid for material to be imbedded in celloidin. Staining Nerves in Muscle.*— To obtain good images of the ramification of nerves in muscle, Dr. K. Mays gives the following process. For small muscles, lay freshly prepared portions in a recently made mixture of 1/2 per cent. alkaline solution of gold chloride, 1 grm.; 2 per cent. osmic acid, 1 grm.; water, 20 grm., until the arbo- rescent nerve ramifications can be perceived; then in the following mixture: glycerin, 40 grm.; water, 20 grm.; 25 per cent. hydro- chloric acid solution, 1°0 grm., for about a day. This prevents them from becoming too dark. Thicker muscles are placed for 12 hours in a 2 per cent. solution of acetic acid, then into a freshly made mixture of 1/2 per cent. alkaline solution of gold chloride, 1 grm.; 2 per cent. osmic acid, 1 grm.; 2 per cent. acetic acid, 50 grm. In this they remain for two or three hours and are then placed in the glycerin mixture. The muscle becomes transparent and amber-coloured, the nerve black- brown. By this method the nerve-end-plate is stained, but not the hypolemmal parts of the nerve. Anilin-green.t—Dr. J. H. List controverts Schiefferdecker’s statement that anilin-green requires exposure to light before it is fully capable of staining cell-structures. He finds that solutions of methyl-green and anilin-green (0°5 grm.—100 c.c. distilled water) always colour, even when freshly prepared, the reticulum of goblet and other cells. He also recommends Bismarck-brown and rosanilin nitrate, either in union or alone for the same object. In reply to List, Dr. P. Schiefferdecker{ maintains that the former has confused the reticulum which is perfectly apparent even in unstained specimens, with the reticulum only demonstrable by anilin-green solution which has undergone certain changes from lapse of time and exposure to light. The latter reticulum is much thicker than that which is described by List, but otherwise there does not seem to be much difference between them. * Zeitschr. f. Biol., xx. (1884) pp. 449-528 (5 pls.). + Zeitechr. f, Wiss. Mikr., ii. (1885) pp. 222-3. t has pp. te N 904 SUMMARY OF CURRENT RESEARCHES RELATING TO Perchloride of Mercury in the study of the Central Nervous System.*—Golgi’s methods for staining nerve-elements black are based on the action of nitrate of silver and perchloride of mercury following the use of bichromate of potash. The mercurial salt, how- ever, does not give a real black colour, but renders the elements opaque and causes them to appear black under the Microseope. For small pieces the method is to immerse in a 2 per cent. solution of bichromate or in Miiller’s fluid for a month. They are then trans- ferred to a 0°5 per cent. solution of perchloride, which is daily renewed until all colour traces of bichromate have disappeared. Dr. C. Mondino applies the foregoing method to whole brains by injecting through a carotid (the other and the vertebrals being tied) Miiller’s fluid by the pressure-bottle process. The excess fluid passes out by the jugular veins, and when the stream has become very slow or stopped, the brain may be transferred to Miiller’s fluid, where it should remain for a couple of months, though a longer period is not harmful. The carotid injection process is not absolutely necessary, as the brain after removal from the body may be placed in Miiller’s fluid at once. In this case the membranes must be stripped off. Directly after removal from the fluid, the brain must be placed in a 1/2 per cent. aqueous solution of perchloride and this must be continually changed so long as the solution is stained by the bichromate. It is proper to leave the brain in the perchloride solution for at least two or three weeks after all trace of bichromate has disappeared. Sections are best made by Gudden’s microtome. It is unnecessary to soak these brains in paraffin; owing to their consistence, imbedding alone is found to be sufficient. Out of a whole brain not more than twenty sections will be lost. While by other methods thin sections are a sine quad non for observation, in this, thick slices are almost necessary, the chief advantage of which is obviously that any fibre can be followed throughout its course in the brain. When a section has been made it is placed at once on a slide and then washed with water to remove any bits of paraffin. It is then dried with blotting-paper. Next a little pure creosote is placed on the centre of the section, which is thereby rendered quite transparent in a few hours. After draining away the excess of creosote, the specimen is covered with dammar.. No cover-glass is used. The author claims the following advantages for this method. It is the only one which shows the course of nerve-fibres throughout the brain. It is extremely simple. In all other methods, the speci- mens must be thin, require to be stained after section, and to go through many processes; all this renders them liable to injury. It is inexpensive, as the reagents used are very cheap when compared with those required for other methods. Macroscopically, in other methods there is diminution of volume, disappearance of difference between white and grey matter, while brains prepared in perchloride show the difference between the white * Zeitschr. f. Wiss. Mikr., ii. (1885) pp. 157-63. ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 905 and grey substances even more markedly than in the fresh state. Moreover, if we wish to have them dry they are merely placed in glycerin for a few days, and on removal the excess of glycerin is allowed to drain off. Decalcification and Staining of Osseous Tissue.*—After alluding to methods for obtaining specimens by grinding and by section of bone decalcified by acids, Dr. G. Pommer advocates the advantage to be derived from using bone softened by osteo-malachic or rachitic changes. He states that Miiller’s fluid possesses properties hitherto unnoticed by previous writers; and that by an extensive series of experiments on bones softened by disease, he has been enabled by the use of certain anilin dyes to distinguish with precision between those parts of bone out of which the salts have been removed artificially, and those parts from which the salts are naturally wanting. This important property of Miiller’s fluid apparently depends on the fact that its acid salts decalcify less completely than pure acids. Decalcification by acids produces many deceptive appearances from shrinkage, &c., and these are altogether obviated by the use of Miiller’s fluid, which while allowing the bone to be easily cut, does not produce any of these deficiencies or dangers. These advantages are in no way lost from long immersion or frequent change of fluid. The author’s method of staining with anilin dyes depends on the fact that those parts which have at one time contained lime salts become coloured, while those which have never been impregnated remain unaffected. The dyes, six in number, are the blue and red methyl-violets, dahlia, Parma violet, safranin, and methyl-green. The strength of the solution is for the violets 02 per 1000; for dahlia -04 per cent. ; for safranin -1 and ‘16 per cent.; and for methyl-green -3 per cent. The sections are allowed to remain in solution from12 to 18 hours. The first five give a dark stain, the last only a pale green. Staining the Nucleus of the Germinal Vesicle in Arthropoda.t{— Though the methyl-green and acetic acid solution recommended by Mayzel and Strasburger usually produces a good nuclear stain, Dr. yv. Wielowiefski states that the nucleus of the germinal vesicle in Arthropoda, and as he suspects in all animals, is absolutely, or almost, unstainable even though the cell be completely isolated in order that the staining fluid may have certain access to the nucleus. Only a few cell nuclei, e.g. the nuclei of nerve-cells and of Gre- garinz, show this peculiarity. Double Injections for Dissecting Purposes.t—Professor H. F, Osborn’s method for double injections § was to fill the whole vascular system with a thin coloured injection-mass. When this has passed through the capillaries and well filled the veins, there is forced into the artery a differently coloured plaster mass which pushes the * Zeitschr. f. Wiss. Mikr., ii. (1885) pp. 151-6. t Biol. Centralbl., iv. (1884) pp. 360-70. t Amer. Natural., xix. (1885) pp. 526-7. § See this Journal, iv. (1884) p. 325, 906 SUMMARY OF CURRENT RESEARCHES RELATING TO previously injected thin mass before it until the plaster has reached the capillaries, where its onward movement is arrested. Prof. O. P. Hay uses the following method, based on the same principle. A canula is fitted into the aorta of a cat, and a gelatin mass coloured with carmine injected until it is seen to flow from the right side of the heart ; then the tube conveying the red mass being detached, a tube conveying a blue gelatin mass is slipped over the same canula, and the pressure again applied. Into this blue mass had been mixed thoroughly a quantity of starch, preferably from wheat. This starch- bearing mass pushes the carmine mass before it until the starch-grains enter the capillaries and effectually plug them up. The arteries are thus left blue and the veins red, and so well is the work accomplished» that a lens of considerable power must be used to discover any admix- ture of the colours in the smallest vessels of thin membranes. Double Injections for Histological Purposes.*—Prof. O. P. Hay refers to the usual method of producing a double injection of the blood-vessels preparatory to making sections for the Microscope, by injecting first a gelatin mass of one colour into the artery until the increasing pressure gives notice that the mass is entering the capil- laries, and immediately after to inject a differently coloured mass into the vein. The injection being thus accomplished, one of two things, it seems to him, is likely to happen; either the vessels will not be well filled, or the mass intended for one set of vessels will be driven through into the other. To avoid these accidents he’has practised the method of filling both sets of vessels at the same moment and under exactly the same pressure. This pressure is kept low at the beginning, so that all the arteries and veins shall be thoroughly filled before either mass begins to enter the capillaries. Then as the pressure is increased the differently coloured masses meet each other in the capillaries; and if the pressure on each is equal, the vessels may be filled as full as compatible with safety, without danger of either colour being driven from one set of vessels into the other. The desired pressure is secured by allowing a stream of water from a hydrant or cistern to flow into a tight vessel. As the water flows in, the air is forced out through a rubber tube A (fig. 218) into the wide-mouthed bottle F, whose tightly fitting cork gives passage to two other glass tubes. These extend below just through the cork, and above connect respec- tively with the rubber tubes C and D. Into the side of F near the bottom is fitted another tube E, reaching to a height of ten inches or more, open above, and graduated into inches. If preferred, this tube may also pass through the cork, and extend down well into the mer- eury with which F is partly filled. B is a bottle of suitable size in which is contained a blue injection-mass for filling the veins, and R a similar bottle containing a red mass for the arteries. The interiors of these bottles are connected with the bottle F by the tubes D and C. Each of the bottles B and R has a tube which, starting from near the bottom, passes through the cork, and is, a little above this, bent at * Amer. Natural., xix. (1885) pp. 527-9 (1 fig.). ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 907 right angles. With these are connected the rubber tubes H and I. When water is allowed to flow into the reservoir mentioned above, the air is forced out through A into F, and thence along the tubes D and C into B and R. As soon as the pressure in these bottles becomes sufficiently great, the liquids which they contain will be driven out Fia. 218. through the tubes H and L. If there should be any obstacle to the escape of these fluid masses, the pressure in all the vessels will rise and be registered by the height of the mercury in E. If now it is desired to inject, for instance, the kidney of a pig, a canula made of a glass tube must be fitted securely into the renal artery, and a similar one into the renal vein. The canule must be of such a size that the rubber tubes H and I will fit them well. Heat the gelatin-masses in the bottles B and R to the proper temperature, and keep them so heated until the injection has been finished. Special care must be taken with the tubes H and I, to prevent the gelatin passing through them from becoming frozen. Having clamped the tube H, have an assistant turn on a small stream of water until the gelatin begins to flow slowly from I. If the diameter of the canula is not too small it may be held with the free end directed upward and filled with gelatin allowed to drop from the mouth of J. Then slip I over the canula. Unclamp the tube H, and when the gelatin from B has begun to flow, slip it ‘over the canula inserted in the vein. Then increase the pressure gradually until it has reached as high a point as experience has taught to be safe for the organ operated on. By this apparatus double injections may easily be made of any organs whose veins are not provided with valves. Triple injections of the liver may be made by first injecting the hepatic artery with a green mass until the whole liver assumes a green tint, and afterwards injecting the portal vein and the hepatic vein with red and blue as above directed. 908 SUMMARY OF CURRENT RESEARCHES RELATING TO Double-sided Slide.—Dr. C. V. Zenger suggests that for viewing both sides of an object the slide should be pierced through in the centre, and the aperture surrounded on the upper and under side by countersunk rings for the cover-glasses to rest on, level with the surfaces of the slide. It is to be feared that this plan, though theoretically very perfect, would be too difficult of execution to be practical, though Dr. Zenger writes that “the feat of turning out the slides in their centre without breaking numbers of them is not so difficult as it may seem, if they are well centered and cemented to a cork plate fastened centrally to avoid lateral irregular pressure.’ He adds, “Such a slide will do extremely good service to the microscopist as well as to the biologist, and amply repays the amount of labour spent on its construction.’ * Dr. W. Krause has also suggested what appears to be a similar arrangement.T Uses of Collodion.{—Mr. E. L. Mark gives an historical account of the development of the use of collodion in histological technique. The concentration of the collodion was rendered capable of varia- tion by Merkel, through the use of celloidin dissolved in absolute alcohol and ether in equal parts. Schiefferdecker has shown that by dehydrating sections with 95 per cent. alcohol, and clarifying in oil of origanum or bergamot, they can be mounted in balsam. In com- bination with oil of cloves collodion can be used as a fixture for sections in series, which can be stained after they have been arranged and fixed on the slide.§ Gage || applies the collodion and oil of cloves separately, first coating a number of slides with collodion, which is poured on to one end of the slide and allowed to flow quickly over it and back into the bottle, and then adding a wash of oil of cloves. In order to remove any cloudiness that may arise in the collodion-film a little oil of cloves is added to the balsam. The use of collodion to prevent the crumbling of brittle sections originated with Mr. N. N. Mason,{] who applied it by means of a fine brush, taking up a small drop and placing it in the centre of the object, so as to allow it to flow out on all sides. After being allowed to harden for a minute, the section may be cut and placed on the slide with the film of collodion underneath. The following formule are given for the preparation of celloidin injection-masses. . A. Asphalt celloidin. 1. Pulverized asphalt placed in a well-closed bottle of ether and allowed to remain 24 hours, with occasional shaking. 2. The brown-coloured ether is turned off, and small pieces of celloidin dissolved in it until the solution flows like a thick oil. * See also this Journal, ante, p. 377. + Internat. Monatsschr. f. Anat. u. Histol., i. (1884) p. 353. t Amer. Natural., xix. (1885) pp. 626-8. § Arch. f. Mikr. Anat., xxii. (1883) p. 689. || Med. Student, Nov. 1883, p. 14. 4 Amer. Natural., 1880, p. 825. ZOOLOGY AND BOTANY, MICROSCOPY, ETO. 909 B. Vesuvin celloidin. 1. Make a saturated solution of vesuvin in absolute alcohol. 2. Dissolve in this pieces of celloidin until the desired consistency is reached. C. Opaque celloidin. 1. Dissolve celloidin in absolute alcohol and ether in equal parts. 2. Add vermilion or prussian blue. Mounting in Cells with Canada Balsam.*—Mr. H. Sharp de- scribes a method which obviates many of the difficulties usually experienced. A cell of paper or card of the requisite thickness is cemented on the slide with gum, and a small piece cut away on opposite sides of the ring. The object (which has never been allowed to dry, but has been transferred from the medium in which it was arranged, into strong spirit and thence into oil of cajeput, into benzine and finally into tur- pentine) is next placed in the centre of the cell with a single drop of turpentine on it to keep it moist, and the cover-glass is put on the gummed surface of the cell. When the gum has set and the cover is quite firm a little benzine is taken up with a pipette and applied to one of the openings cut in the card cell, when the benzine instantly runs in and fills up the cell, and in a few minutes the card is thoroughly soaked with it without any effect on the gum. The benzine is then all drawn away with blotting-paper, and balsam applied to one of the openings. When the slide is gently warmed, this soon fills the cell and shows freely at both openings. When the balsam is sufficiently hardened the slide is put on the turntable and trimmed up, leaving a ring of balsam. ‘The final finishing touch is done by holding the slide, cover side down, and giving it a circular sweep over a flame so that the latter just touches the balsam ring all round for an instant, leaving it as even and smooth as glass. A great advantage of the method is claimed to be that when once the cover is in its place and the gum has set there is not the least danger of the cover shifting or the object being displaced when finish- ing and cleaning the slide. Monobromide of Naphthalin and Tribromide of Arsenic.— Dr. C. V. Zenger finds that a concentrated solution of tribromide of arsenic in monobromide of naphthalin has a mean refractive index of 1°72, nearly approaching the index of the tribromide itself (1°78).f The author says that the “aspect of Diatomacee mounted in this substance is simply surprising both as regards the crispness of the images and the amount of light received from the more minute details of the valves.” Mayer’s Carbolic Acid Shellac.t — Finding that clove oil and creosote produce fine granulations when used in the ordinary shellac method, Dr. P. Mayer has adopted a new method of dissolving the * Journ. and Proce. Roy. Soc, N.S. Wales, xvi. (1883) pp. 286-8. + See also this Journal, ante, p. 377. ¢ Amer. Natural., xix. (1885) p. 733, 910 SUMMARY OF CURRENT RESEARCHES RELATING TO shellac, by which an excellent fixative is obtained that never shows any traces of granulation. ‘The fixative is applied by a fine brush to the cold slide. Mayer prepares the solution in the following manner :— 1. Dissolve one part of bleached shellac in five parts of absolute alcohol. 2. Filter the solution and evaporate the alcohol on a water-bath. A yellowish residue quite stiff when cold is thus obtained. If any cloudiness arises during evaporation, the solution must be filtered again. 2 3. Dissolve the shellac residue in pure carbolic acid on a water- bath. A concentrated solution of carbolic acid is obtained by ex- posing the crystals to the air until they dissolve, or by adding a small amount of water (about 5 per cent.). The quantity of acid should be sufficient to give a thickish liquid when cold. This fixative is painted on to the cold slide with a brush, at the time of using. The sections are then put in place, and the slide left in the oven of a water-bath for some minutes (10-15 minutes is found sufficient). The carbolic acid is thus evaporated, leaving a perfectly transparent stratum of shellac on the slide. The sections are next freed from paraffin in the ordinary way and mounted in balsam. This method is considered to be the best and simplest for fixing stained sections. The shellac can be dissolved directly in carbolic acid, but then the fluid must stand a long time in order to become clear, as it can- not be filtered. For this reason it is preferable to dissolve first in alcohol. [According to a note just received, Mayer now prepares the shellac as follows :— The shellac is pulverized and heated with crystals of colourless carbolic acid until it dissolves. In Fia. 219. filtering, the funnel should be heated over a flame. It will filter slowly but quite well. If it is too thick, crystals of carbolic acid may be added until the desired consis- tency is reached. | Slide- Boxes. — Messrs. Beck have supplied us with one of the most convenient slide-boxes that we have yet met with, and very econo- mical in price (8s. 9d.). It consists _ of a cloth-covered pasteboard box = 15in. x 84in. x 35 in. which con- = tains twelve trays of the form —————— = shown in fig. 219, holding twenty- i a four slides each (or 288 in all). The bottom of the tray is divided into four parts by two cross-pieces, and the slides are prevented from shifting by shutting down the two ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 911 hinged frames (also of cardboard) which cover the ends of the slides and keep them in place. ’Chapman’s Mould for Cells.*—This mould is a convenient im- plement for making cells out of such plastic material as shellac, sealing-wax, or paraffin. It consists of a cylindrical core, and a removable collar concentric with it—both of brass. A rounded or bevelled shoulder inside the collar shapes the top of the cell, and a small shoulder on the core moulds a countersink suitable for the reception of the cover-glass. As a single mould is intended for one size and one depth of cell, several are necessary to an outfit. Selection and Preparation of Objects for Photographing.{—Dr. G. M. Sternberg has found that success in making photo-micrographs depends quite as much upon the selection of suitable objects and upon their proper preparation with reference to photography, as upon the optical apparatus used and the technical skill of the operator asa microscopist and photographer, and he accordingly indicates the kind of objects most suitable for making photo-micrographs, and the methods of preparation which have given him the best results. Micrococci require a high power for their detection. When properly stained, they may be photographed with a good 1/10 in. objective; but a higher power is better. The author has obtained his best results by the use of the 1/18 in. homogeneous-immersion objective of Zeiss. It is well to adopt a standard amplification for each class of objects, so that they may be readily compared as to dimensions by a simple inspection of the photo-micrographs made at different times and places. The standard adopted by the writer for bacterial organisms is 1000 diameters. A less amplification than this will not show the smallest micrococci in a satisfactory manner, and a greater is not necessary for a majority of the Bacteria. The method of mounting bacterial organisms in general, for the purpose of photographing them, is essentially to spread out a drop of the fluid containing them upon a very thin and perfectly clean glass cover. This is allowed to dry, and the bacteria are thus attached to the cover in a very thin and tolerably uniform layer. The aim of the operator in preparing unicellular organisms or vegetable and animal tissues for photography should always be to secure a single layer of cells; for when the cells are piled upon each other, those in the background are necessarily out of focus, and interfere with the beauty of the picture. Amebe.—Especial attention is called by the author to the photo- micrograph of an Ameba from life, as it illustrates the fact that transparent objects are the best suited for photography inasmuch as they alone show interior details of structure in a satisfactory manner. Transparent objects which have a different refractive index from that of the medium in which they are placed, do not usually require to be stained ; for the increased photographic contrast which is obtained * Journ. N. York Mier. Soc., i. (1885) p. 188. + ‘ Photo-mierographs and how to make them,’ 1883, pp. 91-117, 912 SUMMARY OF OURRENT RESEARCHES RELATING TO by staining destroys the natural appearance, and the picture no longer conveys the idea that the object is transparent. It is consequently brought nearer to the level of a woodcut and to a certain extent loses its value as a photo-micrograph. Unicellular Alge.—These should be mounted for photography in very shallow cells, made by turning a circle of white-zine cement upon a slide. Their colour and natural appearance will be preserved in an aqueous medium, such as weak carbolic-acid water or camphor water. Unfortunately, photography cannot reproduce the rich ruby colour of Protococcus nivalis, or the bright green of Protococcus viridis. The deeply coloured protoplasm of the former arrests light entirely, and we have in a positive print only a uniformly black mass with circular outline, surrounded by another line representing the cell-wall, to delineate the beautiful little ruby sphere with its more or less granular contents. The green colour of P. viridis is better adapted for photography. Infusoria.—Many of the Infusoria may be successfully photo- graphed, but it will be necessary to exercise great care in the preparation of slides for this purpose. Generally but a single individual should be in the field of view, and this should be a perfect specimen ; for it is difficult to obtain fields containing several indi- viduals all in the same plane, and in order to show cilia, flagella, and interior details of structure, high powers and very careful focusing will be required. ; Occasionally a living Infusorian may be quiet long enough to have its photograph taken ; but usually the Infusoria are in rapid motion, and it will be necessary to arrest this motion by means of some chemical agent fatal to their vitality. A weak solution of iodine does this very effectually, and at the same time stains the protoplasm a brownish colour. A ciliated Infusorian killed by adding a drop of this solution (iodine 1 gr., potassic iodide 2 grs., water 100 grs.) to a drop of the fluid in which it is swimming, remains for a time as if suddenly frozen, with its cilia rigid, and projecting like rays, from the surface of the body. ‘This is a favourable time for photographing the creature, as, later, it is liable to undergo changes which destroy the internal structure. . Another method is to place a drop of fluid containing the Infu- soria in the centre of a clean glass slide, and to invert this over the mouth of a bottle containing a 1 per cent solution of osmic acid. A very brief time is sufficient to destroy the life of the Infusoria, which may then be selected under a low power and transferred to a drop of clean water. They must be mounted in the thinnest possible stratum of fluid, otherwise they are likely to change position while the exposure is being made. As a general rule, transparent objects, like Amcbe and the Infu- soria generally, should be mounted in an aqueous medium for photo- graphy, as this gives better photographic contrast than does a medium having a higher index of refraction, such as glycerin. Spores of Fungi.—The spores of many of the fungi are suitable microscopic objects to photograph, and a photographic method could ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 913 not fail to be of value to one especially interested in the study of the fungi. The deep brown colour of some of these spores, however, causes them to arrest the actinic rays so completely that the photograph does not show plainly the internal septa which are characteristic features of certain species (Coniomycetes). The spherical or oval spores of moulds and mildews (Penicillium, Aspergillus, Botrytis, &c.,) are better adapted for photography than are the more deeply coloured septate spores referred to. They may be dusted upon the surface of a slide and photographed, dry, without the use of a cover-glass, or they may be mounted in an aqueous medium, or in glycerin, in a very shallow cell. The latter method gives the best results. To get rid of air-bubbles, which will give great trouble if the attempt is made to introduce the spores at once into water or gly- cerin, it is best first to wet them thoroughly with alcohol, and before this has entirely evaporated, to place them in the medium which has been selected. A good plan is to place a drop of alcohol in the centre of a glass slide, and to bring in contact with it a patch of mould in full fruit. The spores will be detached upon contact with the alcohol, and will sink to the bottom of the drop. By a little agitation of the slide they will be distributed in a tolerably uniform layer upon the surface of the glass. When they are nearly dry, in consequence of the evaporation of the alcohol, this is replaced by a drop of distilled water, or of glycerin, and the thin glass cover is applied. The superfluous fluid is removed with blotting-paper (Swedish filtering-paper is the best), and a circle of zinc cement may be turned around the edge of the glass to prevent evaporation while the exposure is being made, or if the intention is to preserve the preparation. A circle of cement is not used to support the margin of the glass cover, as the aim should be to have as thin a stratum of fluid as possible, in order to prevent the spores from floating about. It may be that mounting in glycerin- jelly would be a good plan for the spores having some colour, and this method would have the advantage of retaining them in position. Scales.—The scales of Lepidoptera—butterflies and moths—are suitable objects for photography. They may be mounted dry, and extemporaneous preparations are quickly made by applying the wing or body of a lepidopterous insect to the surface of a clean glass slide. - Blood-corpuscles.—The blood-corpuscles of man and the lower animals are among the objects most suitable for photography. Com- paratively high powers will be required; and, for purposes cf comparison as to dimensions, it is well to adopt a standard of ampli- fication, say 1000 diameters. The author’s best results have been obtained with the 1/12 and 1/18 homogeneous-immersion objectives of Zeiss. The corpuscles are spread upon a thin glass cover in as uniform & layer as possible, and are allowed to dry in situ. They do not require staining, and are mounted, dry, over a circle of cement. The simplest method of spreading them is to place a small drop of blood 914 SUMMARY OF CURRENT RESEARCHES RELATING TO on one edge of a glass cover resting upon a smooth surface, and to draw the end of a glass slide, held obliquely, across the face of the cover. No pressure must be used, or the delicate corpuscles will be crushed and distorted. In selecting a field for photography, the aim should be to obtain one in which the circular form of the red corpuscles is preserved, in which they do not overlie each other, and in which one or more white corpuscles are to be seen. Unfortunately, an ideal field is hard to find, and the patience of the operator will often be sorely tried in the effort to find one. The white corpuscles being larger than the red, and spherical in form, are very commonly drawn to the edge of the stain in the opera- tion of spreading. Care must be taken that the blood-stain is quite dry and the circle of cement upon which the cover is to be mounted quite hard, before it is placed in position on the slide; for moisture, or chloroform from the cement, would injure the preparation. A series of photo-micrographs of blood-corpuscles, made with a standard amplification, would not only be interesting and instructive, but might also be useful for reference, to those who are called upon to examine blood-stains for the purpose of giving expert medico-legal testimony. The photographic method would also be useful for recording differences in the form and appearance of blood-corpuscles due to disease, if any constant peculiarities of this kind were associated with particular diseases. But the Microscope does not reveal any such peculiarities of a sufficiently definite character to justify the expecta- tion, at one time extensively entertained, that its use, in the examina- tion of the vital fluid, might prove of value in deciding questions of diagnosis. Differences in the relative proportion of the white and red corpuscles are, however, shown in a rough way, and the depth of — colour of the red corpuscles is indicated, to a certain extent, by the photographic contrast with the ground; or, better still, with white corpuscles in the same field. The presence of foreign elements— parasitic organisms—is shown very satisfactorily in photographs ; and if a sufficient power is used, their absence is rendered apparent when there are none. The method is therefore especially useful for recording facts-of this kind, as the observer is able to substantiate the truth of his state- ments, positive or negative, by unimpeachable evidence, and at the same time to show that his skill as a microscopist is sufficient to give confidence in his ability to manipulate the higher powers with which such observations are necessarily made. For example, the photo-micrograph of yellow-fever blood given by the author, in which the amplification is nearly 1500, and in which the white and red corpuscles are well defined, may be taken as evidence that there were no parasites in the blood of the patient from whom this specimen was obtained ; and a sufficient number of similar photo-micrographs of blood from different patients, and drawn at different stages of the disease in question, would prove the absence of any foreign elements, demonstrable with the power used, from the ZOOLOGY AND BOTANY, MICROSCOPY, ETO. 915 blood of yellow fever. This has been demonstrated by the author in the manner indicated for the disease in question. Pollen-grains.—Not all of these objects which it would be most desirable to photograph are suitable objects to be photographed by transmitted light, for the reason that the bright yellow colour and comparatively large size of some render them practically opaque. Doubtless this difficulty in the case of pollen-grains, the deeply coloured spores of fungi, &c., can be overcome by special methods of preparation,—the use of decolorizing agents, mounting in media of high refractive index, &c. The limits of the author’s volume do not, however, permit him to go very extensively into details with reference to the preparation of objects, even if the technique were completely worked out, which is far from being the case. The general state- ment may be made, however, that objects which, in water, are not sufficiently transparent for photography, should be mounted in media having a higher refractive index, of which the most useful are glycerin and Canada balsam. Some pollen-grains swell up and the membranous envelope is ruptured when they are immersed in water. For this reason, as well as for that already given, glycerin is commonly a more suitable fluid in which to mount them. When first placed in glycerin, the cell- wall becomes collapsed from exosmosis of the watery contents; but after a time the natural form is recovered by endosmosis and the fluid within and without is of the same density. To prevent the trouble arising from the presence of air-bubbles, which are apt to adhere tenaciously to the pollen-grains, it is best to immerse them first in alcohol, as recommended for the spores of fungi. A drop of alcohol is placed in the centre of a glass slide, and the ripe anthers, held in slender forceps, are brought into contact with it; the pollen is detached, and falls to the bottom of the drop. A little agitation of the slide causes it to be distributed in a stratum consist- ing of a single layer of cells. When the alcohol is nearly evaporated, a drop of glycerin is put in its place, the thin cover is applied, and the superfluous fluid removed with bibulous paper. Plant Hairs.—Some ingenuity will have to be exercised in pre- paring objects of this kind for photography. Hairs that are closely applied to the surface of the leaf may be photographed in situ by mounting the epidermis, or by reflected light. Others will require to be detached, and may be shaved off with a razor, and mounted in a very shallow cell in water or in glycerin. It is always desirable to obtain a field in which the objects do not overlie or cross each other ; and with long plant hairs, like cotton, this is not an easy matter unless they are carefully arranged one by one. A good plan both for long plant hairs and animal hairs is to place several side by side on a dry glass slide, fixing the ends to the edges of the slide with sealing-wax. When they are adjusted in position the central portion is wet with alcohol, then with water, and finally with glycerin, if it is to be used. A thin glass cover is then applied. Animal Hairs.—A series of photo-micrographs of animal and vegetable hairs would be extremely interesting and instructive. 916 SUMMARY OF CURRENT RESEARCHES RELATING TO Reagents will often be required to show the structure of animal hairs, which is not so simple as that of those from the vegetable kingdom. The thickness of these hairs makes it desirable that photo-micro- graphs should be made with low-power objectives, as these have the greatest penetrating power. At the same time, good definition is required to show the outlines of the imbricated cells in wool, for example. Wool, ready dyed, of any shade required, is to be had by picking out a little end of coloured worsted. Sections of Vegetable Tissues.—Photo-micrographs are especially well adapted as illustrations of vegetable histology; and the ease with which sections of vegetable tissues are made and mounted for the purpose, as well as the beauty of the result, cannot fail to make this one of the most popular applications of the art. Sections—transverse, oblique, or longitudinal—are quickly made with a sharp razor from the petioles of leaves; from succulent stems, like the new growth of asparagus, geranium, &c.; from bulbous roots and tubers; from endogenous plants, such as canna, maize, &ec.; and from recent sprouts on exogenous trees and shrubs. No section-cutter is required for this purpose; and every one engaged in work of this kind should make himself an expert in free-hand section-cutting, as many of the best photographs are made from extemporaneous pre- parations. The proportion of mounted preparations in animal and vegetable histology to be found in every collection which are not suited for photographing, will surprise one who attempts to save himself the trouble of mounting his own specimens for the purpose. The first requisite is a very thin section ; the second, a very clean specimen, free from dirt or air-bubbles. ‘To secure cleanliness, wash the leaf or stem or tuber perfectly clean before commencing to make sections, and place the sections in filtered water when they are made. Use a very sharp instrument, and cover the face of the stem, or what- ever it may be, with water or alcohol; the razor also should be wet before making each cut. “ Be extravagant in the number of sections cut, and select only the best. The selected sections will often require soaking for a con- siderable time in alcohol, to get rid of the air-bubbles. They are to be mounted in water, solution of acetate of potash, glycerin, or Canada balsam.