ox ie} ALE: | : . ° aa) i 5 a) 5 -. . | " > N Fa i> JT ge ‘ 2] = . aS cat C1 VN JOURNAL OF THE ROYAL MICROSCOPICAL SOCIETY: CONTAINING ITS TRANSACTIONS AND PROCEEDINGS, AND A SUMMARY OF CURRENT RESEARCHES RELATING TO Ag Owes. ASNED Boe ALIN (principally Invertebrata and Cryptogamia), MICROSCOPY, &c- Edited by ERAN. CR ES PP -1i.L25; .BUA., 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.Z5S., Lecturer on Botany at St. Thomas's Hospital, Professor of Comparative Anatomy in King’s College, JOHN MAYALL, Juy., F.Z.S., R. G. HEBB, M.A., M.D. (Cantad.), AND J. ARTHUR THOMSON, M.A., Lecturer on Zoology in the School of Medicine, Edinburgh, FELLOWS OF THE SOCIETY. POR Tbr sy YE Avr 1888. PUBLISHED FOR THE SOCIETY BY WELLIAMS & NORGATE, LONDON AND EDINBURGH. JAN 20 1903 Royal Microscopical Society, (Founded in 1839. Incorporated by Royal Charter in 1866.) The Society was established for the communication and discussion of observations and discoveries (1) tending te improvements in the construction and mode of application of the Microscope, or (2) relating to Biological or other subjects of Microscopical Research. It consists of Ordinary, Honorary, and Ex-officio Fellows. Ordinary Fellows are elected on a Certificate of Recommendation, signed by three Fellows, stating the names, residence, description, &c., of the Candidate, of whom one of the proposers must have personal knowledge. The Certificate is read at a Monthly Meeting, and the Candidate balloted for at the succeeding Meeting. ° The Annual Subscription is £2 2s., payable in advance on election, and subsequently on Ist January annually, with an Entrance Fee of £2 2s. Future payments of the former may be compounded for at any time for £31 10s. 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The Council, in whom the management of the affairs of the Society is vested, is elected annually, and is composed of the President, four Vice-Presi- dents, Treasurer, two Secretaries, and twelve other Fellows. The Meetings are held on the second Wednesday in each month from October to June, in the Society’s Library at King’s College, Strand, W.C. (com- mencing at 8p.M.). Visitors are admitted by the introduction of Fellows. In each Session two additional evenings are devoted to the exhibition of Instruments, Apparatus, and Objects of novelty or interest relating to the Microscope or the subjects of Microscopical Research. The Journal, containing the Transactions and Proceedings of the Society, with a Summary of Current Researches relating to Zoology and Botany (principally Invertebrata and Cryptogamia), Microscopy, &c., is published bi-monthly, and is forwarded post-free to all Ordinary and Ex-officio Fellows residing in countries within the Postal Union. The Library, with the Instruments, Apparatus, and Cabinet of Objects, is open for the use of Fellows daily (except Saturdays) from 10 a.m. to 5 p.M., and on Wednesdays from 6 to 9 p.m. also. It is closed for four weeks during August and September. Forms of proposal for Fellowship, and any further information, may be obtained by application to the Secretaries, or Assistant-Secretary, at the Library of the Society, King’s College, Strand, W.C. a 2 patron. HIS ROYAL HIGHNESS ALBERT EDWARD, PRINCE OF WALES, K.G., G.O.B., F.BS., &e. Past-Presidents, Elected, Srr Rionarp Owen, K.O.B., D.C.L., M.D., LL.D., F.R.S. 1840-1 S oun eLaNDLAW, Eh. D. BRS. « sis ells cls wine wie seers eisai 1842-3 = OH GAVAR AEs IGIY;, iF aes 12 ste iste wes eerste @ ialici oe) eceiaiese siete Sualtetane 1844-5 *James Soort Bowrrpank, WL.D., FBS. ....5 2.5 0200. 1846-7 PIGRORGM ES UK, lyse ues fis bus ayers we ahanie nls eheushode ile ralasoxse es 1848-9 PS AETHUR VEARRE, NT)! EID. cise se ats ne aiere ete lie louere 1850-1 SGRORGR aVAOKSON. WM HO. 9.08 cin otslete cis ele ale Sete eae 1852-3 *Wittiam Bengsamin Carpenter, O.B.,M.D., LL.D.,F.R.S.. 1854-5 (GRORGREOHADBOEM jc o's cis) clever ecdlals Sas e'sielye's lores are stir 1856-7 Shpwimy Wancesrer, MD. D., FIRS. 6. ee sc cee 1858-9 SOHN -LHOMAS QUBR ETT ol abyss. \ccrevs alaisis Seisinis-ole"s'slelwle.s 1860 *Ropenr J amne: Mankans, RGIS. 00. 06 cece wens occas 1861-2 SU AARUES BROOKE, MLA: WOR S, % ¢ 4s 0¢,s 0 ese so.6 esau oe 1863-4 AMS AGEL NISHRIG S CcER ea Susie oye c ob presen’ ecards. sheimiaeeu are 1865-6-7-8 *Rev. JosepH Banorort Reape, M.A., F.R.S........... 1869-70 Wri Krronmn Parker, PORIS: sc< cca oo < ciaee oe Se 1871-2 *CoanuEs. Broone, MA. DB ics.s esis) sjelp sin sfa(ersitinalele see 1873-4 Huney Crmton Sorey, GOLD. WARS. 22.02.5605 08 0s 1875-6-7 FIENRY, << AMES UAGHS BEIGE S eS aie aie c.c00 » ws a's re wid a ade ois 1878 TONE 3S. DRAGE, NE OE .C.P;, Weliso. oe basso eae 1879-80 DP: Wanna UNBAN, eles OS. a eel ote s inless essueets 725 Ticnommrorr, A.—Parthenogenesis in Bombyx mort... we we we egg 725 Lucrant, L., & A. Prorri—Respiration of Silk-worm Ova .. 3 726 CARLET, G. ee of Locomotion of Caterpillars % 726 Wuitr, W., & G. C. Grirritas—Colowr-relation wien Pupes ia tr roundings oP 50 Fon MOCt Si0 So oe 20 ad Ac Hy 727 Kessier, H. Heads om aes rivets me 727 GRABER, V.—Primary Segmentation of the Cen es a Fasccis -- . Parté 941 Nuspaum, J.—Germinal Layers of Meloe hn Dehn: wie Scare mes 942 Pruanta, A. v.—WNutrient Food-Material of Bees .. 4. 64 we nee - 942 Ginson, G.—Odoriferous Glands of Blaps Spain ces Cree ae 943 CASAGRANDE, D.—Alimentary Canal in Aisne hess: Ch EEE RGD ates 943 CuHATIN, J.—WNerve-terminations in Lepidoptera 3 943 Reuter, E.—Basal Spot on Palps of Butterflies .. aoe fate R55 943 Biscuit, O.—Development of Musca .. .. i ok as 55 944 Branpt, E.—Larva of Sarcophila Wohlfartii in Gia of Man ate 944 Cuccati, G.—Brain of Somomya .. .. .. « . Se aaa we 944 8. Myriopoda. PLATEAU, F.—Powers of Vision .. ayes.) wasp) wae eartolu oe Hearucore, F. G.—Post-embryonic Dae enon a dh Fe: BO 00.8 te coon Brin 418} Sarnt-Remy, G.—Brain of Iulus .. .. .. « Part3 408 Hearucores, F. G.—Post-embryonic Dae pions of Tits foriestre Syepo soe denny) Pr GAZAGNAIRE, J., & R. BLANcHARD.—Phosphorescence in Myriopoda .. Part 6 945 y. Prototracheata. SHELDON, L.—Development of Peripatus Nove-Zealandize .. .. .. .. Partl 33 Sepewick, A.—Development of the Cape Species of Peripatus .. .. .. Part3 409 Sciater, W. L.—Development of a South American Peripatus FO OG. MEE 410 Srepewick, A.—Monograph of the Genus Peripatus .. .. .. « « Part4 576 SHELpoN, L.—Anatomy of Peripatus capensis and P. Nove Zealandizx 577 6. Arachnida. Avrivituius, C. W.8.—Acarida on Trees 1. «1 06 4+ «6 «+ oe Partl 34 PLATEAU, F'.—Vision in Arachnids .. .. o» «+ «+ of «+ «+ » Part 2 214 % » Respiration of Arachnida Cathal cicapaeicy- Mate sipued si Wes matcemenes™ 214 Wacner, V.—Regeneration of Lost Parts .. .. co | Od rs 215 M‘Cooxr, H. C.—Age and Habits of American Tar tila Ont Meee ou dS 215 ZacHanias, O.—Distribution of Arachnida .. sem oe +s oe ee we 5 215 Parker, G. H.—Eyes in Scorpions.. .. 2. «+ co oF oF of («« PartS 411 Wacner, W.—So-called Auditory Hairs saul) sale aot con Sy Sonate 411 M‘Cooxr, H. C.—WNew Orb-weaving Spider .. «1 «6 6 «2 08 0 412 Micnar., A. D.—British Oribatide c BO 0. Oo. moe Precxuam, G. W. & E. G.—WMental Powers of Sa 50 owe dh Sarnt-ReEmy, G.—Brain of Phalangida Ae EOD S50 «dose a OA aise | ee 576 Winker, W.—Anatomy of Gamaside .. . Part 5 729 M‘Coox, H. C.—Relations of Structure and fae 5 Gale Changes in Spiders... 5 00 eee bart: Gii94o Faussnx, V. SS naen mee of Genmnante Ghar in Meanie ieFaeswaaen ae 946 Wacner, V.—Blood of Spiders... «2 sew ia 946 xiv CONTENTS. e. Crustacea, PAGE Kinasiey, J. S.—Development of the Compound Eye of Crangon ~ (antalimeee Sars, G. O.—‘ Challenger’ Cumacea : e Bs 35 £ * ‘ Challenger’ Phyllocarida . 36 Ganrsin1, A.—Structure of Cypridinide .. re “6 36 Marcuar, P.—Z cretion in Brachyurous Crustacea . Part 2 216 Rawirz, B.—Green Gland of Crayfish p 216 Grarp, A., & J. Bonnter—The Lopyridze sie *3 216 a Two New Genera of Fioiear dis 30 5 217 Cuavs, C.—Lerneascus and the Philichthyde oe St ete 9 217 Nussspaum, M.—First Changes in Fecundated Ovum of Ta 1s ; 218 PLATEAU, F.—Palpiform Organs of Crustacea c C Pad 3 413 Herricr, F. H.— Abbreviated Metamorphosis - Alphows “pe tts Relation - the Condition of Life Brag a4 oe oo dG kobe SG. ef, 414 Broox, G.—Reproduction of Lost Paris: Fe ers so Cp 414 Giarp, A.—Parasitic Castration in the Eucy plates of Spalenon and Hippolyte 3 + 414 Mine-Epwarps, A.—F’ as AEs Cr ae of 4 price 3 415 VALLENTIN, R., & J. T. CunnincHam—Photospheria “of Mm ptiphanes norvegica 30 + 415 CuHEvreEvxX, E., & J. DE Si een Gane il Mrapnined 3 416 Cuats, ee neeiaes and the Tanaide .. = 416 Tuompson, I. C.—New Parasitic Copepod 55 417 WELTNER, W.—New Cirriped .. tcp tye Pa 417 Norman, A. M.—WNew Crustacean Parasite .. oy piss 418 Mackay, W. J.—Intercoxal Lobe of certain Cray fides .. Part 4 977 Hernrics, F. H.—Development of Alpheus : 35 577 Norpevist, O.—WVoina bathycolor and the greatest d athe bi iohich Cleaners are found S008 oc 50 oo 0b Oe 578 Catraneo, G.—IJntestine and iDajestine Glands of Dna 5 oo see) 728) Petit, L.—L£ffects of Lesions of the oe a-ceesopha sak Gan cas & the Crab (Carcinus Meenas) .. 5a © 03 30.) ack) 66 730 BERGENDAL, D.—ale Lisanne: on antes 730 Bepparp, F. E.—Lyes of Cymothoide .. Se Fe 730 Giarp, A., & J. Bonnrer—New Species of Caachi Te wt Ks 9 Beg 731 GuERNE, J. DE, & J. RicHarp—Geographical Distribution of iphraene Gen sy 73 Scuwarz, C. G.—So-called Mucous Gland of Male Cypride ad ch 7al Sramati, G.— Castration of the Cray-fish oD = He . Part 6 947 % », Digestion in Cray-fishes .. 6 947 BIEDERMANN, W.—ZJnnervation of Crabs’ Claws - 947 Bate, C. SpENcE—‘ Challenger’ Crustacea Macrura .. pane ao 948 RosENsTApt, B.—Structure of Asellus.. sa ase Ain eer Lat keer cf 948 Barrois, T.—Sexual Dimorphism in Amphipoda .. 949 PEREYASLAWZEWA, SOPHIE—Development of Gammarus ns 949 ELYMANN, E.—Zuropean Daphnide .. 22 «2 oe we ee we - 949 CHEVREUX, E.—Orchestia ; Sine a es 949 Carranno, G.—Amebocytes of Oustaces Sy tee a Sddu ea Soca 949 Vermes. a. Annelida: Wurman, C. O.—Germ-layers of Clepsine Part dion BeErTELu, D.—Salivary Glands of Leech 38 Witson, E. B.—Germ-bands of Lumbricus 3 388 GiarD, A.—Photodrilus apes ca g a wae Genus of Phospho- rescent Lumbricids.. .. : 50 er 40 CONTENTS. MicHaAetsen, W.—Lnchytreide Draco, W.—Parasite of Telphusa .. : CUNNINGHAM, J. T.—Anatomy of Polychex tie Grarr, L. v.—Annelid Genus Spinther .. SmMONELLI, V.—Structure of Serpula Satensky, M.—Development of Annelids Bourne, A. G.— Vascular System of Hirudinea 5 Brunorre, C.—Structure of the Eye of Branchiomma.. VEsDOvaKy, F.—Larval and Definite Excretory Systems in Gnenliriciaee BEppDARD, F. E.—Roproductive Organs of Moniligaster 5 » So-called Prostate Glands of Oligocheta .. Rove, L.—Histology of Pachydrilus enchytreoides .. .. 4. Benuam, W. B.—New Earthworm. sialic Meyer, E.— Organization of rele JOYEUX-LAFFUIE, J.—WNervous System of Chatpiar Us Watencinss FRATrONT, J. Ep opjordas Be Wetec Sovurer, A.—Formation of Tube of legdhe bc Horst, R.— Cardiac Body of Annelids Ersie, H.—Monograph of the Capitellide LrexHMANN, O.—Homology of Segmental Organs and Fiferent Ducts of Genital Products in Oligocheta .. ‘ Bepparp, F, E.—Structural Characters of arereson ms FLercHer, J. J.—New Australian Earthworms Bepparp, F. E.—WNephridia of Earthworms .. Anatomy of Allurus tetraedrus.. a = Anatomy of Pericheta = Mucous Gland of Urochxta ” ” Pate W. A.—Embryology of Vermilia cxespitosa a ponte “Asie Part 4 Bepparp, F. E.—feproductive Organs of Phreoryctes.. : Bourne, G. C.—Kleinenberg on Development of Lopador pachusl KiKENTHAL, W.—Zaperiments on Earthworms .. «2 «1 +s Kouacin, N.—Russian Lumbricidz Eisen, G.—New Annelid, Sutroa rostrata i. ne Stokes, A. C.—Two new Aquatic Worms from North Wee Ad Coun, A.—Criodrilus lacuum Oligochzte Cunnincuay, J. Nereis of Giants conch MiIcHAELSEN, W.—New Enchytreide is ApstTuy, 8.—Laternal Morphology of Hirudinea . HEYMANN, J. F.—WNerve-endings in the Leech : FRIEDLANDER, B.—Creeping Movements of Earthworm Bereu, R. 8.—ELzecretory Organs of Criodrilus B. Nemathelminthes. Carnoy, J. B.— Maturation and Division of Ascaris Ova 5a as Polar Bodies in Ascaris i ete Os ZacHARtias, O.—Fertilization of Arcaris iegiliceuiate PY ales LABOULBENE, A.—Larval Stoge of Specics of Ascaris .. Lez, A. BottEes—Spermatogenesis in Chetognatha CamERANO, L.—Life-history of Gordius .. 3 Vittot, A.—Development and Specific Determination of Gordii a6 Bos, J. Rirzema—WNatural History of Tylenchus.. .. «. Korner, R.—Structure of Echinorhynchi .. .. s. aeartol 7 Part: 2) 218 PPeartio Route, L.—Formation of Embryonic aga ae Calon of a encore = Lathe BENEDEN, E. vaN—Fertilization and Segmentation in Hens is mec ineeorais ” XV PAGE 40 40 41 42 42 219 XVi CONTENTS. PAGE Bovert, T.—Polar Globules of Ascaris ... «oe , ee DAth oes Lutz, A.— Life-history of Ascaris lumbr aes ee ‘Tenia elliptic a ae eens a 426 Kouxtsomrzky, N.—VFertilization of Ascaris Atel Sica wnt » «o Path teoeo Luxsanow, 8. M.—Jntestinal Epithelium of Ascaris .. .. +1 +6 +e yy 583 VEJDOVSKY, F'.—Studies on Gordiide .. .« . «« - AL ce Be 5 583 CHatin, J.—Anguillulide of the Onion .. .. 26 26 oe ve we te 585 Bos, J. Rirzema—Tylenchus devastatrin .. «6 «s « «+ oF oF 49 585 Kuutscnirzky, N.—Fertilization of Ascaris... .. . «+ « + «+ Part 5 736 CAMERANO, L.—Structure and Position of Gor Bindi aoe eels Ge oh ty 737 STRUBELL, ct ucture and Development of Heterodera Schachtit scm eas A 737 Cuatrin, J.—Integument of Heterodera Schachtii .. .. Py 73 Grasst, B., & 8. CaLANDRUCCIO—Lchinorhynchus pana in ian a ie w fae intermediary host is a Blaps B= | HON team Modano hore 739 Serrert, O.—Ankylostomum duodenale .. .. MODS SOC fa 739 WALSINGHAM, Lorp, & H. D. WALKER—Gape Wor m “of Tunis AO oe | cp 740 Lamerrr, A.—Alnormal Ova of Ascaris megalocephala .. .. « «+ Part6 953 WiuL0o1T—Heterodera Schachtii eres SOE Ne eens Wn Soames Wit oe 953 y. Platyhelminthes. TINTON, Hi—Cestoid Bmbryos. «1 6 tee a te wee oe) Grassi, Bi—TZenia nana.. .. Sah. whe tee a5 46 Wricut, R. Ramsay, & A. B. MAcar.0m—Sphyranura paler ey esas, Wes 47 Porrier, J.—New Human Distomum .. whee Hane ee 49 Heckert, G.—WNatural History of Leucochlor or paratosum ae Merle Deets 33 49 Haswet, W. A.—TZemnocephala .. .. Baek sore rorn. "23 50 Linton, Ha tenaede in white of Wor pete ‘Hen’ s s Ba Geet ter Sag NSD. op 51 DEvVoLeTzkY, R.—Lateral Organs of Nemerteans .. .. +0 se ve we 15 ol Husrncut, A. A. W.— Challenger’ Nemertea .. 1. 2» «1 of + 4 52 Montez, R.— Tenia nana AC a Re EA, OCA DO sca ALS. Isa, 1.—Some European Triads. or 2 HOE Ans Ac. oe * 229 Scumipr, F.—Development of Generative Or: ae of Gesell jel es |e eS ieee TUCKERMAN, F'.—ZJnteresting Specimen of Tenia saginata (see footnote, 2538). co. oe Acie DOO ee 427 ZELLER, E.—Generative ecaiiue of Daplevaen piragome yee Sngheatsie hey tess 427 Repracuorr, W.—Second Species of Turbellarian living on Nebaliv .. .. 4, 428 Kunstier, J.—New Remarkable Worms 50 mois Use Teen tee Uso ems 428 Hauuez, P.—Embryogeny of Fresh-water Detinocdla Sol sad coe no mon tecnan es. Systy SAMENSIGYs| Wi——LGteraliOngans “cele. os se | oc ce oe 06 eel 199 587 Fritscu, G.—Bilharzia .. .. Adem eer nee Sauer Mie 588 Hoye, W. E.—General Sketch of the Taig BO oo om oo Le SS. VorttzKow, A.—Aspidogaster conchicola .. 1 ++ ue ete gg 954 BRAN DESH G.—— EH OLOSLONMEN: “lesie | “ests aie) (ies Me loo, Weis, Nels sal Mise) tei) fis 954 Branpt, E.— Tenia cucumerina in Man nom Soe‘ oonly ‘cow “kagit toa wears ep 955 TGCKERMAN, Hi ——Tenid Saginata 2. ise) se oe ws tele ‘5 955 5. Incerte Sedis. ZELINKA, C.—Parasitic Rotifer—Discopus aes One od co coer et iae ihe ie Hoop, J.—Floscularia annulata .. +e SM Bote! ses cent oe eather NAnsEN, F.—WNervous System of Myzostoma.. .. «1 se «+ «8 «8 499 231 SonimKEwitscu, W.—Balanoglossus Mereschhovshkii .. .. «. « « Part 4 588 Greerr, L. von—‘ Challenger’ Myzostomida., .. 1. se +8 40 oe 145 590 GuERNE, J. DE—Asplanchnide Sao ee Gam So CEE Sao ee. woe let aan Fait, Cosmovicl, L. C.—Contractile Vesicle of ene BH HON ohh) bo eco HERI Saw Winepon, W. KL R.—Aaplodiscuspiuger., G. se se) se ee oe ew og 955 CONTENTS. Echinodermata. Hamann, O.—Histology of Echinoderms "Oe w60- 00 sca. 1820 Part 1 5 » Wandering Primordial Germ-cells in Bcnitiodorine Bc =F Hantoc, M. M.— True Nature of the Madreporic System of Echinoder ee pS Cutnot, L.—WNervous System and Vascular Apparatus of Ophiurids .. “= Carpenter, P. H.—Development of Apical Plates in Amphiura squamata.. ,, He¥rovarp, E.—Calcareous Corpuscles of Holethurians.. .. = Bury, H.—Development of Antedon rosacea .. «1 0s ae Part 2 Groom, T. T.—New Features in Pelanechinus corallinus .. » Sarasin, P. & F.— Budding in Star-fishes 1. 64 ewe 5 Semon, R.—Wediterranean Synaptide .. - Sarasin, P. & F.—Longitudinal Muscles and Stewarts Or. in in arin: HORUS! “oh 0b =o nce , Part 3 ProvnHo, H.—Researches on Darosiane peptilata ‘ond oiler Mediterr¢ ranean * Echinids .. .. Cie 6c * DO6ODERLEIN, L. =e eheanion of Gara Soest 53 Sarasin, P. & F.—Gemmatior in Linckia malinera ae Auer Dusguan, H. E.—Lmigration of Amaboid Corpuscles in Siarfiates. ro OS - Madreporite of Cribrella ocellata soil Aoi cues eee 5 HAMANN, O.—WMorphology ef Ophiurids . 5 Re uF FLEISCHMANN, A.— Developments of Egg of Echinocar eee cor sndaten ae Part 4 Sarasin, P. & F.—Renal Organ of Echinoids ni do. ‘do, | Wee s BELL, F. Jerrrery—Remarkable Ophiurid from Brazil pot ~ Lupwic, H.—New and Old Holothurians as ea a % JIcKELI, C. F.—WNervous System of ohitodemantas . Part 5 Sarasin, P. & F.—Anatomy of Echinothurida and Pinglogony & Holinos dermata .. : ac . Part 6 Grirritus, A. B. ee Grsane of Gi elas 0. ob -c0. Sao. sco oS gy Curnot, L.—Anatomy of Ophiurids .. 1. we sn see + Bagrrots. J.—Development of Comatula .. co” OC - CaRPENTER, P. H.—‘ Challenger’ Comatule.. .. .. 3) Coelenterata. Ouun, C.—Morpho’ogy of Siphonophora .. .. 1. « os Part 1 KrukeEnBere, C. F. W.—JLnfluence of Salinity + 5 ss Colours of Corals .. c ‘5 Nervous Tracts in Alcyonids 35 a eae C. POlitonanike Santen, eal eer eee Part 2 Lewy, J.—/ydra BD moe mca a Frwkes, J. W.—Are there Deegsen Medusee? Ost ay ees » Hickson, 8. J.—Sex-cells and Development of ano no 00) 00 OG) Nicuotson, H. A.—Structure and Affinities of Parkeria .. 1. 22 48 455 MARENZELLER, E. von—Growth of Flabellum saps + Sruper, T.—Classification of Alcyonaria .. .. = GrieG, J. A—WNorse Alcyonaria.. .. eet. So Mo! Brooks, W. K.—New Method of Maliplcation in nace Part 3 Fow er, G. H.—Anatomy of Madreporaria .. .. .. . + Wuson, H. V.—Development of Mancinia areolata 33 Kocu, G. v.—Gorgonidz of Naples .. 5 Frewkes, J. W.—New Mode of Life among Mana Part 4 on $5 Meduse from New England oo 0S, (ph oe op cs New Physophore .. .. a6 Sad sant oe ” Fowzer, G. H.— New Pennatula from the Bae De FiscuEer, P.—Actinix of Coasts of France .. FA 1888. b XvVli XVlil CONTENTS. PAGE Buocamany, F., & C. Htnarr—Gonactinia prolifera .. «6 0s ae oe Part 4 593 Haacke, W.—Nature of Polyparium _.... os se 06 06 oF oF 08 9 594 Harcke., E.—System of Siphonophora .. .. ce, fe) Gee? oo oe GCTiDROMMIEIN Brooks, W. K.—Life-history of Epenthesis McCr tp n. se bah ace eee 743 Voar, C.—Arachnactis and Cerianthus ae + 743 Vicurer, C., & H. pz Lacaze-Durutrrs—New Type of Wniieess - 745 Miines Marsa, A., & G. H. Fowner—‘ Porcupine’ Pennatulida .. 745 Korotnerr, A. pE—Development of Hydride «1 su ue ne we we, Part 6 963 Kocnu, G. v.—Flabellum .. .. 5 963 Hickson, 8. J.—Sexual Cells and ie i Stage in Development of llenon a plicata on. 0 50 6 a0 A - co. » 964 Havppoy, A. C. sr eal Actinis ee on SEAEE serie. do koe. foo of 965 Fiscuer, P.—Scyphistomata of Bonespedote WORE 55 0 cen ale, aise 965 Hertwic, R.—Supplementary Report on ‘ Challenger iceaarn ia 3 965 Porifera. Sotzas, W. J.—Sponges .. .. 3 eis Ea eel bar) ee” ne darted Epsner, V. v.—Skeleton of ealeineous Saenges Hon edo} oo & oso. | og} op 63 Tae IN IME SURGE OF (HPATRIDER, G5) 166 “95 “6G 0p ob 9 so Gp 63 Ports, E.—Fresh-water Sponges .. Ate y ow ato. cp 63 Firpier, K.—Development of ononttia Pr acs. m Spongilla 66s om. Oo op 64 TorseNntT, E.—So-called Peripheral Prolongations of Clione.. .. .. .. Part 2 239 THomson, J. ARTHUR—Structure of Suberites 1. 12 « oo oF of 45 239 Denpy, A.—Comparative Anatomy of Sponges .. +s oe oe oe «+ Part 4 594 MacMunn, C. A.—Chromatology of Sponges... .. . s+ co «+ 8 495 595 ToprsEntT, E.—Gemmules of Silicispongiz ee ce ope chee soy nto «Ge 596 IGieiy, 1H, Chole co. ao. ba <00. Om dO 60 ne MES 596 Wetner, M.—Survival of Sponge after Development of Sear Tate GEA no op 596 Riwtey, 8. O., A. Denpy, & F. E. Scnutze—‘ Challenger’ Sponges... .. 55 597 Nott, F. Cm atural History of Siliceous Sponges .. .» « « « Part d 745 Scuuuzp, F. E.—‘ Challenger’ Heaactinellida . oa 6 ” T47 WiERZmISKi cAG——Hyresh-wateniSMONGeS fs) sl sel eee ee ei ss) 748 Hinpz, G. J.—New Species of Uruguaya ue we | Os 748 Bet, F. J.—WNote on the Large Size of the Spices of Acie or Wisitans .. Part 6 921 Nassonorr—Boring Clionids » 6a Fiepier, K.—Vormation of Ova and SperTatieea in Sonqilla Huabitis =p 966 Priest, B. W.—Remarkable Spicules from the Oamaru Deposit .. .. « 967 Protozoa. GuLutver, G.—Note on the Minute Structure of Pelomyxa palustris .. .. Part 1 11 Mavupas, E.—Conjugation of Paramzcium .. 1. 2s ae oe oe weg 65 Stones, A. C.—WNew Fresh-water Infusoria .. 2 66 40 oe wees 65 Neumayr, M.—Relationships of Foraminifera Soine GOmie GRNENAOm, Gd) s-G0k ch 66 ScuewiaKorr, W.—Karyokinesis of EHuglypha «ss uu we weg 66 Kinsrier, J.—Diplocystis Schneideri .. 2. 26 au ne oe wwe 68 Greenwoop, M.—Digestion in Khizopods wees sar ak se aa on Baripeecn Grassi, B.—Protozoa Parasitic in Man.. : gee ee Pa VAGHARTAS; O:—Psorospermium sacckelis Va. fie a Sos bs ses 5p 240 Dawson, J. W.—Lozoon Canadense Burrows, H. W., C. D. SHerzorn, & Rev. G. Bane ae horaratiaferd of the Red Chalk .. oe joe al? Glas ie arhoeess Mostvs, K.—Direct Division of Nae in apioies one ae hn Ree Anperson, H. H.—WNew Parasitic Infusoria .. 4. 11 ae ue we eg 436 Danay, E. v.—Wonograph of Tintinnodew .. .. CONTENTS. Scntirr, F.—Spore-formation of Peridinee® .. 1. 1s as Harcke., E.—Radiolaria ma 866. MO “aes AGO Ioo! MACHR aan icSrere KounstLer, J— New Foraminifer .. oe Carter, H. J.— Nature of Opaque Scarlet Splenutes Fear in many Fossilized Foraminifera... 5G 00) | 200 Gat soe Be oo we Norrine, C.C.—New Boece of Aeintta poly Ase", “bec ¥ob AGGtl wholestar Prrroncito, E.—Lncystation of Megastoma itesiinale ae Howcaty, Rev. W.— Additions to the Knowledge of the Car Den ferous ere a= MUN CRC ma CEAOLESMV LEE SORA EAG)\ wee eens ele be es Birsowy’s (O.) Protozoa ods 08) = #00 dos’ Show ae Grouper, A.—Multinucleate Infusoria Mostus, K.—/olliculina ampulla .. .. Stoxes, A. C.—Fresh-water Infusoria of the United seas , Buanc, H.—New Foraminifera SY core st Wierzevski, A.—Psorospermium Haeckelii Grasst, B., & W. Scurwraxorr—WMegastoma ian Brapy, H. B.—Note on the Reproductive Condition of Orbitolites pate var, Laciniata. (Plate X.) .. : Stokes, A. C.—WNotices of New paneer ia Flac pela fr om Aner ican Fresh Waters. (Plate XT.) 5 Se S66 gb. 6 Kunstuer, J.—Vesicular Elements of Provepiasins im rr beeen Meissner, M.—Physiology of Nutrition in Protozoa Brouyne, C. ppe—Nature of Contractile Vacuole Grouper, A.—Further Observations on Multinuclear ene a] Fasre-DomERGUE—Rescarches on Ciliated Infusoria .. Maupas, E.—Conjugation of Vorticellidew .. .. .. Fasre-DoMEeRGUE—Structure of Urceolariz .. FanKuAtseR, J.—Luglena DANGEARD, P, A.—Cry Paton tate Bp wis GourretT, P., & P. Rorser—-Protozoa of Corsica.. VeERWoRN, M.—Biological Studies on Protista a ot GRUBER; AV—Wew Rhizopous’ s,s. a) se ee ces as Carter, H. J.— Observations on Parkeria 30°! to, “Bo Sods. Se Suerporn’s (C. D.) Bibliography of the For re So. 60) DO. 00. on Bitscwx1, O.—Phylogeny of Protozoa .. 1. 1. oe ae GRUBER SAL——NoresionProtoz0G tse ss) Ge. cele) Uke sail. ree dee os RuvumeBier, L.— Various Sain and Developmental History of (Gol podacn esate ag ol 6G a0 “Ape sor co’ !a Cuark, J.—Ciliary Mosayientis Sp Opie enh na Ey) Sse bon SaGaee CatTaneo, G.—WNew Parasitic Ciliated apenas Masxei, W. M.—Fresh-water Infusoria iu Wellington Distr ae es Zea- land... «. Oo Ho ool a6 C0! 0) “con 80)" So wo Garcty, A. G-Smuglena oc ate nate Meee ie Brvuyne, C. pe—New Monad, Endobiella Bambehit ee BLANCHARD It: —Monas-Dunalit a ae se se) Geek Geet ee we EZIATT OL —A SCLILGOLGRGNGIALG ae) sie) oe) os) ee) ere cle Tele) ele 5 tn esleneaiotes og ooh ea’ ao aa 0 900 a0 oe Grassi, B.—Parasitic Protozoa .. .. Scuuserc, A.—Protozoa found in the Bromacl of Gamat BEpDDARD, F. E.— New Gregarine .. 1. «. 06 wea Part 4 Part 5 . Part 6 ” XX CONTENTS. BOTANY. A.—GenerAL, including the Anatomy and Physiology of the Phanerogamia. o. Anatomy: (1) Cell-structure and Protoplasm. PAGR ZACHARIAS, E.—Part taken by the Nucleus in Cell-division .. s+ ++ ve Part I 69 Kuess, G.—Albumen in the Cell-wall .. ae ae 69 Picut, P.—Thickening of the Cell-wall in the Baie stalk “of ue Ente wai) ia ~ 70 Moors, 8. Le M.—Jnfluence of Light upon Protoplasmic Movement .. .. Part 2 242 Went, F. A. F. C.—WNuclear and Cell-division 4. 1 ae oe ewe 243 Wicanp, A.—Crystal-plastids.. .. «2 «ow - ny inh ory oo. do «(p 243 Boxorny, T.—Separation of Silver by active Tigres AD on ge oO OG, oy 244 Decaeny, C.—Nuclear Origin of Hyaloplasm see es ‘iiss elev anit). velo Remmeten Haustep, B. D.— Three Nuclei in Pollen-grains 1. «1 oe Co tf 440 Zacuartias, E., & G. BertHoLp—Nuclear and Cell-division .. + 440 Krapsse, G.—Structure and Growth of the Cell-wall .. Ae cy 441 Nout, F.—Growth of the Cell-wall . vedas 442 ZIMMERMANN, A.—Worphology and een of the Cell Soe end apdykon. sp 442 SraspurGER, E.—Division of the Nucleus, Cell-division, and Impr ato Part 4 600 Korscue.t, E.—FRelation between the Function and Position of the Nucleus.. 4, 601 JAnsE, J. M.—Permeability of Protoplasm .. «. ss 601 Fiscuer, A., J. WIESNER, & F. Cc ulnar copa of Celt-wall 9 602 AMBRONN, FOP ecin omism of coloured Cell-walls .. .. «ss «6 of 145 602 Boxorny, T.— Action of basic substances on living Protoplam .. .. .« Part 5 758 IRRERA, L.—Forms of Celis... s «5 «1 2 8 08 c8 «eo ce 499 758 Kurss, G.—Physiology of the Cell .. 6 2 oF o8 «ss 8 6 «8 9 758 Wie.er, A.—Plasmolysis in Flowering Plants... « 759 STRASBURGER, E., & ZACHARIAS, E.— Division of the Watts i of the Cell Part 6 978 FrommMann, C.—Properties and Changes of the Membrane, Protoplasm, and Nucleus of Plant-cells .. .«. . of pO SO Sp 980 Went, F. A. T. C.—Jncrease of Normal Waeioles tb Divtion ato ty 981 Wisner, J.—Albumen in the Cell-wall .. 04 se «6 06 oF «6 cs 499 982 (2) Other Cell-contents (including Secretions). Beuzune, E., & F. W. Scutmper—Starch- and Chlorophyll-grains ,. .. Part1 70 TscuircH, R.— Quantitative estimation of Chlorophyll .. 1. os «8 «+ 4 71 Beuvct, G.—Formation of Starch in the EET née 980 oe | t5 Tl Fick, R.—Inosite .. . « Are me oor bce Ecos Mooe kop) Md 72 ScuNETZLER, J. B.— Tannin in learns: spines SON OGe CO OU Pade © ip 72 Barpacuia, G. A.—Chemical substances contained in the Box An) hte 72 TscutrcH, A.—Aleurone-grains in the Seed of Myristica surinamensis.. .. 95 72 Moors, 8. Le M.—Zpidermal Chlorophyll ad Part 2 245 Cucini, G.—Fluorescence of Chlorophyll... .. ss» 6 06 6 «6 99 245 Maccuratt, L.—Preparation of Pure Chlorophyll... 1. «2 se ae ee 245 Loew, O., & T. Boxorny—Presence of active Albumin in the Colaap 9 246 Zorr, W.—Fibrosin, a new Cell-content .. .« « «2 «ce «6 «2 «© 9 246 Mouiscu, H.—Secretion from the Roots .. .. 5 5 246 PALADIN, W.—Vormation of Organic Acids in the ete a of Pints op 247 JoHANNSEN— Localization of Emulsinin Almonds... .. «2 «6 of +» 49 247 WakkeER, J. H.—Formation of mica sts der fos. be) eu baniioeeae ie 5 TNGROOLASE- 57a) «tee @icePe ati, ade) eek) Sot” Ser, ee Mrkoscu, K.—Structure of Starch-grains .. .. «1 06 00 ee oe HriH0vse, W.—Function of Tannin .. aoe come ty 444 Scuimper, A. F. W.—Formation of Oxalate a Tae in Aine =o CONTENTS. Wakxrrr, J. H.—Crystals of Calcium oxalate 90. Sop 69 “bo too, oo Jef inna: KIsELEN, J.—Position and Number of Raphides .. «ss. on os ae gg HORNBERGER, R.—Spring-sap in the Birch and Hornbeam 4... 41 oe 45 IBAGCARINI, P:—Spherocrystals 6. ss cs 06 «o ee . Part 4 Tassi, F.—WNectar of Rhododendron... .. «6 «se oF 8 oo yf Wacener, E.—Tannin in the Crassulacexr 0? ROO AOD SOON NOU SIC DANMET CS Later Minrz, A.—Occurrence of the Elements of Sugar of Milk in Plants .. .. 4 Tscuirce, A.— Development of some Secretions and their Receptacles .. .. 4 Micuaup, G.—Alkaloid and Sugar in Cyclamen .. «6s 4 00 ae Part 5 Hecke1, E., & F. SCHLAGDENHAUFFEN—Laticiferous product of Mimusops (hse! THONG “oa! GB 00 OD oe slepeaMefys «Melee Seley. evs p Aoton, E. H.— Formation of Sugars in the Sepist, Glands of Narcissus .. 45 Tscurrcu, A.—Contents of the Cells of the Aril of the Nutmeg .. ss «6 4 BERTHELOT, & G. ANDRE—Phosphorus and Phosphoric Acid in Plants .. 4, RENDLE, A. B.—Development of Aleurone-grains in the Lupin .. .. .«. Part6 3 . Occurrence of Starch in the Onion 1. 22 oe oe ” Bexuvccr, G.—Formation of Starch in the Ohleronhyteageastes a9 Oo woo Scnuuz, E.—Reserve-substances in Evergreen Leaves .. «1 «6 0s 08 459 Fiscuer, A.—Glucose as a Reserve-material in Woody Plants .. .. .. 45 Lunpstrom, A. N —Colourless Oil-plastids in Potamogeton SG 8 Gos Sao°, np HOune,, FB’. v.—Substance of which Gum-arabic is formed .. 10 oe ae 5g Moe.ver, H.— Tannin and its connection with Metastasis .. .. 5 (3) Structure of Tissues. Catvert, Acnes, & L. A. Boopte—Laticiferous System of Manihot and CUCL Paceenis ence Roser cee ee wom ee as Gel eeas Ga eR Artel HeErricuer, E.—Tubular Cells of the Fumariacez .. 2. ov ae Fr TrecHem, P. van—Super-endodermal Network in the Root of the Cupre i- JOLLUEE B5° oo 0b 6 bom co coy, 6b Ge) Wado 54 5 DANGEARD, P. A., & Panne ae angpment of the Fibro-vascular Bundles in Pinguicula ., 2. oe «» JO. "a0" 160. “06 6 Petit, L.— Distribution of Fibr mee Buniiles in the Petiole. a0 = Laux, W.— Vascular Bundles in the Rhizome of Monocotyledons .. 06 60 gp JANNICKE, W.— Comparative Anatomy of Geraniacex .. 65 0a OO A“ Greece, W. H.—Anomalous Thickening in the Roots of Cras a0 50 dO RD Krasse, G.—Formation of Annual Rings in Wood Sea al BAP mmr; oy GrReEvILLIvs, A. Y.—Wechanical system of Pendent Organs.. .. Lourer, O.— Comparative Anatomy of Roots so ba og 08 ae Immicu, E.— Development of Stomata .. . .6 «es «oo «es é Part 2 Praiit, E.—Protecting-wood and Duramen .. 4. 5. on oe newegg Krasser, F.—Split Xylem in Clematis .. .. . ao. ¢ O6e 0 YO! gh ScHONLAND, S.—Apical meristem of the Roots of Pontetortnceie Ne 3 Bovucer, G. 8.—Lndosperm .. oe At Part 3 Mer, E.—Formation of the Duramen ., .. 4 00. 6e " SavuvaGEAv, C.—Diaphragms in the Air-canals of the Root 50 00 a TRIEBEL—Oil-passages in the Roots of Composite .. .. + vs 0 & LrecomtTr, H.—Effects produced by the Annular Decortication of Trees. 55 eee SoLEREDER—Systematic value of the Perforation in the Walls of Vessels FA Putt, C.—Anatomy of the Leaf-stalk .. .. 1s se 0s 06 os 08 yg Manern, L.— Permeability of the Epidermis of Leaves to Gases .. 4. «2 4 Vesqut, J.—Lpidermal Reservoirs for Water Ps GRC ich eae NS el WAT Tad HiLpEBRANDT, H.—Comparative Anatomy of Ambrosiacex and Senecioidese 3 JUEL, O.— Anatomy of Marcgraviacew .. 1. 10 «se ov os oo we Lesxois, A.—Secretory Canals and Secretory Reservoirs xa Part 4 Xxl PAGE 445 445 72 73 73 247 248 248 248 446 446 447 sti 447 447 448 448 448 449 449 604 EXli CONTENTS. PAGE MiLier, C.—Secreting Canals of Umbellifere and Araliacex contained in the Phloem .. «. - « Part 4 605 Scnarer, R. P. C ES iilience of ae Trg y of the Epider nal “Cells on the SOMES oo G0 59 0 +, 605 Wiiiamson, W. C. saa eire Cells in we iniers ior of the Tissue oF Fosait JET on or Bo: STA ste hae’ tee ete mee 605 Dovtior, H.—Periderm of ie, aannnoee Soe tere ale 606 AverrTa, C.—Anomalies in the Structure of the Roots Hf Dicot, yle rae #5 666 Dumont, A.— Comparative ase of Malvacex, Bombacex, Tiliaceex, and Sterculiace® .. «. a ee fs 606 TRIEBEL, R.—Oil-receptacles in Se Sreacte of Gonpiste 2) Fo 1* eee oon ATtOMOO DouLior, H.—Hormation of Periderm) ‘es. oe 22 ee tee) ce ee gs 761 Pra, E.—Protecting-wood and Duramen .. «. Saou, ce 76% Mer, E.—Causes which produce Eccentricity in the Pith in Pines Me = 761 » » Lnfluence of Exposure on the Formation of the Annual Ringen in the Savim.. © .. AGE Wee COL MCOL aR Nota cok MCAD) mon re 762 Comrs, O.—WMal nero of the Vie 6G 0D. ao» ‘dt 0m ~ ad, a0 55 762 Lignier, O.—Importance of the Foliar Fibrovascular ye mm We ge table AVM en | Ga. oD oe bon os se? pee | oe. URartiGmoee WISSELINGH, C. VAN— Wall of Sablndils Cells ae akico Mest OM settee cf Nets a 985 PETERSEN, O. G.—Reticulations in Vessels 3. =. «« «6 ss so of 959 986 DanGEArD, P. A.—Secretory Canals of Araucaria - 986 Tirguem, P. van—Super-endodermal Network of the Root of Leuninose and Ericacee.. . BS 986 op cs & Morar. ane cpilermal iNeteoEE of ie Rs sot of : Geraniacee .. .. : 40 cog eas 986 Pe 3 Eupeorong, Wetork. in the Cores of the ‘Root oc Sa. 986 Haoderm of the Root of Restiace® .. .. .. ss «6 455 987 Doura07, H.—Periderm of Rosacex ae ae a 6 . 987 TrecHem, P. van, & H. Dovutior— Plants sphich one ‘tial. Roailets without a Pocket . Ho 00 cc a 987 DANGEARD, P. ess Obseroations on Pouca eum peed gabe Mucis | Nee. 4 ct, Mees 987 59 Anatomy of the Salsolex.. co oO Go BH & 988 Moxrsou, on SUE a me Coe Roe ROLE TON oct. Moe mee eae! eteoe | Ss 988 (4) Structure of Organs. Jost, L.—Respiratory Organs... sc. ss 0» «20 e« 00 « ce ws Partl 76 SGHIRGH- PA: —— Ong ays Oia SECHCHON soe misa) | Mes) em cte nae? Nesta) i /s|s0 sje ice ns 77 ScuEencK, H.—Anatomy of Water-plants Ae rors atic MOON | Soe at 77 TS orspeGon (6h, Ip! brea ra ROMS Uy COTES Go, OB 00 co cd oa oo mn. 78 Focksr, W. O.—Dichotypy ari altos 60, 150 Al Gita Day Goat Pay 78 Dietz, S.—Flowers and Fruit of Sainaanin ae Typha Sinn a pee 78 Warp, H. MarsHat, & J. Duntop—Fruits and Seeds of Rhamnus .. .. yy 78 Lunpstr6m, A. N.—Masked Fruits - 79 CouttrEr, J. M., & J. N. Romak Detebonment of the Fr uit ef Uinblifere. ;: 79 Kern, O.—Azwis of the Inflorescence .. . 50% 0 5 79 Hove iacque, M.—Development and Structure of Or angie im a young eg Je, and of its Suckers .... PAT tae m 80 GRANEL— Origin of the Suckers in Pia ogamous pe ies Sau 00h = en 80 TiecHEem, P. van—Arrangement of Secondary Roots and Buds on Boots bse Ss 80 VUILLEMIN, P.—EZpidermal Glands.. 2. s0 se 08 00 20! ae wey 81 Buake, J. H.—Prickle-pores of Victoria regia aC au) Mee: (Eco une 8 Bower, F. O.—WMorphological Peculiarity es Cord, te iiatralis as Be 8I Heimert, A.—Nyctagince .. .. nie Gee st Hominy icles ches * 82 XXill CONTENTS. SoRAvER, P.—Root-tubers and Bacteria .. .. ss 6 «8 oe os « Partl Prrottra, R.—Lndosperm of Gelsominex (Jasmine®) .. . A Pro. Hae ele any Martort#, R., & G. VoLKENs—Salt-excreting Glands of Tomesis iscinese Pe Kocs, L.—Organs for the absorption of vegetable food-material by plants con- taining chlorophyll.. .. .«. sb © od tp SasLon, Lecterc pu—Haustoria of the Rhingnthes hee Sent Wee ys oF TreeHEM, P. vaN—Structure of the root and arrangement of the rootlets in Centrolepidex, Eriocaulex, Juncee, Mayacexr, and Xyridex a Fr 3 Geminate Root-hairs .. . . ” Marrtoto, O., & L. BuscaLtion1i—oot-tubercles of eave 5 Warp, H. MARSHALL— Tubercular Swellings on the Roots of Vicia Faba Baupini, T. A.—Lmergencies on the Roots of Podocarpus .. .. «. cf Cotoms, G.—Stipules nO MOO “NOOR. ROCMMECDU ED OOR GGretOs: > RCC ane 3 Druz, .—Vernation of Leaves %, as, ss: wes. eer, we (ee se oe, ae | 99 KRonFeELD, M.— Double Leaves bs Boe “aio 0) cosa Beep Lacumann—Pitcher-like Leaflets of Seapnyted ‘pinata: do, 00) 00-66. an barrett. — Chinging Plants ser ese * 36) Sow coe) fem ve, cel oe. “eePme gy Krasser, F.—AHeterophylly .... oe pyen oo yee Ost Mico Meader Corn Ss Colours oft Leaves aud Prints. wey corte Rome Uacumet-leemiace 55 BrrcHe, K.—Anatomy of the Floral Axis... 4 an 5 on oe oes gy HeEnstow, G.—Comparative Anatomy of Flowers 1... 06 we as Derino, F.—Floral Nectary of Symphoricarpus .. Sc po, Migat” Sop. Mes OEMS Ach miiinOf -DOrrAgunee cael 262 Trevus, M.—Life-history of iaemadumn: CORO: SC tt MC oMBO Ces Ur fame 262 Bucutien, O.—Prothallium of Equisetum .. . Sse Reet sa use es 262 Renavwt, B.—Leaves of Siyillaria and Reprtndendr OM geeenacis A so een vant eas 263 Ktwnpie, J.—Development of the Sporangium of Polypodiacee .. .. .«. Part3 459 M‘Nas, W. R.—Stomata and Ligules of Selaginella .. 4, 11 ue we gy 460 Bower, F. O.—Oophyte of Trichomanes.. .. a Os art 4 6L7 CamrseE.LL, D. H.—Development of Gracies Siruhioptois, Hof. (Struthi- opteris germanica, Willd.) .. .. cetecea gOM rece net, eec 8 as 618 Mourine, W.—Branching of the Frond of Tops Spiraea oe coc lines ets 619 Brenze, W.— Leaves of Polypodiacee .. ECommerce aces aol i sce hese 619 Daccomo, G.—Aspidol from Aspidium Filion STOH) 60° posctode So) wo 00 619 LrciErc pu SasLon—Selaginella lepidophylla .. —4u nu nw wee gg 620 Soutus-Lavsacn’s (H.) Introduction to Fossil Botany .. .. +e we wey 620 Wanes, S: H.—Systematic Position of Tsoctes... .. .« oo «6 oe ee Part 5 773 VaizEy, J. R.—Derelopment of the Root of Equisetum.. .. ss «+ 08 5 773 Lrcierc pu Saston—Antherozoids of Cheilanthes hirta .. .. .. .. Part 6 999 BERGGREN, 8.—Apogamy in Notochlana 50 Sue oe oe 999 Newcomen, F, C.—Dissemination of the Spores of uit Ses isthe 9 LOOO Muscinee. Varzry, J. R.—Transpiration of the Sporophore of Mosses .. .. .. « Partl 92 Scuuize, H.— Vegetative reproduction of a Moss... oe oe oe we gy 91 Watpner, M.—Sporogonium of Andreea and pica cb tage oem BL aa aliss 91 MUiuuer, C.—WNew Sphagna .. as 91 Livericut, K. G.—Rabenhorst’s ‘ Crate anne Fi flora of Coentge Hf > (Musci) - 91 GoEBeEL, K.—Epiphytic Jungermannice .. A Mas, Jct? So. Boor. Sy 92 Karsten, G.— Production of Gemmez by Ragateitae 50) 8c 35 92 Vazey, J. R.— Absorption of Water and its Relatwn to the Constination of the Oell-wall an Mosses) se. i 00 cel oe ee oo 06 wer § vn HAXt 2) 263 Brereton Oy JOG Soc. oo) 60 G0 0G Go. 06 co. 263 Sanrio, C.—Hybrid Mosses ae BA Gtr mnie pico eon ee Ae, Macy 264 Massatonoo, C.— Distribution of Hepaies 50. BO ye 264 Vaizry, J. R—Anatomy and Development of the Sporagnitm of ees .. Part 3 460 Pritizpert—JInternal Peristome of Mosses .. 1. +1 00 «© «8 «8 4 461 LrEcLEeRc pu SasLon—Antherozoords of ean, Sow eGom 50d Moon coe ea: 461 IPHITIBERT———Leristome Of, MOSSES “tees (acl) os), sels eebapres) ayes) seh ae ath 41620 iRussows, Hi——German Sphagnace@ ... joc 2 ss) wee) ee) gy 621 ScHNETZLER, J. B.—Reproduction of Thamnium alopecurum Aa ao so Eta Gy 7/73 Nou, F.—Protonem of Schistostega osmundacea.. .. Co co 774 Russow, E.—Physiological and Comparative Anutomy 2 Beha anise. BO 00> ns Tiss R6LtL—Forms of Sphagnum 2. ae oe we PE Ce 208 (6) IBHIGIBERT——IeTIStOMens Jel Moers Venue eehy ee lel Ue 90. 00 ‘oC Part 6 1000 Waupner, M.—Development of the Sporogonium of Andrexa pane Sphagnum ,, 1000 MarrtroLo, O.—Hygroscopic Movements of the Thallus of Marchantiee .. 4, 1001 Characee. ALLEN, T, F.—WNew Species of Characez i sn Maee ee se tee ot DARL I. oie - ‘s American Characez don so! So sc 0d oo og om eG) CURT INORDSTEDIN O:——WewlChardivs. +0 ee se oe p ee e eiueeeee. bart Glo INGD ISITE op ok ae 00 on on 0. od bo SH ary SOON ” > XXVill CONTENTS. Algee. PAGE Bennett, A. W.—Fresh-water Algx. (including Chlorophyllous ee yta) of the English Lake District. (Platel.) .. « . .. Part igeee Maskett, W. M.—WNote on Micrasterias Americana ae its var ee @Blateil en, ve. ne bork Ooh ndde cod) GO ch oo 7 JANSE, J. M.—Plasmolysis of Me. a Ce ee eae AON coe oor

eT TONI, '@ B. DE—Diatoms from a Trygon a : 3 allel RatrTray, J.—Revision of the Genus Auliscus, Ehrb. sp Aaah cy some allied (GACERE (CHT OIUED NID) oy 65 Oo co xx we cs art6 86 Retnscou, P. ¥.—New Genera of Fi lomibee 3c » 1002 KLeBauNn, H.—Zygospores of Conjugatz 3 ~1002 Morray, G., & L. A. Boopte—Spongocladia a L002 Hanscire, A.—Aerophytic Species of Ulotrichacez » ~ 1002 IsTVANFFI, G. —Structure of Ulothriz = 1003 WILDEMAN, E. p—E—Bulbotrichia as = L008 Tont, J. B. peE—Hansgirgia, a new genus of cabin. ies » 1003 DanGEARD, P. A.—Chlorogonium » 1003 5 35 Chlamydomonas 3c » 1004 s is Chlamydococcus pluvialis ., - ees LOOt HAvprrieiscu, P.— Cell membrane and Gelatinous Envitlone a Desmiina » 1004 Suiru, T. F.—Structure of Pleurosigma formosum nO™ ccd wn LOGS Lichenes. Forssewu, K. B. J.—Gleolichenes .. «2 se oF Part1 95 Massreg, G.—Gasterolichenes .. +s 00 ee se is 95 Miter, J.—Action of Lichens on Rocks 66. od uc anus 95 HEGETSCHWEILER & STIZENBERGER—Lichens on unusual eulstnaea ae 96 Mo.ier, A.— Culture of Lichen-forming Ascomycetes without Algz és Part 3 466 \ WENN, IDE SOUT eo ano, eo O00. 00 op ee oO on Tech GT! Sypow’s:(D.) Lichens of Germany .. .» o co «8 «2 Bee ye 621 Fungi. Errera, L.—Accumulation and Consumption of ae by Fungi . Part1 96 WerrstE1n, R. v.—Function of Cystids.. AG.) 56 = 96 SEYNEs, J. DE—Rhizomorpha subcorticalis of Armillaria onelien Me Pare 97 Diete., P.—Uredinew .. . o68 od Es 97 PRILLIEUX, EH. ee eeu Ovinathieian diplodiella bs a. net ee 98 GaASPERINI, G.—WNew Disease of Lemons.. «2 +» «+ 98 WAHRLICH, Tue SEWUPOTE 0. AO 08 Og, 3 98 Zor‘, W.—Chytridiacea parasitic on Diatoms .. «1 we ss 5 99 ScHROETER, J., Cohn’s ‘ Cryptogamic Flora of Silesia’ .... 9 99 Massez—On the Type of a New Order of Fungi (P1, IV.) .. oC Part 2 173 Frank, B.—New Forms of Mycorhiza .. .. . oe 35 268 WETTSTEIN, R. voN—Abnormal Fructification of Sierras Paper i 269 Morini, F.—Seaxuality of Ustilaginee .. . < aan SES Met ee ‘ a 269 9s » Germination of the Spores in Uattaaa Ab. Shoe Boom ted 5 270 Boupmr, E.—Tremella fimetaria .. .. ae F 5 270 TrecHEeM, P. Van—WNew Genera of Asaoniceten Oleints and Ponoenpes OO FF 271 ZuKaL, H.—Asci of Penicillium crustaceum .. .. .. «ws . PM» ker: 271 Rotruert, W.— Formation of Sporangia and Oe in the Suproteqnien 100 5 271 ScHNETZLER, J. B.—Jnfection of a Frog-tadpole by Saprolegnia feraz 55 Die Reess, M., &*C. Fisco—LHlaphomyces.. .. «6 2s a» oe oe weg 273 Bruncuorst, J.—Cabbage-Hernia .. 15 «ss «» 8 oe oo os K 273 . ape OLOLOMHUTG US = ooh 2 s/n) eels to Reis nn a aI ete - 274 Rosinson, B. L.—TZaphrina .. Bc ie dd 274. VuILLemin, P.—Disease affecting Gan ea Phemcivecs 274 Hanz, ©. O.—Oidium Fragarie 1. ws ies se oo we oe a es 274 XXX CONTENTS. Rosrrvpv, E.—Fungi of Finland sob oe Maaenus, P.—Sterility of Fungi... aC ParovurttarD, N.—Classification of the ioe Moror, L.—Jdentity of Polyporus abietinus, Fr. and Irpex ee: eee O88 ape 468 ee ”? Fr. “9 GASPERINI, Cie of the aehaniieties AC Zorr, W.—Cultivation of Phycomycetes .. «+ 8 vs BerveEse, A. N.—Pleospora ic Harrie, R.— Trichospheria san a Happote ichia fee JOHANSON, ©. J—TZaphrina .. .. PAGE . Part 2 275 . Part 3 467 Fs 467 Peres wo hy eae 2) ee ot ae Srymour, A. B.—Character of the Tavares. Soden iy Parasitio Fungi upon their Host-plants .. .. . sett ties Tousevr, C. v. Pee Disease of the ovgiassne Brouncuorst, J.—New Potato-disease 0 a THUMEN, F. v., & = Ratruay—WNew Vassease.. ae Montez, R.—New Parasite of the Silk-worm .. Roiuanp, L.—Blue Coloration of Fungi by Lodine.. Karsten, H.— Classification and Description of Fungi .. Vumttemin, P.—Biological Studies of Fungi .. of oe oe ” 470 #3 471 Set at das 471 Foal la 471 Se Gs 471 .. Part 4 628 no. ap 628 A ata) 628 Hecke, E.—Vormation of two fertile hymenia in Poli us Tappinndias ab. 629 Fiscuer, E.—Stretching of the Receptacle of the Phalloidet .. Masses, G.—Revision of the Genus Bovista .. ; Fricuou—Fformation of the Asci in Physalospora Bidwellit 50 Durour, L.—Development and Fructification of Trichocladium Srynes, J. DE—Ceriomyces and Fibrillaria Saccarpo, P. A.—New Genus of Sphexriaceous Bieter oe Beruese, A. N.—New Genus Peltospheria Bovuprer,—New Mucedinex Bo Bo Ok Berxesz, A. N.— Scan and Pe nner Seal eee Lise CosTANTIN, J.—New Papulaspora .. ee Macunvs, eee Rope ot oat oe : RovuMEGUERE, C.—Fungus Parasitic on the Pines Sanrorn, E.—Anatomy of the Common Cedar-apple Puriips, W.— Luminosity of Fungi 1. 10 we wes Bovupier—Conidiferous Form of Polyporus biennis.. «2 « BREFELD, O.—Classification of Basidiomycetes «+ ws PATEUILLARD, N.—WNew Tubercularia .. . ho 00 Masser, G.—Calostoma, Desv. (Mitremyces, ae gt Groves, W. B.—Pimina, a new Genus of ce ieee oe Tuimen, F. v.—Fungi of Fruit-trees .. 1. oe oc Bonnet, H.—Parasitism of the Truffle .. 1. « Srynes, J. DE—Fungus Parasitic on the Pine-apple Bruncuorst, J.—Fungus Parasitic on the Salt-fish Barter & VuILLemMInN—“ Rouge” of the Scotch Fir .. .. DaNnGEARD, P. A—Parasites of the Peridiniew .. VuILLEMIN, P.—Disease attacking Amygdalex Zorr, W.—Haplococcus reticulatus .. .. + LaGERHEIM, G.—New Puccinia .. . . ‘ Massnx, G.—Seaual Organs in Acidium Ae Lob... om Grarp, A.—Symbiotic Fungus in Molgulide .. te Lister, A.— Plasmodium of Badhamia and Br es at DANGEARD, P. hs INOteS ate eee 39 Mouter, A.‘ Spermatia ” of the Ascomycetes Scur6tTeR, J.—Basidiomycetes .. Soa ss 629 ios es » 629 ns oy we BBO Jo= ee va! ids gE tle 5 688 See ee nc Se teem 53) G8 a» 1680 Rot ot, eae ct 631 dip os ee DESO Ache obe sad th 778 Gute ate c ees 778 He eh resi Nees, 779 it eee teen Gs 780 Se ine Se tess 780 sepee: waco ras 780 5 180 >» M80 5) aig La ee OV ee i ee OG rene: £2 HO OO 0 782 Pole SAE RE oo 782 Ao coe 6 on 783 yews 783 " Part 6 1006 » 1006 CONTENTS. CosTaNTIN, J.—Heterobasidial Basidiomycetes Srynus, J. DE—Polyporex ParournLaRD, N.—Prototremella VurmLLemin, P.—Ascospora Beijerinckii .. Dieter, P.—Uredinex and their Hosts .. re Warp, H. MarsHati—Structure and Life History of Puce inia Grains Ble CuBONT. G.——Peronospora wilicola) 2." 42 se wes ewe ee » Leronospora of the Rose .. .. op, 60) sn6 Morini, F.—Ascophorous form of Penicillium Phun Ae See te EIcHetBaum, F.—WNew Aspergillus.. 1. 1. 42 oe QuéLET, L.—Ombrophila and Guepinia .. KLEBAHN, H.—Peridermium Pini .. Bovupter, E.—Pilacre .. ‘ WASSERZOG, H.—Fusoma.. .. CosTaNntTIN, J.—Diplocladium .. Sen aay eck, SHON ets Miter, H.—‘ Edelfiule” of Grapes .... as CosTaNTIN, J., & RoLLAND.—Stysanus and Hormona? on. me Eipam, E.—New Mould .. .. .. DOM Gdn Obie (Bd) SEDO 00 THAXxtTeER, R.—Entomopthorex of the Ui nited States .. Krenitz-GEer.orr, F.—Gonidia of Gymnosporangium .. Harroc, M.—Recent Researches on the Saprolegnice .. 1. « Perronciro, H.—Chytridinn elegans, n. sp., a Parasite of the Roti itp id) ee TomascHEer, A.—New Chytridium.... ae 3 CostantTIn, J.—Parasites of the Higher Fungi oop Mester e Teer | ce Protophyta. Hy—WMicrochxte a AO 0 DC COr me wGe. Boole, (58a scan Giese WEIBEL, E.— Vibrio from N asal Mutts ae rare ae as 5, Lwo kinds of Vibrios found in decrees hag ‘Tafuson _ Karz, O.—Phosphorescent Bacteria from Sea-water 4. 4. ae ue Bary’s (A. Dr) Lectures on Bacteria .. . ACT thG. Bt Scorr, D. H.—WNucleus in Osciilaria and Toh, Upciien HY ope 100 og. Cb Borzi, A.—Wicrochete .. .«. a dy Atte oe 8 Be Bitter, A.—Life-history and Mor Pikcteniee Variations of Bacterium JOGUTAEAES 66) HO ~ OG OB EO Oe Oe oo Doge 64 ne Ge Tomascuek, A., & A. Hanscrrc—Bacillus muralis 1... ae oe Bunwip; ©.——Bacteriaan Hailstones a) wv wiles el Fiscupr, B.—Phosphorescent Bacillus .. .. .. . a ee a6 Kirasato, §8.—Spirillum concentricum, a new species = from Posen blood a, 66 “On ‘oo Go oD Be Bornet, E., & C. FLanauLtT—Filamentous eter Petints N pnioclinies. Smitu, J. AA—New Chromogenic Bacillus—Bacillus ceruleus AS BAUMGARTEN, P.—Scheurlen’s Cancer Bacillus .. .. Cait leet peare ie 3, Spore-formation in the Bacillus of Genders aie ENGELMANN, T. W.—Bacterio-purpurin sn bx Gowont, M.—Cellular Envelope of the Palanan Werte es Borzi, A.—Development of Mischococcus confervicola .. 1. 4 ss ee LaGERHEIM, G.—Stichococcus bacillaris .. 46 as De Tont, G. B.— Remarkable Flos-aque : Prrroncito, E., & L. VARALDA—Composition of « cy : Muffe a ARCANGELI, G. See arenes MNOS 2, v2 real MOM ate WasserzuG, E.—Spores of the Ferments bay dol 6 Sige peGene: TomascHEeK, A.—Symbiosis of Bacteria with Gleocapsa agente Ae XXX1 PAGE . Part 6 1007 » 1007 eeeLOOM LOOK os 1007 ae LOO sa 1008 » 1008 3) L008 » 1008 3 L008 » 1009 » 1009 e009 » 1009 = L009 a LOO es 1010 a LOLO a LLOKO on LORO, ay COT so LOM a LOU Part 1 99 » 99 100 x 101 a 102 Part 2 275 cf 275 op 275 - 276 5 277 a 277 £ 278 . Part 3 472 a 472 be 472 » 473 473 Part 4 632 “5 632 on 632 - 633 ~ 633 a 633 A 633 5 634 XXXxll CONTENTS. PAGE ARLOING, 8.—Presence of a Phlogogenous matter in the Cultures of certain Microbes . io, oot, 8 FOUN eho ule A cet wise ae eety Uketcamk un Deion GALTIER— Chr “anioanciavie Wisreae. ag) (oom Ure occ oom DSO dae 6 cy 634 Hauser, G.—Sarcina of the Lungs righ oe + 634 Borpont-uFrREDvzz1, G.—New Pathogenic Mic a onee in ee aaa Meenas a 634 SPILLMANN & HavsHaLTER—VDissemination of Bacillus by Flies... 1... 635 Gomont, M.—Relationship between Phormidium and ee oo ee 6s OTC ON Woe Macs, E.—Cultures of Cladothrix dichotoma .. .«. Soh ae ounets ae 7 784 TiaGHEEEm, G.—WNew Pleurocapsa.. .. thy 784 ScunerzueR, J. B.—Colouring matter of the EE of the Take of Bret one re 785 JACQUEMIN, G.—Saccharomyces ellipsoideus and its Use in the Preparation of Wine from Barley .. «. AY OG) Go oe od ry 785 LAvRENT, E.—Organic nourishment of Bees apr iy cote iodo boy 785 Ermencem, E. Van—Scheuerlen’s Cancer Bacillus Ae scos ecu eo ck 785 IWENOGRADSKY, S:—(701 PD ACLETIO Nasi) Wee itas)) Wiss!) (eet Uwe) Wilco) ie lees 786 TomascHEK, A., & A. Hanseinc—Bactllus muralis .. .. «6 «+ oF 49 786 Prazmowski, A.—Spore-formation in Gacteria +e ss «+ 08 te we ogg 787 Bitter, AW—New Marine Bacterium 14 20 news AO 5G Od ce 789 FRANKLAND, Grace C., & Percy F. Abin w and Typical Micro-organisms from Water and Soil .. 14 . oF «8 «© oF 49 789 BaumMGARTEN’S (P.) Pathological Mycology .. ss «+s 28 48 8 791 Gomont, M.—Cellular Envelope of the Filamentous Nastoarege ate Male gists Pant 6 1012 Borzi, A.—Chlorothecium of set, cay eeibalsoe | Gale ® ees mmm Daneerarp, P. A.—Leproduction of Wop sonia: Hoe sore Och ech op a LUI: Ansa, Av—Trochisciaand Tctrahedron;. =. 6 os a «= °«s 55 siUNo Retysou, P. F.—Polyedriacex Ae : edie ae poor. LONE Miquet, P.—Bacillus living at a ineorenure ing 70° Ce, Sea Fae ale despa HiscHmR—Dacterial Growthrat OCC. 3c) ee eee ae) ee | ei e055 IEVANRGIRG AY — Cellar PB aChenia wee re) ee) vais deel Miele) Noelle tele » 1014 Kocu, A.—ndosporous Bacteria .. Som aoe acd “oe bye ae It Bucuner, H.—Supposed Spores of the Typhoid Beatie Bch Dt >, LOG NEIsseR—Spore-formation in the Bacilli of .Xerosis conjunctive, Streplocsors and Cholera spirilla ee eden Reo uuaiie eel Tiwana see >, LOlG Gautinr, V.—Pathogenic Heise TE Mier on ae Sane Gor od. = Oey WIN WIEBEL, E.— Vibrios ae 3 LOU Ouzvier, L.— Physiological Tienes on on EHS of Glairine ae ONCE eB Sane waen! Wier wane an ere sds Tinwts Yona. Vag’ coum ce tenuate MICROSCOPY. a, Instruments, Accessories, &c. (1) Stands. Co.iins’s (C.) Aquarium Microscope (Fig. 1) aa <2 os arta ales GOLFARELLI’S (1.) Micrometric Microscope for Farce (Fig. » 5050 103 Lenuossték’s (J. v.) Polymicroscope (Figs. 3-6) .. «2 « Bry be Bile 104 Doururt’s (H.) Polarizing Microscope (Figs. 7-9) .. .. «2 oF «2 « 49 107 Dvusosco’s Projection Microscope (Fig.10) .- .. «6 «2 «of « «2 499 108 Campant’s Compound Microscopes (Figs. ll and12) .. .. ~ 109 Winuiams, G. H.—Bausch and Lomb Optical Co.’s Eevee eee scope (Fig. 40) ne | Ge ae else aks wes Hare eone Czapski, 8.—Bamberg’s Goieroneice easeeee (Fig. 41) ieee, CeO a 280 GaALLAND-Mason’s (R.) Microphotoscope (Figs. 42-44) Srp MOC Om Owe cy 281 Nacuet’s (A.) Crane-arm Microscope (Fig. 62) .. . oe « « « Pait3 475 Doumaice’s Travelling Microscope (Fig.63) .. .. «2 «2 00 0 of 99 476 CONTENTS. Netson’s (HE. M.) Wechanical Stage INE-ADJUSTMENT by tilting the Stage (Figs. 64-7 3) Minor, C. S.— American Microscopes—A Complaint” Zuiss’s (C.) IIa. Microscope (Fig. 96) Basvucwin’s (A.) Microscope (Fig. 97) GALILEO’s Microscopes (Figs. 98 and 99) JosLot’s Microscope (Fig.100) .. .. 3c HeEnsoupt’s (M.) Reading Microscopes (Figs. 101 ae 102) . Taury’s Five-tube Microscope (Fig. 120) Oc Scurecr’s (F. W.) Meat-examining Microscope (Fig. 121 * Travelling Microscope (Fig. 122) Zeiss’s [Ta Microscope—Babuchin’s Microscope .. . swe ae Lerrz’s Demonstration Microscope—Old Demenethahn Mi ier Wear Fic an 123 and 124) . ae eU SG) SOG=, Mou. ur Wurrr’s (8S. 8.) Dentist’s navninne Bliss (Fig. 125) Ao ac Bavuscw AND Lomp Opticat Co.’s ‘* Watchmaker Glass” (Fig. 126) .. Ganz’s (J.) Pinakoscope with Dreyfus’s Reflector (Fig. 127) Trr-ocuLar, Quadri-ocular, §c., Prisms (Figs. 128-132) AHRENS’ (C. D.) New Erecting Microscope (Fig. 161) .. Kirnm’s (L.) Lzcursion Microscope (Figs. 162-164) oa PrircHaryd’s Microscope with “ Continental ” ia thaeate (Figs 166) GrirritH’s (EH. H.) omen (Fig ie 167 hae 168) MAYALL, J.— Necessity for a Sub-stage .. oe ee . ae oa oe oe . 165 and oe oe oe oe (2) Eye-pieces and Objectives. GunpLacu, E.—Apochromatic Objectives CueapP Objectives .. : 36° G0 | BO do, te Swirt, J.— The Jena Optical Glass Gace 14 and 75) 53 Vocen, H. W.—Hartnack’s new Objective aa Zetss’s “‘ Compensation Lye-piece 6 with 1/1 Mier onedninon 2 (Fig. DEFECTIVE Objectives and the Binocular Microscope ee oe oe oe oe 133) 3s (3) Illuminating and other Apparatus. Zeiss’ (C.) Lris Diaphram (Figs. 13-15) ja pried weaeyah, PHAl Oeog Ane Epmonps’s (J.) Automatic Mica Stage (Fig. 16) .. RovssEver’s (C.) Life-box (Fig. 17) noe 00 Mayer, P.—Large form of Abbe Camera Lucida ., Hircsucock, R.—WMay’s Apparatus for Marking Objects so. 06 Dewirz, H.— Simple Method of Warming and Cooling under the Mieroncns (Fig. 18) se ° GraBer, V.—Apparatus for determining Sensibility to eae Gutsster’s (G. F.) Culture Tubes (Fig. 45) Gas and Moist Chambers (Figs. 46-55) . Ma.uarp, E.—Bertrand’s Bapractombrens 50 50 LrexamMann, O.—Apparatus for Microphysical Tanesiagatanes oe Doumatcen’s Camera Lucida (Fig. 76) 30 EXYE-SHADES 50 oe Dumaice’s Nose-piece for eas Objectives wr a 1) Matassez’s (L.) Hot Stage (Fig. 78) .. Ot BC HA.ustin’s (K.) “ Compressorium” (Fig. 79) Harpy’s (J. D.) Growing Slide (Fig. 80) 50d Scurecn’s (J. W.) Microscope Lamps (Figs. 81-84) Geruacu’s Embryoscope (Figs. 85 and 86) 1888. oe oe oe oe oe oe oe oe oe oe oe ee oe oe o- oe oe oe ad ne Nise . Part 4 XXXlil PAGE . Part 3 477 478 482 637 637 639 640 ss 640 792 793 794 794 ” 794 795 799 796 796 : pant 6 1020 » 1020 1022 1022 1024 . Part 2 285 287 ” . Part 3 486 . Part 4 646 Part 5 797 . Part 6 1025 Parti) it 111 112 113 113 114 114 287 287 291 292 487 488 488 488 489 489 490 491 XXXIV CONTENTS. PAGE Hincenporr’s (F.) Auxanograph (Fig. 103)... ee we .. « Part4 646 Cuapman, F. T,—Slide for observing Soap-bubble Films (Fig. 104) 00 it 647 Scuiren’s (BE. A.) Hot-water Circulation Stage and eae Regulator CFig:105): Ase gees een seak eee Moe tree ty 60s. fous 7p 649 BeErtTRAND’S (B.) Refractometer .. . SMe: ce corr bay ad 3 649 Erernop’s (A.) Drawing-board (Figs. 134 -139) nah See ee ee, ae em AGRO MOS Bass’ (V.) Hot Stage (Figs. 140 and 141) .. «ew 5 800 Cuasry, L.—Capillary Slide and accessories for the ciawination of Oo8 (Figs. 142 and 143) .. «. 06. 00)

oe) we «Part, 2 177. Hearuer’s ‘ Mathematical Instruments’... -» Part 3 501 Ricker, A. W., A. D’Apnpante, & R. B. Sie ors cialianetie 5b SS 502 Cox, ©. F.—American Microscopes.. .. .. «+ «+ o « « «» Part 4 652 Deatu of Mr. Webb . Sie pike 3 654 Quinn, E. P. re method of Pr cane con the sereen iNBasacenas Rock Sections, both by ordinary and by polarized light .. .. .. «. « Part5 819 Jupp, J. W.—Wicroscopy and the Study of Rocks... .. «2 «6 « 0» 43 820 Hovuzeav, J. C.—Wicroscope and Telescope .. «1 +6 +e ve new 820 (Cosa, es eb WOOF co 56 fon © Go too be «0d 00 Part 6 1061 B. Technique. (1) Collecting Objects, including Culture Processes. Stone, W. E.—Cultivation of Saccharomycetes .. . op oo oo Jeti dl Zbl Axssot, A. C.—ZImprovement in the method of ones Tee um for use in Bacteriology .. .. « 60.) Gu, .00. , 60: © & 142 Karz, O.—Improved method for cultivating Dacron ete on Potatoes po eh 142 Boiron, M.—WMethod of preparing Potatoes for Bacterial Cultures 5 143 Witrartu, H.—Cultivation-bottle .. .. - AD and Bo bok Sao rsh 143 Cunnincuam, K, M.—Collecting and Chae Desert ac 0 06 143 Ports, E.—Collecting, Growing, and Examining Fresh-water Rn ws Part 2 305 EISENBERG, J.—Potato Cultivations 60 Ba Po Sa pace Or S 310 Puavur, H.—Sterilization of Potato, Apples, Ae Water for oan jietees of 310 XXXVi CONTENTS. PAGE Tarcuanorr, J., & Kotessnixorr—Alkaline Lyg-albwmen as a Medium for Bacteria Cultivation on elhoeere Gas > ceece (00 ae) LO ReCmeEes Manrrept, L.—atty Matters in Cultivation Media cd. Oy Con Oo? cy 504 Jacost, E.—Preparation of Nutritive Media .. .« «1 «+ «6 «+ «+ Part 4 655 FREUDENREICH, E.—Preparing Agar-agar .. «2 «ss 6 08 «8 ++ 4 656 Raskin, M.—WMilk-peptone-gelatin for cultivating Pathogenic Micro-organisms 4, 656 DiaKonow, N. W.— Vessel for the Culture of Low Organisms (Fig. 108) -. 657 Bircu-Hirscurep — Cultivation of Schizomycetes in Coloured Nutritive MCG Te ca po: (ie en Pe a eke, Sa rere 1 MPC ONSTITUTIONM et. L -ctt a eel. bets soso 2 Gl, care OE i oe 2-3 III. Manacement SE ae eel oe 8 Pied bs, Oe 4 IV. Fettows :— A. Election— (a) Ordinary Wellows 9%. a. Se Pe, es =O (b) Honorary Fellows erent, SaaS) bsnl @)elx-oficio Bellows\c | asta. ttn in om e LOKLD B. Admission Fee, Annual Subscription, and Com- position ea ee ca os nel oe ee AO CP PTVMGIOS sae toict | ts ae ae ae AO ey Pa) SOU D. Withdrawal and Removal 5 rs cf ee lest V. Covuncm :— A. Hlection .. ie = “ - * : a5 SS ib. Proceedings- 9.00 2-4 ade 21.) Gdn lao dos VI. OFrFicers :— A. President and Vice-Presidents AA a Gc eae ods. See aR B. Treasurer .. 5% ms = 3 ce if Se 55 DSK ES C. Secretaries Sie We FS tas Stet Ses Oe ie tO tA WME GrNnnnat, Memrines.. -2:4 4.'9 eso a” os on ObZTS AMOrdmary 25-620 Wa de Or | GENS be EEL R76 B. Annual... soy Rr hea ee yt Geek ee 65 SIL Ce Specials. 9 2i/ 40 “ohh avai Ce Soe eed OR S84 VIII. Lisrary anp CaBINET if re ete fe ee eR Br, IX. Papers AND PUBLICATIONS Bie Nea taxi Sen 7 OS =94: X. Notices ee ee ee eh eer os - wi - co) DO XI. ALTERATION OF ByYE-LAWS £ = te Peer SA ae! gee og COIN TERPRETATION US kok vate eee ie ch Se ae 100 I. Objects. 1. The Objects of the Society are the promotion of Microscopical and Biological Science by the communication, discussion, and publica- tion of Observations and Discoveries relating to (1) Improvements in the Construction and mode of Application of the Microscope, or (2) Biological or other subjects of Microscopical Research. slvin BYE-LAWS. II. Constitution. 2. The Society shall consist of Ordinary, Honorary, and Ex-officio Fellows, without distinction of sex. 3. The number of Ordinary Fellows shall not be limited. The number of Honorary Fellows shall be limited to fifty, and of Ex-officio Fellows to one hundred. III. Management. 4, The management of the Society's property and affairs shall be vested in a Council consisting of twenty Members (all being males), viz.:—eight Officers (a President, four Vice-Presidents, a Treasurer, and two Secretaries) and twelve other Ordinary Fellows (hereinafter referred to as “Ordinary Members of Council”). IV. Fellows. A. Election. (a) Ordinary Fellows. 5. Every candidate desirous of being elected an Ordinary Fellow must be proposed by three or more Ordinary Fellows who must sign a certificate setting forth his names, place of residence, and deserip- tion. The Fellow whose name stands first upon the certificate, must have personal knowledge of the candidate. 6. The certificate shall be read by the President, Vice-President, or other Chairman, or one of the Secretaries at the General Meeting next after its receipt, and shall then be suspended in one of the rooms» of the Society, and shall be read a second time at the next succeeding General Meeting. 7. The votes on any election of Ordinary Fellows shall be taken by ballot. 8. The ballot shall take place at the General Meeting at which the certificate shall have been read for the second time. No ballot shall be valid unless ten or more votes are recorded ; and when at least two- thirds of the votes are in favour of the candidate, he shall be declared duly elected. 9. The Secretaries shall send a notice of election, together with a copy of these Bye-Laws, to every Ordinary Fellow so elected. 10. Every person elected an Ordinary Fellow shall sign the following form of declaration and shall pay the admission fee and first annual subscription or composition within two months from the date of election, or within such further time as the Council may allow. In default of such signature and payment the election of such Fellow shall be void. I, the undersigned, having been elected a Fellow of the Royan MicroscoricaL Socrery, hereby agree that I will be governed by the Charter and Bye-Laws of the Society for the time being; and that BYE-LAWS. xlix Twill advance the objects of the Society as far as shall be in my power. Provided that when I shall signify in writing to one of the Secretaries that I am desirous of ceasing to be a Fellow thereof, IT shall (after payment of all annual subscriptions that may be due from me, and returning any books, or other property belonging to the Society in my possession) be free from this obligation. Witness my hand the day of 18 (b) Honorary Fellows. 11. Any person eminent in Microscopical or Biological Science shall be eligible for election as an Honorary Fellow. 12. Such person must be proposed by five or more Ordinary ‘ Fellows, who must sign a certificate setting forth his names, place of residence, and description, and stating that he is eminent in Micro- scopical or Biological Science, and that they have a personal knowledge of him or are acquainted with his works. 13. The certificate shall be laid before the Council, and if they approve of the person named therein, shall be read and suspended, and the ballot for such person shall take place in the same manner as is hereinbefore provided for the election of Ordinary Fellows. 14. The Seeretaries shall send a notice of election, together with a copy of these Bye-Laws, to every Honorary Fellow so elected. (c) Ha-Officio Fellows. — 15. The President for the time being of any Society having objects in whole or in part similar to those of this Society, shall be eligible for election as an Ex-officio Fellow. 16. Such person must be proposed by ten or more Ordinary Fellows, who must sign a certificate setting forth his names, place of residence, and description, and the name of the Society of which he is President. 17. The certificate shall be laid before the Council, and if they approve of the person named therein, shall be read and suspended, and the ballot for such person shall take place in the same manner as 1s hereinbefore provided for the election of Ordinary Fellows. 18. The Secretaries shall send a notice of election, together with a copy of these Bye-Laws, to every Ex-officio Fellow so elected. i9. On any Ex-officio Fellow ceasing to be President of such Society as aforesaid, his successor shall ¢pso facto become an Ex-officio Fellow, unless the Council shall otherwise resolve, in which case such successor must be proposed for election and balloted for in manner provided in Arts. 16 and 17. B. Admission Fee, Annual Subscription, and Composition. 20. Every Ordinary Fellow shall pay an admission fee of two guineas, and a further sum of two guineas as an annual subscription. | BYE-LAWS. 21. The annual subscription shall be due on election and there- after in advance on the Ist of January in each year. 22. Ordinary Fellows elected in March or April in any year shall be exempted from payment of one-sixth of the annual subscription for that year; those elected in May or June, in October, or in November or December, shall be exempted from payment of two- sixths, four-sixths, and five-sixths respectively of such subscription, according to the month in which they are elected. 23. Any Ordinary Fellow who may permanently reside out of the United Kingdom shall be exempted from payment of one-fourth of the annual subscription; and any Ordinary Fellow who may be absent from the United Kingdom during the whole of one year, shall, upon notifying the fact to one of the Secretaries in writing, be similarly exempted during such year. 24. The Council may remit all or any of the past or future annual subscriptions of any Ordinary Fellow if they shall think desirable, but the reason for such remission shall be stated in the resolution by which it is granted. 25. Every Ordinary Fellow who may desire to compound for his future annual subscriptions may do so by a payment of thirty guineas ; or, if permanently residing out of the United Kingdom, by a payment of three-fourths of such sum. If such last-mentioned Fellow shall sub- sequently come to reside within the United Kingdom, he shall forth- with pay the remaining one-fourth of such sum. 26. Honorary and Ex-otiicio Fellows shall not be liable to pay any admission fee or annual subscription. C. Privileges. 27. All Ordinary Fellows shall be entitled to propose candidates for election as Fellows; to be elected, and to nominate Fellows for election, as Members of the Council or as Officers; to introduce one male visitor at any General Meeting; to receive the publications of the Society; and to inspect and use the books, instruments, and other property of the Society, under such regulations as the Council may from time to time determine. All Ordinary Fellows (being males) shall have the right to be present, to state their opinion, and to vote at all General Meetings. 28. No Ordinary Fellow shall vote on any occasion, or be entitled to any of the privileges of a Fellow, until he has signed the declara- tion and made the payments mentioned in Art. 10, nor if his annual subscription is twelve months in arrear. 29. Honorary Fellows shall have all the privileges of Ordinary Fellows, except those of proposing candidates for election as Fellows, being elected and nominating Fellows for election as Members of the Council or as Officers, receiving the publications of the Society, and yoting at General Meetings. 30. Ex-officio Fellows shall have all the privileges of Ordinary BYE-LAWS. hi Fellows, except those of proposing candidates for election as Fellows, being elected and nominating Fellows for election as Members of the Council or as Officers, and voting at General Meetings. D. Withdrawal and Removal. 31. Any Fellow may withdraw from the Society after having paid all annual subscriptions due from him, returned any books or other property belonging to the Society in his possession, and given written notice to one of the Secretaries of his desire to withdraw. 32. The Council may remove any Ordinary Fellow from the Society whose annual subscription shall be more than two years in arrear, but before removing him shall serve him with a notice stating the amount of his arrears, and that in the event of non-payment thereof within twenty-eight days he will be lable to be so removed. Such removal shall not prejudice the right of the Society to recover the arrears at any time thereafter. 33. Any Ordinary Fellow who shall have been removed under the provisions of Art. 32 may, on payment of all arrears, be reinstated by the Council. 34. Whenever there may be any other cause to remove any Fellow from the Society, the Council shall propose a resolution to that effect, which shall be read at two successive General Meetings, and suspended in the interval in one of the rooms of the Society. At the second of such meetings a ballot shall be taken, and if two- thirds of the votes shall be in favour of the removal of such Fellow he shall be removed from the Society accordingly. V. Council. A. Election. 35. The Council shall be elected at the Annual Meeting in each year, at which Meeting all the Members of the Council shall retire from office. 36. The President and Vice-Presidents shall be ineligible for election to their respective offices for more than two years in succession, and four of the twelve Ordinary Members of Council shall in each year be ineligible for re-election as such Ordinary Members. 37. The Council at their meeting in December, shall prepare a list of Fellows to be recommended to the Society for election at the ensuing Annual Meeting, which list shall be read at the General Meeting in January. 58. Any three or more Fellows who shall be desirous of nomi- nating any other Fellow for election may do so by delivering a nomination paper to the Secretaries, duly signed, before the close of such General Meeting. 39. The votes on any election of the Council shall be taken by ballot. hii BYE-LAWS. 40. The names of all the Fellows nominated shall be printed in one balloting paper, which shall state by whom the nominations are made. 41. Any Fellow may erase any name from the balloting paper, aie insert in place thereof the name of any other duly qualified “ellow. 42. If for any reason a new Council shall not be elected at the Annual Meeting, the Council for the time being shall continue in office for the year ensuing, or until a new Council shall be elected by a Special General Meeting, and if the place of any Officer or Ordinary Member of Council is not filled up the Council shall have power to fill such vacancy. 43. If in the interval between any two Annual Meetings the place of any Officer or Ordinary Member of Council shall become vacant, the Council shall have power to fill such vacancy. B. Proceedings. 44, The Council shall hold their Meetings at such times as they may appoint. 45. Meetings may be called at any time by the President or by three other Members. 46. Five Members shall constitute a quorum, and if within half an hour from the time appointed for the Meeting a quorum be not present, the Meeting shall be dissolved. 47. In the absence of the President and Vice-Presidents from any meeting, the Members shall choose one of their number to take the Chair, and such Member shall, for the time being, have all the authority and privileges of the President. / 48. The votes on any question before the Council shall be by show of hands, unless a ballot shall be demanded by any two Members. 49. The decision of the majority of Members voting at any Meeting shall be considered as the decision of the Meeting. 50. The Council may, from time to time, appoint any Members of their body to be a Committee to deal with any matter referred to it. Any such Committee shall conform to any regulations that may be imposed on it by the Council. 51. No resolution of the Council shall be rescinded by a sub- sequent Meeting, unless notice of the intention to propose such rescission shall have been sent to the Members one week prior to the subsequent Meeting. 52. The common seal of the Society shall not be affixed to any document, except at a meeting of the Council and pursuant to a resolution duly passed thereat; and such document shall then be signed by the President, Vice-President, or other Chairman of such meeting, and by one of the Secretaries. 53. At the commencement of each year the Council shall prepare a Report on the affairs of the Society for the preceding year. BYE-LAWS. hii VI. Officers. A. President and Vice- Presidents. 54. The President shall take the Chair at all meetings of the Society or Council, and shall regulate the proceedings thereat. He shall be a member of all Committees appointed by the Council or by any General Meeting. 55. In the case of an equality of votes at any Meeting, the Presi- dent shall be entitled to a second or casting vote. 56. In the absence of the President from any Meeting, it shall be the duty of one of the Vice-Presidents to take the Chair, and he shall for the time being have all the authority and privileges of the President. B. Treasurer. 57. The Treasurer shall receive all moneys due to the Society, and shall pay therefrom only such amounts as may be ordered by the Council. 58. All moneys received by the Treasurer shall be paid by him to the Society’s Bankers, a sum not exceeding 20/. being retained for the payment of current expenses. 59. The Treasurer shall keep an account of his receipts and payments, and shall produce the same whenever required by the Council. 60. The Treasurer shall lay before the Council at their meeting in January a list of ail Ordinary Fellows in arrear of their annual subscriptions. 61. Two Ordinary Fellows, one a member, and the other not a member of the Council, shall be appointed at the General Meeting in January to audit the Treasurer’s account for the past year. They shall have the power of calling for all necessary books, papers, vouchers, and information. 62. ‘The account so audited shall be signed by the Auditors, and laid before the next succeeding Annual Meeting. C. Secretaries. 63. The Secretaries shall take, or cause to be taken, minutes of the proceedings of all Meetings, and produce and read them at the ensuing Meetings; they shall conduct the business and corre- spondence of the Society ; and shall discharge all such other duties as are usually discharged by Secretaries of Scientific Societies. 64. The Council may appoint an Assistant Secretary and Librarian, and assign to him such duties as it may think desirable, at such remuneration as it may deem proper. liv BYE-LAWS. VII. General Meetings. 65. The General Meetings shall be of three kinds—Ordinary, Annual, and Special. 66. Ten Ordinary Fellows shall constitute a quorum, and if within half an hour from the time appointed for the Meeting a quorum shall not be present, the Meeting shall be dissolved. 67. In the absence of the President and Vice-Presidents, the Members of Council present shall choose one of their number to take the Chair, or if no such member shall be present, the Meeting may elect any Ordinary Fellow present to take the Chair, and the Fellow so presiding shall for the time being have all the authority and privileges of the President. 68. All votes shall be taken by show of hands, except in the cases where by these Bye-Laws it is provided that votes shall be taken by ballot. 69. The decision of the majority of Fellows voting at any Meeting shal] be considered as the decision of the Meeting. 70. The President, Vice-President, or other Chairman may, with the consent of the Meeting, adjourn any Meeting from time to time and from place to place, but no business shall be transacted at any adjourned Meeting other than the business left unfinished at the Meeting from which the adjournment took place. 71. At any Meeting a declaration by the Chairman that a reso- lution has been passed or lost, and an entry to that effect in the Minute-Book of the Society, shall be sufficient evidence of the fact, and in the case of a resolution requiring any particular majority, that it was passed by the majority required, without proof of the number or proportion of the yotes recorded in favour of or against such resolution. 72. Minutes shall be made in a book provided for that purpose of all resolutions and proceedings of General Meetings, and any such minutes, if signed by any person purporting to be the Chairman of the Meeting to which they relate, or by any person present thereat and appointed by the Council to sign the same in his place, shall be received as conclusive evidence of the facts therein stated. 73. Visitors may be present at any Meeting if introduced by Fellows, and provided they sign their names in the Attendance Book. A. Ordinary. 74. The Ordinary Meetings of the Society shall be held at 8 o'clock p.m. on the second Wednesday in each month, from October to January, and March to June inclusive. 75. The ordinary course of business shall be as follows :— 1st. The minutes of the proceedings of the previous Meeting shall be read, submitted for approval, and if approved, signed by the President, Vice-President, or other Chairman of the Meeting. BYE-LAWS. lv 2nd. The certificates of candidates for election shall be read and the ballot for the election of Fellows shall take place. 3rd. The donations received since the last Meeting shall be announced. 4th. The objects exhibited shall be described. 5th. Scientific communications shall be read and discussed. 6th. Any other business connected with the affairs of the Society shall be transacted which can be properly transacted at an Ordinary Meeting. 76. No question relating to the Bye-Laws or the management or affairs of the Society shall be discussed or voted upon at any Ordinary Meeting. B. Annual. 77. The Annual Meeting shall be held at 8 o’clock p.m. on the second Wednesday in February. 78. Scientific communications shall not be read or discussed at the Annual Meeting, but in lieu thereof the following shall be the ordinary course of business, in addition to the matters Nos. 1 to 4 in Art. 75. 5th. The Report of the Council for the past year shall be read by one of the Secretaries. 6th. The Treasurer shall read an account of his receipts and ayments during the past year. 7th. The Ballot shall take place for the election of the Council for the ensuing year. 8th. Any alteration proposed in the Bye-Laws of the Society shall be discussed and, if necessary, voted on. 9th. The President shall read his Annual Add@ress. 10th. Any other business connected with the affairs of the Society shall be transacted which can be properly transacted at an Annual Meeting. 79. The President, Vice-President, or other Chairman shall appoint two Scrutineers from among the Ordinary Fellows present, not being members of the Council or nominated for election thereto, to take the ballot for the election of the Council. 80. The Scrutineers shall receive the balloting papers from the Fellows present and entitled to vote, and shall report the names of the Fellows elected and the number of votes to the President, Vice- President, or other Chairman, who shall thereupon announce the names of the persons elected. 81. Any balloting paper containing a greater number of names for any office than the number to be elected thereto shall be rejected by the Scrutineers. C. Special. 82. The Council may at any time convene a Special General Meeting. lyi BYE-LAWS. 83. Any ten Ordinary Fellows may, by a requisition in writing signed by them specifying the object of the Meeting, require a Special General Meeting to be held for the purpose of discussing and voting upon any question relating to the Bye-Laws or the management or affairs of the Society; and the Secretaries, upon receiving such a requisition, shall call a Meeting accordingly. 84. One week’s notice at least of every Special General Meeting shall be given, either by announcing the same at the Ordinary Meeting immediately preceding the Special Meeting, or by notice in writing served upon the Ordinary Fellows as hereinafter provided. Such notice shall state the place, day, and hour of meeting, and the general nature of the business for which the Meeting is called, and no other business shall be brought forward thereat. VIII. Library and Cabinet. 85. The books, instruments, and other property of the Society may be inspected and used by the Fellows, under such regulations as the Council may from time to time determine. 86. No instruments or other property, except books, shall be taken out of the Society's rooms without the permission of the Council. 87. A Catalogue of the contents for the time being of the Library and Cabinet, and of the other property of the Society, shall be kept by the Librarian, who shall also keep a list of all donations to the Society, and of all property borrowed by the Fellows. IX. Papers and Publications. 88. All papers shall be approved by the Council previously to being read at any Meeting, but such approval shall not be taken as expressing any opinion upon any of the statements contained in such apers. "89. Papers shall be read in such order as the Council shall think fit. 90. The Society shall in all cases have the right to publish any paper read, or taken as read, at any Meeting. 91. Papers shall be published either in the Journal of the Society, or in such other manner as the Council shall think fit. 92. The copyright of a paper (and of the drawings, if any, accompanying it) read, or taken as read, at any Meeting shall be the property of the Society, unless the author at the time of sending the same shall stipulate to the contrary, and provided that the Society publish the same within six months after its receipt. 93. The authors of papers published by the Society shall be entitled to such number of copies thereof as the Council shall from time to time determine. BYE-LAWS. lvl 94, The Council may present copies of any of the publications of the Society to, or exchange the same with, such persons and Societies as they may think fit. X. Notices. 95. A Notice may be served upon any Fellow either personally or by sending it through the post in a prepaid letter addressed to such Fellow at his last known address. 96. Any notice sent by post shall be deemed to have been served on the day following that on which it was posted; and in proving such service it shall be sufficient to prove that the notice was properly addressed and posted. 97. Any Fellow residing at any place not within the Postal Union may name an address within the Postal Union at which all notices shall be served upon him, and all notices served at such address shall be deemed to be well served. If he shall not have named such an address, he shall not be entitled to any notices or to receive any of the publications of the Society. XI. Alteration of Bye-Laws. 98. No alteration in the Bye-Laws of the Society shall be dis- cussed or made, except.at an Annual Meeting, or at a Special General Meeting convened for the purpose. 99. Notice of every alteration proposed to be made in the Bye- Laws shall be given either by announcing the same at the Ordinary or Annual Meeting immediately preceding the Meeting at which the alteration is intended to be proposed, or by notice in writing served upon the Ordinary Fellows as hereinbefore provided. XII. Interpretation. 100. In the construction of these Bye-Laws words denoting the singular number only shall include the plural number also, and vice versd, and words denoting the masculine gender only shall include the feminine gender also, unless there be something in the context inconsistent therewith. ee. paid tink ot? i as sy i i of Be ie, GIRS WD Wit Scale n ; Leo i - = \é 5 ee The Title, Contents, and Index will be issued on February 15th. ys 1888. Part 1. FEBRUARY. { To Non-Fellows, | JOURNAL OF THE ROYAL MICROSCOPICAL SOCIETY; CONTAINING ITS TRANSACTIONS AND PROCEEDINGS, AND A SUMMARY OF CURRENT. RESEARCHES RELATING TO ZOOLOGY AND BOTAN TZ (principally Invertebrata and Cryptogamia), MICROSCOPY, &c- Edited 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., B.Sc., F.L.S., 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.Z5., R. G. HEBB, M.A., M.D. (Cantad.), AND J. ARTHUR THOMSON, M.A., Lecturer on Zoology in the School of Medicine, Edinburgh, FELLOWS OF THE SOCIETY. WILLIAMS & NORGATE, LONDON AND EDINBURGH. \Prs (STAMFORD STREET AND CHARING CROSS, PRINTED BY WM. CLOWES AND SONS; LIMITED, ] CONTENTS. —— TRANSACTIONS OF THE Soommty— I.—Fresu-watrr Atam (1noLupiInc CaLoropHyiiovs Proropryta) or THE ENnaiisn Lane Distriot. II. Wire pusoriprions oF A NEW GENUS AND FIVE NEW sPEcIES. By Alfred W. Bennett, F.R.MLS., F.L.8., Lecturer on pOeny at St. Thomas's Hospital (Plate ay PHS ah SAN ¥ IT.—Novts on Memeaermaris! AMERICANA, Hates. AND ITS Vee By W. M. Maskell, F.R.M.S. (Plate 1.) Sees: III.—Norr on tue Minvute Srrvcrure or PELOMYXA PALUSTRIS. Dy. Gi. Cavan SAN, An ie Ponce ae aS SUMMARY OF CURRENT RESEARCHES. ZOOLOGY. A. VERTEBRATA :—Embryology, Histology, and General. a Embryology. Lerypie, F.—Animal Ovum Carini, A.—Maturity of the Ovum... ScuuiTzE, O.—Avis of Frog Ovum KACzANDER, J.—Relation of Medullary Canal and Primitive Streak JENSEN, O. S.—Spermatogenesis ‘ Vine woes Janosix, J.—Two Young Human Embryos eRe Gao SV Meth, tee pay Geruacn, L.—Ezperimental Embryology... «ss nae tet 8. Histology. Louxyanow, 8. M.—Morphology of the Cell. v0 6. ee ee a on Wrbclee, of Miagclaceu ssa so: es ok Weatee ean Ge tT de he Tane., F.—Cell-division .. .. ELE Oe Sig OE at Ts rah airs y. General. MENS Aqwikic LOcomayon 5.0" os 20 oe". i we de aw bless ted = see ch ee cata B. INVERTEBRATA. Mollusca. B. Gastropoda. Lica H. pr, & G. Provor—ZLarval Anal Hye in Optsthobranch Gastropods .. .« st ae ite Sieh Sate tt ee Lacaze-Duruirrs, H. * pe—Nervous System of Aplysia SER eh GROW a ee PI Bovyier, E. L.—Nervous System of Prosobranchs .. se ss cs et Sarasin, P. & F.—Development of Helix Waltont .. 1 6s ke aw GRoBBEN, C.—Morphology of the Heteropod Foot BS Te One eS sae (aa : y. Pteropoda. ; PELSENEER, P.—Nervous System of Pteropods .. perisesnted paascenee & » ‘Challenger’ Pteropoda (Gymnosomata) .. eats fess eee oneen et 6. Lamellibranchiata. Dusors, R.—Photogenic Property of Pholas dactylus .,. .. 2. 2s ew ee we PFAGB Il S355) Molluscoida. q Tunicata, LAHILLE, F.—Central Nervous System .. +» B. Polyzoa- esta A. DE—Spermatogenesis Verworn, M.—Fresh-water Bryozoa Arthropoda. Grassi, B.—Primitive Insects .. Res nes : a, Insecta. Emery, 0.—Love-lights of Luciola . : Ss 4 ra Hoey and Parasitism of Camponotus lateralis a HAnovuirson, A.—Sand-wasps.. ., eS GRABER, V.—Thermic Experiments on Periplaneta orientalis .. Uneon, F.—Diminution in Weight of Chrysalis .. ++ «2 ss Cracero, G. V.—Eyes of Diptera .. .. 2 Buocumann, J.—Bacteria-like Bodies in Tissues ‘and Ova. Merenin, P.—Fauwna of the Tombs .. «1 en we ee tee B. Myriopoda. PLaveau,. F.—Powers of Vision 9 6s 00 ee ae ne y. Prototracheata. SHELDON, Ee Pecclapmnent of Peripatus Nove-Zealandiz .. 6. Arachnida. AURIVILLIUE, C. W. S.—Acarida on Trees .. e Crustacea. Kinestey, J. 8. —Development of the ie tent Hae oe Cong Sars, G. O.—‘ Challenger’ Cumacea .. ee Fi ‘ Challenger’ Phyllocarida SaSe Lo Bait in oe Ge Ganemr, A.—Structure of Cyprinide 1. - +e se noe Vermes. a, Annelida. WuitMan, ¥ O.—Germ-layers of Clepsine... .. «+ »» Berrecit, D.—Salivary Glands of Leech .. .. «» « pel tage E. B.—Germ-bands of Lumbricus .. Griarp, A.—Photodrilus Bers us, Type of a New Genus of Phosphorescent Lumbricids .. .. ‘ ieee = ere W.—Enchytretdz Diae Someee pace kee prameeces Draco, W.—Parasite of Telphusa.. .. ete Cunnincuam, J. T.—Anatomy of Polychata X Grarr, L. v.—Annelid Genus Spinther . 1. ++ « pe SmonELui, V.—Siructure of Serpula .. aan! tae Sten B. Nemathelminthes. Canrnoy, J. B.—Maturation and Division of Ascaris Ova = = Polar Bodies in Ascaris = ve Zacuartas, O.—Fertilization of Ascaris megalocephala LABOULBENE, A.—Larval Stage of Species of Ascaris.. y- Platyhelminthes. Linton, E.—Cestoid Embryos... «1 + Grassi, B.—Tenia nana . Wnricut, R. Ramsay, & A. B. MAcaLtum—Sphyranura osleré Porrter, J.—New Human Distomum Heckert, G.—Natural History of Leucoch loridium paradceum Hasweti, W. A.—Temnocephala .. oe Liyton, E.—Trematode in white of newly-laid Hen’s Egg. Drvo.etTzKy, R.—Lateral Organs of Nemerteans Husrecut, A, A. W.—‘ Challenger’ Nemertea .. ee vo oe PAGE City) 5. Incertee Sedis, PAGE Zevinka, C.— Parasitic Rotifer—Discopus Synapte 2 6. ee ee ee te OD Echinodermata, Hamann, O.—Histoloqy of Echinoderms ae ate La EP eh: " RS » Wandering Primordial Germ- cells. in Echinoderms TAS ace ioe pani. ie M.—True Nature of the Madreporic System of Echinodermata ... .. 97 Curnot, 8.—Nervous System and Vaseular Apparatus of Ophiurids Oe Wii athe Carpenter, P. H.—Development of Apical Plates in Amphiura squamata .. «58 Hetrovarv, E.—Caleareous Corpuscles of Holothurians 4. 4. awe ee 88 Ceelenterata. Cuun, C.— Morphology of Siphonophora 3 pa aaa Kruxenserc, C. F. W.—Influence of Salinity Pall Mie ate eet a ec 3 9 Colowrs of Corals.. —.. FE PEAS ye at oh £ 9 Nervous Tracts in Aleyonids iat aad On ee ga ei ae Porifera. Sonuas, W. J.—Sponges .. — pS eo IR hal a isiacs awe NCE a eae a Epner, V. v.—Skeleton of calcareous Sponges TN eee Denpy, A.—New System of ‘Chalining# ... 9 fe a ea oe wh oe oe pe fae Ports, E.—Fresh-water Sponges .. Wing irre tener Tay f(% Fyepuer, K.—Development of Gener ative Products in Spongilla sakes ic Swe Se PP ore :, Protozoa. Maupas, E:—Conjugation of Paramecium .. 0. se ae ne Stores, A>:C.—New Presh-water Infusoria i205 69 ek ee ee a ae, Necmayrk, M.—Relationships of Foruminifera .. .. xe fOb Scuewianorr, W.—Karyokinesis of Euglypha : 66 Kinsrien, J.—Diplocystis Schneidert .. ~ .. ~ 68 BOTANY. A. GENERAL, including the Anatomy and Physiology of the Phanerogamia. a. Anatomy, (1) Cell-structure and Protoplasm. ZAcHARIAS, E.—Part taken by the Nucleus in Cell-division Kuees, G.— Albumen in the Cell-wall .. Wn Gh aes Pica, P.—Lhickening of the Cell-walls in the Leuf-stalk of Aralia. «. (2) Other Cell-contents (including Secretions). Beizunc, E.—Starch- and Chlorophyll-grains =. 6. ee ee ee TP Tscutrow, R.—Quantitative estimation of Chlorophyll NRE a Ne RET ER ee ele Beniucr, G.—Formation of Starch in the Cllorophyll-granates Seca konpa Fics, R R.— Inosite 3 SPL PA aac MD pe ae ag sha ie 37 - Scunerzver, J. B. —Tannin in n Acanthus spinosus dain! ee Bing ey Sie, se ole ae BarRBAGLIA, G. A.—Chemical substances contained in the Bow .. 16 ve ewe Tscuurcn, A.—Aleurone-grains in the Seed of Myristica surinamensis .. .. 4. 7 (3) Structure of Tissues. Gatvert, AcNEs, & L. A. Boopie-—Laticiferous System of Manihot and Hevea... —72— Heiricuer, E.—Tubular Cells of the Fumariacer .. Pet Real Bhs eh TizcHEem, P. van—Super-endodermal Network in the Root of the Caprifoliacess 5 ere DANGEARD, P. A., & Barsi—Arrangement of the Fibro-vascular Bundles in ~ Pinguicula it tpn ia: Wied baker eed 5: Petit, L.—Distr Ghuteoe of Bibtovasoular Bundles in the Petiole EME South aespey te ff eg Laux, W.—Vaseular Bundles in the Rhizome of Monocotyledons ., ws se JANNICKE, W.—Comparative Anatomy of Geraniace®.. .. +1 ee me os Greoc, W. H— Anomalous Thickening in the Roots of Cycas... 2. ss us ve ST KRraspe, G.— Formation of Annual Rings in Wood 1. ete ese Grevitiius, A. Y—Mechanical system of Pendent Organs ~ .. 4 Longer, O.—Comparative Anatomy of Roots Be Ve eens : C5) (4) Structure of Organs. Jost, L.—Respiratery Organs... as aac ee ee Tscuiron, A.—Organs of Meteo Be eee Scuence, H.— Anatomy of Water-plants BS ge Retype OSE Hennine, E.— Lateralness in Conifere... -, Seyi eae tan ees Fockxs, W. O.—Dichotypy BERD cba ote eh eee es Dierz, 8.—Flowers and Fruit of Sparganium and Typha mA ae Ee Warp, H. Marsuauy, & J. Dountop—Fruits and Seeds of Rhamnus Lounpstrom, A. N. —Masked Fruits. es Coutrer, J. M., & J. N. Rose— Development of the Fruit of Cinbeltijera Sates Kuen, O. Bey Ei of the Inflorescence .. Hoveracqup, M eg ened onee: and. Structure of Orobanche am a young stage, and of its suckers oe ae GraNeEL-—Origin of the Suckers in Phanerogamous ‘Parasites. i ‘TiscHem, P. van—Arrangement of peg sue Roots and Buds on Roots Vomzemin, P.— Epidermal Glands ; Pom SARS tas te SS ey near eee Buake, J. H.—Prickle-pores of Victoria regia wis Pepten Sate Ras Bower, F. O.—Morphological sie ee of Cor dyline astenlie ee ee Hermer., A.—Nyctaginew ~~ .. REE eee SUSI cat ag. eer PY aay Base Soravzr, P.—Root-tubers and Bacteria... pin Rat oat Cai en aT | B. OEE ae qd) Reproduction and Germination. Rogerson, C.—Insect relations of Asclepiadew 2... ss ee eee MacLeop,.J.—Fertilization of Flowers... ++ +e on ee anes ARCANGELI, G.—Flowering of Euryale ferou.. Rape aos. relate yo SE wa aiaks toes (2) Nutrition and Growth (including Movements of Fluids). Masser, G.—Growth and Origin of Multicellular Plants = Dvrovr, L.— influence of Light. on the Form and Structure of Leaves .. (4) Chemical Changes (including Respiration and Fermentation). Mayer, A.—Fxhalation of Oxygen by ce ved Plants in absence Ve Carbunie Anhydride .. + ss a Borum, J.—Respiration of the Potato... Sat bet Sey St eee eke Werner, ©.—Action of Formose on Cells destitute of Bistch 3 ES y: General. Kocu, L.—Biology of Orobanche ie SWS pe ea tes: Sepp eens tae eee ca KronreLv, M.—Biology of the Mistletoe Bes Sieh a Seen: Ree Frann, B ’—Root-s) IML COSTE BI LBC TICACO gee oot agi So ee Be eat BN aS ORT oe Lunpstrom, A. N.—Domatia.. RIED ake ee eared ee Myr mecophilous Plants. get Bownr, F. 0. —Humboldtia laurifolia as a 5 a Plant . se Sea es RewKe, J.—Oxidation-process in Plants after death .. .. oi Seki aera: Krazan, F.—Retrogression in Oaks... Outver, F. W.—Phenomenon analogous to Leaf: fall .. Bo ae Know ues, Evta L.—* Curl” of Peach-leaves .. Faia ar eres y eae - Apsorr, H. C. pe S—Plant Analysis as an Applied Science .. B. CRYPTOGAMIA. Artnur’s Report on Minnesota... Faeter ss Rae ere Cremona ‘Maccularia, GorBEL, K.—Germination of Ferns .. Pie alta pi Lyon, F, M.—Dehiscence of the Sporangivm of Fert: se es GOEBEL, sae aahale ae lia Berns... +s oa ae Pe raneen es Gharacecs: AEN, T. F.—New Species of Characez «+1 ve ue te ee ote ws Muscinee. Vaizey, J. R.—Transpiration of the Sporophore of Mosses.. ++ 01 se ess ScHULZE, ar —Vegetative reproduction of a Moss.. 1. s+ ae nee te WALDNER, M.—Sporogonium of Andreea and Sphagnum .. pelt rae tat ers Mitrer, C.—New Sphagna .. ee K. G.—Rabeihorst’s * Cryptogamie Flora of Germany’ Muse) . GorseEL, K Peel Sie tic Jungermannie® —. SS parts eis ER a ERY POLY KARSTEN, G.— Production of Gemme by Fegatella RRS Pe Sete IY ERO Ce Algee. PAGE Jansp, J. M.—Plasmolysis of Algz See R Soak” hve iv usdatles eogn) aaah jaws pee Sed eee Hauck, F.—Choristocarpus tenellus Set ap ent iow 1c was. tee. cis qi taeen Cele bak he ener eem Mosius, M.—New Fresh-water Floridea 44 se. se ee tee ewe we OS Krrev, F.—Lemanea “3 sels Web eg ae ction AGG ike Fee hee een ane Witpeman, EB. Du—Microspora ein at Raa ts to oc el ae late Sogo hb ihe ne eee Surra, T. F.—Some points in Diatom-structure ae AYRE TR Hae EY ear hae CASTRACANE, F.—Deep-sea Diatoms _.. ia aston, eee Grove, E., & G. Srurt—Fossil Marine Diatoms from New Zealand .. ss cs 94 Wour’s (F.) ¢ Fresh-water Algz of the United States’ eT mr pe et" Lichenes. Forsseni; K. B. J.—Gleolichenes webs. es ba ge i 0s ee, ae) Kee Soros |b eh we Massep, G. —CGasterolichenes .. .. Sate ere ia 8-51) Bois ACR oe ee MiuEr, J.—Action of Lichens on Rocks “5 vai eevee Roe ae HEGETSCHWEILER & S1TizENBERGER—Lichens on unusual substr dbs ca oo Gah Fungi. Errera, L.— Accumulation and Consumption of Glycogen by ph Seer aig ines. WertstEIn, R, v.—Funcetion of Cystids « MR Patti om Srynes, J. "pn— Rhizomorpha subcorticalis of Armillaria mellea. Be Fe aes ae Dieter, P.—Uredinee .. Seamer arty Meecha PRILLIEUX, E.— —Grape-disease—Comothyriwm diplodiela sina. hg Skid, Orfiod kee poe am G-ASPERINI, G.—New “Disedse Of, Leming a. 540 6s. wed oe eS eke cha eee eee Bae Waur ion, W.—New Pythium 1:45 a Me 145° -. 6" 139,795 151,530 184,147 2°1038 +690 1:44 se A 142°: 39’ 138, 830 150,485 182,877 2° 074 694 1°43 za a 140° 22' 137,866 149,440 181,607 2°045 +699 1-42 ee fe 138° 12’ 136,902 148,395 180,337 2-016 704 1:41 Sie i 136° 8’ 185,938 147,350 179,067 1-988 *709 1°40 a a 134° 10’ 134,974 146,305 177,797 1°960 “714 1°39 BS ts 132°°16' 184,010 145,260 176,527 1'932 ody ib | 1°38 ae e 130° 26’ 1338, 046 144,215 175,257 1:904 *725 1°37 na Je 128° 40’ 132, 082 145,170 173,987 1:877 +739 1:36 oe ae 126° 58’ 131,118 142,125 172,717 1°850 "735 1°35 oa os 125° 18’ 130, 154 141,080 171,447 1‘823 *7A6 1:34 os es 123°. 40’ 129,189 140,035 170,177 1:796 | «741 1°33 180°: 0’|" 122° 6’ 128,225 138,989 168,907 1:769 "752 1:32 ae =U 1659-56!s; 120933" 127,261 137,944 167,637 1°742 *758 1°31 we 160°: 6’) 119° 3! 126,297 136,899 166,367 1‘716 ‘763 1:30 is 155° 38/} 117° 35’ 125,333 135, 854 165,097 1°690 "769 1-29 ts 151° 50’| 116° 9° | 124,369 134,809 163,827 1:664 “7715 1:28 ar 148° 42’ | 114° 44’ 123,405 133,764 162,557 1638 “781 127 “js 145° 27") dd 3° 21" 122,441 132,719 161,287 1°613 +787 1-26 5 142°: 39" | T1T9 59% 121,477 131,674 160,017 1°588 , 794 1:25 a 140°. 3’ | 110° 39! 120,513 130,629 158,747 1'563 +800 1°24 wi 137° 36’ | 109° 20’ 119,548 129,584 157,477 | -1°538 *806 1:23 e. 135° 17" |: 108°" 2! 118,584 128,539 156,207 1°*513 “813 1°22 133° 4’ 106° 45’ 117,620 127,494 154,937 1°488 +820 1:21 ae 130° 57’ | 105° 30! 116,656 126,449 153,668 1:464 826 1:20 of 1289 55" 11042915? 115,692 125,404 152,397 1°440 +833 1:19 oy 126°: 58’ | 1039-2! 114,728 124,359 151,128 1°416 840 1:18 a 125° 38’ | 101° 4O’ §- 113,764 123,314 149,857 1-392 +847 1:17 a 123° 13/ |' 100° 388’ 112,799 122,269 148,588 1°369 +859 1:16 - L219: 26412 992.298 111,835 121,224 147,317 1'346 “862 1:15 of 119° 41’ | 98° 20' 110,872 120,179 146,048 1°323 *870 1:14 os 2 9 Wc heeeag (yor Lace Hae be Fe 109,907 119,134 144,777 1300 “S77 1:13 a 1162: 20% QB9 “2 2" 108,943 118,089 143,508 1-277 *885 1:12 os 114° 44’) 94° 55’ 107,979 117,044 142,237 1*254 >} -893 1-11 as ISO | 93°47! 107,015 115,999 140,968 1°232 “901 1:10 oe 111°'36' | 92° 48! 106,051 114,954 139,698 1-210 *909 1°09 aS LOO 2 OIo aS. 105,087 113,909 188,428 1-188 POLY, 1-08 o's 108° 36’ 90° 34’ 104,123 112,864 137,158 1:166 eed ty ds 1:07 oe 107° 8’ |. 89° 30° 103,159 111,819 135,888 1145 “985 1:06 = 105° 42’) 88°27’ 102,195 110,774 134,618 1*124 7 945 1°05 ae 104°.16' | 87° 24" 101,231 109,729 133,348 1-103 *952 1:04 ae 102° 58’ | 86° 21’ 100,266 108, 684 132,078 1:082 962 1:03 is 101° 30 | 85° 19! 99,302 | 107,639 | 130,808 | 1:061 | :971 1:02 53 100°°10' | 84° 18’ 98,338 106,593 129,538 1-040 +980 1:01 a 98° 50’ | 83°17’ 97,374 105,548 128,268 1020 +990 1:00 180° 0! OTE L | = 822 17? 96,410 104,503- | 126,998 1:000 | 17:000 0:99 163° 48’ 96°12’ 81° 17’ 95,446 103,458 125,728 *980- 1*010 - 0:98 157°. 2’ 94° 56’) 80° 17’ 94,482 102,413 124,458 “960 | 1°020 —— 0-97 151° 52’ 93°. 40' | 79° 18’ 93,518 101,368 123,188 “941 J 1°03) 0-96 147229" 92° 24’) 78° 20’ 92,554 100,323 121,918 ° G22 1°012. 0:95 143° 36’ ESD Wefan 1 ON) Ree UF ise 7 91,590 99,278 120,648 “903 /1°058 0:94 140° 6’ 89°. 56’ |} 76° 24’ 90,625 98,233 119,378 “884 | 17064 0:93 136° 52’ 88° 44’ | 75° 27° 89,661 97,188 118,108 *865 7 1°075. 0°92 ~ |} 133° 51’ 87°32’ | ‘74° 30° 88, 697 - 96,143 116,838 | *846 1 087) 0:91: 131° 0’ 862. 20" 73238! 87,733 95,098 115,568 *828 7 1°099.-~ 0:90 128° 19’ 85° 10'| 72° 36’ 86,769 | 94,053 114,298 7810-4 12s 0:89 125° 45’ S40 SOL TIC) 85,805 93,008 113,028 792 el EDA es 0:88 || 123° 17’ 82°:51' | 70°44! 84,841 91,963 | 111,758 774-1136 Numerical “Aperture. Air (a sin u = a.)\| (m = 1°00). } 0:87. || 120° 55’ 0:86 118° 38’ 0°85 116° 25! . 0°84 F14e 17? 0:83 $499579" 0:82 110° 16! 0:81 108° 10° 0:80 106°. 16’ 0:79. | 104° 22° 0-78 102° 383i’ 0:77 100° 42° 0:76 98° 56’ 0:75 S7° 11’ 0:74 95°. 28" * 0773 93° 46’ 0:72 OAS re st he 0-71 90° 28” 0°70 88° 51" 0:69) 87° 16’ 0:68 85° 41" 0:67 - 84° 8’ 0:66 82° 36’ 0:65 81° 6’ 0:64 79° 36’ 0°63 48° 6 0°62 | 162 38! 0:61 || 75° 10’ 0:60 73° 44! 0:59 || 72° 18’ 0°58 70° 54’ 0:57 69° 30’ 0:56 68° 6’ 0°55 66° 44’ 0:54 65° 227 0:53 64° 0’ 0:52 62° 40’ 0:51 61°. 20’ 0:50 60° 0’ 0:48 sy fen WG 0-46 54° 47 0°45 53° 30’ 0°44 . Gy Agen BY 0:42 49° 40’ 0-40 47°.- 9! ~ 0°38 44° 40’ 0°36 42°. 12” 0:35 40° 58’ - 0°84 39° 44’ 0°32 37° 20’ 0:30 34° 56’ 0:28 - j|- 32° 32’ 0:26" || 30° 10’ 0°25 28° 58’ 0:24 27° 46’ 0:22 25° 26! 0:20 FBO 42 0:18 20° 44" <= 0-16 18° 24’ . 0°15 L7o 14! "~0°14 Gee Catceetey: he O° 12 13°47! E2Os20 11° 29’ ~ 0:08 re gas i Ws 0:06 ep Y 0:05 5° 44’ APERTURE TABLE—continued. Water (@ = 1°33). 81° 42! 80° 34’ 79° 37’ 78° 20! 77° 14’ 76° 8 73° 3 73° 58! 72° 53! 71° 49° 70° 45’ 69° 49! 68° 40" 67° 37° 66° 34" 65° 32! 64° 32" 63° 31’ 62° 30’ 61° 30° 60° 30" 59° 30’ 58° 30" 57° 81! 56° 32" 55° Bd! 54° 36" 53° 38" 52° 40! 51° 42’ 50° 45! 49° 48” 49° 5i’ 47° 54" 46° 58’ 46° 9! 45° 6! 44° 10’ 49° 18 40° 28! 39° 33° 38° 38’ 36° 49’ 35° 0! 33° 19! 312 24" 30° 30° 29° 37 27° 51" 26° 4 24° 18 92° 33! 21° 40’ Corresponding Angle (2 «) for i Limit of Resolving Power, in Lines to an Inch.) Homogeneous ; Monochromatic A Tipp sion White Light. | (Blue) Light. | Photography. Cis esa), [ee ee eee eds, ine .) Line F.) near Line h.) 69949% 83,877 90,918 110,488 68° 54’ 82,913 89,873 109,218 68° 0! 81,949 88,828 | 107,948 67° 6’ 80,984 87,783 106,678 66° 12’ 80,020 86,738 105,408 65° 18’ 79,056 85,693 104,138 64° 2+" 78,092 84,648 102,868 63° 31’ 77,128 83,603 101,598 62° 38’ 76,164 82,558 | © 100,328 61° 45’ 75,200 81,513 99,058 60° 52’ 74,236 80,468 97,788 60° 0’ 13,272 79,423 96,518 59° 8" 72,308 78,378 95,248 58° 16’ 71,343 77,333 93,979 O71? 24" 70,379 76,288 92,709 56° 32’ 69,415 75,242 91,439 55° 41’ 68,451 74,197 90,169 54° 50’ 67,487 73,152 88,899 93° 59° 66,923 72,107 87,629 53° 9! 65,959 71,062 86,359 52° 18’ 64,599 70,017 85,089 o1° 28’ 63,631 68,972 83,819 50° 38’ 62,667 67,927 82,549 49° 48’ 61,702 66, 882 81,279 48° 58’ 60,738 69,837 80,009 48°" 9! 59,774 64,792 78,739 47° 19' 58,810 63,747 77,469 46° 30’ 57,846 62,702 76,199 | 45° 40’ 56,881 61,657 74,929 44°51’ 59,918 60,612 73,659 $4062! 54,954 59,567 72,389 | 43° 14 53,990 58,522 71,119 42%::25! 53,026 97,477 69,849 41° 37 52,061 96,432 68,579 40° 48’ 51,097 55,387 67,309 APO! 50,135 o£, 342 66,039 39° 12! 49,169 53, 297 64,769 38° 24" 48,205 92,252 63,499 36° 49! 46,277 50, 162 60,959 35° 15! 44,349 48,072 98,419 34°. 27! 43,385 47,026 57,149 33° 40! 42,420 45,981 55,879 32° 5! 40,492 43,891 93,339 30° 31’ 38,064 41,801 50,799 28° 57’ 36, 636 39,711 48,259 27° 24" 34,708. - 37,621 45,719 26° 38’ 33, 744 36,576 44,449 25° 51’ 32,779 35,531 43,179 94° 18’ 30,851 33,441 40,639 22°. 46° 28 ,923 31,351 38,099 24°14! 26,995 29,261 39,559 19° 42’ 25, 067 27,171 33,019 18° 56’ 24,103 26,126 31,749 18° 10’ 23,138 25,081 30,479 16° 38’ 21,210 22,991 27,940 Le ak 19., 282 20,901 25,400 — 13° 36’ 17,354 18,811 22,860 12°. 5’ 15,426 16,721 20,520 119°°19' 14,462 15,676 19,050 10° 34’ 13,498 14,630 17,780 SOAS 11,570 - 12,540 15,240 Cee 9,641 10,450 12,700 6° 3! 7,713 8,360 10, 160 4° 32! © 5,785 6,270 7,620 3° 46 4,821 5, 225 6, 350 a ak 2 : : BISCO VOD O> CLOTHE HS He 09,09 09 CO DO DODD ORO DO DOD bo DO ND ee ee eet et et ee ee ee bo (S*) Pene- [Illuminating] trating Power. F ash alr Nae 1 1 o> orgs) 117 ( 10 ) GREATLY REDUCED PRICES OBJECT-GLASSES MANUFACTURED BY R. & J. BECK, 68, CORNHILL, LONDON, E.C. PRICES OF BEST ACHROMATIC OBJECT-GLASSES. Focal length. Sle _-_ =| ° = ia i=] o,E i) om or Cn] HAD ete eel =) ic) i= a =] ic) is Angle of aper- ture, about | | Linear magnifying-power, with 10-inch body-tube and eye-pieces, | 2000 | Price No. 1. No. 2, No. 3.| No. 4,| cee Bee a | 110 O 10 16 | 30 | 40 3 oy . \ re |= 24 45 | 60 - = 2 } 22 36 67 go 210 07}. 30 48 g0 | 120 " ie f } 70 112 210 280 210 OO} 100} .160]| 3001 400 4 O O} 125} 200} 375.) 500 5 O O} 150} 240 | 450 | 600 810 0} 200] 320] 600} 800 410 O} 250) 400] 750 | 1000 5 O O|} 400} 640 1200 | 1600 5 5 0 |~400)} 800 } 1500 | 2000 8 O O} 750 | 1200 | 2250 | 3000 10.0 OQ} 1000 tase 3000, | 4000 20 0 0 3209 | 6000 | 8000 No. 5. 50 75 112 150 350 500 625 759 1000 1250 2000 2500 3759 5000 ° 10,060 ECONOMIC ACHROMATIC OBJECT-GLASSES, APPLICABLE TO ALL INSTRUMENTS MADE WITH THE UNIVERSAL SCREW. No. Focal length. 150 | 8 inches 151 | 2 inches 157 | = imm. aper- 1 DWOR RH Rt roy ooannnoo % SCOOCCOOOOs | MaGNIFYING-POWER, | with 6-inch body and eye-pieces, No. 1.| No, 2. No. 3.| ; { 12 15 27 18 23 41 46 61 106 gO | 116 | 205 170 | 220 | 415 250 | 330 | 630 350 450 800 654 844 |1500 Revised Catalogue sent on application to Rk. & J. BECK, 68S, Cornhill. pa" nt ‘ics aes JOURN.R.MICR.SOC.1888. Pl, |. Lat sq00 SPEED? 900g) ro) 209. pores Ro por o 570 9900 0 9 oS AT AZARIAN VALANULARM ALAN UA a C00 9600500 0060 eT ALTARRTAL ALARA S OD LAD IAD REOALAE 12 West, Newman &Co. lith KEB.del. ie e Distrie < nélish Lal =, i = Algze &e Gin JOURNAL OF THE ROYAL MICROSCOPICAL SOCIETY. FEBRUARY 1888. TRANSACTIONS OF THE SOCIETY. I—Fresh-water Alga (including Chlorophyllous Protophyta) of the * English Lake District. 1. With descriptions of a new genus and five new species. By Aurrep W. Beyyert, F.R.M.S., F.L.S., Lecturer on Botany ‘at St. Thomas’s Hospital. (Read 11th January, 1888.) Puate I, Tue following is a list of species gathered in the English Lake Dis- trict in August and the early part of September 1887, not included in my previous list from the same district.* A few species only are noted which are recorded in that list, where it seemed desirable for some special reason, and these are placed between brackets. The gatherings were all within the county of Cumberland, in the lower part of Borrowdale, and near the southern end of Derwentwater, mostly EXPLANATION OF PLATE I. Figs. 1-8.—Hormospora mutabilis Bréb. x 200. 1888. 4.—Acanthococcus anglicus Benn. x 200. 5.—Urococcus insignis Hass. (?) x 400. 6.—Capsulococcus crateriformis Benn. Tegument with single pseudo- cyst, front view x 200, 7. ” x + Tegument with nest of eight pseudocysts, front view x 200. 8. ss as Empty tegument, side view x 200. 9.—Chroococcus pyriformis Benn. x 200. 10.—Gomphospheria (?) anomala Benn. x 200. 11.—Calothrix minuta Benn. x 200. 12.—Gonatozygon Brebissonii dBy (?) x 200. 13.—Euastrum rostratum Ralfs, yar. cumbricum Benn. x 400. 14.—Cosmarium globosum Buln. x 400. 15.—Staurastrum spongiosum Bréb., var. cumbricum Benn., side view x 400. 16. ” ” ” ” ” front view x 400, * This Journal, 1886, pp. 1-15, 2 Transactions of the Society. from bog pools at a comparatively low elevation. On the whole, they were not so rich as those made in the Loughrigg district, but some interesting forms were obtained.* PROTOPHYTA. Protococcacr® (including PALMELLACE®). Gleeocystis ampla Ktz. Scenedesmus obtusus Mey. Homospora mutabilis Bréb. Figs. 1-8. As, according to Dr. Cooke, this interesting plant has at present been observed only in Ireland, as far as these islands are concerned, a figure is appended. The completely unbranched gelatinous sheath is about 37°5 w in diameter, and rounded at both ends, usually quite straight, but sometimes with a knee-shaped bend, as in fig. 1. The pseudocysts are globular or elliptical, about 20-25 w long by 15-20 pw broad, with bright green and strongly granular endochrome, frequently exhibiting rudimentary transverse bipartition (fig. 2). They are either in close contact or with an evident space between them. In only one instance (fig. 3) were the pseudocysts seen in two rows within the sheath. It was observed only in gatherings from a bog pool near the Bowder-stone, but was there abundant. ACANTHOCOCCUS ANGLIcUS n. sp. Fig. 4. Of this interesting genus, first separated by Lagerheim, as many as fourteen species have been described and figured by Reinsch.t I have already noted (see this Journal, 1887, p. 12) the occurrence of several of these forms in this country; the one now described I am unable to identify with any of Reinsch’s species. It occurs in isolated individuals, the stifily gelatinous or cellulose membrane of which is irregularly spherical, varying between 65 and 95 w in diameter, and is distinctly laminated or folded in several layers, and prolonged into long slender colourless protuberances, from one-third to two-fifths the diameter of the globe. ‘These spines are sufficiently solid to be dis- tinctly bent by passing diatoms or animalcules, thus being clearly distinguished from the very much more fluid envelope which, in some desmids, is also not unfrequently raised into spine-like prominences. The cell-contents are bright green and granular. This species corre- sponds very closely in size and in the structure of the cell-membrane with Reinsch’s A. énsignis, which, however, is described as without spines; but I cannot but think it probable that they are different stages or conditions of the same organism. It is larger than any of Reinsch’s spined species, coming nearest to A. Hystrix, but differs also in the nature of the cell-wall. At first sight it resembles Hremosphera viridis dBy., but is somewhat smaller, and at once distinguished by * The names of new species are printed in SMALL CAPITALS; those of species new to Britain in italics. + Ber. Deutsch. Bot. Gesell., 1886, pp. 237-44. Fresh-water Alge, &c. By A. W. Bennett. 3 its very distinctly spiny envelope. It is endowed with a slow motion, not in any way connected with the spines. It was observed only very sparsely in a sphagnum bog in Borrowdale. Urococcus insignis Hass.(?) Fig. 5. Pseudocyst large, solitary, nearly globular, of a brick-red colour, from 28 to 35 yw in diameter, inclosed in a colourless gelatinous sheath composed of a number of rings, which form a short stem. The species described under this name has been observed only by Hassall, and as he gives no measurements, it is impossible to identify with certainty my plant with his, but it appears to agree. It is larger than U. Hookerianus Hass., the only species of which Dr. Cooke gives measurements, and differs in other respects from the remaining species recorded as British. Bog pools, Borrowdale; very scarce. CapsuLococcus n. gen. Protococcacearum. Cellule virides, globose, solitariz vel 2-8 in familias associate, tegumento lamelloso, firmo vel subgelatinoso, subgloboso vel ovoideo, crateriformi, fusco, denique subsolido. CaPSULOCOCCUS CRATERIFORMIS n. sp. Figs. 6-8. Pseudocyst large, bright green, usually solitary (fig. 6), and then from 20-25 w in diameter, or even more, globular or elliptical; or divided into a nest of 2-8 smaller pseudocysts (fig. 7). Tegument a lighter or darker brown, lamellose, nearly globular or ovoid in general outline (fig. 8), varying in diameter from 25 to 75 or 80 yp, but with a deep round saucer-shaped depression (at one end when the tegument is ovoid), with very sharply defined rim. At the bottom of this depression is seated the single pseudocyst or nest of pseudocysts. The teguments appear to assume a darker and somewhat indurated character after shedding the pseudocysts (fig. 8). Bog pools, Borrow- dale ; not uncommon. CHARACIACER. Dictyospherium reniforme Buln. Bog pools. CHROOCOCCACER. CHROOCOCCUS PYRIFORMIS n. sp. Fig. 9. Pseudocysts very large, somewhat pear-shaped, 50 w long by 37°5 broad, associated in pairs, and each pair inclosed in a very thin muci- lage; the two pseudocysts but slightly attached by their somewhat broader base. Mndochrome very bright blue-green, somewhat granular. Pool near Derwentwater. Celospherium Kiitzingianum Nag. Frequent. GoMPHOSPHERIA (?) ANOMALA n. sp. Fig. 10. Tegument quite globular, well-defined, from 110 to 120 w in diameter, composed of perfectly colourless and transparent mucilage. B 2 4 Transactions of the Society. Pseudocysts light blue-green; those near the periphery of the tegu- ment comparatively large, 6—10 wu in diameter, and loosely scattered ; those towards the centre much smaller and more crowded. Bog pool near the Bowder-stone; not unfrequent. I have much hesitation in placing this organism under Kiitzing’s genus Gomphospheria, as its inclusion would require the modification of the character from which the name of the genus is taken, the wedge-shaped form of the pseudocysts. On the other hand, it shows a striking resemblance in the interspersal of a large number of minute pseudocysts among a smaller number of larger peripheral ones. If this is regarded as the more important character, the diagnosis of the genus will have to be modified accordingly. Aphanocapsa montana Cram. Bog pools; not unfrequent. OSscILLARIACE. Oscillaria princeps Vauch. Occasional. Symploca Ralfsiana Ktz. Among Sphagnum. ScyTONEMACER. Tolypothrix zgagropila Ktz. Bog pools. B flaccida Ktz. Bog pools. RIvULARIACE®. CALOTHRIX MINUTA DN. sp. Fig. 11. Sheaths about 12-5-20 yw in diameter, and 2-6 times as long as broad, yellowish-brown, several grouped together in tufts. Filaments several within each sheath, excessively fine, moniliform, very pale blue- green. Heterocysts basal, colourless, visible within the sheath. Bog pool, Borrowdale ; seen only floating, but probably attached in tufts to other alge. NostocacEs. Anabeena flos-aque Ktz. [ Nostoc hyalinum Benn. Occasional. | ALG fi. PEDIASTRE®. Pediastrum rotula Br. SoRASTREZ. Sorastrum bidentatum Reinsch. PANDORINER. Eudorina elegans Ehrb. Gonium pectorale Mill. Hresh-water Algx, de. By A. W. Bennett. 5 DeEsMIDIES. Spheerozosma pulchellum Rabh. Hitherto, according to Dr. Cooke, not observed in Great Britain. Docidium granulatum Benn. (in Journ. R. Mier. Soc., 1887, p- 8). Occasional. Gonatozygon Brebissonii dBy (?). Fig. 12. Cells perfectly straight, very long and slender, 24~30 times as long as broad, 7°5 wu broad, 190-250 w jong, very nearly uniform in diameter throughout, with slightly dilated and truncate extremities, and no constriction in the centre. Endochrome homogeneous, with a single row of from 2U-24 vesicles down the centre; extremities and small space in centre colourless. ‘The whole clothed with short very _ thickly-set spines or hairs. I am somewhat doubtful about this identification, as I only saw the celis detached, and not united into filaments, and as also it was not seen in conjugation. It differs also somewhat in size from the description and figures, being longer and narrower. Bog pools, Borrowdale ; occasional. Closterium rostratum Ehrb. = lineatum Ehrb. me setaceum Ehrb. Pool near Derwentwater. | Micrasterias papillifera Bréb. | The character given in text-books—“ Frond bordered by a row of minute granules ”—is by no means accurate in all cases; as often as not I find them scattered over the whole surface of the frond. Micrasterias angulosa Hantsch. Euastrum humerosum Ralfs. 55 Jenneri Arch. Frequent. = rostratum Ralfs., var. cUMBRICUM n. var. Fig. 13. About the size of the typical form, but narrower in proportion to its length ; average length 45-50 yu, breadth 25 w ; the outline nearly rectangular ; each segment with two rounded lobes, each projecting about as far as the blunt terminal beak ; terminal lobe rather deeply divided at the apex. A single large prominence near the centre of each segment. Bog pools; frequent. Cosmarium bioculatum Bréb. ‘3 pygmeum Arch. Fe Wittrockii Lund. Frequent. Cosmarium globosum Buln. Fig. 14. Minute ; outline elliptical ; length 20-30 »; breadth 15-20 p; segments sub-reniform; sinus acute. Endochrome homogeneous, without vesicles; cell-wall not punctated. Bog pools ; frequent. Cosmarium quadrum Lund. This fine species was found in one gathering only. 6 Transactions of the Society. Cosmarium Broomei Thw. e sphericum Benn. (in Journ. RK. Micr. Soc., 1887, p. 10). Occasional. y, ochthodes Nords. es speciosum Lund. Occasional. | Cslogjlinares annulatus dBy. Bog pools; not unfrequent. Xanthidium antilopeum Bréb. Bog pools ; occasional. No British locality is given by Dr. Cooke, but it has been gathered in this district by Mr. Bisset. Xanthidium cristatum Bréb. Arthrodesmus octocornis Ehrb. Staurastrum armigerum Bréb. Hs spongiosum Bréb, var. CUMBRICUM n. var. Figs. 15, 16. Side view somewhat longer than broad, about 60 pu long, 50 pw wide ; each segment elliptical, with an oval protuberance in front, covered with hyaline bifurcate processes. Front view triangular, with slightly convex sides and obtuse angles, about 48-52 w in diameter, completely covered with bifurcate hyaline processes. Slightly larger than the typical form, not so orbicular in outline, and distinguished by the pro- tuberance on each segment. Moss pool, Grange-in-Borrowdale. Staurastrum pygmeum Bréb. Length 23 1; breadth 26 « ; each segment nearly elliptical. Pool near Derwentwater. Staurastrum tumidum Bréb. This fine desmid was not unfrequently seen ; always inclosed in dense hyaline jelly. Staurastrum cornubiense Benn. (in Journ. R. Micr. Soc., 1887, eli): brachiatum Ralfs. 5 tricorne Bréb. : inflexum Bréb. 7 paradoxum Mey. = proboscideum Bréb. - aculeatum Menegh. ZYGNEMACER. Zygnema pectinatum Ag. MEsocaRPE®. Staurospermum capucinum Ktz. JOURN .R.MICR.SOC.1888.P1.10. Tom i ak sel clei Jee ie i ae > « ‘ ° aetoro Chiba ay SEF ESS SSO sper a) II.—WNote on Micrasterias americana, Ralfs, and its Varieties. By W. M. Masxent, F.R.M.S. (Read 14th December, 1887.) Puate II. Since the publication of Mr. Ralfs’s work on the British Desmidies, its author must have been pleased to observe the great extension which the study of these beautiful little organisms has received. From 1848 until the present day, scarcely a year hag gone by without an increase in the number of species and of the works relating to them, so that in fact the list of writers on desmids is now -quite of respectable, even formidable length, and the study of these plants is getting to be almost as complicated and difficult as that of diatoms. The time has arrived when a comprehensive monograph of the family is not only desirable but necessary. The present note has been prepared in anticipation of such a work. Simplification is, I take it, much to be desired in all scientific manuals, and especially so in these days of almost infinite subdivision and specialization of observation. So close and minute is nowadays the examination of the minuter forms of animal and yegetable life, so careful is the diagnosis of each, so numerous are the workers in nearly every branch, that the separation of “species,” “varieties,” and “forms,” has become almost unbearably multiplied: differences so slight as to be apparent only to the very closest scrutiny are necessarily looked on as sufficient distinctions, and the student is wearied, confused, and perhaps frightened, by the infinite labours entailed upon him. Not only so; he is also puzzled by the fact (at least in the microscopic forms) that there is no absolute uniformity even in things which he has considered identical. A desmid, for example (I speak from my own observation) kept in a growing cell for some days, will undergo minute changes which it requires a good deal of knowledge of the EXPLANATION OF PLATE II. Fig. 1.—Mierasterias americana Ralfs, forma genuina. wana Fs - »» integra Turner (forma 6 Rabenhorst). Sees - a » recta Wolle. ey 1 oe re »» spinosa Turner (MS.). ea ey - 55 » alfsii Turner (forma 8 Ralfs). ay 0: > “e » major Wills. ad “¢ » excelsior Wallich (Turner MS.). 4.8 a 53 » Mahabuleshwarensis Hobson. eo: ES re » Wallichii Grunow. 3 10: = r- » Wallichii forma suecica (Turner MS.). rl x. a 35 Hermanniana, Reinsch. OR ne # 5 jijiensis Macdonald. AS: a ~ » ampullacea Maskell. », 14. x 9 »» ampullacea var. B Spencer. The magnification of these figures is not uniform, as the object has only been to exhibit gradations of outline. 8 Transactions of the Society. family not to mistake for real variations. Sometimes we attain a position where it may be possible to simplify this, and to reunite under one species, as merely “forms” of it, various plants, whether of one or of different countries, which their discoverers may have con- sidered to be separate. I believe that this can now be done with the desmidian species Micrasterias americana. In a paper of mine in 1880 (Trans. New Zealand Inst., xiii. p. 304), on New Zealand Desmidiex, I reported the existence of a plant to which I gave the name of M. ampullacea, and I indicated that it was nearly allied to M. americana. Mr. Archer, in ‘Grevillea,’ September 1881, referred my plant nearly to M. Her- manniana Reinsch. I understand that Professor Nordstedt, of Lund, would include mine and some others under M. Mahabulesh- warensis Hobson. My object in writing now is to advocate that all these, and the other cognate forms, should be merely considered as variations of one type species; and I select M. americana as the type, because it was the first described. The outline of M. americana was very correctly delineated in Mr. Ralfs’s work, first under the name M. morsa, afterwards corrected. Since that time, as far as I know, thirteen plants more or less closely resembling the original have been described from various countries. The last of these was reported by Dr. Spencer (Trans. New Zealand Inst., xiv. p. 296 and pl. xxii.) as a variety of my M. ampullacea, and although at first sight there undoubtedly is no very close resemblance between it and Mr. Ralfs’ type, yet when all the fourteen plants are placed together, the gradations are seen to be so gradual that they form a regular series. With the object of showing this, I have attached hereto figures of them all in juxta- position. For most of these figures I am indebted to the kindness of Mr. Barwell Turner. Beginning with the type-species No. 1, it will be seen that the two lateral lobes of each segment are broad at their bases, and are cut at their extremities into four short cylindrico- tapering lobules. In the forms 2, 5, 4, and 5, there is not much difference in this respect; No. 2 has its side lobes apparently even widening towards their ends, or rather with an indication of a small fifth lobule on each side which will be useful for comparison presently. In No. 6 the side lobes are evidently narrower and more deeply incised in the middle, giving an approach to the form No. 7, where the incision is deep enough to produce the effect of only two divaricating lobules. This form passes easily into No. 8, and thence into No. 9, where we have a more pronounced extra lobule than in No. 2. From No. 9 the gradation to No. 14 is quite easy; in fact, if it were not for other points to be mentioned presently, all these last forms are almost alike. In point of fact, judging merely by general outline, the whole series might be divided into two groups: the one including those forms in which the lateral lobes are obscurely bifid; the other, the forms in which they are distinctly bifid. The extra lobule appears Note on Micrasterias americana. By W. M. Maskell. 9 to be accidental, and is here not taken into consideration. The first group would include Nos. 1 to 6; the second Nos. 7 to 14. Even then, when a plant is found which will lessen the apparently more distinct gap between No. 6 and No. 7, the two groups would be merged into one. There are, however, two other considerations which seem to me to forbid the subdivision into only two groups. The first is the presence or absence of serrations on the middle or terminal lobe; the second is the shape of the lateral lobes and lobules. Whilst anxious, as I remarked just now, for simplification of species and varieties, I believe the convenience of students and observers will be consulted by em- ploying subdivision wherever clearly marked, just as a farmer finds it convenient to separate shorthorns from Devons, or Leicesters from Cheviots. A glance at the accompanying figures will show that there ‘are three different shapes of the lateral lobes and lobules, and three different characters of the edges, whether all round or on the median lobe. I propose therefore the following arrangement as probably correct, and at the same time likely to help a student to identify or to allocate correctly any plant whicn he may find agreeing with the series. Micrasterias americana Ralfs. * Lateral lobes thick, lobules short. 1. Forma genuina Ralfs. , tmtegra Turner (forma b Rabenhorst). recta Wolle. , spinosa Turner (MS.). » Lalfsii Turner (forma 8 Ralfs) MS. 5 major Wills. > OV O2 bo ** Lateral lobes with directly-tapering lobules: sides of median lobe smooth. 7. Forma excelsior Wallich (Turner MS.). 8. ,,. Mahabuleshwarensis Hobson. 9. ,, Wallchit Grunow. 10. ,, = Wallichit forma suecica (Turner MS.) ** * Tateral lobes with sinuous or flask-like lobules: sides of median lobe smooth. 11. Forma Hermanniana Reinsch. 12. ,, ~—_ fiyiensis Macdonald (1856), perhaps. **** Lateral lobes with flask-like lobules; sides of median lobe serrated. 13. Forma ampullacea Maskell. ***** Lateral lobes with flask-like lobules: margins of all the lobes smooth. 14. Forma ampullacea var. 8 Spencer. 10 Transactions of the Society. The sketch of Mr. Macdonald's Fijian plant from which my figure has been taken is on too small a scale to show whether the median lobe has a smooth or a rough shaft. As a matter of strict classification, perhaps, a regular series might be formed from the whole genus Micrasterias, even such apparently dissimilar plants as M. denticulata Brébisson, and M. dichotoma Wolle, which might be placed at opposite poles, ex- hibiting the generally trilobate form characteristic of the whole series. ‘T'o some extent the same might be done in other genera, say Cosmarium, Stawrastrum, or Closterium ; but in these the gradations would not be nearly so easy to find at present. Micrasterias, a small genus of few species which run almost into one another, offers a good opportunity for some such simplification as I have endeavoured to effect in one case. | There is, as has been hinted above, a slightly wider gap between my No. 6 and No. 7, than between any two others, and probably this is an inducement to separate my series into two. Still, the gap is so slight that I think it may be disregarded, and it only needs the finding of one specimen of either of these two plants varying the least bit either way, to fill it up as much as in other cases. The suggestion which I have made may be, perhaps, by some con- sidered trivial, and taken per se is of course only interesting to students of the Desmidiee. Yet I venture to express the thought that it may have a wider bearing, and that future generations of workers in science may not be over-thankful to those who, with the very best intentions, are nowadays multiplying “ species” with such exuberant fertility. The remark applies to all branches of zoological and botanical inquiry as far as my experience extends. At the present rate, the papermakers and bookbinders profit greatly, and the shelves groan more and more under the weight of books; but there is pro- spect of much trouble and weariness for future students. tee) I1I.—WNote on the Minute Structure of Pelomyxa palustris. By G. GULLIVER. (Read 11th January, 1888.) Tis interesting Protozoon was first described by Greef, and there is a good account of it in Prof. Ray Lankester’s article in the ‘ Encyclo- peedia Britannica.’ It is found in mud at the bottom of pools, often in association with Amab#x and other allied forms. It is distinguished by its large size—for it often attains to a diameter of 1/30 in.—its sluggish movements by means of blunt pseudopodia, and its voracity, the protoplasm having in general much foreign matter in it. On looking at living specimens, it struck me that the minute structure was probably more complicated than might at first be imagined; and the large size of the animal enabled my friend Mr. Pode to cut some sections which form the subject of the few remarks which I wish to make. ‘These sections were exceedingly friable, but portions remain in a sufficiently perfect condition to allow me to demonstrate a few points which I venture to think have not before been sufficiently dwelt upon. My remarks refer first to the exoplasm, and secondly to the endoplasm. Exoplasm.—Professor Ray Lankester divides the Protozoa into Gymnomyxa and Corticata, the former containing, besides many other forms, Amceba, and the genus which is the subject of these remarks, and the latter the higher Protozoa only. The distinction which he makes between the two groups rests upon the statement that a definite cortical layer is present only in the latter. He says, “The distinction into so-called exoplasm and endoplasm recognized by some authors is not founded on a permanent differentiation of sub- stance, but is merely due to the centripetal aggregation of granules lying in a uniform undifferentiated protoplasm. This may be true of many forms, but the sections under the Microscope show that not only is there in Pelomyzxa a distinction into exoplasm and endoplasm, but that the two, instead of passing into one another gradually, as one would have expected, are sharply defined by a definite boundary, without transitional phases of structure. The exoplasm forms a complete investment to the endoplasm in the form of a layer of uniform thickness apparently composed of delicately reticulated firm protoplasm, containing small vacuoles, and, as I think, devoid of nuclei, such few as are seen being apparently pushed on to its sub- stance from the endoplasm beneath. In the process of hardening, this layer readily separates from the subjacent softer endoplasm. Here and there a large vacuole, and in some cases a diatom or other foreign body can be seen in its substance. Endoplasm.—This is evidently much softer, more friable, and has its parts more loosely held together than the outer layer. Prof. Lankester speaks of it as composed of a richly vacuolated protoplasm, 12 Transactions of the Society. containing numerous small nuclei and not a single large nucleus as in the allied Amaba. It appears to me, however, that it is in reality composed of a number of nucleated cells loosely held together. What have been taken for vacuoles seem to me to be the delicate translucent cells, the nuclei alone of which are visible in the entire animal, especially when unstained. These cells are about the size of a white blood-corpuscle. Prof. Lankester suggests to me that they, with their nuclei, may be swarm-spores; and though I feel inclined to regard them as the permanent arrangement of the protoplasm, and to look upon the animal as one of those Protozoa which have been described as multicellular, yet without examining other individuals to see how far the structure is permanent, it would be premature to speak definitely. SUMMARY OF CURRENT RESEARCHES RELATING ‘TO LZ, O70 OG ALN. DB OT A NY. (principally Invertebrata and Cryptogamia), MICROSCOPY, &c., INCLUDING ORIGINAL COMMUNICATIONS FROM FELLOWS AND OTHERS.* ZOOLOGY. , A. VERTEBRATA :—Embryology, Histology, and General. a. Embryology.t+ Animal Ovum.{—Prof. F. Leydig gives a preliminary notice of the results of his investigations into the egg-cell. Germinal Rudiment and Egg-follicle.—It is now generally recognized that the egg is from the first a cell, and that it does not commence as a nucleus ; the error of observation is due largely to the small quantity of protoplasm which often surrounds the nucleus. As bearing on the question of the affinities of Annelids, Arthropods, and Vertebrates, the author points out that if we can imagine a germ-cord from the stroma of the ovary of a mammal it would have a close resemblance to free cords, such as those of the leech. The earliest mark of differentiation is that the cell-mass divides into germ-cells and matrix-cells, the former becoming the primordial ova, and the latter the follicular cells; these latter excrete cuticular layers, so that the follicular wall becomes thicker and takes on the character of connective tissue. The relation of the secreting matrix-cells and the cuticle to the primordial ova is exactly the same as that which obtains between the ganglionic sphere of a spinal ganglion and the investment. A membrana granulosa, or layer between the egg and the follicular wall is, when present, a later addition ; the author is inclined to refer its origin to leucocytes and matrix-cells. In Lithobius and Geophilus leucocytes certainly enter from the stalk of the follicle, while in mammals the elements of the granulosa are derived from the matrix and connective-substance cells of the follicle. The granulosa of a mammal and the follicular epithelium of an insect appear to be corresponding structures. Egg-cell.—Germinal spots are of two kinds ; some have the characters of Amebe with pale margins, and consist of spongioplasm, hyalo- * The Society are not intended to be denoted by the editorial “we,” and they do not hold themselves responsible for the views of the authors of the papers noted, nor for any claim to novelty or otherwise made by them. The object of this part of the Journal is to present a summary of the papers as actually published, and to describe and illustrate Instruments, Apparatus, &c., which are either new or have not been previously described in this country. + This section includes not only papers relating to Embryology properly so called but also those dealing with Evolution, Development, and Reproduction, and allied subjects. t Zool. Anzeig., x. (1887) pp. 608-12, 624-7. 14 SUMMARY OF CURRENT RESEARCHES RELATING TO plasm, and nuclear spot; others have a dark margin, a fat-like cortex, and paler contents. Notwithstanding these differences there are some indications of the passage of the former into the latter state. The germinal spots arise from the nodal points of the nuclear framework ; when they multiply, the larger germinal spot produces a brood by gemmation and fission ; differences are exhibited in different groups of animals. In consequence of their amoeboid nature, germinal spots which have become independent are capable of uniting into columns, and it must, therefore, be supposed that the transversely striated cords are not always directly due to the multiplication of germinal spots. The membrane of the germinal vesicle may present differences in one and the same animal; for example, in Triton it may be proportion- ately thick and perforated, or it may be thin and apparently without pores, and possibly it may disappear altogether. The name of mantle-layer is applied to a layer of germinal vesicles, first described by Eimer in reptiles; it is only temporarily present, and presents numerous variations ; it consists of granules, which look like germinal spots, and are often so grouped as to seem to have a radial striation. An account is promised of observations which seem to show that this layer is connected with processes of germinal spots. Among the general structural relations of the egg we must reckon the cavity around the germinal vesicle, which is filled by a clear, very soft and almost fluid protoplasm ; from this space hollow passages extend into the yolk, where they vary considerably in form and direction. This cavity was first noticed by Pfliiger. The germinal vesicle, which is ordinarily spherical, may be seen in the fresh state to exhibit depressions and processes, or pits and lobes, which may be regarded as due to movements. But it must remain uncertain whether this change in form is due to the vesicle itself or to the whole egg-cell. The yolk consists of spongioplasm and homogeneous hyaloplasm, to which are added vitelline granules and spheres. The spongioplasm is generally a fine closely-felted network, without any regular arrangement, but in others there are pretty regular concentric lines, or radially arranged bands. The intermediate spaces vary in size, but are often very small; in addition to these there may be larger cavities arising from the germinal vesicle, extending through the yolk in a radial manner, and anastomosing with one another. It is erroneous to suppose that the spaces seen by Reichert in the yolk of bony fishes were due to coagula. When larger yolk-spheres appear and become regularly arranged in the periphery of the egg we can distinguish an outer from an inner yolk. It has often been supposed that nuclear and cellular structures may be seen in the yolk, before the commencement of segmen- tation. These bodies are of two kinds; some resemble germinal spots, while the others are like thickenings of the nodal points of the spongio- plasm. The former are really germinal spots, which have passed into the yolk ; the others resemble the secondary nuclei of other cells, and of the egg of Ascaris megalocephala. As to what becomes of them there is some difficulty, but it seems to be certain that they do not form the material for the membrana granulosa. Prof. Leydig’s own observations, supported by those of Heider and Blochmann on Arthropod ova, lead him to suppose that they form a cellular layer round the yolk, but that the boundaries between the cells are not well marked; the “internal 5 ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 5 epithelium” of Clark, Eimer, and Klebs, the existence of which has been so often denied, may be dueto them. As to the function of the second kind of bodies no suggestion is offered. Maturity of the Ovum.*—Dr. A. Carini discusses the problem of maturity in the ovum. He refers to the probable importance of fhe inquiry, as Thury has emphasized, in connection with the determination of sex. In an historical résumé he notes the various contributions which from Barry onwards have been made to this subject. Barry referred to the smaller mass of cellular droplets, Wharton Jones to the disappear- ance of the germinal vesicle. Bischoff emphasized the increase in size, the looser structure of ripe follicles, and the increase of liquor folliculi, while Waldeyer called attention to the richer vascularity of ripe follicles, the differentiation of layers in the granulosa, and the radiate striation of the zona pellucida. His noted the increase of lymph spaces on the wall of the follicle, Hensen emphasized the larger size, the oval form, and the changes of the follicular cells. Von Baer had noted the peri- pheral position of the nucleus. Carini has been impressed by the occurrence of eosinophilous elements in the follicies of mature ova. In younger ova, both in nuclei and protoplasm, the follicular cells have most attraction for hematoxylin, while eosin staining only sparsely occurs in the protoplasm. He believes that the susceptibility of eosin characteristic of the cells of ripe follicles points to the progress of a degenerative process in these cells. Axis of Frog Ovum.t—Dr. O. Schultze responds at considerable length to some strictures made by Roux upon his work on frog ova. He reaffirms his old positions, and gives his reasons for doubting the satisfactoriness of some of Roux’s experiments. The axis of the ovum corresponds in its course from dark to clear pole to the dorsoventral axis of the embryo. The relation of this axis to the unfertilized egg is the same as in all telolecithal vertebrate ova. From the moment of the oblique posing of the egg after fertilization onwards, since the point lying uppermost in the clear portion represents the position of the blastopore and that of the future tail, the longitudinal axis is fixed; it passes from the point just mentioned at right angles to the transverse axis. Relation of Medullary Canal and Primitive Streak.{—Dr. J. Kaezander has investigated the somewhat obscure point of the relations between the primitive streak and the medullary canal. Chick embryos were examined, beginning at the stage when the primitive streak is visible to the naked eye, surrounded anteriorly by the dorsal folds. It was seen that the residue of the streak—unused in the differentiation of the body—includes the solid rudiment of the medullary canal. So far the latter conforms to the rule in passing through a groove-like stage before it is closed into a tube. Similar processes are seen in the bony fishes, where, according to Schapringer, the central canal of the spinal cord arises by a process of splitting within the solid rudiment, or, according to Oellacher, by the divergence and partial dissolution of the innermost cell-layer of the solid rudiment. There is this difference, however, that in the Teleostei the groove-form never occurs, but the tube is formed directly from the solid rod. * MT. Embryol. Inst. Wien, 1887, pp. 69-77. + Biol. Centralbl., vii. (1887) pp. 577-88. J MT. Embryol. Inst. Wien, 1887, pp. 26-32. 16 SUMMARY OF CURRENT RESEARCHES RELATING TO Spermatogenesis.*—Herr O. S. Jensen studied the ontogeny of spermatozoa in the rat, horse, sheep, and to some extent in man. His research bears especially on the much debated point of the structure of the tail, but some observations on the head-portion were also made. The fibrillar composition of the axial filament, the apposition and not twisting of the thread-like halves, the lumen passing up the entire axial filament, the spiral thread round the axis-filament in the connecting portion, are all minutely described and figured, but hardly call for detailed summary. Two Young Human Embryos.t — Prof. J. Janosik has studied a young normal and satisfactorily preserved human embryo. A second less favourable specimen also came into his hands. The first was probably the youngest human embryo as yet satisfactorily described. It measured 3 mm. in length, the ovum itself 8 mm.; the whole surface was covered with villi 1 mm. in length. The relations of the skin, body-wall, skeleton, nervous system, sense organs, alimentary tract, urinogenital organs, heart and vascular system, are described in detail. The embryo described corresponds to the embryo of M. His, which was probably slightly younger, but less well preserved. The relations to other young embryos are also noted. Experimental Embryology.t—Prof. L. Gerlach gives an interesting account of a new method applicable to research in the comparatively new field known as experimental embryology. There can be no doubt that a young form is more in the grasp of environmental influences, and is more plastic towards them than an adult can well be; an influence borne in persistently on a series of generations during embryonic life must be of the most potent character, That experimental embryology has not been earlier attacked has been due on the one hand to the necessity for preliminary study of the normal development, and on the other hand to the absence of a proper method. To attack such a problem as that of testing mutability during embryonic life, it is necessary that accessible embryos be obtained, that some know- ledge be forthcoming as to the influence and application of definite, not mortal external agents, and that it be possible to rear the subjects of experiment. As regards accessibility, the ova of birds, amphibia, and fishes are among Vertebrata the forms best adapted for experiment. The external influences, the operation of which may be studied, are manifold, from pressure to electric currents. Under increased pressure, Rauber produced short compressed forms. With over-abundant oxygen, the gills of tadpoles remained rudimentary. The influence of gravity on segmentation has been abundantly studied. Roux has investigated the results of pressure and mechanical injuries. In spite of these and other important researches, there are many obvious desiderata. It is necessary to have a more exact method of ex- periment, the varying plasticity of the embryos must be appreciated, a graduated series of influences must be established, and successive generations must be reared. Experiments on the mutability of embryos are still relatively premature, but birds afford the most convenient subjects for experiment as to the operation of external influences and * Arch. f. Mikr. Anat., xxx. (1887) pp. 379-425 (3 pls.). + Ibid., pp. 559-95 (2 pls.). t Biol. Centralbl., vii. (1887) pp. 588-605. Anatom, Anzeig., 1887, pp. 18-9. ZOOLOGY AND BOTANY, MICROSCOPY, ETO. jy their transmission under persisting conditions to subsequent genera- tions. Following the ancient attempts of Beguelin (1749), and numerous more elaborate expedients since proposed, Gerlach introduced an air- tight glass window in an aperture formed by breaking a portion of the egg-shell at the pointed pole. A permanent window was, however, in- convenient for experiment, though most useful for demonstration. After trying half-a-dozen different instruments, Gerlach at length devised the apparatus which he has used for about a year, and which he calls the Embryoscope. Generally, the contrivance consists of a metal ring fastened on the egg-shell, and of an air-tight glass plate covering the space where the shell had been removed within the metal ring. The operation is accomplished with antiseptic precautions. The window can be easily opened and reclosed so that the embryo may be subjected to experimental influences. For demonstration purposes, for watching the differences of growth in various regions, for studying heart-beat and other functions, and above all for investigating the operation of external influences, the device promises to be indispensable. Embryos with such windows have lived as long as thirteen days, over half the period of hatching. On till the fifth day the embryo could be readily brought under the window. When the embryo itself could no longer be directly observed from the window, the circulation of the blood could be caught sight of, and the life of the embryo proved. Gerlach watched the effect of localized heat and cold, of mechanical pressure, and of chemicals. He watched the appearance of bifurcation or anterior doubling of the heart, and the diminution or entire disappearance of the amnion. By hindering the development of the primitive streak, he tried to find out whether the blood-elements came from mesoderm plates or from parablast. His results were, however, too few and negative to admit of certain conclusion. He was able to show that the heart may go on beating two or three days after the death of the embryo. The amnion may survive still longer. The retarding influence of chloral hydrate on segmentation, and other facts were noted by the aid of this useful contrivance. 8B. Histology.* Morphology of the Cell.t—Dr. 8S. M. Lukjanow has studied the intimate structure of the glandular and epithelial cells in the mucous membrane of the stomach of Salamandra maculata. His research is accompanied by a prodigal wealth of illustration, forming seven coloured plates. (1) The cylindrical epithelial cells and the glandular elements inclose a large number of paraplasmic structures which are very similar in the two sorts of cell. One and the same cylindrical epithelial cell may include different kinds of accessory nuclear body, and also mucus spheroids of various kinds. The deep glandular cells show a distinct tendency to produce accessory nuclear bodies and zymogen granules ; the more superficial tend to mucinoid metamorphosis, only the cells of the limiting zone can be placed almost without limitation on the same morphological level as epithelial cells. (2) The extra-nuclear paraplasmic inclosures consist of the same * This section is limited to papers relating to Cells and Fibres. + Arch. f. Anat, u. Physiol. (Physiol-Abth.), Suppl. Bd., 1887, pp. 66-90 (7 pls.). 1888. C 18 SUMMARY OF CURRENT RESEARCHES RELATING TO structures as the intra-nuclear, and stand in direct connection with them. They may be stained with eosin and safranin, or with hama- toxylin. Like the intra-nuclear structures, they may be isolated, or united in complex systems. The following main types may be dis- tinguished:—(a) plasmosomata (stained with eosin and safranin) ; (b) karyosomata (stained with hematoxylin); (c) achromatic granules (forming all sorts of chains, circlets, and aggregates) ; (d) combinations of (a) and (c); (e) combinations of (b) and (c); (f) combinations of (a) and (b), combinations of (a), (b), and (c); (4) combinations of sickles and spheres, rich in eosino- and safranophilous substances, but also plus colourless elements; (7) similar combinations, staining dirty violet or deep blue; (7) combinations of sickles and spheres with finely granular protoplasmic masses; (/) nucleus-like structures containing various forms of the above; (J) zymogen granules (stained with eosin and safranin); (m) combinations of (1) with (a); (n) combinations of (7) with (c); (0) mucinoid spheroids ; (p) combinations of (0) with (a), &e. ; (q) combinations of (0) with (1). Surely enough of permutations and combinations! Several may occur both as intra- and extra-nuclear, viz. a, b, c, d, e, f, and g. The others are wholly extra-nuclear, though they may be in special indentations of the nucleus. (3) The above types occur constantly, and must express definite structural relations. The variations are always quantitative, the fundamental structure is constant. Nuclei of Muscle-cells.* — Dr. S. M. Lukjanow, continuing his contributions to cellular morphology, has investigated the nuclei of unstriped muscle-cells in Salamandra maculata, As regards form, the following types of muscle-nuclei have to be distinguished :—(a) Regular cylindrical rods rounded at the ends and curved when elongated; (b) S-shaped, doubly or trebly curved ; (c) spirally coiled, with 2, 3, 4, or more twists; (d) spindle-shaped ; (e) like those of cylindrical epithelium, round or oval in optical section. The size varies greatly, and is exposed in a series of tables. The staining properties are also very diverse even in the same section, and there was no relation between these variations and those of size. Internal Structure.— The presence of hyaline vesicles or achro- matic portions is noted. They form chains within the nuclei. Fine chromatin granules are seen at the poles of contact, and also at times peripherally. The author distinguishes with combined staining the following kinds of nuclear corpuscles :—(a) The so-called plasmosomata ; (b) the so-called karyosomata; (¢) elements of a mixed character. The various forms and sizes are noted. Disposition—The nuclei may (1) lie parallel to one another, or (2) in rows one behind the other. In the chain arrangement, the rows may consist (a) of two members of similar appearance ; (b) of more than two members which are not uniform; and (c) of one large rod or spindle-shaped nucleus which bears a much smaller but similar nucleus at one of its poles. Cell-division.j—Herr F. Tang] has studied the exact connection between the nucleus and the body of the cell during mitosis, and comes to the two following main conclusions :— (1) With the dissolution of the achromatic nuclear membrane the * Arch, f. Mikr. Anat., xxx. (1887) pp. 545-58 (2 pls.). ¢ Ibid., pp. 529-45 (1 pl.). ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 19 sharp boundary between nucleus and cell-body disappears, until the formation of a new membrane round the danghter-figures. (2) During the mitosis the connection between cell-body and nucleus is much more intimate than obtains with the resting nucleus. This is probably due to the mixture of “nuclear sap” and the “ interfilar mass.” y. General.* Aquatic Locomotion.t—M. Amans has made a mechanical study of the modes of aquatic locomotion effected by solid jointed levers. All animals with such apparatus are bilaterally symmetrical ovoids. The mechanical relations of various ovyoids are described. He draws a parallel between forms of ovoid and fin, distinguishing on the one hand (a) spheres (lower organisms), (b) circular ovoids (ciliated echinoderm larve), (c) elliptical ovoids (vermiform organisms), (d) unisymmetrical ovoids (most Vertebrates and Arthropods), and (e) asymmetrical ovoids (Pleuronectids, certain Crustacean and Arthropod larve). As parallel to these he notes the following forms of fin :— (a) embryonic bud, (b) circular cone (vibratile cilia), (c) bisymmetrical cone, the basilar section of which forms an elongated ellipse (ap- proached by dorsal fin of Hippocampus), (d) unisymmetrical cone (dorsal, anal, caudal fins), and (e) asymmetrical cone (pectorals and abdominals), the base of which forms an oval analogous to the contour of the profile. He distinguishes the various forms of torsion in the appendages, and emphasizes the enormous influence of the resistance of the water on the form both of the body and of its appendages. B. INVERTEBRATA. Mollusca. B. Gastropoda. Larval Anal Eye in Opisthobranch Gastropods.t{—Prof. H. de Lacaze-Duthiers and M. G. Pruvot report the presence of a remarkable sensory organ in all the embryos of Opisthobranchs which they have examined—Aplysia, Bulla, Pleurobranchus, Doris, and others. It is an eye of a size relatively colossal, for it is one-fifth of the total height of the embryo. It has been particularly studied in Philine aperta, where a small lobe, destined to form the intestine, is detached on the right side of the endodermal sac, at about the fiftieth hour. At the same time, and just above it, four ectodermal cells, belonging to the ventral surface of the embryo, become slightly raised and begin to be charged with fine pigment-granulations of the brightest carmine colour. They are so arranged as to form a cross with the angle turned upwards; in this cavity a fifth ectodermal cell appears, which will give rise to the crys- talline element; it gradually becomes a rich yellow colour, but does not lose its transparency ; it is spherical, with a diameter of 15 yp. The four peripheral cells soon encircle it in such a way as to leave at the tip a small pupil, which is elongated transversely. Just by the upper extremity of the eye a small tuft of vibratile cilia make their appear- ance, and indicate the proximity of the future anus. Just before the larva escapes, that is, about the sixth day, the anal * This section is limited to papers which, while relating to Vertebrata, have a direct or indirect bearing on Invertebrata also. + Comptes Rendus, cv. (1887) pp. 1035-7. ¢ Ibid., pp. es Cc . 20 SUMMARY OF CURRENT RESEARCHES RELATING TO eye is completely formed; it is placed in the concavity of the last intestinal loop, and its upper extremity, which carries the pupil, is placed at the level of the anus. The base is less strongly pigmented than the rest, and has on its inner surface a small mass of cells, which are found in section to be insensibly continuous with the ectodermal integument, and which must be considered as the rudiment of the asymmetrical nerve-centre. Longitudinal sections of the organ show that the upper half of the pigmented sac is entirely occupied by the crystalline portion, while its inferior half is lined by a relatively thick layer, which is finely dotted, and evidently represents a retina. It is clear that this organ presents all the essential parts of a highly specialized eye, and there is no doubt that its duty is to make up for the absence of the cephalic eyes, which are always wanting in the long free larval life which is led by Philine. In Bulla hydatis there are two well-developed cephalic eyes, but, nevertheless, the anal eye has the same structure and relations as in Philine ; but it is interesting to remark that it has no function to per- form, for the larva does not become free till the twenty-fifth day, and the eye commences to atrophy before the embryo leaves the egg. As to the morphological significance of this organ, we are reminded that Prof. Lacaze-Duthiers long since described, at the entrance of the mantle-cavity of aquatic Pulmonates, a “special organ” in the form of a vibratile pit set in a small ganglion; this has always been since regarded as having an olfactory function. As it is always proportionately larger during embryonic life it has been regarded as a larval organ. With this M. Fol has compared the ciliated pads, which have the same innervation and appear to have the same function in Pteropods and Heteropods. It seems to the authors that the anal eye of Opisthobranchs is in them the representative of this structure, the physiological differences in no way implying differences in morphological value. The otocysts of Philine are formed in exactly the same way as the eye, the otolith appearing before the neighbouring cells surround it to form the wall of the auditory vesicle, which only later becomes sunk into the substance of the foot; the pedal ganglion, as is the rule for sense-organs of Gastropods, appears last. Nervous System of Aplysia.*—Prof. H. de Lacaze-Duthiers con- tinues his morphological study of molluscs, and describes the anatomical nervous relations found in Aplysia. The esophageal commissure, at the level of the large tentacles and eyes, has this first peculiarity, that the commissure of the pedal ganglia being very long, these two centres become lateral. The two first ganglia of the asymmetrical centre are oblong and small, and situated behind the former. The brain owes its apparent quadrilateral form to connective tissue, but consists of two rounded ganglia. The external and superior angles give off all the nerves to head and cephalic sense-organs. The inferior external angles give origin to the connectives uniting the brain with the pedals and with the first ganglia of the asymmetrical group. Where the cerebro-pedal connective plunges into the pedal ganglion there arises the very short connective uniting the latter to the asymmetrical ganglion. The cerebral nerves are very closely apposed, the optic is almost always distinct from the tentacular. The latter forms five ganglionic thicken- * Comptes Rendus, cy. (1887) pp. 978-82. ZOOLOGY AND BOTANY, MIOROSCOPY, ETO. 21 ings in its organ. The rich innervation of the two buccal lobes is described. Other nerves supply the lips proper. The pedal centre has really a double commissure. Each ganglion gives off three large nerves below and three above. The largest and most internal of the latter innervates the sensitive region of the foot below the labial palps, the other two go to the portion of the foot in front of the head. Of the inferior pedal nerves, the two medians supply the middle region of the foot, the two outer pass outwards to the two large lateral lobes which ascend dorsally, and are sometimes erroneously called the mantle. The intermediate pair innervate the most external portion cf these same lobes. The asymmetric centre——From the two little ganglia which lie on the pedal centres, and belong to the cesophageal collar, there rises on each side a cord which passes to the neighbourhood of the heart and the base of the gill. There the couple unite in two closely adjacent ganglia, A ‘ long closed loop forms with the two superior ganglia the transversal chain of the asymmetric centre. From the first ganglion on the left, near the pedal of the same side, a nerve descends to where the mantle properly begins, and there divides, The two precardial ganglia give off two large nerves, which are dis- tributed on mantle and viscera. The details of their distribution and the nature of the branchial ganglion are noted. The nerves of the neck arise from the dorsal surface of the pedals. It is important to notice that mantle, viscera, and gill are supplied as usual by the asymmetric centre, the median ganglia of which are far separated from the collar, and in the cardiac region. They are united by a long connective-like commissure. The mantle-like lobes of the foot are innervated from the pedal ganglia. Nervous System of Prosobranchs.*—The following are some of the more important general conclusions reached by M. E. L. Bouvier. The nervous system of Prosobranch Mollusca is characterized by a crossed visceral commissure, which is only wanting in the orthoneuroid Azygobranchs. Except, perhaps, in the Docoglossata, there are also two pallial anastomoses; the right anastomosis is related to the right pallial nerve which arises from the pallial ganglion of the same side, and with another right pallial nerve which arises from the subintestinal ganglion, or (when that ganglion is absent) from the subintestinal branch of the visceral commissure. The left anastomosis is established between the left pallial nerve, which arises from the left pallial ganglion, and a branchio-pallial nerve which is given off from the subintestinal com- missural branch. If the right pallial nerve passes by the subintestinal ganglion before passing to its area of distribution, the nervous system is zygoneurous to the right, or there may be zygoneury to the left; in all other cases the nervous system is dialyneurous. Right is much more frequent and important than left zygoneury. We may classify the Prosobranchiata thus :— (A) Dialyneurous Nervous System: Chiastoneurous Diotocardata ; Holostomatous Proboscidifera ; the majority of the Rostrifera. (B) Right Zygoneurous Nervous System: Siphonostomatous Pro- boscidifera; Stenoglossata ; some Rostrifera. * Ann. Sci. Nat.—Zool., ili. (1887) pp. 1-510 (19 pls.). 22 SUMMARY OF OURRENT RESEARCHES RELATING TO (C) Left* Zygoneurous Nervous System: Ampullariide, some Crepidulide, Naticide, Lamellariide, Cypreide. (D) False Orthoneurous Nervous System: Helicinide and Neritide. Right zygoneury becomes more marked as one ascends the scale of Prosobranchs ; the right pallial anastomosis of the Aspidobranchs is at some distance from the right ganglion. In Paludina, Littorina, and Cyclostoma, the two pallial nerves fuse in the walls of the body. Among the Cerithiide, Melaniidew, and Cypreeide, there are some genera more or less dialyneurous, and others which are more or less distinctly zygoneurous. Once right zygoneury is realized, the right anterior pallial nerve becomes a connective; this is generally pretty long, but in most of the Stenoglossata it is so short that the subintestinal ganglion becomes intimately connected with the right pallial ganglion. The nervous system of Diotocardata is essentially characterized by the diffusion of the nervous centres. From the point of view of the nervous system there is no solution of continuity among the different groups which compose the order of Prosobranchs. Thus, in the Tznio- glossata the Ianthinide and the Ampullariide have a very long cerebroid commissure; the Ampullariide, Paludinide, Cyclophoride, &ec., have a labial process and a labial commissure, and the Ampullariide and the Tanthinide very long lateral connectives. The successive transitions between the Diotocardata and the Monoto- cardata are more sharply indicated by the ganglionic cords of the foot; the buccal ganglia also undergo progressive modifications as one ascends in the order, for in Halia and the Purpuride they are closely ap- proximated and almost concentrated into a single mass. Other modifications are presented by the cerebral commissure, and the maximum of concentration is exhibited by the Stenoglossate Monoto- cardata, where the buccal ganglia are very close to the cerebral ganglia, and very far from the buccal mass. With these variations there cor- respond changes in the relations of the buccal connectives. In the most primitive types the anterior part of the mantle is almost symmetrically and solely innervated by the pallial ganglia. If the right gill and false gill are absent, there is no subintestinal ganglion, and its position in the commissure or in its vicinity is simply indicated by one or two right pallial filaments. As one ascends the Tznioglossata the asymmetrical innervation of the mantle increases in importance, especially on the right side. The Diotocardata are the least asymmetrical of all the Prosobranchs. After describing the innervation of the gills, and the characters of the visceral ganglia, the author proceeds to consider the otocysts; these may be divided into three groups; (1) Otocysts with numerous otoliths as in Diotocardata and some Rostrifera; (2) Otocysts with numerous otoliths inclosing a large round otolith, as in Turritella rosea ; and (8) Otocysts inclosing a single otolith, as in remaining Prosobranchs. Although it would be an error to deny all systematic value to the oto- cysts, the author thinks that their importance, from this point of view, has been over-estimated. The penis is not always, as has been stated, a cephalic formation innervated from the cerebral ganglion, for four kinds may be distinguished. * In the text B and O are both “Systeme nerveux zygoneure a droite.” ZOOLOGY AND BOTANY, MIOROSCOPY, ETO. 23 A pedal penis, as in most Tenioglossata and Stenoglossata; a cephalic penis, as in Neritide, Paludinide, and Calyptreide; a dorsal penis, innervated from the subintestinal ganglia as in the Cyclostomide and Bythinia; and a pallial penis, as in the Ampullariide. With the ex- ception of the Neritide all the Diotocardata hitherto examined have been found to be without a penis. Among the Pulmonates the torsion of the body displaces the organs or modifies the asymmetry of the nervous system; but among the Prosobranchs it is not so; for the dextral Ampullariidz have the anus, the penis, the gill, and the rectum to the right, and the siphon and the false gill to the left; it is exactly the same in the sinistral forms, and they have the nervous system twisted in just the same way as that of the dextral forms. In the Prosobranchs, then, the torsion of the body does not displace the organs or modify the asymmetry of the nervous system. We must, therefore, reject all the hypotheses which explain ‘the torsion of the nervous system by that of the body. In Prosobranchs the presence of a lung is no indication of a relation- ship between pulmonate forms; the Cyclophori, which are always placed near the Cyclostomata, are much closer to Turbo or Delphinula. After indicating the various modifications undergone by different parts of the digestive system, M. Bouvier points out that the Proso- branchs, which have become adapted to a special mode of life, have, as a rule, undergone profound and apparently abnormal changes in their organization ; in their progressive evolution the members of the group have gone through three chief stages. The nervous system was at first dialyneurous, diffused, and provided in the foot with ganglionated scalariform nerve-cords ; the gill was bipectinate; the heart, with two auricles and a ventricle, was traversed by the rectum; the very well deve- loped buccal mass was situated behind the nerve-collars; the salivary glands were applied to the buccal mass, and their ducts did not traverse the nerve-collars; there was no siphon, or penis, and the renal organ opened by a tube into the pallial cavity. In the second stage the nervous system was dialyneurous or zygoneurous, and more or less concentrated ; there were no scalariform cords in the foot; the gill was monopectinate, and a false gill more or less developed; the heart had but one auricle, and the ventricle was not traversed by the rectum; the buccal mass moderately developed, and situated in front of the nerve-collars; the salivary glands were separated from the buccal mass, and the ducts traversed the nerve-collars; a penis was generally present, the renal organ opened by a cleft at the base of the pallial cavity; the otocyst had one or more otoliths, and the buccal ganglia were applied against the buccal mass. The characters of the third stage are a zygoneurous, highly concentrated nervous system, no scalariform pedal cords; gill monopectinate, well developed, bipectinate false gill; heart with one auricle and untraversed ventricle; poorly developed buccal mass, from which the salivary glands—whose ducts traverse the nerve-cords—are separated ; buccal connective very short, but deep; siphon, penis, pro- boscis, unpaired special gland; renal organ opening by a cleft at the base of the pallial cavity ; a single otolith in the otocysts. These characters appear to be sufficient to justify the establishment of three great divisions of the Prosobranchiate Gastropods, the Dioto- cardata, teenioglossate Monotocardata, and stenoglossate Monotocardata ; and this mode of classification is supported by the facts of paleontology, 24 SUMMARY OF CURRENT RESEARCHES RELATING TO for the first division had a number of representatives in paleozoic times, the second was abundant in secondary epochs, and the Stenoglossata are common in tertiary strata. The author appends a somewhat detailed table of affinities and classification. Development of Helix Waltoni.*—Drs. P. and F. Sarasin found that Helix Waltoni is very abundant in Ceylon. The young are re- markable for the long time that they remain in the egg, where two larval organs—caudal vesicle and primitive kidney—develope to a con- siderable size. The former is finally as much as 14 cm. long; it is, doubtless, as Gegenbaur has suggested, the embryonic respiratory organ. The primitive kidney is large enough to be seen, on dissection, with the naked eye, and has the function of an embryonic renal organ. On some parts of the body-epithelium small bud-like structures, which are found to be sensory, may be seen; they consist of a small number of large pyriform sensory cells with stiff processes, and are inclosed by long supporting cells. The whole structure calls to mind the lateral organs of Amphibia. The lateral organs found by Haller in rhipidoglossate molluscs appear to be more diffuse; the lateral organs of Helix are regarded as larval organs. The rudiments of the central nervous system are laid down very early; before the tentacles are visible the cerebral ganglia appear as rounded masses of cells, still connected with a well-marked thickening of the epithelium of the sensory plates. When the cerebral mass is well developed there appear on either side of the sensory plates two invagina- tions, which grow out into long tubes with cecal widened ends; these the authors call the cerebral tubes. Later on a large lobe may be seen on either side of the cerebral mass ; these, which have a different struc- ture from the brain, may be called the accessory lobes; the spaces in them are nothing else than the cavities of the two cecal sacs of the cerebral tubes; later on the two spaces and the efferent duct disappear. These observations will doubtless explain the discrepancies in different accounts of the development of the brain of Mollusca; the authors who state that the brain is formed from an epithelial thickening have probably examined early stages, while those who have described it as arising by invagination have seen the later. The authors believe that these cerebral tubes are the homologues of the olfactory organs of Annelids, described by Kleinenberg in Lopado- rhynchus ; in Molluses they do not permanently retain the character of open tubes, but pass into the brain, of which they form the lobes. Morphology of the Heteropod Foot.{—Prof. C. Grobben gives a critical account of the views of Huxley, Gegenbaur, Leuckart, Ray Lankester, and others on this subject; but brings forward nothing which can be called new. The investigation shows that in connection with the pelagic life, and the associated development of a swimming- lobe upon the foot, the primitive Gasteropod sole has degenerated into a sucker-like structure, which in the Pterotracheide forms a secondary sex character through its absence in the female. With the shortening of the foot-sole is connected the specialization of the portion bearing the oper- culum, which forms the tail-like posterior part of the body, and whose fin-like development is in relation to the pelagic life of the Heteropoda, * Zool. Anzeig., x. (1887) pp. 599-602. { Arbeit. Zvol, Inst. Univ. Wien, vii. (1887) pp. 221-82 (1 fig.). ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 20 y. Pteropoda. Nervous System of Pteropods.*—Dr. P. Pelseneer has studied the nervous system of Pteropods, in regard to which a certain degree of vagueness has hitherto existed, (1) In Gymnosomatous Pteropods, the central nervous system, com- pared with that of thecosomatous types, is characterized by the position of the cerebral ganglia, which are apposed one upon the other, and situated on the superior surface of the cesophagus. (2) In all genera except Halopsyche the pleural ganglia are paired, and not unpaired as Von Ihering has maintained. Each pleural ganglion gives origin to a nerve which anastomoses with a pedal (lateral cervical) nerve. All the Gymnosomata exhibit a double pedal commissure. (3) The buccal appendages of Clione and Pneumodermon are innervated by the cerebral ganglia, and not by the pedals as Gegenbaur stated. These appendages are therefore not pedal in their nature. (4) The visceral commissure of typical Gymnosomata exhibits two superposed ganglionic masses, which give origin to the asymmetrical nerves, three from the left, and one from the right, and not to symmetrical branches as most authorities describe them. As to Thecosomatous Pteropods, the central nervous system has been often described. Pelseneer contents himself for the most part with emphasizing that the system is characterized (1) by the separation of the cerebral ganglia, which are situated on the sides of the cesophagus, and united by a long supra-cesophageal commissure, (2) by the absence of pleural ganglia, the pedals and viscerals being directly apposed to the cerebrals from which they are separated only by a constriction, and (8) by the coalescence of all the ganglionic elements of the visceral commissure in a single elongated mass. The nerves which spring from the visceral ganglion are in origin asymmetrical. The left portion of the ganglion gives origin to three principal nerves, the left pallial and two viscerals, while the right portion only gives rise to the right pallial. Souleyet alone has given a correct representation of this fact. The nervous system of Cymbulia is discussed in detail. Halopsyche among Gymnosomata agrees with Cymbulia. Three types may be distinguished : one represented by the two genera just named, a typical Gymnosomatous, and a typical Thecosomatous arrangement. The author then discusses the homologies between the various Pteropod types, and between these and molluscs generally. (1) The two lateral ganglia—right and left—of Halopsyche and Cymbulia are homologous with the anterior or pallial visceral ganglia of other molluses, for they give origin to nerves which supply similar regions. The unpaired median ganglion of the same genera corresponds to the united posterior visceral ganglia of other molluscs, for they give rise to nerves which supply the circulatory, respiratory, and reproductive apparatus. (2) The left ganglion of typical Gymnosomatous Pteropods is homologous with the left anterior visceral, and posterior visceral together, while the right ganglion of the former corresponds to the right anterior visceral. (8) The left portion of the visceral ganglion of typical hecosomata is homologous with the left anterior visceral and posterior visceral together, while the right half corresponds to the anterior right visceral. The visceral ganglionic mass of typical * Arch. de Biol. vii. (1887) pp. 93-129 (1 pl). 26 SUMMARY OF OUIRENT RESEARCHES RELATING TO Thecosomata thus corresponds to the sum of the four ganglia of the visceral commissure. In general, (a) the pleural ganglia are paired in Gymnosomata as in all molluscs where they are present; (b) the buccal appendages of Gymnosomata are innervated by cerebral ganglia, and cannot therefore be compared with Cephalopod arms ; (c) the Pteropods are thus separated from Cephalopods. The asymmetry of their visceral commissure separates them from all molluscs with symmetrical visceral commissure. They approach the Gasteropods, and especially, as Spengel noted, the EKuthyneura. ‘Challenger’ Pteropoda (Gymnosomata).*—Dr. P. Pelseneer has published the first part of his report on the Pteropoda collected by H.M.S. ‘Challenger,’ which has become a critical account of all known genera and species. The adult Gymnosomata are characterized by the absence of a mantle-skirt, pallial cavity, and shell; by the presence of a well-developed head, bearing two pairs of tentacles, of which the two posterior bear rudimentary eyes; by two fins of which the anterior edges are not joined together backwards, above the mouth; and by the anus being situated at the right side of the body. They are carnivorous, and often feed on their thecosomatous allies. Eleven species were collected by the ‘Challenger, four of which are new; all the known twenty-one forms are discussed in the systematic portion of this memoir. 6. Lamellibranchiata. Photogenic Property of Pholas dactylus.;—M. R. Dubois has made a series of experiments which show that the photogenic property of Pholas dactylus is independent of any organ, and is a chemical phenomenon. From the luminous parts of the animal the author has succeeded in extracting two substances, the contact of which, in the presence of water, determines the appearance of the light. One of them was obtained in the crystalline state, and possesses the special optic properties which give to photogenic tissues their opalescence. It is soluble in water, and hardly soluble in alcohol; it may be called luci- ferine. ‘The other body is an active albuminoid of the class of soluble ferments, and may be called luciferase. These two substances are necessary to, and sufficient for the production in vitro of the phenomena of animal luminosity, improperly called phosphorescence. The results here obtained confirm and generalize those attained to by the author after his study of the luminous Elateride. . Molluscoida. a, Tunicata. Central Nervous System.{—M. F. Lahille has studied the develop- ment of the central nervous system in a large number of Tunicate embryos, and comes to the following conclusions. The typical central system consists of a median tube of epiblastic origin, with bilateral symmetry, and with numerous ganglionic masses. If the principal masses are considered as forming so many ganglia, the following may be distinguished: (1) the anterior (tactile); (2) the sensory (ocular and * Reports of the Voyage of H.M.S. ‘ Challenger,’ lviii. (1887) 72 pp. and 3 pls. t+ Comptes Rendus, ev. (1887) pp. 690-2. { Ibid., pp. 957-60. ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 27 auditory); (3) the cerebral; (4) the posterior (branchial); (5) the visceral; and (6) the caudal. The brain of the adult Tunicate arises from the union of the first ganglia. As to the segmentation of the nervous system in Tunicates, it is a matter of appreciation. B. Polyzoa. Spermatogenesis.*—M. A. de Korotneff finds in Aleyonella fongosa a very fit object in which to study the process of spermatogenesis. ‘The succession may be summed up in La Valette St. George’s familiar formula, spermatogonia give rise to spermatocytes, these become spermatides and mature into spermatozoa. The young endodermic cells of the funiculus of a bud have spherical transparent nuclei. ‘These contain nucleoli and these alveoli. The nuclei of these spermatogonia multiply without trace of karyokinesis. Multinuclear cells result, the nuclei being situated just below the ‘cellular membrane. The individual spermatocytes bud off spermatides, and the whole mass comes to have the appearance of a transparent vesicle covered superficially by a thick layer of maturing sperms. The external surface of the peripheral (outer) end of each nucleus is surrounded by a homogeneous sheath, which gives off a process forming the central filament of the tail. The internal surface of the nucleus has a gradually thickening cap of protoplasm, The first-mentioned sheath acquires a swollen vase-like form, and after certain modifications becomes the neck of the spermatozoon. The internal cap separates from the nucleus, and becomes gradually conical. The nucleolus, a small well- defined spherule, becomes finally lodged in this cap, where it is pro- tected, and forms the essential part of the head. The details are minutely described. M. Korotneff suggests, in regard to the peculiar sperm of Ascaris megalocephala, that the caudal portion is the head-cap, and its nucleus really the nucleolus. The other portion contains a number of filaments plunged in a protoplasmic mass; these structures may be identified with the tails of other spermatozoa, and compared, for instance, with the processes seen in the crayfish sperm. Fresh-water Bryozoa.t—Herr M. Verworn has investigated the structure and development of Cristatella. He finds that the chief anatomical peculiarities are the presence of a movable pedal disc on which the individuals are arranged in parallel rows, the complete absence of an ectocyst and of a fold of the endocyst; as a consequence the anterior and posterior parieto-vaginal muscles have disappeared ; there are a comparatively large number of tentacles. The author adopts provisionally the view of Kripelin that the whole outer cell-layer of the integument is formed by ectoderm, the inner lining of the body-cavities by mesoderm, and the inner epithelium of the enteric tract by endoderm; embryological investigations are, how- ever, needed on these points. The pedal disc consists of an outer ecto- dermal layer, a median muscular layer, and a mesodermal pavement epithelium. The first of these has, in addition to large vesicular cells and others containing a clear slimy mass, long cylindrical glandular cells with a broad base on the lower surface and at the sides; between * Comptes Rendus, ev. (1887) pp. 953-5. + Zeitschr. f. Wiss. Zool., xlvi. (1887) pp. 99-130 (2 pls.). 28 SUMMARY OF CURRENT RESEARCHES RELATING TO these there are pores by which the mucous secretion passes to the exterior. The cylindrical cells have an important function in the move- ment of the colony, as they secrete a thin transparent and chitinous membrane, which affords a smooth surface which lessens friction and affords a strong fulcrum. The musculature of the foot consists of a longitudinal and a transverse layer, the fibres of which are set at right angles to one another. The cells of the mesodermal epithelial layer are provided with very short cilia which can be easily missed, and which the author only saw with certainty in living specimens. The septa which traverse the cavity of the pedal disc are completely formed of mesoderm ; they are made up of a hyaline supporting membrane on either side of which are longitudinal fibres and pavement epithelium; their layer of transverse fibres is feebly developed or completely wanting. The integument of the separate individuals is the direct continuation of the upper covering of the disc, and consequently consists of the same three layers as compose it; although there are, of course, certain differ- ences in the details. The walls of the lophophore and of the tentacular crown are formed of the same layers as the cystid. The tentacles are to be regarded as evaginations of the cavity of the lophophore, which, again, communicates with the body-cavity. The enteric tract is made up of the endodermal enteric epithelium, a median muscular layer, and an outer mesodermal coelomic epithelium. The epistome carries externally a layer of ciliated cells, which are highest near its base. The foregut is divisible into two parts, which are histologically quite distinct. The lining epithelium of the pharynx is the direct continuation of the ciliated investment of the epistome, and presents very long, delicate, ciliated cells, separated from one another, like those of the epistome, by clefts. About the middle of the foregut the ciliated cells suddenly cease, and the epithelium of the cesophagus commences. Its cells are long, delicate, and cylindrical, but they have no cilia, and do not stain like those of the pharynx; nor are they sepa- rated from one another by clefts. Inferiorly, the foregut is bounded by a circular valve, which at its margin takes on the characters of the epithelium of the stomach. As in Alcyonella, the stellate form of a trans- verse section of the lumen of the stomach is due to the fact that the cells which form the longitudinal ridges of its wall are knobbed at their free ends and greatly elongated, while the intermediate cells have sharper tips and are comparatively short. It will be observed that there is no formation of true folds, but it is of greater interest to note that the cells and the ridges are histologically and physiologically different from those which are found in the intermediate grooves. The former have generally one or two thin transverse walls which appear to be formed by hardened secreted surfaces ; the grey finely granular contents at the knobbed end are much darker than those of the rest of the cell, and often, indeed, the upper cell-boundary is quite broken through by the finely granular secretion which passes freely into the stomach. The secretion of the ridge-cells does not stain, while those of the groove-cells always take a dark colour throughout their whole extent; that of the former is a slimy mass which envelopes the particles of the food and connects them with one another. The rectum is sharply distinguished from the stomach ; the contour of its lumen is round, and its lining cells low and broad. The mechanism of digestion has been observed in living specimens ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 29 by the aid of the horizontal Microscope. Diatoms and desmids are caught by the currents set up by the cilia of the tentacular crown, and passed into the foregut, at the base of which they lie until a quantity of them have been collected. By a wave-like constriction of the foregut they are then passed through the circular valve into the stomach. By the peristaltic action of the stomach the food is driven backwards and forwards; the food is next impregnated with the enteric secretions, and then begins to be absorbed. A fresh quantity of food again enters from the cesophagus, and the indigestible portions of the first mass are driven into the rectum. With regard to the reproductive apparatus, the author is confident that the funiculus is formed solely by the mesoderm. Little can be added to Nitsche’s account of the nervous system ; osmic acid preparations showed that the cells composing the ganglion have rather large nuclei, and especially those that are central. The ganglion is invested by a thin mesodermal layer, by means of which it is attached to the upper part of the pharynx; as there is no meso- dermal layer between the pharynx and ganglion, the latter appears to be constricted off from the pharyngeal wall. With regard to a colonial nervous system, the author remarks that it may be thought that if ever it be present in a fresh-water Bryozoon it must be found in Cristatella, but he has convinced himself that the creeping movements are effected in a way which makes such a system superfluous. They are the resultants of the pressures exerted by the separate animals on the pedal disc, and their direction is caused by the direction of the separate animals. Herr Verworn has investigated the development of the statoblasts, and finds that at a definite point of the funiculus the epithelial cells increase, and form a small swelling, which presses on the lumen; one cell now passes into the lumen and becomes an egg-cell, while the others form a follicle; the egg goes through a regular process of cleavage, the final result of which is a solid morula; it is clear from this that the statoblasts have not the nature of buds, and it may be said that the statoblasts are parthenogenetic winter ova which, unlike the fertilized ova, are developed on the funiculus. Arthropoda. Primitive Insects.*—Prof. B. Grassi continues his researches on the ancestors of Myriopods and Insects. He calls attention at the outset to an overlooked memoir by Meinert, which describes the genital organs of Machilis, Grassi’s present memoir begins with a classification of Thysanura, which includes the four families Campodeade, Japygide, Machilide, Lepismide. The latter comprise three genera, Nicoletia, Lepismina, Lepisma. The characters of the family and of the three genera are given in detail. He then proceeds to give a useful summary statement of the characteristics of the species. The next chapter is devoted to an account of the anatomy of Lepisma and Lepismina, which he compares with his previous results, gained from the investigation of Machilis and other forms. Prof. Grassi next discusses the musculature of Thysanura, seeking to discover whether the Thysanura once had wings or not, and whether there are any traces of the previous existence of abdominal appendages. He finds in the musculature no evidence whatever to warrant the first of * Bull. Soc. Entomol. Ital., xix. (1887) pp. 52-74. 30 SUMMARY OF CURRENT RESEARCHES RELATING TO these suppositions. In the musculature of the pseudo-appendages some traces of the musculature of lost true abdominal appendages may probably be detected. It is not possible to make any direct comparison between the musculature of Thysanura and that of Annelids or of Peripatus. a. Insecta. Love-lights of Luciola.*—Prof. C. Emery has given a most enter- taining account of his observations on the love-lights of Luciola, which he studies in the meadows round Bologna. By catching females and imprisoning them in glass tubes in the meadows he satisfied himself that sight, not smell, was all important. When the females caught sight of the flashes of an approaching male then they allowed their splendour to shine. The dance of the male round the female, the gathering crowd of rivals, the insatiable desires of the female attracting one lover after another, the accomplishment of fertilization, are all most beautifully and graphically described. In the two sexes the colour of the light is identical; the intensity appears much the same, but that of the female is more restricted. The most noteworthy difference lies in the fact that the rhythm of the male is more rapid and the flashes briefer, while that of the female is longer, more distant, and more tremulous. Besides undoubtedly serving for purposes of attraction, the light appears to be utilized for illuminating the path, especially if there be obstacles in the way. Mimicry and Parasitism of Camponotus lateralis.} — Prof. C. Emery has made some observations on the mode of life of one of the more common ants of the Mediterranean fauna—Camponotus lateralis. Two forms occur in Italy, one red, the other quite black (C. foveolatus Mayr, ebeninus Em.) The black variety, with only the prothorax red (0. dalmaticus Nyl.), is very rare, and seems to be represented only by isolated forms. The red and black worker ants of C. lateralis are so like Cremastogaster that an inexpert eye would not distinguish them. The two forms seem to live on friendly terms. In the same way the black variety is related to other black ants, such as Formica gagates. Prof. Emery was inclined to suppose that C. lateralis might utilize its colour-likeness to other ants by associating itself with them so as to have the benefit of their guidance to food-supphes. But he thinks that the imperfect vision of ants makes such a supposition improbable. He is of opinion that the red and black form of C. lateralis finds an advan- tage in being like its companion Cremastogaster for the usual reason, that it thereby escapes from some enemy which mistakes it for Cremas- togaster, whose taste the myrmecophagous enemy is supposed to dislike. More observations are obviously necessary. In regard to the habit of C. lateralis, Prof. Emery records an interesting case where he found a society living parasitically on a bee- hive. They appeared to him to feed on spoils of honey from the combs. Sand-wasps.t—Herr A. Handlirsch publishes a monograph on the forms of Sphegide related to Nysson and Bembex. The memoir is of purely systematic interest. It includes a bibliography of 15 pages, and is accompanied by 5 plates. Sixty-four species of Nysson, a few of them new, are described. * Bull. Soc. Entomol. Ital., xviii. (1887) pp. 406-11. + Ibid. (1886-7) pp. 412-3. t+ SB. Akad. Wiss. Wien, xev. (1887) pp. 246-420 (5 pls.). ZOOLOGY AND BOTANY, MICROSCOPY, ETO. 31 Thermic Experiments on Periplaneta orientalis.*-—Prof. V. Graber describes a long series of experiments conducted with a view to deter- mining the sensibility of the cockroach to heat. A tin chamber whose ends were kept at different temperatures by water-baths was the appa- ratus, and the results obtained are briefly as follows:—The animals lost power of locomotion at 11-12° C., and death resulted at 5-6° C. (vital minimum). Life, again, was barely sustained with the air at 37° and the floor of the chamber at 39°, a temperature of 41-42° producing death. Other experiments proved the creatures to have a decided liking for situations where the floor temperature nearly resembled the air temperature, and a bad conductor of heat was much preferred as a resting-place to a good one. The optimum temperature seemed to be between 25° and 29° C., though some experiments contradicted this ; and a series of observations in which the animals were allowed a choice between extreme temperatures seemed to show only that they preferred _ heat to cold, unless the heat was too excessive. Diminution in Weight of Chrysalis.;—Herr F. Urech has studied the quantitative relations of metabolism in the chrysalis of Pontia brassicee. He finds that the weight of the chrysalis continually decreases. At a constant temperature, the weight steadily decreases, but the decrease becomes finally more rapid, especially some days before libera- tion. If the temperature be slightly raised the period of chrysalis diminishes. Dry air also shortens it. Eyes of Diptera.t{—Professor G. V. Ciaccio has published a series of twelve double plates illustrating the histology of the eyes of Diptera. This iconographic work includes one hundred and seventy-three figures, each family is figured by itself, with a representation first of the entire organ, and then of the component parts. It is to be regretted that the health and engagements of the author did not permit of the addition of a descriptive text. Full explanations, however, accompany each plate. Bacteria-like Bodies in Tissues and Ova. §—Herr J. Blochmann has studied the occurrence of bacteria-like bodies in the tissues and eggs of various insects, e.g. in Periplaneta orientalis and Blatta germanica. In the central cells of the fatty body, in the ova, and in the embryos these curious elements were abundantly found. They occur in other animals besides insects, and closely resemble the bacteroids noted in the roots of Leguminose. Leuckart observed similar bodies, which he was inclined to regard as parasitic, under the cuticle of Distomum cercarizx. Schneider observed similar structures in Mesostomum. F. E. Schulze suggested that similar structures in Pelomyxa were symbiotic Bacteria, or perhaps reserve accumulations. Korschelt noted the appearance of small strongly refractive granules in the yolk-grains of bug ova. Zacharias and Van Beneden have observed similar elements in the ova of Ascaris megalocephala. They grow and divide, and are to be regarded as primitive granules. Altmann has also described their physio-chemical import. * Arch. f. d. Gesammt. Physiol. (Pfliiger), xli. (1887) pp. 240-56. + Arch. Sci. Phys. ct Nat., xviii. (1887) pp. 433-6. t~ Mem. Acad. Sci. Bologna, vi. (1885) pp. 45-72 (12 pls.). § Biol. Centralbl., vii. (1887) pp. 606-8. Versamml. Deutsch. Naturf. u. Aerzte, Wiesbaden, 1887. 32 SUMMARY OF CURRENT RESEARCHES RELATING TO Fauna of the Tombs.*—M. P. Mégnin has shown that the popular notions that corpses formed the food of worms, and the less vulgar one that they crumbled to dust under chemical and physical agencies, are both erroneous. He has studied the fauna of the tombs, having had opportunity for this gruesome task in connection with sanitary inquiry. Corpses are devoured by insects which attack them at various and definite periods of decomposition, so definite indeed that from the insects on the corpse the date of burial could be proved to a medico- legal investigation. Some of the insects were larval, others chrysalids, others adult. The list is as follows :—Four species of Diptera: Calliphora vomitoria, Curtonevra stabulans, Phoras aterrima, and an undetermined Anthomyia ; one species of Coleoptera, Rhizophagus parallelocollis ; two Thysanura, Achorutes armatus and Templetonia nitida ; and lastly a young undeter- mined Julus. These occur in definite succession on the body. How do these insects get down to a depth of two metres, and through well-jointed boards? Dampness and pressure cause the latter to give way, and paths of penetration are readily formed. The larve of Calliphora and Curtonevra were found only on bodies which had been buried in summer, and must have been deposited on the dead before inhumation. The larve of Phoras and Rhizophagus must be supposed to penetrate the whole stratum of earth. Phoras is specially found on thin bodies, Rhizophagus on the reverse. Rhizophagus parallelocollis is a rare insect, its larva has not before been known. No wonder. “Besides revealing these facts extremely interesting from a biological point of view, this research had contributed some entomological material of use in legal medicine.” 8. Myriopoda. Powers of Vision.{—M. F. Plateau contributes an historical summary of past researches on the structure and function of simple eyes, and gives an account of his observations as to the vision of Myriopods. A very simple and lucid account is given of the general structure of asimple eye. This is accompanied by a few diagrammatic figures. The second portion of the memoir is devoted to a summary of the various opinions held in regard to the function of simple eyes, and especially of those of Dujardin, Exner, Grenacher, and Patten. The author then gives a detailed account of his experiments on numerous Myriopods, and summarizes his results. (1) Myriopods distinguish light from darkness; (2) as this power is exhibited by normally blind forms, the perception of light in forms with eyes may be partially due to dermatoptic sensations; (8) Myriopods see very badly, and supplement their insufficient sight by touch, which is princi- pally localized in the antenne; (4) species with eyes are not much better situated than those which are blind; (5) forms with eyes perceive at a distance an object placed in their path only when it reflects much white light, or light belonging to the most refrangible region of the spectrum; this perception is probably in part dermatoptic; (6) Myrio- pods do not distinguish the forms of objects ; (7) but some of them can * Comptes Rendus, ev. (1887) pp. 948-51. + Bull. Acad. R. Sci. Belg., xiv. (1887) pp. 407~48 (1 pl.). ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 33 perceive big movements. Theoretical conclusions must be carefully corrected by experiment. The imperfection of visual sensation in some, and the total absence of eyes in others, must be considered in association with their mode of life. y. Prototracheata. Development of Peripatus Nove-Zealandie.*—Miss L. Sheldon commences by explaining that the want of completeness in her account of the development of the New Zealand species of Peripatus is due to the necessity of killing the gravid parents as soon as they reach England. The ripe ovum of this species is large as compared with that of P. capensis or P. edwardsii, the length of 1:5 mm. being due to the amount of food-yolk with which the egg is charged. There is a thick tough shell, and a thin and membranous vitelline membrane. The nucleus of the egg before segmentation varies somewhat in position ; it may have a ‘peculiar lobed form, and consist of three masses of deeply staining material, between which is a portion of nuclear substance which stains less deeply. The segmentation is like that of some other Arthropods, and agrees with the mode lately described by Henking in certain Phalangide in the irregular arrangement, in young stages, of the nuclei of the blastoderm; but Miss Sheldon does not consider each yolk-seg- ment as a single cell, for she found no relation between the yolk and the nuclei. What differences obtained between eggs of the New Zealand and Cape species are probably due to the presence of yolk in the former; in neither are there any cell-outlines, the protoplasm of both forming a perfectly continuous reticulum in which the nuclei are imbedded. As to the mode of development it might be said that the embryo is “formed by a process of crystallizing out in situ from a mass of yolk, among which is a protoplasmic reticulum containing nuclei.” The embryo obtains its nutrition from the yolk contained within its body, and from a peripheral layer of yolk in which are imbedded numerous small, round, highly refractive bodies. This latter is a very remarkable and unusual mode of embryonic nutrition, but its object is evidently to supply the ectoderm with a constant source of nourishment. A somewhat comparable arrangement has been described by Ganin in Platygaster, and a somewhat similar result is brought about, though by different means, in those insects which undergo an internal development, and in which the embryo is completely imbedded in the yolk ; the pro- cess in P, Nove-Zealandiz is simpler, for nothing corresponding to the amnion is present. It is, at any rate, clear that there are in Arthropods various modes for the protection of the embryo and the nutrition of the ectoderm, and that, though these differ very largely in their mode of origin and structure, they resemble one another in their physiological functions. The segmentation is on the centro-lecithal type; the protoplasm is mainly at one pole of the egg, and in it nuclei arise, probably by the division of the original segmentation nucleus. In the latest stage observed the loose protoplasmic reticulum covered above half the periphery of the egg. In the course of development the protoplasmic area becomes more compact and flattens out, forming a plate-like mass densely packed with nuclei; at this time the embryo is a closed sac, the * Quart. Journ, Mier. Sci., xxviii. (1887) pp. 205-38 (4 pls.). 1888. D 34 SUMMARY OF CURRENT RESEARCHES RELATING TO walls of which are separated from the vitelline membrane by a thick layer of yolk; it is inclosed in a thin layer of protoplasm with nuclei which represents the ectoderm. Along one live there is a prominent ridge on the outer side of the ectoderm, composed of proliferating nuclei ; anteriorly this ridge divides into two, which remain attaehed to one another above and below, and so inclose a cavity between them. The preoral lobes next appear; not far from the anterior end of the embryo the yolk is divided by a protoplasmic septum, which divides the body of the embryo into two sacs, one lying above the other ; posteriorly these two sacs communicate. By the ingrowth of the surrounding tissue the septum becomes divided into two layers, and the embryo now con- sists of a sac doubled on itself in such a way that the ventral face of the anterior part of the body is opposed to that of the posterior part. The embryo next begins to straighten itself out; in the anterior region the somites are represented by a series of definite cavities at the side of the body, and, later on, they appear throughout the whole length of the embryo. When the peripheral food-material has been completely absorbed the embryo lies just within the vitelline membrane and egg- shell. Along a lateral ridge the appendages begin to appear as blunt rounded protuberances ; the antenne arise as buds on the przoral lobes. The nerve-cords first arise as special rounded elements at the internal ventral angles of thickenings of the ectoderm over the leg-ridges. 6. Arachnida. Acarida on Trees.*—Herr C. W. S. Aurivillius was prompted by the researches of Dr. Lundstrém on “domatia” (see infra, p. 87) to in- vestigate the nature and behaviour of some of the Acarid guests which abound on the leaves of trees. He describes in detail the structure and mode of life of three forms—Tydeus foliorum, Gamasus vepallidus, and a third, found as nymph and larva, and apparently an Oribatid, very like Cepheus tegeocranus. All the three were found on leaves of Tilia. From observation, and from a study of their mouth-parts, the author was con- vinced that these guests could not derive their food from sucking wounds which they might not unnaturally be supposed to make on the leaves, nor did Tydeus appear to attack the Aphides. They more probably live on small solid particles, not due to their own exertions, but such for instance as fungoid spores. e. Crustacea. Development of the Compound Eye of Crangon.j—Dr. J. S. Kingsley, who has already published a preliminary notice on this sub- ject,f now gives full details as to his observations on the development of the compound eye of Crangon. The compound eyes begin to make their appearance soon after the closure of the blastopore: there is a shallow pit, which rapidly grows deeper, and, extending outwards, downwards, and forwards, soon comes to occupy a position beneath the anterior and outer part of the optic disc before any striking changes are visible in the external appearance of the embryo. The separation of the pit from the epiblast is completed at about the time of budding of the first pair of appendages, and the * Nova Acta Soe. Sci. Upsala, xiii. (1887) pp. 1-16. t Journ. of Morphology, i. (1887) pp. 49-64 (1 pl.). t See this Journal, 1887, p. 84. ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 35 appearance of the stomodeum. There are now three layers, all of which are concerned in the development of the optic apparatus; the outermost is the epiblast, and the two others are derived from the invaginated portion of the same layer. The innermost may be called the gangliogen, as it will give rise to the chain of ganglia and nerves which lies within the stalk of the adult eye, and connects the optic apparatus with the brain. The middle layer—which may be called the retinogen—will give rise to all the retinal parts of the eye. Some complex changes in the appearance of the cells are brought about by the mode of division of their nuclei; after a time it will be found that the ectodermal nuclei has come to correspond with those of the underlying layer, and that the nuclei of the retinogen and gangliogen have each given rise to five nuclei arranged in a row, while the rows are arranged in sets. In section two will be seen closely appressed to each other, and separated from the adjacent parts by a rod of apparently structureless material; this last is the rudiment of the crystalline cone, and the adjacent rows of nuclei belong to different ommatidia, or optic elements. In the ganglionic layer the rows of nuclei have broken, and formed the rudiments of two ganglia. In a later stage the epidermis-cells will be seen to be distinct from those of the retinogen and to have become the cuticle, which is modified into lenses over each crystalline cone. Development and differentiation have gone on in the rows of retinal nuclei, each of the cells having become greatly elongated, the protoplasm extending out toa considerable distance from the nucleus in a thread-like prolongation; the nuclei are placed at different heights in those cells, and the tail-like prolongations are arranged in layers around the crystalline cone; the distal cell of the retinal row is clearly the crystalline cone-cell or retinophora. Four of these surround the cone, and their wails so touch that they form a cup in which the cone is situated, and from which it is secreted. Below the calyx the ends of the retinophoral cells unite to form a slender pedicle, which is clearly the rhabdom of Grenacher, and which is, as clearly, formed by the retinophore, and is not a secretion from the surrounding pigment-cells, As to the phylogeny of the Arthropod eye, we may suppose that the invagirated pit had sensory functions, and either wall must, for a time, have been like its fellow, as is shown by its having similar nuclei, and by the similar development of rows of nuclei. The position of the eye at the extreme ends of the nervous cords would indicate that it was differentiated as part of the primitive nervous system; but it is not yet to be said that the invagination was confined to the eye alone, and did not extend through the whole length of the cords; on this question the fact that the supra-cesophageal commissure developes much later than the optic cords may be of significance. ‘Challenger’ Cumacea.*—Prof. G. O. Sars commences his account of the Cumacea collected by H.MS. ‘Challenger,’ by considering their morphology. He cannot agree with Boas in regarding them as very nearly related to the Mysidz, but thinks they represent an isolated branch, which cannot strictly be derived from any of the recent groups; it is possible that some of the paleozoic Phyllocarids formed a direct trans- ition to the Cumacean type. * Reports of the Voyage of H.MLS. ‘ Challenger,’ ly. (1887) 78 pp., 11 pls. D 2 30 SUMMARY OF CURRENT RESEARCHES RELATING TO Short diagnoses of the families are given, and the several genera eontained in each enumerated, so that the work becomes a handbook to the group; thirteen new species, and one new genus—Paralamprops— are described. ‘Challenger’ Phyllocarida.*—Prof. G. O. Sars has a report on the interesting forms allied to Nebalia, the zoologieal position of which has been so much discussed. For the group we must adopt Packard’s name of Phyllocarida, as it has some slight priority over Claus’s term of Leptostraca, Prof. Sars is inclined to agree with Dr. Packard in believing that the Nebaliide may have descended from some Copepod-like ancestors, whereas they do not show any relation whatever to the Podophthalmata, which probably developed independently by a separate line from some Nauplius- or Zoéa-like form. Prof. Sars thinks that the other Branchio- pods may be derived from the same line as the Nebaliide, the former having apparently become rather considerably modified in various ways to adapt themselves to the somewhat exceptional conditions under which they live, whereas the Nebaliidz have still preserved much of the ex- ternal appearance which may have distinguished the progenitors of the order, while their internal organization has become much more modified. A new genus—Nebaliopsis—is instituted for forms in which the branchial legs are imperfectly developed, the exopodites and endopodites being only slightly indicated as small triangular lobes, while the epipodite is well detined. Structure of Cyprinide.j—Dr. A. Garbini has investigated the anatomy and histology of Cypridina mediterranea. (1) Antennules.—The eight little cupping-glass structures (“ventose ”) situated on the branches of the antennules are described. They serve the male as external sexual organs for grasping the female. Quite distinct from these are the two large stalked discoid expansions at the base of the antennules, which appear to be olfactory or tactile organs. (2) Alimentary System. (a) The buccal portion.—(1) The upper lip bears a variable number of glandules, with granular content, opening on the inferior free margin, and functional during eating. There are two others on the upper portion of the labrum, differently disposed, two in number, and apparently comparable to salivary glands. (2) Csophagus. The walls exhibit four layers, (1) chitinous, (2) epithelial, (3) longi- tudinal muscles, (4) circular muscles. An epithelial circular partition lies at the union of fore- and mid-gut. Special muscles serve to elongate the cesophagus. (b) The mid-gut. Its walls consist of three tunics, (a) epithelial, (b) muscular, (c) pigmented. The first is most important. No hepatic ceca were to be seen. The cells of the internal tunic discharge digestive functions. The passage from mid- to hind-gut is guarded by a kind of sphincter. (c) The hind-gut. There are again three layers, (a) epithelial, (b) longitudinal muscles, (c) circular muscles. The histology of the different regions is noted. (3) Central Nervous System—The cerebral ganglion is very well developed. The peripheral nerve-cells are all of moderate size. Four divisions may be distinguished. These spaces contain a granular substance. The connection between the latter and the ganglionic cells * Report of the Voyage of H.M.S. ‘ Challenger,’ lvi. (1887) 32 pp. and 3 pls. + Bull. Entomol. Soc. Ital,, xix. (1887) pp. 35-47 (5 pls.). EOOLOGY AND BOTANY, MICROSCOPY, ETC. oe was not determined. His description of the rest of the nervous system does not reveal any fact of special importance. (4) Sense-organs—The median eye and the frontal organ are strictly inseparable structures. The structure and movements of the former are briefly described. The structure and nervous relations of the latter clearly point to a sensery function. Its connection with the eye is described. (5) Reproductive Organs. (a) The Male.—The testes are spherical and lateral in position, slightly in front of the rectum. The epithelial ceils giving origin to spermatozoa, and the rigid form of the latter are described. The vasa deferentia with delicate elastic walls, with an anterior epithelium like that of the testes, with a posterior epithelium near their union, apparently glandular, are then described. They unite to form the penis, which has a funnel-like form, and a strong sheath of circular muscles. The “urethra” has a superior section like an X, but further down becomes triangular. A small sac-like reservoir is formed superiorly, and lined with cylindrical epithelium. The walls of the penis are in part glandular. A pair of thoracic appendages are intimately associated with the penis, which opens at their free extremity. They end in two chelate structures, which have an accessory glandular apparatus, and are intimately described. (6) The Female—The internal arrangements have been already described by Claus. The external sexual appendages end in two large ovoid glands, which contain small refractive spheres, mixed with numerous needle-like crystals. Bichloride of mercury in aqueous solu- tion, in which the organisms were left for 5-7 minutes, followed by 75 per cent. alcohol, and Mayer’s fluid (Kleinenberg’s plus nitric acid) yielded the best results. Vermes. a, Annelida. Germ-layers of Clepsine.*— Prof. C. O. Whitman deals very thoroughly with the history of the germ-layers in Clepsine and its allies. He commences with an account of the process of cleavage, in which bilateral symmetry early becomes established. In dealing with the history of the mesenteron he points out that the earlier endoderm cells arise beneath the cephalic lobe, and are probably budded off from the endoblasts as distinct cells; to these, others are soon added, which first arise as endoplasts, so that no line of distinction based on the mode of origin can be drawn. The larger portion of the mesenteron, or all but a small cesophageal portion, passes through several stages of development ; the first is represented by three large macromeres or endoblasts, the second by endoplasts (each a nucleated mass of protoplasm without cell- boundary); the third by an exceedingly thin layer of flattened epithelium, and the fourth by a columnar epithelium. Fresh arguments and evidence are brought to prove that the entire ventral nerve-chain arises as two simple longitudinal rows of cells, and that each row is produced by the continued proliferation of a single cell —the neuroblast. Connected with the neural cell-row is another which the author calls the nephric, and evidence is afforded that the nephridia are derived from the ectoderm, that they make their earliest appearance * Journ. of Morphology, i. (1887) pp. 105-82 (3 pls.). 38 SUMMARY OF CURRENT RESEARCHES RELATING TO in the form of simple, longitudinal cell-strings, and that each nephridial cell-string is a product of a single terminal cell—the nephroblast. It is suggested as an explanation of the divergent accounts which have been given as to the origin of the nephridia that both mesoblasts and nephroblasts arose primarily from a common ectodermic basis; the genetic relations of the two cells have remained essentially the same, but the time of their differentiation as distinct cells varies. If the division takes place within the ectoderm, then each makes its exit from the original seat separately and independently of the other; if, on the other hand, division is delayed until after the separation from the ectoderm is accomplished, then the nephroblast appears to arise from the same source as the mesoblastic bands, and thus to form a part of them. There is a special note on the significance of the teloblasts or blasto- meres derived from the posterior macromere of the dividing ovum; they are one of the most remarkable features of annelid development, and represent specialized centres of proliferation, with most marvellous powers of assimilation and reproduction. The author regards them as constituting the trunk-bud, and as thus being the primary seat of all the truly metameric elements of the animal. Primarily they represented the basis of non-metameric organs, in which the regenerative power was, or became, pre-eminent. He refuses to recognize the tenability of the theories which regard the somites of segmented animals as derivatives of gut-pouches, and declares that metamerism does not first exhibit itself either in the archenteron or the mesenteron. Salivary Glands of Leech.*—Sig. D. Bertelli has investigated the structure of the salivary glands in Hirudo medicinalis. These glands are situated at the so-called roots of the jaws. They are unicellular, nucleated, pyriform, and very numerous. Tach has an efferent duct, and contains a granular substance which is also observed to occur in the ducts. These proceed upwards, penetrate the jaw beside the elements forming the root, and open on the free margin. By setting the animal to work, and then rapidly examining the jaws in a 1/2 per cent. salt solution, the author was able to observe the granular substance flowing from the free margin. Germ-bands of Lumbricus.}—Prof. E. B. Wilson has a preliminary notice of his study of the development of Lumbricus olidus (= L. fotidus). As in the species examined by Kowalevsky and Kleinenberg, the germ- bands end behind in a pair of large “mesoblasts” at the expense of which the bands increase in length throughout the whole course of development. As development proceeds six other large cells are added, and these eight may, in the language of Whitman, be spoken of as telo- blasts. Each of the eight gives rise to a row of cells, at first single, which extends forwards between the ectoblast and endoblast; the rows proceeding from the “mesoblasts” soon widen into a pair of broad plates which ultimately give rise to the septa, muscles, vessels, and possibly setigerous glands. The six remaining rows are intimately related to the mesoblast. ‘The two inner rows give rise to the halves of the nerve-cord, and their large cells are, therefore, neuroblasts precisely as in Clepsine ; the adjoining rows will give rise to the nephridia, and * Proc. Verb. Soc. Toscana Sci. Nat., v. (1887) pp. 284-5. + Journ. of Morphology, i. (1887) pp. 183-92 (1 pl.). ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 39 are therefore nephroblasts; the ultimate fate of the remaining pair of rows has not yet been made out. The neuroblasts fit closely into the ectoblast, and in some cases unquestionably extend to the outer surface. The ventral nerve-cord is formed by the gradual concrescence of the neural rows in the median line; there is no invagination from the exterior, and the continuity of the ectoblast across the median line is never broken. Unless there is a great difference between L. rubellus and LZ. olidus, Dr. Hatschek must have mistaken the narrow angular interval between the converging halves of the cord as evidence of invagination. The nephridia and their nephroblasts have a very similar history to the nerve-cord and neuroblasts; the nephridia arise as paired metameric outgrowths from the nephridial rows, and there is in each somite a single pair. The meseblastic bands arise as single rows of cells at the latero- _ posterior angle of the mesoblasts, curve round their outer sides so as nearly to meet in the middle line, then bend rather abruptly outwards and run forwards; they soon become broad bands that pass between the endoblast and the remaining six cell-rows. They give rise to all the muscles and vessels of the body, as well as to the ciliated funnels and outer investments of the nephridia. Not only the neuroblasts, but also the nephroblasts and “ lateral teloblasts” appear to be modified ecto- blastic cells. Prof. Wilson cannot doubt but that the nephroblasts are derivates of the outer germ-layer, and thinks, consequently, that the likeness between the development of the nephridial row and that of the segmental duct of vertebrates (as recently described by Spee and others) is very significant, for in the rabbit, the guinea-pig, and Raja, the segmental duct has been found to arise as a solid cord of cells that is split off from the outer layer, and grows at its hinder end by the proliferation of a limited area of the ectoblast. The conclusion is arrived at that the “nephridial row” of Lumbricus must be regarded as homologous with the segmental duct, and the series of nephridia as homologous with the vertebrate pronephros. The likeness between the germ-bands of Lumbricus and Clepsine seems to indicate a very close relationship between the Oligochzta and the Hirudinea ; the development of the six anterior teloblasts in Lumbricus may be explained as due to the greater and greater concentration of developments at the posterior ends of the germ-bands ; they are at first ordinary ectoblast cells which afterwards sink below the surface. In Clepsine they are covered by the ectoblast at a very early stage owing to acceleration of development. - Photodrilus phosphoreus, Type of a New Genus of Phosphorescent Lumbricids.*—M. A. Giard establishes a new genus for the Lumbricus phosphoreus of Dugés. It was observed by him at Wimereux, and the light was seen in points of a fine opalescent green. The luminous points were of unequal size, the largest giving a light as bright as those of the Lampyride, and being visible even in a well-lit room, If one of the points was rubbed between the hands, the two palmar surfaces were for a short time luminous, and near each point a small earthworm was found. Photodrilus phosphoreus is 45 to 50 mm. long and about 1:5 mm. wide; it has about 110 segments; the skin is very transparent and * Comptes Rendus, ey. (1887) pp. 872-4. 40 SUMMARY OF CURRENT RESEARCHES RELATING TO richly vascular; the sete are not bigeminate but separated as in Pontodrilus. There is no distinct buccal segment, and only one pair of copulatory pouches. The clitellum extends from the thirteenth to the seventeenth ring, the female orifices are on the fourteenth, and the male on the eighteenth. The digestive tract has a protrusible proboscis, and as it comes and goes one may see on the lower surface of the buccal segment a tuft of long clear filaments which are very delicate, and are sometimes transversely striated. It is possible that they are the homologues of the cylindrical rods described by Prof. Perrier in the interior of Pontodrilus, or they may be broken muscular fibres. The gizzard is replaced by four swellings; the cesophagus is invested dorsally and laterally by large glands which decrease in size from before backwards; these are regarded as being homologous with the septal glands described by Dr. Vejdovsky in the Enchytreide. Notwithstanding their position, these are not enteric glands, and they open on the dorsal surface; the author thinks that the photogenic property of Photodrilus is due to the secretion of these glands. The circulatory apparatus differs little from that of Pontodrilus; there are two pairs of testes, and one pair of ovaries. As Dugés’ worm was found in hot-beds in the Jardin des Plantes at Montpellier, and the Wimereux specimens in a cultivated garden to which earth had been brought by a horticulturist, it is probable that the species is not French but exotic, Enchytreide.*—Dr. W. Michaelsen has made a_ preliminary systematic study of the interesting family of Enchytreide. His system is as follows :— Setae S-shaped. Head-pore large, at or near point of head-lobe. No salivary glands. Colourless blood. Dorsal vessel with heart. Vas deferens short; at most, eight times longer than the seminal funnel. Mesenchytrzus Hisen. Head-pore small between head-ring and lobe. Long vas deferens. No salivary glands. Blood yellow to red. Dorsal vessel without heart. Pachydrilus Claparéde. Short salivary glands opening into cesophagus. Blood colourless. Dorsal vessel rises from a diverticulum in VII. segment. Buchholzia Michaelsen. Sete straight, with only a slight internal curvature. Head-pore small between head-ring and head-lobe. Blood colour- less. Dorsal vessel without heart. Salivary glands usually well developed. Vas deferens long. Enchytreus Henle. Setze aborted. Head-pore large at apex of head-lobe. Blood colourless. Dorsal vessel with heart. An unpaired salivary gland on the intestine. Vas deferens long, more or less regularly spiral. Seminal sac large, intruding freely into the body-cavity, not coalescent with the gut. Anachexta Vejdovsky. Parasite of Telphusa.t—Signor W. Drago has described a parasite which Prof. B. Grassi found some time ago on the gills of Telphusa fluviatilis in considerable abundance. It was at first suspected to bea Branchiobdella, but was soon recognized as an oligochete. It is in fact * Arch. f. Mikr. Anat., xxx. (1887) pp. 366-78 (1 pl.). + Bull. Soc. Entomol. Ital., xix. (1887) pp. 81-3. ZOOLOGY AND BOTANY, MICROSCOPY, ETO. 41 a new genus and species of Enchytreide, and from its host and habitat (Catania) has been called Epitelphusa catanensis. Signor Drago describes the main features in the structure of this worm which attained a maximum size of 15 mm. If it is to be admitted among the Enchytreidew, some of Vejdovsky’s characters of the group must be somewhat modified, especially as regards the pair of protractile gustatory lobes, the hard and resisting integument, the presence of a pair of salivary glands, the nature of the lateral vessels and of the clitellum. The genus Epitelphusa may be distinguished from Pachydrilus, Enchy- treus and Anacheta by the following characters. ‘lhe epidermis without cuticle. The sete straight and short. The blood coloured. The dorsal vessel with four lateral vessels. The absence of the so-called gustatory lobes. The septal organs between IV. and V., V. and VL., VI. and VII., segments. The receptacula seminis open between segments TV. and V. The clitellum extends from XI. to the anterior portion of XII. The testes in “ bouquet” form as in Pachydrilus. Anatomy of Polycheta.*—Mr. J. T. Cunningham takes occasion to point out the general inaccuracy of Cosmovici’s essay on the “ Glandes génitale et organes segmentaires des Annélides Polychétes ” published in 1880. His account of the nephridia and gonads is, however, very correct, but he separates in “an absurd manner” the nephrostomata from the nephridia ; a few corrections are made in his observations. In Cirratulus cirratus both the large anterior pair of nephridia described by Keferstein and Claparéde, and the series of pairs in the middle and posterior region mentioned by Cosmovici are present; the simple nephridia act as efferent ducts for the reproductive elements ; the position of the gonads of this species is still doubtful. Nerine cirratulus, which has not hitherto been recorded as British, is common between tide-marks at Granton ; in it the relations of the nephridia are in some small points exceptional ; the nephridial aperture is extremely dorsal in position, and the efferent duct is long; in it and N. coniocephala the nephridia serve as the ducts for the gonads. Cosmovici’s account of the nephridia of Lanice conchilega is erroneous ; we have already } noticed Mr. Cunningham’s discovery of the remarkable coalescence of nephridia seen in this species. The identity of Pectinaria belgica and Amphitrite auricoma, urged by Mr. Harvey Gibson, is disputed; P. belgica has three pairs of nephridia, of which the first are the largest; all the organs are of the usual type, but a peculiar glandular organ, of unknown function, lies between the nephridial opening and the root of the branchia. The gonads are, as usual, masses of undifferentiated cells. In Nereis virens the generative products appear to escape by dehiscence. The curious organ called the “cardiac body ” has been examined in some Chloremide, Terebellide, and Cirratulide. Mr. Cunningham has examined the neural canals of various Poly- cheta, and comes to the conclusion that they are supporting struc- tures which serve to prevent the nerve-cords being bent at a sharp angle, and so being injured during the wriggling and burrowing of the worm ; it is noticeable that the canals always reach their highest develop- ment in worms which are extremely long in proportion to their thickness ; their maximum development is seen where the nerve-cord is not separated * Quart. Journ, Micr. Sci., xxviii. (1887) pp. 239-78 (3 pls.). + See this Journal, 1887, p. 591. 42 SUMMARY OF CURRENT RESEARCHES RELATING TO from the epidermis, or, in other words, where it is more exposed to the danger of being injured than when more internal in position. Annelid Genus Spinther.*—Prof. L. v. Graff gives an account of the polychxtous genus Spinther. After an historical introduction and some general remarks the author gives a full definition of the genus; the body is elliptical, all the segments except the cephalic and anal have, in addition to a pair of short marginal parapodia, paired dorsal dermal folds, which arise above the parapodia and extend as far as the middle line of the strongly curved back. Both the lamelle and the parapodia radiate from the foci of the ellipse. At the base of the dorsal tentacle are four small eyes covered by integument. The upper free surface of the dorsal lamelle is supported by chitinous spines which are ordinarily arranged in two rows, but the tips only of these spines project. The two ventral nerve-cords are widely separated, and have but feeble segmental swellings. The pharynx is tongue-like, muscular, and pro- trusible, with a ventral groove; there is no maxillary apparatus ; the mideut has paired diverticula, and the hindgut gives off a forwardly directed dorsal caecum. There are no special gills or segmental organs, and the sexes are separate. The worms live on marine sponges to which they attach themselves by their sete. Definitions of the species follow; of these there are three—Spinther oniscoides, S. miniaceus, and S. arcticus. The second of these is the most widely distributed, and its varieties show relationship sometimes to S. oniscoides, and sometimes to S. arcticus. S. miniaceus must be regarded as the primitive species. Full anatomical details are given. The peculiar elliptical form of the body of Spinther (and Euphrosyne), with the radial arrangement of the segments anteriorly and posteriorly, as well as the gradual shortening of the segments and their appendages towards the anal end of the body, are certainly not primary structures ; here, asin the very similar Myzostomida, the radial configuration of the body must be regarded as the consequence of an adaptation to the parasitic fixed mode of life. In both groups the ancestor must be sought for in elongated forms with equally developed somites, but we cannot yet say where this ancestor of Spinther is to be looked for. Structure of Serpula.t—Sigr. V. Simonelli has investigated the microscopic structure of Serpula spirulza Lam., and finds that his results furnish new evidence in favour of that separation of this species which Defrance (1847) long since suggested. He describes the complex struc- ture of the limy tube, which he succeeded in satisfactorily sectioning, and shows how it differs from other Annelids. Nor can the species be ranked beside Vermetus. S. vertebralis and S. heliciformis were also studied, which closely resemble S. spirulza. It seems at least necessary to drop the title Serpula as applied to these forms, and to revive the generic titles Rotularia or Spirulza. B. Nemathelminthes. Maturation and Division of Ascaris Ova.{—Prof. J. B. Carnoy laid the results of his observations before a conference of microscopists at Brussels. * Zeitschr. f. Wiss. Zool., xlvi. (1887) pp. 1-66 (9 pls.). + Proc. Verb. Soc. Toscana Sci, Nat., v. (1887) pp. 298-5. t La Cellule, iii, (1887) pp. 225-45, ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 43 I. First of all, in regard to the kinetic phenomena of maturation, he maintains that the primitive nucleus of the ovum is an ordinary nucleus; that it divides into eight batons (“ trongons”) in two groups of four; that there are always two polar bodies in A. megalocephala; that there are no globules, nor chromatic discs, nor prothyalosoma ; that the typical kinetic figures are dimidial; that the ypsiliform figure does not exist as such. A new spindle of separation is formed, again a dimidial figure, again no globules, discus, nor prothyalosoma. Each semi-spindle bears at its equator two of the primitive batons. One of the groups is isolated with the second polar body. The other remains in the ovum. The two last batons form the final nucleus. The polar bodies owe their formation to a true plasmodieresis, by the aid of a cellular plate. They are true cells, and not nuclei. IJ. Variations of polar kinesis. The author distinguishes three different types within the same genus Ascaris, and maintains the great variability of the polar kinesis. III. The cellular plate. In animals cell-division (plasmodieresis) is accomplished by constriction, by aid of a cellular plate, or by both processes at once. The cellular plate occurs in all kinds of cells. It occurs distinctly in the formation of the polar bodies of Nematode ova. Polar Bodies in Ascaris.*—Prof. J. B. Carnoy adds several appendices to his well-known, much-criticized, investigations on the phenomena of maturation, fertilization, and division of Ascaris ova. He describes the formation of polar bodies in A. clavata and A. lumbricoides, noting the transversal equatorial division, the incomplete longitudinal division, its possible retardation, the occasional absence of the polar ascent, the normality of the polar kinesis, the diverse modes of separation to be seen in one preparation. A- second appendix is devoted to a discussion of the normality of the figures. He emphasizes the fact of individual variations. Some observations are made anent the critique of the Hertwigs, and the method pursued by Boveri. A third appendix is for the most part an answer to Flemming, and discusses the facts of varia- tion in kinesis, maintaining the impossibility of any general formula. In reply to Flemming’s strictures on the new terminology, Carnoy criticizes the old, and justifies his own. Fertilization of Ascaris megalocephala.t—Prof. O. Zacharias has made a fresh study of the process of fertilization in the case of Ascaris megalocephala, which has been honoured with the attention of so many naturalists. He gives at the outset a short sketch of the well-known series of researches on this subject, he notes the various points of con- trast, for instance, between Nussbaum and Van Beneden, between Carnoy’s and Hertwig’s theory, and so on, and expresses at the outset his con- viction that what all observers from Auerbach onwards have regarded as pronuclei are structures of entirely different import. I. Ova and Spermatozoa.—The author proceeds to describe the reproductive elements themselves, noting the changes in the maturing ova, the early hyaline spherules and cavities, the appearance of a mem- brane, the peripheral position of the nucleolus and its various parts, the subsequent division into two portions, the further division of each of these into four, the differentiation of each of these into connected rows * La Cellule, iii. (1887) pp. 247-324. + Arch. f. Mikr. Anat., xxx. (1887) pp. 111-82 (3 pls.). For the author’s method see infra, Microscopy B. td SUMMARY OF CURRENT RESEARCHES RELATING TO of spherules, and the appearance of two separate spindle figures. At the very first there is dualism, each half contains an equal number of chromatin rods; the dualism is still preserved in the formation of the two polar bodies ; a double fertilization also occurs; each of the chro- matin portions unites with half of the sperm chromatin; two segmenta- tion nuclei are formed, which have, however, a single functional import, since each furnishes at the beginning of segmentation two chromatin coils for the single mother-star of the first segmentation. The two segmentation nuclei have been wholly misunderstood, and erroneously interpreted as pronuclet. The germinal spot or so-called nucleolus includes all the formed chromatin substance of the ovum, it is rather comparable to a nucleus, it is a structure sui generis, and to it, as to the similar body in the sperm, the designation mitoblast may be applied. Prof. Zacharias then describes the male elements, noting the successive changes, the amceboid and the passive portion, the important naked mitoblast which does not deserve the name of nucleus, denying that the sperm and ovum are, as Nussbaum says, homologous, while acknowledging that they are complementary cells. He takes a brief survey of incipient dimorphism of sexual elements, and maintains the fundamental physiological and histological differences between ovum and sperm. II. The Conjugation of the Sex-cells—While in the main corro- borating the classic results of Van Beneden, the author differs from him in sundry details, especially as regards the mode in which the sperm penetrates the ovum. He finds, for instance, no micropyle. The egg substance never forms a naked protrusion to serve as the attaching point for the spermatozoon. The penetration of the sperm begins with the emission of pseudopodia, but the rest of its progress appears to be passive. By some local regeneration, the membrane closes upon the entrant sperm. The sperm has in itself power to penetrate the membrane. In regard to the point where the sperm may enter, Zacharias observed that in the elliptical ova of A. suilla, the male elements were seen fixed both at the pole, and on the sides. Polyspermy occasionally occurs, but is to all appearance pathological. It may be that the ovum, being amceboid and exhibiting contractions, may form a small cone of attraction into which one sperm normally finds its way. The membrane thickens after the entrance of one sperm. Some notes on the genital ducts are then made. III. Formation and expulsion of Polar Bodies.—The double structure which results from the originally single germinal vesicle, has been already noticed. The two half-spindles occupy various relative positions. The ypsiliform figure so familiar in Van Beneden’s researches is only a special, and not a typical form of spindle. The division forming the polar bodies takes place radially, and not tangentially to the surface of the yolk, the difference on which Van Beneden lays so much stress does not occur in properly killed and fixed ova. The extrusion of the second body is also normal in its karyokinesis. In the first extrusion the original number of chromatic elements is halved and thus reduced to four, in the second process half is again given off, so that three-fourths of the female chromatin is excluded from share in the embryonic development. At the time of the second polar body formation, the dualism of the male element is well marked. This chapter closes with ZOOLOGY AND BOTANY, MICROSCOPY, ETO. 45 a discussion of the biological import of polar bodies, in which Zacharias seems more inclined to side with Biitschli and with Weismann, than with Minot or with Strasburger. IV. The act of Fertilization.—There are two pairs of conjugating elements, male and female semi-mitoblasts. The result is two nuclear structures mistaken for pronuclei, each consisting of a male and a female semi-mitoblast. Hertwig’s theory is entirely confirmed, though stated in anew form. The whole point is that the union of sexual elements is double, not single. V. The Segmentation—A single segmentation nucleus is formed eventually. The details of division are described. Zacharias confirms Flemming’s formula of repetition, according to which the daughter- nuclei pass into rest by the star and coil stages, through which the mother-nucleus passed out of it. The memoir, which is (unlike some others of the kind) lucid and unambiguous throughout, closes with some general notes on the relative importance of nucleus and protoplasm. Larval Stage of Species of Ascaris.*—M. A. Laboulbéne, in oppo- sition to the recently expressed views of Dr. Linstow, affirms that Ascaris lumbricoides developes directly, or without the intermediation of a second host. The ellipsoidal ova are evacuated before they have undergone any segmentation ; the formation of the embryo takes about thirty or forty days with a favourably high temperature, but may, as Davaine has shown, be retarded for as long as five years with a low temperature and a damp atmosphere. The embryo, as seen in the egg, has an obtuse head, no lips, valves, or cephalic nodules; its tail is merely acute, and not filamentar. This embryo quits its egg-shell in the stomach, or more often in the small intestine of the animal which it has reached ; the shell is softened merely, and not dissolved by the gastro- intestinal juice. The embryos now rapidly pass through a larval stage ; twice only has the author seen it; the first example was filiform, 20°4 mm. and 0°5 mm. wide, and its head had three valvular and nodulose projections; the caudal extremity was truncated below, and no genital organs were apparent. On the second occasion M. Laboulbéne found four examples, the exact dimensions of which were 2 mm., 3°25 mm., 1 cm., and 2:3 em. He concludes that the development of Ascaris lumbricoides is direct, the segmenting ovum giving rise in the body of its definite host to the embryo, which rapidly reaches and soon passes through the larval to reach its sexual condition. The experi- ments of Grassi have shown that ripe ova may furnish sexual Ascarids at the end of a month after swallowing. The ova of Ascarids, after passing with the faces, are washed away by rains, when they make their way into streams and ponds; by watering they are deposited on food-plants, and the evaporation of water allows of their preservation in damp places. In the case of the dog the eggs remain entangled in the hair, and the young, which lick their parents, easily come into contact with them. The comparative rarity of this human parasite in towns, and its frequency in rural places, is to be explained by the fact that in the former the water generally is, and in the latter is not filtered. * Comptes Rendus, civ. (1887) pp. 1593-5. 46 SUMMARY OF CURRENT RESEARCHES RELATING TO y. Platyhelminthes. Cestoid Embryos.*—Mr. E. Linton describes and figures two forms of cestoid embryo which he frequently met with in studying the entozoa of marine fishes. The first eyst described was taken from the peritoneum of the blue- fish (Pomatomus saltatria), and similar forms are common in Teleostei, oceasional in Selachians. It contained an embryo Rhynchobothrium. The thin, transparent, delicate outer cyst inclosed an endocyst (blastocyst of Diesing). The latter was usually a club-shaped, thick-walled sac, and remained active for hours with alternate contractions and expansions. The embryo lay in a coil at the large end. The water vascular canal could be seen through the cyst. The wall of the cyst had two coats, the outer of three layers, granular, muscular and refractile. The endocyst may be regarded as an intermediate or transition form, a nurse to the embryo. The freed embryo was quite active and measured about 24mm. The bothria were two, marginal, oblong, divergent posteriorly, notched on the posterior border, obscurely two-lobed, with free mobile edges. There were four long slender proboscides armed with recurved hooks. These are described in detail. The proboscis-sheaths are long and spiral and exhibit a contractile ligament. The contractile bulbs were thick-walled, acting like syringes, forcing a column of fluid into the proboscides. The bothria are then described. The water vascular system consists of a network of vessels on the borders of the bothria, connected with large sinuous vessels in the centre of the head, and together with these with the reticulated subcuticular vessels of the neck. Behind the contractile bulbs the system is represented by two pairs of lateral sinuous vessels. Behind the bulbs the body is an elongated sac filled with granular parenchyma, with refractive masses smaller than those of the cyst. The posterior end is terminated by a papillary button-like process, retractile, and covered with dense minute bristles. The second cyst described was that of an embryo Tetrarhyncho- bothrium, taken from the surface of the liver of the cero (Cybium regale). It was long, slender, yellowish and opaque. The freed blastocyst was also long and slender with a neck-like constriction at one end. The head-part thus formed was extraordinarily variable. The whole body exhibited irregular contractions and expansions. The embryo lay in a coil in the head-part. The blastocyst remained attached to the body of the liberated scolex. It would not be readily separated. The posterior tapering end of the scolex was again clothed with bristles. The bothria are four, in opposite lateral pairs, are quite mobile, each with a retractile hooked proboscis. The proboscides were as fully developed as in the Rhynchobothrium embryo. The sheaths were spirals, the contractile bulbs slender. A reticulated system of vessels was made out. The connection of blastocyst and scolex is a marked difference at the period in question between this embryo and that above described. Tenia nana.j—Prof. B. Grassi (with the assistance of Signor S. Calandruccio) has a second preliminary note on this small human Cestode. The rostellum may project, like a proboscis, very far from the head, and it may be drawn very far in. In the latter state it has the form of an hourglass; it lies in a sac with a thick wall which has an * Amer. Naturalist, xxi. (1887) pp. 195-200 (1 pl.). + Centralbl. f. Bacteriol. u. Parasitenk., i. (1887) pp. 282-5, ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 47 anterior orifice. When protruded, part of the wall of the sac is pro- truded with it. The rostellum is provided with longitudinal and circular muscles, and in the sac there is a circular musculature from which numerous bundles of oblique or longitudinal fibres are given off. There _ are from twenty-four to twenty-eight hooks on the rostellum. The suckers can elongate like arms, and each is capable of independent movement. They and the rostellum may break off mechanically from the scolex, without the latter suffering any apparent injury. The neck may vary in length. The proglottids differ remarkably in form and number; one very important characteristic is that their hinder angles project in the form of more or less regular triangular points. The separate joints have a certain power of shutting in upon one another. By the examination of well-preserved eggs the authors have been able to see that the substance in the space between the two egg-membranes is often homogeneous near the inner membrane, and that the latter has two scarcely evident swellings, one of which corresponds to the pole of the egg, while the other is just by the other pole. In certain cases it is easy to see that the coiled filaments in the substance correspond to the two swellings. The longest axis of the egg is from 43-53 p» long, the shortest from 35-40 p. Tenia murina from the mouse is probably a mere variety of T. nana, differing chiefly in its greater length, and in the ordinarily greater size of the just mentioned sweilings. Fourteen new cases of T. nana have been observed, chiefly in children ; and it may be said that 7’. nana is much more common than other human cestodes in Sicily. To discover it, it is not sufficient to examine feces once only. The number present varies from forty or fifty to four or five thousand; the hosts frequently suffer little or no pain, but this, of course, is not always the case. ilix mas is an appropriate remedy. Sphyranura osleri.*—Prof. R. Ramsay Wright and Mr. A. B. Macallum give a detailed account of this ectoparasitic Trematode, which is intermediate between Gyrodactylus and Polystomum, and may, if some slight alteration be made in the diagnosis, be placed in the sub- family Polystomide, as defined by T'aschenberg. Sphyranura is found on the skin of Menobranchs, where it is very obvious on account of its want of colour. The investing membrane is very elastic and is provided with a very large number of conical bodies, which the authors regard as tactile organs; the deep surface of the membrane does not lie on the circular muscles, but is separated from them by a narrow space containing fluid ; the presence of tactile organs may be correlated with the comparatively active life led by this parasite, and as compensatory for the absence of eyes. The worm holds on to its host with great pertinacity, owing to the possession of hooks and suckers on the ventral surface of the character- istic caudal lamina. The most striking point about the musculature is the fact that the diagonal fibres, which are so abundantly present in the larger Distomes, are hardly represented. With regard to the minute structure of the muscles, as to which various students of Trematodes have given different accounts, the authors tell us that the longi- tudinal caudal bands, which are generally over 2 mm. in length, offer favourable material for the study of individual fibres. They find that * Journ. of Morphology, i. (1887) pp. 1-48 (1 pl.). 48 SUMMARY OF CURRENT RESEARCHES RELATING TO many of the cells of the sub-cuticular layer are in reality the central protoplasmic elements of the muscular fibres, the contractile elements of which form the musculature on which the investing membrane rests. The fibres consist of a hyaline membrane covering a finely granular and apparently fluid medulla. The connective tissue of Sphyranura is composed of branching cells which form a meshwork; their processes, which are evidently elastic, are homogeneous, the cells are oval, spherical, or irregular in shape, and the greater part is occupied by the nucleus, with little or no protoplasm surrounding it. The excretory system is provided with two anterior contractile bladders which open by dorsal pores ; applied to their walls are large ganglion-cells which, presumably, control their pulsations; these are effected by the muscular fibres which line the bladders. Hach bladder has connected with it a strong lateral stem which gives off numerous twigs to the caudal lamina; the walls of the trunks are highly elastic, and are, in parts at any rate, provided with muscular fibres. The walls of the finer excretory capillaries rarely exceed 1 p in thickness, and seem to be formed by a single coat of a homogeneous refracting substance ; at certain points these capillaries present a funnel-shaped expansion, where the membrane terminates; beyond the mouth of the funnel there isa network of fine intercellular canaliculi; the mouth lies in the interior of a connective-tissue cell, and the fine canal which leads to it passes through the cell-substance. The funnel, as well as the capillary into which it empties, always has a distinct wall up to the rim of its broad mouth. Cilia hang over this rim into the funnel. In connection with the excretory system of Sphyranura the authors describe some remarkable structures which have not, apparently, been observed in other Trematodes. Cells of a polyhedral shape, sometimes with short processes at the angles, and measuring from 37-50 p, are found scattered throughout the body. The cytoplasma forms coarse trabecule, which usually radiate from the centre of the cell to the periphery, and contains a system of communicating spaces which are empty in the fixed, but often unobservable in the fresh condition; each cell has at one pole a process, with an axial wavy channel connected with one of the neighbouring excretory capillaries, the wall of which passes insensibly into the membrane of the cell. This connection suggests that the cells in question are truly renal. With them somewhat similar structures in other Trematodes are compared. The authors have never seen the nervous system so well during life as in Sphyranura, the fibrillation of the plasma of the ganglion-cells being distinctly seen. The ganglion-cells form two masses which are not grouped round the pharynx, but lie at its sides; these ganglia are connected by two commissures, the stouter of which is supra- pharyngeal, and the more slender infra-pharyngeal; on either side are two nerve-stems, which are lateral and ventro-lateral in position, the dorsal stems of Distomum isostomum being, apparently, absent from this form. The system of connecting commissures is described. The digestive tract is without an cesophagus; the intracellular mode of digestion plays only a subordinate part ; the soluble digestive ferment seem to be derived from the cells of the intestinal epithelium. Though this new form is hermaphrodite, the male and female organs are quite independent of each other; the author’s observations on spermatogenesis ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 49 agree generally with the account given by Schwarze of Distomum endo- bolum, but they are confident that the spermatozoa arise wholly from the nuclei of the sphere or spermatogemma. They have been able to observe the passage, under pressure, of the female sexual products to the intestine through the overflow-tube, and regard this as a confirmation of Tjima’s discovery of the true nature of the so-called internal vas deferens of Polystomum. Some detaiis are given as to the minute structure of the female organs; in the ovary there are parietal cells, varying considerably in size, and from them arise, by increase in size and division, the cells which fill the cavity of the ovary; the ripe ova measure about 55-60 p, and their nuclei about 85-40 ». The uterus never contains more than one egg, and the extent of development of this seems to stand midway between the advanced condition found in Polystomum oblongum and P. ocellatum, and the early oviposition which occurs in P. integerrimum. New Human Distomum.*—M. J. Poirier describes, under the name of Distomum rathouisi, a new species of fluke obtained through Pere Rathouis, and taken from a Chinaman thirty-five years of age. As the patient suffered for a long time from hepatic derangements, which were refractory to all remedies, it is probable that this new endoparasite inhabits the biliary canals. In a number of characters it resembles D. hepaticum, but is distinguished from it by the large size—2 mm. in diameter—of the ventral sucker, by the absence of spinous processes from the integument, and by the absence of ramified caeca connected with the two branches of the intestine, as well as by the smaller size of the elements of its parenchyma, and by the structure of its uterus. Natural History of Leucochloridium paradoxum.t—Herr G. Heckert has found that Leucochloridium paradoxum is not rare near Leipzig. It is, as is well known, the sporocyst stage of Distomum macrostomum, and is found in the liver of the snail, where it forms a network of multi- ramified tubes which are filled with a serous fluid, germ-spheres, and the larve developed from them. Parts extend into the tentacles, and thither the ripe forms make their way. Both the sporocysts and tubes are subject to a very high pressure, and if they are injured their contents are rapidly expelled. Even the young tubes exhibit contractions, which are probably of importance in metastasis ; the large tubes not only effect this, but with their colour attract birds, who regard them as living larve; their musculature is very well developed, consisting of longi- tudinal, circular, and diagonal muscles. Below the dermo-muscular layer bright green pigment is found in cells, which are arranged circularly. The brown tubes sometimes seen probably belong to different sporocysts. The sporocyst and tubes are of the same histological structure; there is an external cuticle, a dermo-muscular tube, then a layer of cells which varies in size with the stage of growth, and finally a membrane with distinct cellular elements. In this last the germ- spheres arise as local thickenings, which, when they fall off, pass into the nutrient fluid which fills the sporocyst; they are chiefly made up of small cells with proportionately large nuclei, and only in the centre are there some larger cells. The spheres have at first the form of a lens which gradually becomes oval; the genital apparatus is developed from * Arch. Zool. Expér. et Gén., v. (1887) pp. 203-12 (1 pl.). + Zool, Anzeig., x. (1887) pp. 456-61. 1888. E 50 SUMMARY OF CURRENT RESEARCHES RELATING TO the central cells first; then the sucker begins to appear, and is followed by the pharynx and enteron, excretory organ, and nervous system. The larva now undergoes a double ecdysis, but the cuticle is not lost but forms a protective covering until the Distomuwm has passed into the intestine of the bird. Between it and the cuticle a serous fluid collects, and it is to this that the animal owes its elasticity and its freedom from injury in its host’s gizzard. By feeding experiments, the author found that the Sylviide are the true hosts of Distomum macrostomum. One or two days after feeding the parasites were found in the cloaca, which is their permanent seat. About the eighth day egg-production began, and after fourteen days the Distomum was full of eggs. With regard to the early stages of ege-development, Herr Heckert confirms the results of Schauinsland ; the final result of segmentation is the formation of an embryo with avery thick shell; it is about 1/30 mm. long, and consists of only a few cells; at the hinder end of a ciliated comb there is a powerful cone which acts as a steering organ. Owing to failures in further breeding, the author came to the conclu- sion that the eggs must be eaten by the snail, and the embryos set free in their stomach by mechanical or chemical influences. After feeding Succineze with the eggs, he found that the embryos became free in about a quarter of an hour after eating; they swim about in the stomach and attempt to bore with their head-cone. After eight days, the first stages of the sporocysts were found in the liver, where they were in the form of small rounded spheres with more or less well- marked elevations, which are the first signs of the commencing branches. Temnocephala.*—Mr. W. A. Haswell gives an account of an aberrant monogenetic Trematode found on the large fresh-water crayfish of the northern waters of Tasmania. It is a leech-like animal about half- an-inch long; at the narrower anterior end there are on either side two very long and slender tentacles, which, when fully extended, are one-half or two-thirds the length of the body. In the species from New South Wales or New Zealand there are five equal slender tentacles. The rapidity of the movements, and the extreme sensitiveness of the animals are surprising ; in turning aside from a touch they show a very definite sense of direction. The author distinguishes four species which he calls Temnocephala fasciata (on Astacopsis serrata, streams of New South Wales) ; 7. quadricornis (on A. Franklinii, northern rivers of Tasmania) ; T. minor (on A. bicarinatus, streams of New South Wales); and T. nove- zealandiz (on Paranephrops setosus, rivers of New Zealand). Temnocephala is regarded by Mr. Haswell as most nearly related to the Tristomide, but the numerous peculiarities which it presents require the formation of a new family for its reception. 'These characters are the possession by the cephalic end of the body of slender filiform tentacles with prehensile and tactile functions ; as the tentacles are adhesive they take the place of the anterior suckers; their adhesive powers are increased by the secretion of certain special unicellular glands. There is a single large radiated posterior sucker without hooks. A rudimentary segmentation is indicated by the incomplete transverse dissepiments which are formed by specialized portions of the parenchyma muscle, * Quart. Journ. Micr. Sci., xxviii. (1887) pp. 279-302 (3 pls.). ZOOLOGY AND BOTANY, MICROSCOPY, ETC, 51 and the intestine is constricted at regular intervals by these septa. There are three pairs of longitudinal nerve-trunks, dorsal, dorso-lateral, and ventral, which are connected by numerous commissures. The two apertures of the excretory system are placed far forward on the dorsal surface. The reproductive apparatus has a single orifice from the cloaca, into which the ejaculatory duct and vagina open ; there are two pairs of lobed testes, vitelline glands which are imperfectly segmented, a single ovary, receptaculum seminis, oviduct, and uterus. As in other ectoparasitic Trematodes there is no metamorphosis of the young. Trematode in white of newly-laid Hen’s Egg.* — Dr. E. Linton records the presence of Distomum ovatum Rudolphi in the white of a freshly-laid hen’s egg. The presence of this common avian parasite in this position is not hard to explain; its favourite place is the bursa fabricii, and an individual may well penetrate occasionally one of the passages which communicate with the cloaca. The creature is known to sometimes make its way into the oviduct, and if it should pass beyond the shell-forming glands when an ovum is in transitu, it might easily be enveloped in the glairy albumen which exudes from the glands; the subsequent deposition of the shell would not be interfered with. Lateral organs of Nemerteans.t—Herr R. Devoletzky gives the complete statement of his investigations begun in 1879. After some remarks on the methods used, and a review of former work on the subject, he describes shortly the characteristic head-furrows of Nemerteans, and then treats at length the side organs of Terebratulus fasciolatus in particular, and the other Schizonemerteans in general. Drepanophorus is the type of the Hoplonemerteans and these are also described in general. Carinella is next treated in detail, and the results of the investigation are correlated in conclusion. The occurrence of side organs in all three groups of Nemerteans leads to the conclusion that these are organs of special sense, and their considerable importance is shown by their complex structure and their very general occurrence. In forms before thought to be without them, careful search has revealed their existence, and it is probable that if not always persistent, they are present during some part of the life of every species. In the simplest form (Carinella annulata) a simple inpushing of the outer skin is connected with the central ganglia by fibres which break through the inner skin. In C. polymorpha a large opening in this inner skin forms a passage from the more developed canal to the “ brain” into which, in C. ineaspectata, the canal itself extends directly. In all the higher forms a part of the central nervous system breaks through the body-wall to meet a specialized and inpushed portion of the epithe- lium. These side organs are compared with similar sense organs in other groups of the animal kingdom, especially water-inhabiting ones. Some Annelida and Mollusca are referred to in particular. Side organs cannot be considered to have sight, hearing, or touch as function. Smell and taste are possible since the media in which they work, water and moist air, could convey chemical stimuli to the richly ciliated canals, and to the grooves and furrows of the head. The author does not presume to advance any further hypothesis. * Proc. U.S. Nat. Mus., 1887, pp. 367-9. + Arbeit. Zool. Instit. Uniy. Wien, vii. (1887) pp. 233-80 (2 eS E ae SUMMARY OF CURRENT RESEARCHES RELATING TO ‘Challenger’ Nemertea.*—The more interesting general points in the results of Prof. A. A. W. Hubrecht have already been noted in this Journal.t Many of the specimens obtained during the voyage were fragmentary, but they were excellently well preserved for histological purposes ; 19,560 sections were made, all of which were stained with Ranvier’s picrocarmine. Carinina isa new genus allied to Carinella ; the name of Hupolia is proposed for the genus of which delle Chiaje’s Polia delineata is the type. The anatomy is considered in detail, and the memoir concludes with some general considerations. 5. Incertze Sedis. Parasitic Rotifer—Discopus Synapte.t — The Rotifer noticed twenty years since by Prof. E. Ray Lankester as living parasitically in Synaptze at Guernsey has been found on the same Holothurian by Dr. C. Zelinka. The worm is not, however, endoparasitic, but lives as a “free space-parasite”” in small pits on the skin. This form, which the author calls Discopus Synapte g. et sp. n., is one of the Philodinide ; it is distinguished from all known genera by the following characters. The foot ends in a sucker with a broad round disc and two short pincers ; there is no contractile vesicle; the cement-glands are formed of cells attached to the ventral walls in two semicircular rows, and their efferent ducts, after various loopings, divide repeatedly and finally open on the last joint of the foot by means of pores arranged in a circle. The animals exhibit four kinds of movements, they either progress like a leech, or they make tactile movements by extending their bodies, or by moving from right to left, or they swim with the foot retracted and the wheel-organ extended. The skin, which is not at all thick, except in the wheel-organ, proboscis, and foot, consists of a cuticle or syncytial hypo- dermis. The dermo-muscular tube consists of eleven delicate circular muscles, and a dorsal pair of longitudinal muscles, which have the same structure as in Callidina. The muscles of its body-cavity are highly developed, for there are more than twenty pairs with quite definite functions. In the limbs there are two pairs of dorsoventral fibres; the muscles of the foot are so disposed as to serve for the attachment and fixation of the suctorial apparatus. The nervous system consists of a brain lying in front of, and partly on the pharynx, of connected periencephalic ganglia and ganglionic cells, as well as peripheral nerves which are connected with ganglionic cells, muscles, and sensory cells. At the hinder end of the brain is a multi- cellular ganglion, provided with lateral nerve-fibres; there are ganglia connected with one another, and connecting the brain with a large subcesophageal ganglion. From the two dorsal periencephalic ganglia there arise two dorsal fine nerves which pass to the ganglionic cells on the mid- and hindgut. At the anterior end of the cesophagus there is a unicellular ganglion which sends off fibres anteriorly to the proboscis, laterally to a muscle, and posteriorly to the subceesophageal ganglion. The tactile organ has but one joint, at the end of which are a few stiff sete ; at its base there is a multicellular ganglion, which is connected with the ganglion of the proboscis, and gives off nerves to the cells between the cesophagus and the wheel-organ. The proboscis is also an active organ * Reports on the Voyage of H.M.S. ‘Challenger,’ liv. (1887) 150 pp., 16 pls. + See this Journal, 1887, p. 754. t Zool. Anzeig., x. (1887) pp. 465-8. ZOOLOGY AND BOTANY, MICROSCOPY, ETO. ays) of touch, and is well provided with nerves. The tip of the wheel-organ is not a syncytium, but is composed of several parts. The pharynx is spherical, and surrounded by five large ventral, and several smaller lateral salivary glands. These salivary glands are connected with the cesophagus. The two excretory tubes open into the rectum without any contractile vesicle ; no ciliatcd infundibula were observed. The eggs develope in the ccelom. The author believes that the bilobed wheel-organ of the Philodinid may be referred to the ciliary circlet of the trochosphere, that the proboscis is the homologue of the anterior end and a part of the frontal plate of the trochophore, and that the brain of Rotifers is partly formed by the frontal plate, and partly by the connection with it of primitively peripheral ganglion cells. Echinodermata. Histology of Echinoderms.*—Dr. O. Hamann deals in this essay with the regular Echinoidea and Spatangida. He accepts Valentin’s fourfold classification of the pedicellariz, which he calls gemmiformes, tridactyli, ophiocephali, and trifoliate. The first of these are described in Spherechinus granularis and Echinus acutus. A careful description is given of their musculature and nerve-supply. The glands which are found on the stalks agree in structure with the globifer, and, as in them, stimulation produces a flow of finely granular mucus, which coagu- lates at once in either water or alcohol. The gland-cells are irregular, and their oval nuclei are surrounded by only a small quantity of cell- substance. Below the basal membrane there is a layer of concentrically disposed smooth muscular fibres, by the contraction of which the secre- tion is evacuated. The connective substance in which the glands are imbedded is very poorly developed. The orifice of the gland is dorsal to the calcareous tip of the pedicellaria. The tridactyle pedicellariz, which were found in all the Echinids examined, are described in Centrostephanus longispinus and Dorocidaris papillata. In the latter, one form is remarkable for the possession of glandular tubes on the branches. These tubes are quite different in form from those of the gemmeform pedicellarie. A few short tubes hang together in a racemose fashion, and open into a long efferent duct ; they are set in the connective tissue, and their epithelium consists of finely granular flattened cells, which pour their secretion into the narrow lumen of each tube. These peculiar pedicellarie are principally to be found on the oral membrane. The buccal pedicellariz are the simplest of the trifoliate type, having neither glands nor special sensory organs. In discussing the mechanism of the movements of the mobile termina- tions of the pedicellaria, investigators appear to have confined their attention to the three adductor muscles, and have been content to explain the separation of the arms by the elasticity of the parts. Dr. Hamann has discovered extensor muscles which are inserted into the same calcareous pieces as the adductors, but on the outer surface, and nearer the base of the calcareous plates. As to the functions of these organs, which have been so much discussed, it appears to be necessary to distin- guish between the various kinds. Their numerous nerve-endings seem * Jenaisch. Zeitschr. f. Naturwiss., xxi. (1887) pp. 87-266 (13 pls.). o4+ SUMMARY OF OURRENT RESEARCHES RELATING TO to show that they are tactile organs. The smallest, such as the trifoliate pedicellariw, have certainly the action of scavengers and cleaners; the larger, such as the tridactyles, serve principally to ward off larger living bodies, and also to hold on to fixed foreign objects during locomotion. The gemmeform pedicellariz also have this function, and their seizing power is aided by the secretion of the glandular sacs. The author next deals with the globiferi of Centrostephanus longi- spinus, of which two kinds are described. Some are compressed, and have un exceedingly short stalk, while others are more delicate, and have a longer stalk. Each consists of three spheres, which are closely appressed and fused at their points of contact. The glandular contents are of a yellowish colour. In the centre of the stalk there is a calcareous rod, which has generally a spherical termination, and above it the integument forms a sort of hood. As to the minute structure of the globiferi, the author states that the investing epithelium consists of cubical cells, among which are a large number of yellow pigment cells. The interior of each oviform gland is occupied by long cylindrical palisade-like cells, which have but a narrow central space. Ifa living globifer be compressed, the cells may be seen to suddenly pass out by the orifice of the glands. The cell may be shown to have been broken off above the nucleus. The examination of sections demonstrates that the glandular contents consist of a mucous mass, with an investment of cells along the wall. The latter are surrounded by a small quantity of protoplasm, and do not appear to have definite boun- daries. Their nuclei are of some size, and nearly always contain some distinct nucleoli. Among them there are scattered smaller cell-nuclei. The globiferi can be best made out in Sphereechinus granularis, where they were first observed by the author.* The fact that these organs have hitherto escaped detection is doubtless explicable by their super- ficial resemblance to pedicellarie, from which, indeed, they appear to have been derived. The spines are next discussed, those of Dorocidaris papillata being first descriked. All but the large thick spines present an arrangement which has not yet been detected in any Urchin. At the base there is a mass of large glandular cells. The thickening at the base is due to the thickening of the connective substance and the superjacent epithelium. The latter is made up of ordinary epithelial cells and of glandular cells. The latter are tubular, and are surrounded by a membrane. The cell itself consists of a granular, highly refractive mass, and a large number of cilia project from its free ends. The epithelial cells are fine and fila- mentar, and the base is connected with nerve-fibres. Nerve-trunks can be made out in each spine, and these can be traced to the nearest ambu- lacral nerve. In Spheerechinus granularis there is a basal nerve-ring, whence nerve-fibres pass to the longitudinal muscular fibres, and the capsule of connective substance. Above the ring the superficial epithe- lium is much thickened, and the cylindrical cells, which are long and hair-like, carry long cilia at their free ends. Below the epithelium is the muscular layer, formed of longitudinal smooth fibres, which have their origin in the upper calcareous piece of the spine, and are inserted into the calcareous pieces of the body-wall at the base. The last kind described are the rotating dorsal spines of Centrostephanus * See this Journal, 1886, p. 452. ZOOLOGY AND BOTANY, MICROSCOPY, ETO. 55 longispinus, which are placed round the arms, and which during life may be seen to be continually moving, their tips describing a circle. These spines are from 1-3 mm. in length, according to the size of the animal. On the surface there are a number of sensory prominences. Like the other spines, these are attached to a hemispherical tubercle. Around their base is a nerve-ring, whence fibres pass to the subjacent musculature and to the tip of the spine. There is a rich muscular supply, which is cylindrical in form, and is made up of transversely striated fibres. This transverse striation is very rarely to be detected in specimens which have been preserved in alcohol. The nervous system of a few Echinids was examined, and an elaborate account is given. Nerve-fibres are to be found throughout the epidermis, whence they pass into the cutis. At the middle of the paired ambulacral plates are longitudinal canals. These begin at the apical pole beneath - the fine intergenital plates, and extend to the masticatory apparatus. They are formed from the schizoccel, and lie in the layer of connective tissue. Here, too, are the five radial nerve-trunks which, in the Asteroidea, lie in the ectoderm. The trunks consist of very fine nerve- fibres and ganglionic cells, together with a cellular investment, which is partly formed of supporting cells, This epithelium may be regarded as the homologue of the epithelium of the ambulacral grooves of star-fishes, for it is not only the nervous mass, but also the whole epithelium that has come to lie in the mesoderm, as in Holothurians. From the nerve- ring branches are given off to the cesophagus, which extend over the whole of the enteric tract. The blood-carrying spaces consist of fine longitudinal canals and a circular space surrounding the nerve-ring. These structures in Echinids have nothing to do with the true blood-lacunez, which arise from the blood-lacuna-ring, which lies on the surface of the “lantern,” as a ventral and dorsal enteric lacuna. From the dorsal lacuna branches are given off, which surround the glandular organ (or “heart” of earlier authors). In its terminal portion the lacune of the anal blood-lacuna- ring are brought into connection with this organ. The anal lacuna passes into a circular schizoccel-sinus, which surrounds the anus ; from it blood-lacune are given to the generative organs. Dr. Hamann describes a canal from the water-vascular ring as passing into the “ Polian vesicles”; the canal opens into their cavity while blood-fluid circulates in lacune in the wall of connective tissue, and these lacune are in direct connection with the blood-lacuna-ring. In the Spatangida the five longitudinal canals and an cesophageal sinus communicating with them are present ; the true blood-lacuna- ring has, however, disappeared with the lantern, and the dorsal and ventral enteric lacune open into the sinus. The dorsal lacuna runs beside an enteric vessel, which arises from the circular canal that surrounds the mouth. Later on, this water-vessel and the enteric lacuna communicate with one another, and extend as far as the true stone- canal. In this way a comnection is effected between the water-vascular and blood-lacuna-systems—or, in other words, between spaces of endo- dermal and schizoccelic origin—such as has not been observed in any other group of Echinoderms. We may well suppose that this arrange- ment is secondary, since the Spatangida are paleontologically the youngest form. The ovoid gland or so-called heart is a remarkable organ; so far as 56 SUMMARY OF CURRENT RESEARCHES RELATING TO we can judge at present it may be regarded as an organ in which the materials which are of no further use to the body are stored up. Blood-lacunze open into it at its ends and surround it as in regular Kchinids, but an efferent duct from it has not yet been detected in any form. The mode of origin of the genital products is particularly interesting. The primordial germ-cells lie in a circular genital tube from which arise five saccular outgrowths, into which the germ-ceils wander; these out- growths form the first rudiments of the generative tubes, and the cells not only form the male or female elements, but the general epithelium which, later on, invests the cavities of the generative organs. In the adult these tubes atrophy. Dr. Hamann believes that those naturalists take the most correct view of the phylogeny of the Echinodermata, who regard the Asterida as being the most ancient members of the phylum. He discusses in detail the evidence as to the origin of Echinids from Asterids. Asterids have five or more radial (ambulacral) longitudinal canals in the ventral walls of the arm, and an oral circular canal; in regular Echinids these are present, as the neural canals ; in Spatangids the oral ring becomes connected with the enteric lacune, as it does also in Crinoids and Holothurians. Asterids have blood-lacune and an oral blood-lacuna-ring in the septa of the longitudinal canals, but these are wanting in the other groups. Asterids have blood-lacune in the septa of the dorsal schizoccel spaces at the apical pole, which are present in all Echinoids, placed partly in the arms of Crinoids, and wanting in Holothurians. Wandering Primordial Germ-cells in Echinoderms.*—Dr. O. Hamann here deals with a question which he did not fully treat of in his essay on the Histology of Echinoderms (see above). He finds that the primordial germ-cells appear very soon after the larval stages are passed ; they are present in star-fishes and Urchins 0-5 cm. in diameter. The egg-cell and sperm-cell of all Echinoderms arise from one and the same element of the primordial germ-cell. The canals or genital tubes are placed in Crinoids in the arms, in Ophiurids partly in the dorsal wall and partly in the walls of the burse, and in Asterids and Echinids in the dorsal walls of the disc. They lie in a septum of connective tissue, in the meshes of which are blood-lacune ; the septum is always found in schizoceelic spaces. The contents of the tubes are, in all cases, cells about 0°008 to 0:01 mm. in size, which exhibit amoeboid move- ments, and have but a small quantity of cell-substance which can be stained. The nucleus is from 0:005 to 0:007 mm. in size, and forms a clear vesicle, in which a well-developed plexus, which ordinarily stains very deeply with carmine, can be made out. In Crinoids the primordial germ-cells come to maturity in the pinnules, which are lateral out- growths of the genital tubes; in the Ophiurids they pass into the walls of the burse which are invaginations of the ventral body-wall. In Asterids and Echinids the outgrowths form racemose organs; the Holothurians probably resemble the Echinids, and in both the adult has no remnants of the tubes. The author calls attention to the resemblance between Echinoderms and Hydroid Meduse ; in both there is a migration of primordial germ- * Zeitschr. f. Wiss. Zool., xlvi. (1887) pp. 80-98 (1 pl.). ZOOLOGY AND BOTANY, MICROSCOPY, ETC. D7 cells to definite maturation-centres ; but the resemblance is not complete, inasmuch as the cells in the polyp are already differentiated into generative cells when they begin to wander, while in Echinoderms the differentiation is effected after the migration. True Nature of the Madreporic System of Echinodermata.*— Prof. M. M. Hartog comes to the conclusion that the madreporic system of Echinoderms is morphologically and ontogenetically a (left) nephridium. He has found by experiments that its ciliary current is directed outwards through the madreporite, and that in Comatula an outward current takes place through the pores of the disc. As against the theory that the system serves for taking in water, the author urges that there is no need for this since osmosis is amply sufficient for the turgescence of dilatable organs. The rapid contraction or erection of the tube-foot is due to the transference of liquid from one part to another. The change of position of the madreporite in most Holothurians is, it is suggested, probably due to the usurpation of nephridial functions by the respiratory tubes which are connected with the cloaca. The author takes the opportunity of remarking that it is very probable that, when an Actinian is at rest, the oral slit is ecmpletely closed ; turgescence of the body is effected by osmosis, and the apical pores of the tentacles would appear to have the double function of the periodical or perhaps constant discharge in small quantities of the excess of liquid, and of its rapid discharge when, in defence, the animal wishes rapidly to reduce its bulk. Nervous System and Vascular Apparatus of Ophiurids.t—M. S. Cuénot has examined the nerve-trunks of Ophiurids after treatment with osmic acid and distilled water, and finds that they are formed of an epithelium of elongated cells, among the bases of which very fine nerve- fibrils run. The epithelial nuclei are all placed above the fibrils, and it is they which were taken by MM. Teuscher and Koehler for nerve- cells. The histological characters of the nerve-trunks of Ophiurids are, then, exactly the same as those of Asterids. The nervous ring, in addition to the ambulacral nerves, gives off two branches in each inter- radius; the more external of these goes directly to the large external interradial muscle, and the other, which is larger, gives branches to the dental papille. In the Ophiurids which were examined the cesophagus was found to be directly continuous with the nerve-ring by a delicate membrane in which nuclei are scattered; in Asterids the two are in more obvious connection. In the EHuryalide the cesophagus receives numerous nerves, united into a plexus, which becomes united with the nerye-ring. Branches from the radial nerves penetrate the ossicles of the arm and terminate in the intervertebral muscles, which are the active agents in locomotion. The branches distributed to each spine have each a small swelling formed by nerve-cells or fibres; they extend some way along the axis of the spine, and then become lost in its substance. The circular and radial vessels which MM. Ludwig and Koehler have called the vascular system are only connective-cells and fibres, and have no morphological value. There is a supraneural sinus (the peri- hemal of Ludwig and Koehler), within this a nerve-trunk, then a vascular * Ann. and Mag. Nat. Hist., xx. (1887) pp. 321-6. + Comptes Rendus, cy. (1887) pp. 818-20. 58 SUMMARY OF CURRENT RESEARCHES RELATING TO sinus (perihemal of Ludwig and Koehler, to which alone the term is applicable), and then the ambulacral canal. The vascular ring is con- nected to the aboral by a sinus which incloses the ovoid gland and the sand-canal; the aboral ring gives off the genital vessels which form a blood-sinus around the genital ceca; in the interior of the aboral ring and its appendages there is, as in Asterids, a genital cord, at the expense of which the genital organs are formed; this, in the adult, becomes fused with the base of each genital organ. It incloses a certain number of nuclei and of cells which are similar to those of the ovoid gland; in addition there are cells of large size, with a large nucleolated nucleus, which are identical with young ova and the mother-cells of spermatozoa ; where the genital cord is in contact with the genital ceca the cord is composed solely of these cells. The lymphatic glands are, partly, the Polian vesicles for the ambu- lacral apparatus, as in Asterids and Holothurians, partly the ovoid gland for the vascular apparatus and general cavity, and, partly, the small glands which are placed at the outer extremity of the respiratory cleft ; the products of these last are probably destined for the genital vascular apparatus, Development of Apical Plates in Amphiura squamata.*—Dr. P. H. Carpenter takes as his text Mr. J. W. Fewkes’s recent observations on the development of the calcareous plates of Amphiura squamata. He urges that the radial plates are mutually homologous in Ophiurids and Urchins, Asterids and Crinoids, and that the relative time of their appearance is of no general morphological importance. As against Fewkes’s view that the radial shields of Amphiura are the homologues of the first brachials of a Crinoid, three objections are raised. Many Crinoids have no paired first brachials, for they have only five arms; the only genera in which the paired first brachials rest directly on the primary radials are the aberrant Allagecrinus and Tribachiocrinus, but this is not the case all round the cup; the radial shields are often separated from the primaries by a series of intermediate plates, which exhibit no general constancy of arrangement. Dr. Carpenter would prefer to regard the radial shields of Ophiurids as being, like the terminals of both Ophiurids and Asterids, without representatives in the Crinoidea. In defence of his homologization of certain intraradial plates in Amphiura with the basals of Crinoids the author points out that the plates in question have an interradial position within the ring of radials, and are at one stage of development the only adaxial interradial plates; so that they correspond exactly to the basals of monocyclic Crinoids and to the so-called genitals of Urchins and Asterids. Attention is particularly directed to the considerable difference in the order of formation of the principal apical plates in the American and European varieties of the same species; though this does not seem to have attracted the special notice of Mr. Fewkes, it bears very strongly on any argument as to homology which can be extracted from differences in the time of appearance of plates. Calcareous Corpuscles of Holothurians.;—M. E. Hérouard has examined the calcareous deposits of a number of dendrochirotous Holo- * Quart. Journ. Micr. Sci., xxviii. (1887) pp. 303-17. + Comptes Rendus, cy. (1887) pp. 875-6. ZOOLOGY AND BOTANY, MICROSCOPY, ETO. 59 thurians. He finds that the basis of each is a group of hexagonal prismatic cells, arranged in a single layer. Four adjacent cells serve as the centre of attraction for the calcareous molecules, and give rise to an X-shaped corpuscle. The calcareous deposit next attacks the other lateral walls of the four cells, but the bases of these always remain free from any deposit ; the centre of each cell is occupied by the nucleus, the presence of which explains the holes in these bodies. As the deposit is most abundant along the crests of the hexagonal cells, the surface of the corpuscle becomes ridged. These four cells the author proposes to call the four fundamental cells of the corpuscle, and he applies the term of fundamental calcareous corpuscle to the body which arises by the calcification of the lateral walls of these four cells. This fundamental form is common to all the species; the differences seen in various forms are due to the mode of calcification of the surrounding cells. Ceelenterata. Morphology of Siphonophora.*—In continuation t of his studies on this subject, Prof. ©. Chun describes the post-embryonic development of Physalia. He has been able to undertake this investigation thanks to the collections made on board the ‘ Vittore Pisani,’ and he has been fortunate enough to find specimens which connect the larve described in 1858 by Huxley with adult forms. Ina larva of 5 mm. it was seen that the lower third of the air-sac is converted by a circular constriction into an air-funnel; the polymorphous appendages of the trunk are distinctly differentiated into two groups, one larger than the other. There was no indication of the crest. In the later stages the air-sac was more extensive, the crest developed, and the appendages increased in number. The air-sac traverses the cavity of the enlarged trunk in an oblique direction, and in such a way that the funnel approaches, near the anterior larger group of appendages, the wall of the body, where it flattens out into a sharply circumscribed plate. This “air-plate” consists of a single layer of ectodermal cylindrical epithelium, which passes at the margin into the flattened epithelium of the inner wall of the air-sac. This, though it has escaped the notice of all observers, grows to a considerable size, and is homologous with the secondary ectoderm in the pneumatophore of the Physophoride ; like it, it is the organ for the secretion of the gas contained in the air-sac; the great development of the secondary ectoderm explains the rapid renewal of the air in the bladder. The recognition of a structure homologous to the air-funnel makes it possible to understand the pneumatophore of Physalia in all stages of development. A line drawn from the centre of the air-plate through the pore corresponds to the primary axis of the pneumatophore of the Physophoride; the asymmetry of the bladder of Physalia becomes marked very early. The structure of the crest is more complicated than has been hitherto supposed; there is a longitudinal septum which divides it into two halves; with this tile-like septa become connected, which arise from its free edge and overlie the transverse septa of the first and second order, and extend as far as the air-umbrella. Notwithstanding the great development of its musculature, by means of which the living * Zool. Anzeig., x. (1887) pp. 557-61, 574-7. ¢ See this Journal, 1887, p. 970. 60 SUMMARY OF CURRENT RESEARCHES RELATING TO animal is capable of making the most various changes in the form of its body, it may be referred to the arrangement general among Pneuma- tophora. The supporting lamella of the air-umbrella gradually widens out and forms a considerable layer, which in section is seen to be concentrically striated ; it is clearly secreted by ectcderm cells. The pneumatophore early takes on its characteristic triangular form, which is especially distinct throughout life in P. utriculus. Various parts of the author’s description will be more easily comprehended when they appear in the promised illustrated memoir. Influence of Salinity.*—Herr C. F. W. Krukenberg has made an elaborate series of experiments on the relation of the salt content of Meduse to the salinity of the surrounding water. (1) The fluid in the disc always closely corresponds in salinity to the surrounding water; in waters with less salt, however, the salinity of the disc bears a much greater proportion to that of the water than occurs in the Meduse of salter seas. (2) From the examination of seven different forms of Medusa, it was seen that in regard to the salinity of the water leaving the disc no noteworthy differences obtained. (3) There is no evidence to suggest that the salinity of the disc in salt seas can sink below that of the surrounding water without danger to life. The study of Red Sea forms showed on the contrary that as long as the external salinity does not exercise any injurious influence on the life of the organism the internal salinity is always greater than that of the water. Krukenberg has made a very extensive series of experiments, of which the tabulated results are given, on the loss of water when the Meduse are removed from their medium, and on the influence of numerous reagents. (1) The loss of water, which takes place by a special process, occurs much more rapidly in air than in sea or distilled water. (2) It is much more rapid in the first hours of exposure to dry air. (3) The loss, especially at first, is greater in distilled than in sea- water. ‘The influence of numerous reagents on the loss of water is then chronicled. Finally, the author sums up all the various ways in which water may pass into or out of an organism, and inquires how it passes out in Meduse. He regards it as quite certain that diffusion has nothing to do with the process. The water passes in by absorption, but Krukenberg is unable to decide whether it passes out by exudation or in a purely mechanical fashion, or by both combined. Colours of Corals.t—Dr. C. F. W. Krukenberg has made a study of the colours of the living corals in the Red Sea. It is well known that the coral banks afford a feast of colour hardly to be surpassed by any other of nature’s displays. The species which he investigated were Stylophora subseriata Ehrbg., Pocillopora hemprichi Ehrbg., Seriatopora spinosa M. KE. and H., Madrepora haimet M. E. and H., Favia ehrenbergi Klz., Galaxea irregularis M. HE. and H., Montipora tuberosa K1z., Turbinaria conica K1z., and Tubipora hemprichi Ehrbg. In these species Krukenberg found the following pigments :—(1) the yellowish-brown colouring matter of the so called “yellow cells” of the Actinidz, which exhibits a deceptive resemblance to the hepatochrome * Vergl. Physiol. Studien, II. Reihe, 4 Abth. (1887) pp. 1-58. + Ibid., pp. 172-87 (1 pl.). ZOOLOGY AND BOTANY, MICROSCOPY, ETO. 61 (MacMunn’s enterochlorophyll) of higher Invertebrates; (2) Anthea- green; (3) rose and purple-red Floridine; (4) a (yellow) Uranidine ; (4) chlorophane- and rhodophane-like lipochromes, but in small quantity as in Anemonia; (6) a red lipochromoid which is not readily dissolved out. The extraction and examination of the different pigments are described, and a spectrum table is appended. The colouring matter of the yellow ceils of Anemonia is constantly to be found in stone corals. The most abundant associated pigment is a yellow uranidine which entirely resembles aplysinofulvine. Floridine, which is common in sponges, is also very frequent among corals. The persistent red of the noble coral (Corallum rubrum), and of the organ-pipe coral (Tubipora musica) resembles that of many mollusc shells, and consists of a rhodo- phane pigment combined with the lime. Nervous Tracts in Alcyonids.*—Dr. C. F. W. Krukenberg has investigated the nervous physiology of Xenia in order to elucidate the relations of dependence between the individual polyps and the colony. Something has already been done in this direction with Polyzoan colonies, but hardly anything has yet been achieved with Alcyonids. By a series of experiments the following fucts were established in regard to individual polyps :—(1) conducting nervous strands penetrate the entire body of the polyp, on the sides of the wall as on the basal plate, both in the oral disc and in the tentacles; (2) stimuli from one half of the body to the other pass more readily vid the oral disc than by means of the strands in the basal plate; (3) stimuli pass more readily from the base to the mouth-disc than in the opposite direction. In regard to the more difficult problem of the relation of the indi- viduals to the general colony, Krukenberg draws the following con- clusions from his experiments:—(1) All portions of the Xenia colony are provided with contractile tissue. The contractions are directly under the influence of a ganglionic network, which is somewhat super- ficially spread out in the branches, the stem, and the foot-plate. (2) The ganglionic network is much more sparsely developed in that portion of the colony which simply supports (the branches, the stem, and the foot- plate) than in the oral disc and tentacles of the polyps. Its influence is especially marked in the stem on such portions as underlie the branches, where there must be larger aggregates of ganglia. This fact seems to explain why influences take effect almost exclusively above the point of irritation, and not backwards from it. (3) Stimulation of a point on the stem is much more readily propagated in the transveise than in the basal direction. Hence may be inferred the existence of cross anasto- moses in the ganglionic network. The relations are very lucidly dis- played in a diagrammatic figure. Finally, the author devotes some space to a criticism of certain re- searches of Keller on the contractions of Xenia. The gist of these observations lay in the conclusion that on the peristome, probably on the margin and near the base of the tentacles, motor centres were present which occasioned rhythmic contractions. With the same species (Xenia fuscescens), and at the same locality (Suakim), Krukenberg was quite unable to observe the rhythmic contractions which Keller even * Vergl. Physiol. Studien, II. Reihe, 4 Abth. (1887) pp. 59-76 (1 pl.). 62 SUMMARY OF CURRENT RESEARCHES RELATING TO counted. He suggests that the abundant suspended particles in the canal-water of Suakim caused the contractions which Keller regarded as rhythmic. On experimental and histological grounds Krukenberg regards their existence as very improbable. Porifera. Sponges.*—Prof. W. J. Sollas has a well-illustrated general article on Sponges. In the account of structure and form he commences with a description of Ascetta primordialis, as a simple sponge; the various modifications undergone by the canal-system are next described, in connection with which the term of prosopyle is applied to the pores which lead directly into the radial tubes or paragastric cavity. In the skeleton, megascleres or skeletal, and microscleres or flesh, spicules are distinguished; the modifications of these are described, considerable additions being made to the terminology of the skeletal constituents. In the account of the histology of the mesoderm various kinds of cells are distinguished; the stellate connective-tissue corpuscles are called collencytes, and the tissue collenchyme. Cystenchyme consists of closely adjacent large oval cells, and is particularly found in certain Tetractinellids. Long fusiform connective-tissue cells are called desma- cytes; they often form the greater part of the cortex of a sponge. In all higher forms contractile fibre-cells or myocytes are to be found, and there appears to be more than one kind of them. The supposed sense- cells are called esthacytes. With regard to protoplasmic continuity, Prof. Sollas says, “ In most sponges a direct connection can be traced by means of their branching processes between the collencytes of the mesoderm and the cells of the ectodermal and endodermal epithelium and the choanocytes of the flagel- lated chambers. As the collencytes are also united among themselves, they place the various constituents of the sponge in true protoplasmic continuity. Hence we may with considerable probability regard the collencytes as furnishing a means for the transmission of impulses; in other words, we may attribute to them a rudimentary nervous function.” The extraordinary profusion of sponge-spicules in some modern marine deposits and in the ancient stratified rocks is accounted for by the fact that the sponge is constantly producing and disengaging spicules. Each spicule originates in a single cell or scleroblast. The phylum Parazoa or Spongie is thus divided :— Branch A. Megamastictora. Branch B. Micromastictora. Class. Calcarea. Class I. Myxospongie. » LI. Silicispongie. Sub-class i. Hexactinellida. a ii. Demospongie. Tribe a. Monaxonida. » 0. Tetractinellida. A sufficiently detailed systematic classification is given. The asexual and sexual medes of reproduction are described, and a notice is given of the two chief types of development ; one, which is common among the calcareous sponges, is characterized by the “ amphi- blastula,” and the other by the “ planula” stage. A short account is given of the little that is known as to the physiology * Encycl. Brit., xxii. (1887) pp. 412-29. ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 63 of sponges, and of their distribution, as to which our information is very fragmentary. After a selected list of works treating on sponges, Prof. Sollas gives an account of the mode of taking, cultivation, and prepara- tion for market of officinal sponges. Skeleton of Calcareous Sponges.*—-Prof. V. vy. Ebner has submitted the spicular skeleton of calcareous sponges to a searching analysis, and comes to the conclusion that the spicules are always “ bio-crystals.” “The spicules are mixed crystals, mainly composed of cale-spar, containing no organic material; the outer form is without the true crystalline contour, but is determined by the specific activity of the organism ; the internal structure, though perfectly crystalline, stands in relation to the external form by a peculiar distribution of the mixed ingredients.” The mixture of salts is due to contemporaneous excretion of more than one. More briefly he reviews the skeleton of calcareous Algewe, Foraminifera, Coelenterates, and Echinoderms, in which marked differences, and at the same time, striking resemblances occur. “In the formation of bio-crystals the crystallographic orientation of the substance first excreted is alone determinative, and all the rest of the substance is formed on the above foundation according to the laws of crysiallization, without special activity of the protoplasm, which has only a moulding influence on the external form and on the mixture of material. When, however, organic material is excreted along with the calc-spar, as in the calcareous membranes of corallines and spicules of corals, there is no longer a uniform crystallization.” It is still a crystalline excretion, but the molecules of carbonate of lime arrange themselves in a fashion “ in general like that found in non-calcified, doubly-refractive tissues.” New System of Chalinine.t—Mr. A. Dendy has some criticisms on a recent publication by Dr. R. yon Lendenfeld dealing with the Chalinine of the Australian region. He points out that the generalization that there are no incrusting Chalinids is contradicted by Dr. Lendenfeld’s definition of his new species Hoplochalina incrustans. ‘There are some important divergences between the letterpress describing, and the figures illustrating the canal-system, the latter giving representations of certain remarkable funnel-shaped canaliculi, such as neither Mr. Dendy nor any other author has yet found in a Chalinid sponge. The systematic classification of the Chalinine is severely dealt with, and evidence is afforded of Dr. von Lendenfeld having adopted in the main the classification of Messrs. Ridley and Dendy, “ but instead of giving it in the way we gave it, and with the significance which we attached to the different groups, he has modified it to suit his present pur- poses, thereby, in my opinion, almost entirely destroying its value.” Spicules, it is urged, not spongin, must be taken as guides to classification. Fresh-water Sponges.{—Mr. E. Potts has published a synopsis of the known American forms of fresh-water sponges, with descriptions of those named by other authors, &c., from all parts of the world. After a general account of their structure, and of the means of collecting, observing, and mounting them, the author justifies his method of nomen- clature. From imperfect memoranda Mr. Potts finds that he has examined * SB. Akad. Wiss. Wien, xcy. (1887) pp. 55-148 (4 pls.). ¢ Ann. and Mag. Nat. Hist., xx. (1887) pp. 326-37. t Proc. Acad. Nat. Sci. Philad., 1887, pp. 158-279 (8 pls.). 64 SUMMARY OF CURRENT RESEARCHES RELATING TO Spongilla fragilis from at least thirty-two localities in eighteen North American States, S. /acustris from twenty-six localities in sixteen States, and Meyenia fluviatilis from twenty-five localities in fourteen States. Hardly any two specimens are exactly alike in their so-called typical features, but all may be grouped, and common definitions or descriptions will, without undue elasticity, cover them all. A diagnosis of the European Spongillide, translated from the Bohemian text of Prof. Vejdovsky, follows, and this is succeeded by a synopsis of Mr. Carter’s classification. Then comes a key to the species of Spongilla, and descriptions of the species, those that are American being treated with more detail than the rest. The genera Meyenia, Heteromeyenia, Tubella, Parmula, Carterius, Uruguaya, Potamolepis, and LIubomirskia (?) are treated in the same way, so that a valuable com- pendium is produced. In conclusion the author says, “Some points. ... worthy of the thought and study of future students have already been suggested, such as the necessity of gemmules in fresh water as distinguished from marine sponges; the process of their formation; their functions, and the means by which that end is attained; the law of variation in the quantity and character of the enveloping crust; and the time and mode of formation of the imbedded armature—all have yet to be conclusively studied, Other questions of a more limited character occur in the search for the line of derivation that must be supposed to run through all the genera and species; and in the association, apparently indicated amongst other- wise dissimilar species, by the presence in them of correspondent forms, such as the birotulate dermals found in certain Spongille and Meyeniz, and the more frequent recurrence in several genera of acerate dermals with characteristic, centrally located, perpendicular spines, &c.” Development of Generative Products in Spongilla.t*—Herr K. Fiedler argues, against Prof. Goette, the unicellularity of the ovum of Spongilla. He has always found distinct cell-boundaries in the egg-cell, and only one nucleus. Double coloration with picrocarmine and “ bleu de Lyon,” with quick washing of the sections with slightly ammoniacal alcohol, gives a bright red colour to the nucleus, and colours blue even the smallest parts of the yolk. The author finds that the large round vitelline spheres do not, as Goette imagines, appear first, but that they are preceded by all possible stages of smaller yolk elements. The folli- cular cells are regarded as parenchymatous cells which have been flattened out by the pressure of the growing egg. Some of them appear to be special nutrient cells, and often their amceboid processes may be seen pushing themselves between the ordinary follicular cells towards the egg, without, however, fusing with it. They prepare in their interior material which is to be regarded as preparatory to yolk-stuff, and which is given up to the egg by diffusion. In addition to these, there are certain amceboid wandering cells of another kind, the bedy of which is quite regularly filled by rather large particles. They correspond to those described in the Calcarea by Polejaeff. They are scattered through the whole body of the sponge, but are especially numerous below and among the cells of the cortex, and more particularly near the afferent orifices. They have probably a nutrient function. * Zool. Anzeig., x. (1887) pp. 631-6. ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 65 The growing egg becomes more and more filled by yolk-granules, but the nucleus never disappears completely, though it often approaches the surface. This position is, no doubt, to be correlated with the extrusion of the polar globules. Spermatogenesis is on the second type of Polejaeff. There is no special covering-cell or primitive sperm-cell. In division, karyokinesis was frequently observed. Protozoa. Conjugation of Paramecium.*—M. E. Maupas finds that the con- jugation of male and female pronucleus as previously described by him was admirably figured by Balbiani in 1858. Maupas had known the compressed summary in the Comptes Rendus, but not the full research with plates. Balbiani figured the process beautifully, but regarded what he figured as the longitudinal division of the micro-nuclear (nucleolar) element. At this time only Warneck, in another overlooked ‘research (1850), had observed the conjugation of pronuclei in the ova of Lymnezus. This was reobserved in 1874 by Biitschli in a nematode. The phenomena described by Maupas have now been observed in nine ciliated Infusorians: Paramecium caudatum, P. aurelia, Stylonichia pustulata, Onychodromus grandis, Spirostomum teres, Leucophrys patula, Huplotes charon, Loxophyllum fasciola, and Paramecium bursaria (Balbiani). M. Maupas reaffirms his certitude as to the seven first stages in the complex process. The micro-nucleus increases, divides, eliminates ele- ments, differentiates, elements are exchanged, and two portions (male and female) conjugate. A single nucleus results, and this divides twice. The further reconstitutive changes are less certain. He is, for instance, in doubt as to the persistence of the original nucleus. New Fresh-Water Infusoria.t—Dr. A. C. Stokes describes a number of new fresh-water Infusoria. Hexamita spiralis, from the intestinal canal of the tadpole of the common toad, differs from previously observed species by the presence of two contractile vacuoles and the spiral dis- position of two of the anterior flagella; Petalomonas dorsalis which has a conspicuously developed centro-dorsal upright plane, and P. sulcata are both from pond water. A new genus, Urceolopsis, is established for Urceolus sabulosus Stokes; in it the entire cuticular surface is more or less covered by adherent, irregular, and angular sand-grains. T'rachelo- monas urceolata, T. verrucosa, and T. acanthostoma ; Anisonema solenota, Protopteridinium limbatum, and Holophrya ornata follow. Saprophilus is a new genus for S. agitatus sp.n.; these animalcules are essentially scavengers which, rapidly undergoing fission, swarm in crowds round and within the dead bodies of various small aquatic animals. Bothriostoma undulans g. et sp.n.,is a heterotrichous form, in which the left-hand border of the peristome carries a series of large cilia, while the posterior portion of the right-hand margin supports an undulating membrane. A second species of Hymenostoma, H. magna [um], is described ; it may be easily distinguished from H. hymenophora by its larger body ; conjugation has been observed, union taking place between the ventral surfaces of the right-hand body margins. There are four new species of Vorticella, * Comptes Rendus, ey. (1887) pp. 955-7. See this Journal, 1887, p. 973. + Ibid., xlvi. (1858) p. 628, and Journ. de Physiol., i. (1858) p. 347, pl. iv. ¢ Proc. Amer. Phil. Soc., xxiv. (1887) pp. 244-55 (1 pl.). 1888. z 66 SUMMARY OF OURRENT RESEARCHES RELATING TO V. pusilla, V. mollis, V. aqua [e] dulcis, and V. platysoma. Opercularia allensi is about twice as large as O. nutans, while the height of its colony is much less; O. vestita is also described. Thuricolopsis differs from Thuricola in that the lorice have an internal, narrow, flexible, valve- rest, and the zooid is attached posteriorly to the lorica by a distinctly developed pedicle. In this genus are placed Thuricola inniaa Stokes, and T’ kellicottiana sp.n. Platycola celochila and Lagenophrys patina are next described. Histrio erethisticus is very difficult to study owing to the animalcule having “a most annoying habit of suddenly darting backward for a distance seldom exceeding its own length.” Descrip- tions of Solenophrya odontophora, Acineta bifaria, A. macrocaulis, and A. acuminata complete the paper. Relationships of Foraminifera.*— Herr M. Neumayr divides shelled Foraminifera into three phylogenetic grades; (a) the quite irregular and primitive Astrorhizide; (b) the series with merely agelutinated shells ; (c) the compactly shelled forms which he believes to have arisen from the former. His classification is thus summarized (in compressed form). Spirillinids. Oraueiapens nae Chilostomelle. | Rotalia. Pose t Calcareous Miliolini ; Globigerina. Fusulinell Es grade. Gorin Perforate. Polystomella. I Ke ae ce t jinperforate, * | Textillarids. Nodosaria. Fusuiinid. er : ApS Perforate. : | Cornuspirids. Lituolid: oo se pind Lituolid type, | Fusulinid, e.g. Regular eer aa Textillarid e.g. Lituola Fusulinella agglutinated Siena’ Game type. Endothyra. p- p. (ef. En- grade. Ket eer a Trochammina. dothyra). Trregular agglutinated Astrorhizide. grade. Karyokinesis of Euglypha.j;—Herr W. Schewiakoff has made a careful study of the phenomena of division in Huglypha alveolata. Division is prefaced by the protrusion of cell-protoplasm and of shell plates from the mouth of the shell. The protrusion as it grows is clad with a new shell, over which for a time the alveolar and granular proto- plasm flows. The internal changes begin in the protoplasm of the hyaline zone, which increases in volume, and differentiates into two layers—an outer, denser and reticulate stratum, and an inner clear region round the nucleus. 1) The nucleus is homogeneous, and not rich in chromatin. (2) The “cyto-chylema” of the clear region penetrates the persistent nuclear membrane, and conditions the increase of the nucleus, which acquires a reticulate structure and more chromatin. The nucleo- hyaloplasm and the fine granules accumulate at the nodes of the net- * SB. Akad. Wiss. Wien, xcy. (1887) pp. 156-86. + Morph. Jahrb., xiii. (1887) pp. 193-258 (2 pls.). ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 67 work and form coarser meshes. (3) From the meshwork single filaments arise, with irregularly coiled course. The filaments give off small processes, so that their margins appear zigzagged. ‘The granules fuse to form Pfitzner’s chromatin spheres, and the filaments finally consist of alternate dark and clear discs. (4) The filaments become smooth, and are disposed parallel to one another in the peripheral portion of the nucleus. Only a few processes remain connecting the chromatin filaments in the so-called “ close coil” (dichte Kniéiuel). (5) The filaments shorten and thicken to form the “loose coil,” and are at the same time bent into sickle shape. The nucleolus now disappears. (6) The cytoplasm disposes itself radially to the surface of the nucleus. The loops retire inwards, and have their apices directed centrewards. The swn-form arises. (7) The cytoplasm of the clear region begins to concentrate at the poles, the nucleus exhibits amceboid ‘movements, the increase in size ceases, the nucleus becomes again spherical. The accumulation of cytoplasm at the poles acquires a rayed structure (the polar rays). The rays converge towards the poles of the nucleus, and meet in a depression. Here arises the polar body, and at the same time appear the spindle nuclear fibres. (8) The nucleus becomes ellipsoid, the loops have their angles on the equatorial plane, the stellate form begins. (9) The spindle-fibres grow from the poles into the nucleus, and unite in the equatorial plane with those from the opposite side. A continuous nuclear spindle is formed, which has a directive influence on the chromatin loops. The nuclear spindle elongates in the direction of the axis of division. The loops become disposed in two ways—the outer remain parallel to the equatorial plane, the inner stand perpendicularly to the same. The star-form is at its climax. (10) The loops become ribbon-like, and begin to divide longitu- dinally. The inner loops are bent round to the polar end. The longitudinal division occurs. (11) With re-arrangement the barrel form arises, all the loops lie at right angles to the equatorial plane, their apices are turned to the poles. (12) The loops separate, move polewards, and arrange themselves radially round the somewhat flattened polar body. Thus arise daughter-stars, and immediately after (13) the daughter-sun-forms. (14) The nucleus is constricted into two, the protoplasm of the clear zone is also divided, circulation begins in the bodies of the daughter individuals, the plasma of the alveolar and granular zones is divided between the two in approximately equal portions. (15) Meanwhile the daughter nuclei undergo metamorphosis. The polar body is drawn in, the loops are drawn out into filaments to form the daughter-cells. (16) From the filaments connective threads proceed ; a coarse and then a fine network is thus formed, the nucleolus reappears, the nucleus acquires its normal structure. The plasmic circulation ceases, pseudopodia issue from the opening of the cell, the daughter individuals separate. Changes in nucleus and protoplasm appear contemporaneous. Only the clear zone is active, the rest of the protoplasm passive. Whether the penetration of the cyto-chylema into the nucleus is the very first step or not the author does not venture to decide. The process is ‘clearly one of genuine division, and not, as Gruber maintained, half-way F 2 68 SUMMARY OF CURRENT RESEARCHES RELATING TO between division and budding. An interesting phenomenon was some- times observed, that after the usual protrusion of protoplasm, and after the nucleus had begun to go ahead in its changes, a stoppage occasionally occurred, the nucleus retraced its steps, and everything returned in statu quo. The author concludes by comparing his results with those obtained in other Protozoa, and shows that a considerable manifoldness in the details of indirect division must be allowed to occur. Diplocystis Schneideri.*—Prof. J. Kiinstler gives an account of an aberrant Sporozoon which has been found in the body-cavity of Peri- planeta americana, and which appears to be the representative of a new genus. It is milky white and opaque, and may therefore be easily seen ; the adult individuals may be as much as 2 mm. long. The body is spheroidal and monaxial, and has at first sight the appearance of two monocystid Gregarines united by their corresponding extremities ; each half has its own membrane, and the whole is surrounded by a general envelope, which extends from one to the other without penetrating into the plane of separation. This membrane is double, but it is probable that the outer of the two has been formed by the host, while the inner corresponds to the cuticle (or epicyte of Schneider's terminology); the inner membrane is fine and transparent. The author is inclined to disagree with Schneider and Biitschli as to the superficial nature of the cuticular strie of Gregarines, and thinks them to be due to the minute structure of the cuticle. In the new genus the markings are certainly not regular. Under the cuticle there is a delicate layer of dense protoplasm, which is doubtfully compared with ectoplasm; it is transparent, finely dotted, and scarcely thicker than the cuticle. It entirely surrounds each of the two vesicles of which the body is made up, and forms the septum between them; but, as it is single, and as delicate here as elsewhere, it is clearly not due to fusion, but is the continuation pure and simple of the peripheral layer of the body. ‘The internal protoplasmic mass, which must be regarded as the endoplasm, if the other homologies are correct, is more or less, but never completely, fluid, and is filled with special granulations. When the animal is treated with potash or other reagents which dissolve the granulations, the endoplasm is seen to have a reticular structure. The granules present some of the reactions of amyloid bodies. The structure of the nucleus recalls that of true Gregarines, but a difference from polycystid Gregarines is to be found in the fact that each vesicle has a nucleus or body analogous thereto. The author gives an account of the formation of the nuclei, and of the development of Diplocystis ; as to its systematic position, he believes it to be an aberrant type, showing affinities both to the Gregarinida and the Coccidia. * Tablettes Zoolog., ii. (1887) pp. 25-66 (1 pl.). tt ZOOLOGY AND BOTANY, MICROSCOPY, ETO. 69 BOTANY. A. GENERAL, including the Anatomy and Physiology of the Phanerogamia. a. Anatomy.* (1) Cell-structure and Protoplasm. Part taken by the Nucleus in Cell-division.j—Herr E. Zacharias states, as the result of fresh observations, that the celi-protoplasm does not penetrate into the nucleus during its division. The nucleus appears to be always sharply differentiated from the cell-protoplasm when it passes over into the “spindle” condition. Within the mother-nucleus ‘the groups of filament-segments of the daughter-nuclei separate until they reach the poles of the mother-nucleus, and the daughter-nuclei become differentiated from a central part of the mother-nucleus which remains behind between them. Only the framework of the mother- nucleus which contains the nuclein is completely taken up into the daughter-nuclei; a considerable portion of its matrix passes over into the cell-protoplasm. Within the remains of the mother-nucleus the cell-plate is formed out of the cell-protoplasm which penetrates into it; the remains of the mother-nucleus are thus increased in size, and may be separated from the daughter-nuclei on both sides by cell- protoplasm. Albumen in the Cell-wall.{—Herr G. Klebs commenting on Krasser’s paper on this subject and on Wiesner’s previous communications, contests the assertion of the former that alloxan is an unfailing test for substances belonging to the group CH,CH(NH,)CO,H. The utmost that can be said is that certain nitrogenous substances are characterized by the alloxan reaction ; it is displayed, for example, with glycocoll, and to a less extent with urea and keratinin, as well as with leucin, tyrosin, and other albuminoids. It is also manifested with various inorganic substances, not only with ammonia, bnt with potassium monophosphate, sodium diphosphate, and, the bicarbonates of the alkalies. This test, therefore, in no way proves the presence of albumen in the cell-wall. Herr Klebs further states that if Millon’s reagent is to be relied on, it shows the presence of albumen in the walls of wood- and bast-cells, which is incredible. The author also brings forward arguments in opposition to Krasser’s view that the cell-wall is a living organ, comparable to the nucleus or the chlorophyll-bodies. The incorrectness of this view is sufficiently shown by the fact that cells can be parted from their celi-walls, and then have the power to form new ones. * This subdivision contains (1) Cell-structure and Protoplasm; (2) Other Cell- contents (including Secretions); (8) Structure of Tissues; and (4) Structure of Organs. “+ Versamml. Deutsch. Naturf. u. Aerzte, Wiesbaden, Sept. 21, 1887. Ber. Deutsch. Bot. Gesell., v. (1887) pp. lv.—vi. t Bot. Ztg., xlv. (1887) pp. 697-708. Cf. this Journal, 1887, p. 981. 70 SUMMARY OF CURRENT RESEARCHES RELATING TO Thickening of the Cell-walls in the Leaf-stalk of Aralia.*—Sig. P. Pichi describes the mode of thickening of the walls of the liber-cells in the phloem of the fibrovascular bundles in the leaf-stalk of Aralia trifoliata. In the early stages the thickening takes place chiefly in the angles, producing a very strong resemblance to collenchymatous tissue. Later, very delicate layers of cellulose are formed within each cell, which become rapidly lignified. Sig. Pichi considers it probable that during the early stages, the thickening takes place chiefly by intussus- ception, during the later stages by apposition. (2) Other Cell-contents (including Secretions). Starch- and Chlorophyll-grains.—M. E. Belzungt has made a series of observations on the morphological and physiological relationship between starch and chlorophyll, which has led him to conclusions differing in several respects from those generally accepted. In investigating the origin of starch-grains, especially in the ovules of Leguminose, M. Belzung finds that, during the formation of the ovule, the embryo, the transitory endosperm, and the integuments, in fact, the entire seed, is the seat of a new-formation of starch unconnected with the previous existence of any leucite or starch-generator ; the grains of starch are formed free in the protoplasm by simple crystallization of the amylaceous matter dissolved in the cell. This is true both of accumula- tions of reserve-starch and of such as is at once used up in the growth of the plant. The theory of Schimper that the leucites are the sole generators of starch is further in opposition to the fact that even when a starch-grain is apparently formed within a leucite, it will continue to grow long after the latter has disappeared. During the development of the transitory starch-grains they undergo a curious metamorphosis. A portion of their substance is consumed, and is used for the production of albuminoids, while the other portion is partially hydrated, and takes the form of a granular skeleton of the same shape, which is coloured yellow or reddish-yellow by iodine reagents. These skeletons are analogous to those obtained by the action of saliva or of dilute acids on the starch-grains in the living plant. They are composed of amylo- dextrin, and the author proposes for them the term amylites. They were found in ripe seeds and in the axis and cotyledons of the lupin. The transitory starch which appears during the germination of seeds is deposited in these amylites, and is formed at their expense. This transitory formation of starch has no connection with the actual assimila- tion of carbon. The normal function of transitory starch-grains is to form grains of chlorophyll. The chloramylite is the substratum of the future chloro- phyll-grain, and the cell-protoplasm takes no part in its formation. Chlorophyll-grains with an amylaceous origin must be carefully distin- guished from those with a protoplasmic origin. During the early period of germination chloramylites only are to be found in the stem, to the exclusion of chloroleucites. Reserve-starch-grains exhibit the same phenomena; and they occur in all plants except Fungi, which contain transitory, but no reserve-starch. * Atti Soc. Tose. Sci. Nat., viii. (1887) pp. 455-8 (1 pl.). ft: Sci. Nat.—Bot., vy. (1887) pp. 179-310 (4 ee Cf. this Tecra 1887, p- ZOOLOGY AND BOTANY, MICROSCOPY, ETC. fal In the Floridexw (Polysiphonia, Sphzrococcus,) M. Belzung states that the starch-grains are formed directly in the protoplasm, without the intervention of leucites, and have no definite morphological connection either with the chromatophores or with the nucleus. The general result cf the examination of the embryo of ripe seeds (Leguminose) is that they contain no leucites of any kind. A large number of chlorcleucites and all chloramylites are formed directly ; the former by differeutiation of the cell-protoplasm, the latter by meta- morphosis of starch-grains. Instead of chlorophyll-grains (chlora mylites) producing starch-grains, by the assimilation of carbon, they are themselves formed from starch-grains produced free in the protoplasm. During germination in the dark the transitory starch-grains, after partial absorption, are transformed into amylites. It is these sub- stances, and not the protoplasm, which form the granular substance of the chloramylites. The formation of transitory starch in fungi in the course of germi- nation was demonstrated in the case of the sclerotia of ergot of rye. To this M. F. W. Schimper * replies, denying the accuracy of every one of M. Belzung’s statements, where they conflict with his own, viz. the statement that it is not proved that starch is formed by leucites, that starch-grains can be transformed, without the assistance of protoplasm, into green granules resembling chloroleucites, but composed of a skeleton of starch impregnated with pigment; and that leucites can be formed free in the protoplasm. The existence of “chloramylites” he considers to be entirely a delusion. The objects recommended for studying the true structure of leucites are the pseudo-bulbs of Phajus grandifolius, the rhizomes of Iris florentina and germanica, and the tubers of the potato. Quantitative estimation of Chlorophyll.{—By the use of his method already described, Herr A. Tschirch found the usual proportion of chlorophyll in the dry substance of leaves free from ash, determined as phyllocyanie acid, to be from 1:8 to 4:0 per cent.; in a square metre of surface from 0°35 to 1:23 gr. of chlorophyll. The proportion, of course, varied considerably ; the most common percentage was 0°8 gr. per square metre. Formation of Starch in the Chlorophyll-granules.{—Dr. G. Belluci, in order to determine whether the production of starch under the influence of sunlight, and the subsequent reconversion during night- time, is to be regarded as a physiological or as a chemical change, tried the effect of the presence of various substances. Chloroform, and to a slighter extent ether vapour, destroy chlorophyll, and also prevent the transformation of starch formed during sunlight; carbonic anhydride also diminishes the function of the chlorophyll, but does not destroy it if the action is not allowed to continue unintermittently for twenty-four hours. The saccharification of starch proceeds in the dark, even in cut- off leaves, but more rapidly with free access of air. From these experi- ments, the author concludes that the phenomenon is a physiological and not a chemical change. * Ibid., vi. (1887) pp. 77-89. + Versamml. Deutsch. Naturf. u. Aerzte, Wiesbaden, Sept. 21, 1887. See Bot. Centralbl., xxxii. (1887) p. 57. Cf. this Journal, 1886, p. 346. t Chem. Centr., 1887, p. 572. See Journ. Chem. Soc. Lond., 1887, Abstr., p. 1136, 72 SUMMARY OF CURRENT RESEARCHES RELATING TO Inosite.*—Herr R. Fick finds inosite very widely distributed in the vegetable kingdom, in a large number of plants belonging to a great variety of natural orders,—in the seed, sced-vessel, stem, leaves, and roots, though by no means universally. It is present in larger quantities in climbing than in erect plants. The mode of its separation from the living plant in clusters of needles is described in detail. Tannin in Acanthus spinosus.t—M. J. B. Schnetzler finds tannin present in the leaves of this plant, along the vascular bundles, in the parenchyma of the stem, the peduncles, the walls of the ovary, the ovules, the style, the stigma, and the filaments. He believes it not to be a mere product of excretion, but to play an important part in the life of the plant. Chemical substances contained in the Box.t — Besides the threo well-known alkaloids of the box, buxine, parabuxine, and buxinidine, Sig. G. A. Barbaglia finds in the leaves two others, to which he gives the names parabuxinidine and buxinamine. The chemical properties of these five alkaloids are given in detail. He finds also, besides Walz’s buxoflavina, three distinct pigments, a green, a yellow, and a red, buxoviridinum, buxorubinum, and buxocrocinum. The wax on the upper surface of the leaves he finds to differ from the vegetable waxes previously known, and establishes for it by experiment the composition C,,H,.0. Aleurone-grains in the Seed of Myristica surinamensis.§—Herr A. Tschirch finds that these seeds are peculiar in the extraordinary deve- lopment of the albumen crystalloids of the aleurone-grains. Each cell is almost filled with a large crystalloid of the hexagonal system, either a rhombohedron (R) or a combination of the same with the basal plane (R:OR). Twin forms are rare. These crystalloids form the matrix of very large aleurone-grains. As a rule, to each crystalloid is attached a greater or less number of globoids, each including a needle-shaped erystal of calcium oxalate. Besides the globoids, the oxalate crystals, and the protein-crystalloids, the aleurone-grains also contain a residue of amorphous substance. 'T'o separate these constituents, a section is freed from oil by means of ether, then very dilute aqueous potash dis- solves the albumen crystalloids after washing, acetic acid dissolves the eloboids, and then the calcium oxalate is dissolved in dilute hydrochloric acid, (3) Structure of Tissues. Laticiferous System of Manihot and Hevea.||—In addition to the two systems of laticiferous vessels in Manihot Glaziovii already described by Dr. D. H. Scott, Miss Agnes Calvert and Mr. L. A. Boodle find a third, in the peripheral portion of the pith, usually in the neighbour- hood of a primary xylem-bundle. These laticiferous tubes have reticu- late anastomoses similar to those described by Dr. Scott in the cortex. * Fick, R., ‘ Unters. ib. d. Darstellung u. d. Eigenschaften des Inosit,’ 38 pp, St. Petersburg, 1887. See Bot. Centralbl., xxxii. (1887) p. 133. + Arch. Sci. Phys. et Nat., xviii. (1887) pp. 300-2. t Atti Soc. Tose. Sci. Nat., viii. (1887) pp. 255-70. § Arch. Pharm., xxv. (1887) pp. 619-23. See Journ. Chem. Soc. Lond.—Abstr., 1887, p. 1061. || Ann. of Bot., i. (1887) pp. 55-62, 75-7 (1 pl.). Cf. this Journal, 1884, p. 409. ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 13 In the secondary phloem new laticiferous elements are continually being formed by the cambium. 'The members of one group branch and anastomose freely among themselves, but do not anastomose with the members of other groups. The cortical tubes form a continuous reticu- late cylinder all round the stem. It is probable that at the nodes all the laticiferous systems stand in radial connection with one another. By treating sections of the stem with ether, and staining with hama- toxylin, numerous nuclei were seen in the laticiferous vessels, both of the phloem and pith; and a protoplasmic layer could also be detected lining the vessels, showing that they retain their living contents after maturity. In Hevea brasiliensis, Miss Agnes Calvert also succeeded in detecting ail three systems of laticiferous tissues in older seedlings. In this plant, although the laticiferous tubes consist mainly of vessels formed by the fusion of rows of cells, yet, like the laticiferous cells of other euphorbiaceous plants, they retain the power of independent growth, and may put out branches which grow by their apices. The nuclei are particularly distinct in the laticiferous tubes of all three systems, and may be seen even without staining. They frequently contain very distinct nucleoli. Tubular Cells of the Fumariacee.*—Herr E. Heinricher objects to Zopf’s description ¢ of the idioblasts in the tissue of Fumariacee as * tannin-receptacles.” The contents of these cells consist of a mixture of various substances, and the author prefers for them the designation “tubular cells” (Schlauchzellen), which gives no indication of their contents. ‘The characteristic and universal constituent of their contents is a fatty oil, with which may be associated protoplasm, a pigment or its chromogen, various salts, and tannin. Usually tannin is altogether wanting, and, if present, is only in minute traces. Anthocyan may occur, but is not generally present. The cells which contain anthocyan are generally independent idioblasts, similar to those found in other forms, and quite distinct from the characteristic tubular cells of the Fumariacee. For the demonstration of these cells the author uses potassium biniodide, or an alcoholic or aqueous solution of iodine, by which their contents are coloured yellow-brown or dark-brown, the oil and proto- plasm as well as the tannin. If an alcoholic solution is used, the brown colour soon disappears, owing to the great solubility of the oil in alcohol. The author considers the best reagent for tannin to be the neutral salts of iron; potassium bichromate may also be used. Super-endodermal Network in the Root of the Caprifoliacee.{— M. P. van Tieghem continues to give the result of his researches on the super-endodermal network, as found in the root of various plants. In the present paper this structure is described as it occurs in the various genera of Caprifoliacee. In Viburnum Tinus and V. Opulus, for example, all the super-endodermal cells of the young root are strongly thickened and lignified on their radial and transverse faces. These thickenings are coloured bright red by fuchsin. Here and there a cell of the antepenultimate layer also bears thickening bands. Several * Ber. Deutsch. Bot. Gesell., vy. (1887) pp. 283-8, + See this Journal, 1887, p. 427. t Bull, Soe. Bot France, Xxxiy. (1887) pp. 251-3. Cf. this Journal, 1887, p. 986. 74 SUMMARY OF CURRENT RESEARCHES RELATING TO modifications occurring in other members of the same genus are also described. In Lonicera tatarica the network is complete, but in L. aylo- steum and L. nigra it is interrupted here and there, especially opposite the woody bundles. In Symphoricarpus the network is remarkable on account of the doubling back of the bands on the external face of the cells. In conclusion, the author states that of the nine genera of Capri- foliaceew he has examined, six are provided with a super-endodermal network, and three are destitute of that structure. The structure in Caprifoliacee agrees with that found in Conifer and Rosacez, but it differs from the Crucifere in that, in the latter case, the meshes are reticulated, Arrangement of the Fibro-vascular Bundles in Pinguicula.*— MM. P. A. Dangeard and Barbé describe the structure of the fibro- vascular bundles found in Pinguicula vulgaris. According to MM. van Tieghem and Douliot,+ the conducting bundles may be arranged in three different ways. hey may be grouped in a circle, or in several con- centric circles, round the axis forming a central cylinder surrounded by endoderm and cortex; or they may be grouped in several circles, round several different axes, forming as many distinct central cylinders; or lastly, they may be isolated, and not united into a central cylinder. In the stem of Pinguicula the authors state that the second of these arrange- ments is found, and that this has only been observed in two other genera of Phanerogams, namely, in Auricula and Gunnera. Distribution of Fibro-vascular Bundles in the Petiole.{—M. L. Petit states that, if a transverse section be made at the caulinary end of the petiole of Juglans regia, the fibro-vascular bundles will be found arranged in three circles. These fuse together, and form a single triangular bundle. The arrangement in the other Juglandex is some- what similar, with the exception of the distribution of the accessory bundles situated above this bundle. In Liquidambar imberbe the fibro- vascular system is arranged in three arcs of a circle, which form three bundles. These subsequently fuse together, forming a single bundle. In Bauhinia racemosa the lateral bundles have their xylem inter- nally, their phloem externally ; in the median bundles the phloem faces the median plane, and the xylem is opposite to that of the external bundles. Vascular Bundles in the Rhizome of Monocotyledons.s—Herr W. Laux describes what he terms the “ perixylematic ” concentric bundles in the rhizome of Acorus, the Juncacez, and Cyperacez, as contrasted with the “ periphloematic” concentric bundles of Ferns, the phloem being, in the former, completely surrounded bya layer of xylem. There is no other difference between these concentric bundles of the rhizome and the collateral bundles of the aerial stem and leaves, except in the relative position of the xylem and phloem. Transitions are exhibited from one form to the other in the gradual collection of the xylem round the phloem ; and perixylematic bundles are to be found in the nodes of * Bull. Soc. Bot. France, xxxiv. (1887) pp. 307-9. + See this Journal, 1887, p. 260. + Bull, Soc. Bot. France, xxxiv. (1887) pp. 301-3. § Laux, W., ‘Ein Beitr. z. Kenntn. d: Leitbiindel im Rhizom monocotyler Pflanzen,’ 49 pp. and 2 pls., Berlin, 1887. See Bot. Ztg., xly. (1887) p. 611. ZOOLOGY AND BOTANY, MICROSCOPY, ETC. Lo the aerial stem of certain species of Juncus. Transitional forms between the perixylematic and the collateral structure occur on the same transverse section. The structure of the rhizome of different species of Cyperacee shows an almost endless variety in the construction of the bundles, Comparative Anatomy of Geraniacee.*—From an examination of 14 species of Geranium, 3 of Erodium, and 3 of Pelargonium, Herr W. Jiinnicke gives characters by which these three genera can be distin- guished from one another, derived from the structure and distribution of the vascular bundles in the leaf-stalk and flower-stalk. Anomalous Thickening in the Roots of Cycas.;—Mr. W. H. Gregg finds in Cycas Seemanni, in addition to the abnormal thickenings of the stem well-known in several genera of Cycadez, similar thickenings in the root. These abnormal thickenings of the root always proceed from the pericambium, which consists of several layers of cells. The ‘ primary thickening presents the peculiarity that the normal relative positions of the xylem and phloem are reversed, the former lying out- side, the latter inside. This is followed by an outer secondary abnormal thickening, in which the xylem and phloem occupy their normal relative position. Formation of Annual Rings in Wood. t{—Herr G. Krabbe dissents from the explanation of the formation of annual rings offered by Wieler, that it is due to a difference in the supply of nutriment at different periods of the year, less in the latter part of the summer than in the spring. He asserts that this difference rests on no experimental basis— Hartig maintaining exactly the opposite—and considers that the cause of the formation of these rings is still an unsolved problem in vegetable physiology. Mechanical system of Pendent Organs.§S—Herr A. Y. Grevillius has investigated the peculiarities of structure of the mechanical tissues in a number of plants, both shrubby and herbaceous, whether pendent varieties or organs normally pendent. He finds their general characteristic to be that the organs in question are narrower and more slender, and have their mechanical system less strongly developed, and with a stronger tendency to assume a central position. Comparative Anatomy of Roots.||—Dr. O. Lohrer has examined the histological structure of the roots of representatives of a large number of natural orders, to determine to what extent characters of this kind are common to all the members of groups or families. He finds it to differ in different cases. Members of fifteen families of Papilionacez examined all agreed in these points:—The bast is chiefly prosenchymatous ; the bast-fibres lie scattered or in small groups in and above the soft bast; their cell-cavity is extremely small; the very thick refringent cell-wall is clearly dif- * Abh. Senckenberg. Naturf. Gesell., xiv. (1886) 24 pp. and 1 pl. See Bot. Centralbl., xxxi. (1887) p. 36. + Ann. of Bot., i. (1887) pp. 63-70 (1 pl.). + Ber. Deutsch. Bot. Gesell., vy. (1887) pp. 222-32. § Natury. Studentsallsk. Upsala, March 10, 1887, See Bot. Centralbl., xxxi. (1887) p. 398. || Wigand’s Bot, Hefte, ii. (1887) pp. 1-48 (2 pls.). 76 SUMMARY OF CURRENT RESEARCHES RELATING TO ferentiated from the primary membrane; their diameter in transverse section is small. The Caryophyllacez are also characterized, with some exceptions, by distinguishing peculiarities in the structure of the root. The extra- cambial tissue is usually strongly collenchymatous. The walls of the short cells of the prosenchyma are thin or collenchymatous, but never lignified in the entire xylem. The root of the Chenopodiaces is distinguished by its regular con- centric arrangement. The Cruciferz include several different types ; and the author appends a clavis by which it can be determined to which of the species examined any given crucifer-root belongs. In other orders the characters of the root are by no means so uniform; while in other cases those of particular species are very sharply marked off from all others nearly allied to them. This is the case with Urtica dioica and Rheum rhaponticum. With regard to the rhizome, the author finds that it generally differs from the root in essential anatomical characters, as in the position and form of the vascular bundles ; and from the stem in the strongly developed cortical parenchyma. A true endoderm in the root was observed in only one instance, that of Helleborus niger. (4) Structure of Organs. Respiratory Organs.—Herr L. Jost * proposes the term “ pneuma- thode”’ for those parts of plants which are especially adapted by their structure for respiration, such as aerial roots. These are of specially frequent occurrence in many species of palm belonging to the genera Livistona, Phenix, and others. In L. australis they may rise erect to a considerable height (the result of negative geotropism), and are furnished with an evident root-cap. The “ pneumathodes” here are certain white spaces where the ordinary brown epidermis is replaced by cells of peculiar form, containing air, and very loosely connected with one another. In other palms the pneumathodes do not occur on roots rising erect in the air, but on those with a normal horizontal position, or they are found on ordinary lateral roots. It was shown by experiment that the tendency of an abundant supply of water is to promote the production of aerial roots; while, when the supply of water is limited, the pneumathodes are formed beneath the soil. ‘The influence of water on the direction of the growth of roots is, however, indirect rather than direct ; hydrotropism could not cause the roots to rise erect out of the water ; the author considers that it may in great measure be attributed to the properly-named “ aérotropism ” by Molisch.t+ The structure of the vascular-bundle in the pneumathode differs in no respect from that in the other parts of the root; in the cortical parenchyma the elongated intercellular spaces have almost entirely dis- appeared, as also the epidermis and the hypodermal sclerenchymatous ring, the latter being replaced by a sclerenchymatous layer beneath the peripheral spongy layer of thin-walled cells. Further illustrations of pneumathodes are afforded by Pandanus furcatus and pygmexus, Saccharum officinarum, Cyperus textilis, Luffa amara, Taxodium distichum, and other perennial plants. * Bot. Ztg., xlv. (1887) pp. 601-6, 617-28, 633-42 (1 pl.). + Cf. this Journal, 1885, p. 96. ZOOLOGY AND BOTANY, MICROSCOPY, ETC. q(T) In commenting on this paper Herr K. Goebel * points out that he has already ascribed { to the aerial roots of Sonneratia and Avicennia the property of serving as organs of respiration, their production being incited by the peculiar habitat. Organs of Secretion.t—Herr A. Tschirch has continued his in- vestigations on the secretions and secreting structures of plants. (1) The epidermal glands of Labiate and Composite, which contain ethereal oil, are formed on two different types. In Labiates, wherever the glands occur, they consist of a ring of secreting cells which lie beside one another in fours or a multiple of four. The head-cell is divided by radial partitions at right angles to the surface of the organ. In Com- positee, on the other hand, the cells are arranged in layers one above the other, often only the two upper layers secrete; all the secreting cells are divided by a median radial partition, usually at right angles to the longitudinal axis of the organ. In the head-cell tangential walls parallel to the surface are first formed, then a radial partition in each of these divisions. From the surface the glands of Labiate exhibit a central cell with a surrounding ring usually of eight, while those of Composit form an elongated oval divided through the centre. (2) The origin of copaiva balsam is unique. The balsam is ex- clusively formed in the wood, and there in the older portions. It arises by retrogressive metamorphosis first of the walls of the vessels, but implicating also the adjacent cells. Even in one-year twigs the metamorphosis of some vessels was observed. Except in the case of the very different “resin-gallen’’ of Conifers, this is the first certain illustration of the possible modification of cellulose into resin or resin- like substances. (3) In @ second paper Herr Tschirch notes that the seat of the cinchona-alkaloids is almost exclusively the cortical parenchyma, and the contents of the cells. This cortical parenchyma is greatly increased in the secondary cortex, while all the other elements of the bark dis- appear. The increase in the alkaloid content depends chiefly on an in- creased development of the thin-walled alkaloid-bearing tissue elements, not on an increase of the absolute content of the individual cells. The alkaloids pass only secondarily in the dry bark into the cell-walls. Anatomy of Water-plants.s—Dr. H. Schenck sums up the anatomical characters of plants which grow entirely submerged in water. The leaf is almost always divided into capillary teeth, or is a narrow grass-like ribbon; exceptions are afforded by some species of Potamo- geton. The parenchyma does not assume the spongy form with large intercellular lacunz, the cells being prismatic in form and fitting closely together without intercellular spaces, or else inclosing very large lacune in the interior; stomata are very rare, and the greater part of the chlorophyll is contained in the epidermis. The vascular bundles are of very simple structure, and are inclosed in a parenchymatous sheath, which does not differ essentially in structure from the surrounding * Bot. Ztg., xlv. (1887) pp. 717-8. + See this Journal, 1887, p. 111. } Versamml. Deutsch. Naturf. u. Aerzte, Wiesbaden, Sept. 21, 1887. See Biol. Centralbl., vii. (1887) p. 133. § Uhlworm und Haenlein’s Biblioth. Bot., i. (1886) pp. 1-67 (10 pis.). Of. this Journal, 1886, p. 272, 78 SUMMARY OF CURRENT RESEARCHES RELATING TO parenchyma. The special development of the leaf is described in a number of individual cases. The large air-cavities may be either schizogenous or lysigenous. The mechanical system of the whole plant is reduced to a very feeble development. Organs for secretion and excretion are, as a rule, entirely wanting, though calcium oxalate is sometimes excreted abundantly. The root-system of submerged plants seldom attains any great develop- ment. The central vascular cylinder is probably formed from the union of a number of bundles. Lateralness in Conifere.*—The term “lateralness” of an organ is defined by Herr E. Henning as expressing the distribution of the phenomena of organization on the transverse section, or especially around the axis of growth. Strictly speaking, all the leaves of conifers are dorsiventral, since the vascular bundles are collateral. He describes the lateralness of a leaf as radiar when the tissues are uniformly developed around the vascular bundle, and if the leaf has, in addition, a circular or polygonal transverse section; bilateral when they are flat while the structure of the tissue is the same. A table is given of the variations, within the order of Conifer, of the combinations of these and some other differences of structure connected with the lateralness of the leaves and branches. Dichotypy.t—Herr W. O. Focke adduces the following instances of dichotypy, i.e. of the occurrence of two different forms of the same organ on the same stock :—A number of specimens of a hybrid between Anagallis phenica and A. cerulea, in which most of the flowers were scarlet, a single one having half one of the corolla-lobes dark blue; a specimen of Mirabilis Jalapa, in which most of the shoots had white flowers sprinkled with red, a few pure red flowers; and a hybrid between Trollius europeus and T. asiaticus, in which most of the flowers were yellow, those on a single branch red. Flowers and Fruit of Sparganium and Typha.{—This treatise by Dr. 8. Dietz is now published in detail, with illustrations. The two genera should, he considers, be placed under distinct families, or at least sub-families, Sparganinm having a nearer affinity to the Panda- nacex, Typha to the Aroidee. The fruit of Typha is a caryopsis, that of Sparganium a drupe. Fruits and Seeds of Rhamnus.$—Prof. H. Marshall Ward (assisted by Mr. J. Dunlop) has conducted a series of experiments for the purpose of explaining the phenomena connected with the colouring matter of species of Khamnus, especially R. infectorius. A beautiful golden yellow solution can be obtained by macerating the fruit in water ; but, although the seat of the pigment is evidently the pericarp, the whole berry, including the seed, must be crushed in order to obtain it. The explanation of this phenomenon offered by Prof. Ward is that the xanthorhamnin present in the pericarp is a glucoside, and that it breaks up, under the influence of a ferment present in the seed, into the * Naturv. Studentsallsk. Upsala,’ Feb. 24, 1887. See Bot. Centralbl., xxxi. (1887) p. 393. + Abhandl. Naturwiss. Ver. Bremen, ix. (1887). See Bot. Centralbl., xxxii. (1887) p. 43. + Uhlworm und Haenlein’s Biblioth. Bot., v. (1887) pp. 1-59 (8 pls.). Cf. this Journal, 1887, p. 114. § Ann. of Bot., i. (1887) pp. 1-26 (2 pls.). ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 19 colouring substance rhamnin, and glucose. Further experiment showed that the seat of this ferment in the seed is nearly or quite exclusively the raphe. If toa fresh solution of the boiled pericarp a very small portion of the raphe is added, a copious precipitate is almost immediately obiained of semi-crystalline yellow masses of rhamnetin. The cells of the raphe are found to contain a brilliant oily-looking colourless sub- stance. No trace of this ferment was found in four other species of Rhamnus examined, viz. R. tinctorius, carolinianus, Wicklius, and catharticus. As to the nature of the ferment, nothing definite was determined. Prof. Ward suggests that the purpose of this arrangement is the production of glucose as soon as the seed begins to germinate, for the nutrition of the young seedling. Masked Fruits.*—Herr A. N. Lundstrom describes the heterocarpic condition exhibited by Calendula and Dimorphotheca. In the former (1) wind-transportable, (2) hook-bearing, (8) larva-like fruits occur. He gives reasons for regarding the resemblance between the last- mentioned fruits and the caterpillars of certain butterflies as indeed a case of mimicry. Development of the Fruit of Umbelliferze.;—Messrs. J. M. Coulter and J. N. Rose describe the development of the fruit in Umbellifere, Cherophyllum procumbens being selected as a type. In very young buds groups of three or four parenchyma-cells of the pericarp, next the inner epidermis, begin to be set apart for the forma- tion of oil-ducts. The first indication of this is that they become secreting cells, and are discoloured by the characteristic oily contents, and also become larger than the surrounding parenchyma-cells. Upon approaching the period of flowering, the parenchyma-cells surrounding each fibrovascular bundle subdivide, and when the flower opens, quite a distinct group of small parenchyma-cells is discovered beneath each rib; these subsequently develope into strengthening cells. The exten- sion of undifferentiated parenchyma is effected by radial cell-division, the amount of tangential division being comparatively small. Axis of the Inflorescence.t—Herr O. Klein describes in detail the comparative anatomy of the axis of the inflorescence. The epidermis is not strongly thickened, except in those cases where the inflorescence persists through the winter, as in that of the male catkins of the birch and hazel; here it is strongly suberized. The cortex consists either of chlorophyllous or of non-chlorophyllous cells. The cortical parenchyma increases with the ascending order of the branches, at the expense of the mechanical tissue, especially where the inflorescence is destitute of leaves, as in the Juncacee. The vascular bundles retain nearly ‘the same diameter throughout, but their constitution alters; the hadrome continually diminishing towards the apex, while the leptome increases to a corresponding extent. The number of bundles decreases with the constant decrease in the diameter of the axis. The axis of the in- florescence of Umbellifere is treated in detail, especially in regard of its power of bending. * Nov. Act. Reg. Soc. Scient. Upsala, xiii. (1887) pp. 72-7. + Bot. Gazette, xii. (1887) pp. 237-43 (1 pl.). ¢ Jahrb. K. Bot. Gart. Berlin, iv. (1886) pp. 333-63. See Bot, Centralbl., xxxii. (1887) p. 107. Cf. this Journal, 1887, p. 989. 80 SUMMARY OF CURRENT RESEARCHES RELATING TO Development and Structure of Orobanche in a young stage, and of its suckers.*—-M. M. Hovelacque describes the development and structure of Orobanche, taking as his type O. eruenta. In a very early stage the Orobanche appears on the host as a circular or curved spot. ‘The parasite has penetrated the fibrovascular bundles of its host, and consists of a single unramified sucker which now begins to enlarge rapidly. When more developed, the young Orobanche appears as a hemispherical swelling; it is, however, impossible to distinguish growing point, axis, or appendages. At a later stage the vegetative point is found to consist of dermatogen, which layer covers a meristematic mass undifferentiated into periblem and plerome. At the base of the growing point the first leaves appear in their order. Certain procambial threads reach from the fibrovascular bundle of the sucker to the more developed leaves. The points of growth of the roots may be seen in the middle of a mass of cortical tissue, the elements of which are large. Young plants of O. minor differ from C. cruenta in that they are provided with more numerous roots. In O. Heder, on the contrary, the roots are less numerous, and develope more slowly, but the adventitious buds are more numerous. M. Hovelacque classifies the suckers of Orobanche under four types, viz.:—(1) Small unicellular suckers. When the root of an Orobanche touches the nourishing root of a host by a very small point, this contact is often limited to a single cell of the superficial layer. The morpho- logical value of these suckers is that of root-hairs. (2) Small multi- cellular suckers. When the contact with the host affects more than one cell, these cells elongate and penetrate the host in a single mass. (3) Large unramified suckers. When the surface of contact of the parasitic root with the nourishing root is very large, many of the superficial cells take part in the formation of a sucker. In this case the sucker partakes of the character of a very imperfect root. (4) Large ramified suckers. Ramified suckers differ from the preceding only in the fact that, when penetrating the root of the host, they branch. In this last case the suckers of Orobanche are homologous to a bundle of imperfect roots. Origin of the Suckers in Phanerogamous Parasites.;—M.. Granel states that in Melampyrum pratense the suckers arise in the cortex. The cells of the piliferous layer, after elongation, divide into a filament of cells; one, two, or three cells from the middle of each filament elongate rapidly towards the exterior, and imbed themselves in the host. Among plants with temporary suckers, some develope their organs of absorption on their roots; these are, for example: Osyris alba, Thesium, Melampyrum, Orobanche minor. In others the suckers arise in the stem; for example: the Cuscutex, Cassytha, &c. Osyris alba possesses a large number of normal roots, and also has suckers. It presents then a coexistence of free and parasitic life. In conclusion the author states that in Osyris alba, Orobanche minor, and Thesium divaricatum, the origin of the suckers is to a great extent identical; they arise in the cortical parenchyma, and are joined slowly by some cells formed by the pericycle. Arrangement of Secondary Roots and Buds on Roots.{—M. P. van Tieghem discusses the laws which govern the arrangement of the lateral * Comptes Rendus, cy. (1887) pp. 470-1, 530-3. + Bull. Soc. Bot. France, xxxiy. (1887) pp. 313-20. t} Ann. Sci. Nat.—Bot., vy. (1887) pp. 130-51. ZOOLOGY AND BOTANY, MICROSCOPY, ETO. 81 roots and buds on the root and lower part of the hypocotyl of Phan- erogams in those cases where the structure of these organs is binary. Tn all these cases, which are very common, the root, whether terminal or lateral, primary, secondary, or of any other order, forms its subsidiary roots in the pericycle in front of the intervals which separate its two xylem-bundles from its two liber-bundles, and places them in consequence in four longitudinal rows. The author terms those rootlets “ isostique ” when the mother-root has more than two, “diplostique”’ when it has only two xylem-bundles. Whenever a root, whether primary, terminal, or lateral, is binary, its branching is governed by the second of these laws. The same law governs the arrangement of the normal buds which frequently make their appearance on the hypocotyl. The local production of double roots and double buds is not un- common, especially in Umbelliferee. The normal hypocotyledonary buds above alluded to almost always spring from the pericycle of the root or of the stem; the only known exception is in the case of the Linariacee, where they are of exogenous origin. Epidermal Glands.*—M. P. Vuillemin has examined the structure of the epidermal glands in the natural orders Plumbaginacex, Frankeni- acew, and Tamarisciner. In those of the two latter orders he finds a very strong similarity to one another. Those of the Plumbaginacex, while resembling the glands of the other two orders in their structure, origin, and functions, yet present some well-marked morphological differences. They are, in all three orders, hairs transformed into organs of excretion, and intended to complement the action of the stomata. They detain the waste products arrested by the thick walls which bound the intercellular spaces, but which are able to pass through the walls of these secreting cells, which are always punctated, the gland opening outwards through a very narrow orifice, and being always lined at its base with a layer of protoplasm. In the Plumbaginacexw each gland always consists of eight secreting cells. The substance secreted may be entirely volatilizable, or may be mucilaginous, or may contain a large quantity of salts of lime in solution, which is deposited, on evaporation, over the whole surface of the leaf. In the Frankeniaceew and Tamariscinee each gland consists of only two secreting and two subsidiary glands. The secretion is, in the Frankeni- ace, generally calcareous, solidifying on evaporation; while in the Tamariscinee it is resinous, not yielding a calcareous concretion on evaporation. Prickle-pores of Victoria regia.t—Mr. J. H. Blake, having examined the large prickles on the leaf-veins and petioles of Victoria regia, finds that only the larger ones are penetrated by a fibrovascular bundle, and that the opening or ostiole described as existing at the apex of the spine is not invariably present, and is probably the result of injury. Morphological Peculiarity of Cordyline australis.t—Prof. F. O. Bower records a peculiarity in this plant growing in Ceylon, that, when the stem assumes an oblique or horizontal position, lateral shoots are put out from the lower side of the main axis, which direct themselves vertically downwards. They are of exogenous origin, with exceedingly * Ann. Sci. Nat.—Bot., v. (1887) pp. 152-77 (1 pl.). + Ann. of Bot., i. (1887) pp. 74-5. ¢{ Proc. Phil. Soc. Glasgow, xviii. (1887) pp. 317-9 (1 pl.). 1888. G 82 SUMMARY OF CURRENT RESEARCHES RELATING TO slow growth, and produce roots of endogenous origin. In their function of root-bearing organs they bear a resemblance to the rhizophores of Selaginella. Nyctaginez.*—From the special examination of three species, Mira- bilis Jalapa, M. longiflora, and Oxybaphus nyctagineus, Herr A. Heimer] gives the following as the most characteristic peculiarities of the order :— The ovule presents an intermediate form between the campylotropous and anatropous. The conducting apparatus for the pollen-tubes is re- markably well developed. The three antipodal cells are already invested with cell-walls before impregnation, and continue for a time after this. The endosperm is inconsiderable in quantity, and transitory; the peri- sperm, on the other hand, very fully developed. The wall of the ripe pericarp is of complicated structure, with a central sclerenchymatous layer, and an outer layer containing tannin. Cells containing raphides are very abundant in the short prolongation of the floral axis on which the ovary is seated, and in the lower part of the pericarp; in smaller quantity also in the wall of the ovary; they are altogether wanting in the ovules. The ripe fruit is inclosed in a very thin brown skin, formed by the fusion of two layers, the outer of which is developed from the outer epidermis of the ovary, the inner and stronger one from the testa of the seed. Root-tubers and Bacteria.t—Herr P. Sorauer sums up succinctly the results of the observations of T'schirch, Woronin, Kny, Brunchorst, Hellriegel, Eriksson, Frank, Benecke, and Moller, on the true nature of the root-tubers in Leguminose, as well as in Hleagnacee and in Alnus. B. Physiology.f{ (1) Reproduction and Germination. Insect relations of Asclepiadexe.§ — Mr. C. Robertson describes the insect relations of certain Asclepiads. He states that while in ordinary flowers an insect may be a useful visitor if it can reach the nectar, in Asclepias many other conditions influence the insect relations. Of visitors whose tongues are suited to the nectaries, many are useless, because they do not light upon the flowers (Sphyngide, Aigeriade, and Trochilus) ; others because their legs are not long enough to extract pollinia (Megachile). Others, again, rest their feet so lightly as seldom to effect pollination; e.g. Diptera and small butterflies; while others are not strong enough to free their claws from the slits and break the retinacula. In all seventeen species were found to be kilied on this account. The author describes in detail several species of the genus Asclepias, and also two species of Acerates. Fertilization of Flowers.||—Dr. J. MacLeod has added a sort of appendix to the classic work of Hermann Miiller on the fertilization of flowers. He has extended and corroborated the work of the great * Denkschr. K. Akad. Wiss. Wien, liii. (1887) 3 pls. + Bot. Centralbl., xxxi. (1887) pp. 3808-14, 343-5. ¢ This subdivision contains (1) Reproduction and Germination; (2) Nutrition and Growth (including Movements of Fluids); (8) Lrritability; and (4) Chemical Changes (including Respiration and Fermentation). § Bot. Gazette, xii. (1887) pp. 207-16, 244-50. || Arch. de Biol., vii. (1887) pp. 131-66 (1 pl.). ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 835 master observer in this department. The flowers studied were Silene Armeria, Stellaria graminea, 8. uliginosa, Sagina procumbens var. apetala, Hibiscus syriacus, Viola, Potentilla Fragaria, Ribes nigrum, Lysimachia vulgaris, Ajuga reptans, and Teucrium Scorodonium. He notes, in regard to varieties of Lysimachia vulgaris, that in some direct fertilization is certain, in others all but impossible. He calis attention to the different forms of sexual arrangements observed in Stel- laria graminea. In Teucrium a peculiarity results in cross-fertilization, not only between different flowers, but between different inflorescences. The Caryophyllacee are disposed in two classes:—(1) Where self- fertilization is entirely or almost entirely impossible ; (2) where cross- fertilization is less perfectly insured, and where self-fertilization may, in case of need, occur. Flowering of Euryale ferox.*—It has been a matter of controversy whether this plant, belonging to the Nympheacex, opens its flowers above or below the surface of the water. From observations made in the botanic gardens at Rome, Prof. G. Arcangeli concludes that the flower is perfected under water, and is cleistogamous, self-fertilization taking place in a kind of chamber formed by the perianth, the stigmatic disc, which is curved into the form of a cup, and the stamens. (2) Nutrition and Growth (including Movements of Fluids). Growth and Origin of Multicellular Plants.;—Mr. G. Massee describes the structure and mode of formation of the gelatinous mem- brane exterior to the true cellulose-wall, and extending continuously over the whole plant, which isnot uncommon in Algze, and universal in the Florideze. It can be clearly shown that the formation of the cellulose- wall never precedes that of the mucilaginous sheath, and its function is rather a supporting than a protecting one. The composition of the mucilaginous sheath closely resembles, or is identical with, that of pro- toplasm. 'The sheath is usually homogeneous, even after the appearance of the cell-wall; but in Pandorina the innermost portion consists of parallel rods placed end to end on the cell-wall ; while in Cladophora crispata the rods run parallel to the surface of the wall. The portion consisting of rods stains readily with methyl-violet and other anilin dyes, while the homogeneous portion does not stain. In some cases, as in Polysiphonia, the surface of the sheath is more or less papillose, and not unfrequently a papilla may be seen to extend itself into an exceedingly fine cilium, varying in length from 5 to 100 p, and less than 1 » thick. These cilia are plastic and flexible, but have no spontaneous vibratile motion. They appear not to be unlike those described by the author as occurring on the surface of some of the large stipitate glands on the underground leaves of Lathraa squamaria.t The outermost layers of this mucilaginous sheath often become strongly cuticularized, while the inner portions do not change in their chemical reactions. Internally, as in the stipes of many Alga, it is secreted in such quantities as to force the cells apart, and destroy the connecting strands of protoplasm ; and within this mucilaginous matrix strings of new cells appear as outgrowths from older cells. * Atti Soc. Tose. Sci. Nat., viii. (1887) pp. 281-300. + Journ. of Bot., xxv. (1887) pp. 257-67. { See this Journal, 1887, p. 111. a 2 84 SUMMARY OF GURRENT RESEARCHES RELATING TO The change from a unicellular to a multicellular condition appears to be due to the influence of this external sheath. In Alge the cellulose cell-wall is formed in the middle of this sheath. In unicellular Alga the tendency to form colonies is due to the copious secretion of mucilage, which is external to, and quite distinct from the sheath ; and the primary function of which appears to be to prevent desiccation. This, again, has its analogue in the higher plants in the copious secretion of mucilage from the stipules of Anomoclada among Hepatic, and from the mucilage- cells of Blechnum and Osmunda. Plants remain unicellular so long as the tendency of the protoplasm to resolve itself into a sphere, after cell- division, predominates over external forces; and the same occurs where cells are free from the pressure of the surrounding tissues, as in pollen- grains. The cap-like structure which covers the growing point in Oscillaria is simply the relatively thick undifferentiated portion of the sheath, which contracts as it becomes cuticularized. The ring-like structure at the distal end of the cells of Gidogonium is described in detail, and is regarded by the author as only a special form of apical growth, combined with an unusual rigidity of the investing sheath. Influence of Light on the Form and Structure of Leaves.*—A series of experiments on the influence of various degrees of illumination on the size and internal structure of leaves has led M. L. Dufour to the following conclusions :— The development of the plant increases in proportion to the degree of illumination. It increases in size, it branches more copiously ; its stem and branches exceed in diameter the corresponding parts of the same plant exposed to a less degree of illumination; its leaves attain the largest dimensions both in surface and in thickness; and the flowering is earlier and more abundant. The same law applies also to the internal structure of the leaf. The stomata are more abundant. The elements of the epidermis are more fully developed in the sun; the cells are larger, with thicker lateral and outer walls; the cuticle, in particular, is more strongly developed. The walls of the epidermal cells are more sinuous in the sun than in the shade. The palisade-parenchyma also displays a stronger development ; its cells are longer in the transverse direction than when the plant grows in the shade; they contain more chlorophyll and more starch. The same also is true of the conducting tissue; the vessels are more numerous and larger. The strengthening tissue presents the same characters as those displayed in the sclerenchymatous and collenchymatous elements. The secreting canals are larger, and contain larger quantities of eli- minated substances, and the same is true of the deposition of calcium oxalate. As a general law, M. Dufour comes to the conclusion that the state- ment of some previous observers that there is an optimum degree of illumination for the plant considerably below that derived from the direct rays of the sun, is incorrect ; and that, other things being equal, the plant, and every part of the plant, is more fully developed in pro- portion as it is exposed to a more intense illumination. 5 Ann. Sci. Nat.—Bot., v. (1887) pp. 311-413 (6 pls.). Cf. this Journal, 1887, p. 824. ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 85 (4) Chemical Changes (including Respiration and Fermentation). Exhalation of Oxygen by fleshy-leaved Plants in absence of Carbonic Anhydride.*—Herr A. Mayer, by former researches, has shown that under certain conditions oxygen is exhaled by the leaves of some plants in absence of carbonic anhydride. This is more especially the case with the Crassulacee ; and it was found that leaves of Bryophyllum calycinum, which contain malates, after a period of darkness (during night) have an acid reaction, but during the daytime this reaction becomes much less. The author’s experiments, made since 1883, show that “acid leaves,’ during insolation in an atmosphere free from carbonic anhydride, yield more oxygen the richer they are in free acid. The acid present is malic acid; and this acid and the calcium salt diminish during insolation, just as if the whole consisted of free acid, the products resulting from the change being starch, sugar, &c., and the amount of oxygen which should be separated by the produced carbo- hydrates agrees well with the quantity of oxygen found to be set free by insolation. Respiration of the Potato.j—Herr J. Boehm gives the results of a large number of experiments on the exhalation of carbonic acid by potatoes, whether ordinary or sweet, injured or uninjured. As in the case of seedlings of Phaseolus multiflorus, the intensity of the respiration is, in most cases, independent of the partial pressure of oxygen, though there are conditions under which this is not the case. Herr Boehm finds that when cut into pieces, potatoes respire much more energetically than when uninjured. The internal respiration is independent of external injury, and is much more intense with sweet than with ordinary potatoes ; but in both cases the internal respiration is greatly increased, with cut potatoes, when they are previously placed for a day in moist air at a temperature favourable for normal respiration. Action of Formose on Cells destitute of Starch—By experiments on Frazinus Ornus, Rubia tinctorum, Syringa vulgaris, and Cacalia suaveolens, Dr. C. Wehmer{ has determined that formose (C;H,,0,, obtained by the condensation of formic aldehyde) belongs to the class of carbohydrates which living leaves have not the power of converting into starch; agreeing in this respect with milk-sugar, raffinose, inosite, dextrin, erythrite, trioxymethylen, and some organic acids; and differing from dextrose, levulose, galactose, maltose, cane-sugar, mannite, dulcite, and glycerin. j 1 Commenting on this paper, Herr O. Loew § disputes the accuracy of some of Dr. Wehmer’s results, and especially dissents from a conclusion drawn by that gentleman from the fact that he was unable to obtain starch from formose. This induces Wehmer to oppose the recent view that formic aldehyde is the first product of assimilation in plants, but, as Loew thinks, on insufficient grounds. y- General. Biology of Orobanche.||—Herr L. Koch describes in detail the life- history of several species of Orobanche. 'The seeds, which are produced * Landw. Versuchs-Stat., xxxiv. pp. 127-43. See Journ. Chem. Soc., 1887, Abstr., p. 988. + Bot. Ztg., xlv. (1887) pp. 671-5, 681-92. t Bot. Ztg., xlv. (1887) pp. 713-7. § Ibid., pp. 813-4, | Koch, L., ‘ Die Entwicklungsgeschichte der Orobancheen,’ 389 pp. and 17 pls, Heidelberg, 1887. See Bot. Centralbl., xxxi, (1887) p. 361. 86 SUMMARY OF CURRENT RESEARCHES RELATING TO in enormous numbers, 100,000 to 150,000 on an individual, can germi- nate only when in contact with the root of the host; they may retain their power of germination for two years. 'The embryo developes into a filiform structure; and the penetration is effected, as with parasitic fungi, by a secretion from the parasite which dissolves the tissues of the host. The young plant penetrates to the vascular bundle of the host, but does not appear to inflict any serious injury upon it. In the endogenous formation of the growing point Orobanche shows a resem- blance to Rafjlesia. The structure described by some writers as an “intermediate organ” between host and parasite, results simply from the common growth of the parasite and of the root of the host. From the true haustorium, the portion of the parasite which first penetrates the tissue of the host, secondary haustoria spring, which serve for its non- sexual reproduction. With regard to the plants from which the various species of Oro- banche derive their nourishment, this is not altogether indifferent; each species of parasite has only certain hosts on which it will grow, though these may be numerous and not necessarily nearly related to one another; thus O. ramosa is parasitic on the hemp and on tobacco. O. minor was found to grow on forty-four different species, O. ramosa on twenty-nine, O. speciosa on thirteen, and O. Hederz on three species of host-plant. Biology of the Mistletoe.*—Dr. M. Kronfeld describes at length the mode of life and germination of the mistletoe. He states that the popular idea that the seeds can germinate only after passing through the intestinal eanal of a bird, is correct only with considerable limitation. No doubt seeds are occasionally passed with the excreta, and are then in a favourable condition to germinate. But the majority of the seeds are rejected by birds when feeding on the white pulp of the fruit. The seeds can easily be made to germinate in the ordinary way, but require a long period of rest after ripening. The mistletoe is also propagated non-sexually by buds. Polyembryony occurs normally, a very large proportion of the seeds containing two or three embryos. The development of the plant varies greatly, according to the tree on which it is parasitic; and this has been the source of the manufacture of a large number of false species. It will grow on almost any tree except certain conifers. It is least luxuriant on other species of Conifers ; most so on Robinia Pseudacacia. Root-symbiosis in the Ericacee.j—Herr B. Frank finds this to be an almost universal phenomenon in the Ericacez. The roots afflicted in this way are distinguished by their extraordinary tenuity (0:07-0:05 or even 0:03 mm.), greater length, and sparsity of branching. They usually consist of nothing but a single slender fibrovascular bundle and epi- dermis, the root-hairs being altogether suppressed. The epidermis is well developed; the cell-cavities are large, and completely filled by an irregularly interwoven mass of fungus-hyphe. They are also enveloped in a weft of hyphez, which do not, however, form a closed envelope, but are connected in a variety of ways with the intercellular hyphe. The * Biol. Centralbl., vii. (1887) pp. 449-64 (8 figs.). + SB. Versamml. Deutsch. Naturf. u. Aerzte, Wiesbaden, Sept. 21, 1887. See Bot. Centralbl., xxxii. (1887) p. 57. Cf. this Journal, 1886, p. 113. ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 87 mycorhiza was found in all the localities examined, whether moory or heathy ; and on the following species :— Vaccinium uliginosum, Oxycoccus, Myrtillus, and Vitis-Idea, Andromeda polifolia, Ledum palustre, and Calluna vulgaris, as well as on cultivated specimens of Vaccinium macro- carpum, Azalea indica, and Rhododendron ponticum, and on Empetrum nigrum. Domatia.*—Dr. A. N. Lundstrém defines as “domatia” those formations or transformations on plants adapted to the habitation of guests, whether animal or vegetable, which are of service to the host, in contrast to cecidia, where such habitation is injurious to the plant. He describes these domatia in detail on the lime, alder, hazel, and other trees and shrubs, and gives a very long list of species, belonging to a great variety of natural orders, on which they are found. The principal types of shelter are as follows :—(1) Hair-tufts, e. g. in Tilia europea; (2) recurvatures or foldings in various parts, e. g. in “Quercus robur, Ilex, Schinus, Ceanothus africanus; (3) grooves without hairs, as in Coffea arabica, Coprosma baueriana ; with marginal hairs, e.g. in Psychotria daphnoides, Rudgea lanceolata, Faramea, Rhamnus glandulosa, Coprosma Billiardieri ; with basal hairs, as in Anacardium occidentale ; (4) pockets, as in Elxocarpus oblongus, E. dentatus, Psy- chotria, Lonicera alpigena ; (5) pouches, e. g. Eugenia australis. These different types of domatia are connected by transition forms. The habit of producing domatia in a species may become hereditary without the actual presence of the predisposing cause. Certain orders, e. g. Rubiacex (famous also for ant-domatia), show a marked predisposition to acaro- domatia, Many groups seem entirely without them, e. g. Monocotyledons and Gymnosperms, and all herbs. They are most abundant and_ best developed in tropical (and temperate) zones. In the second chapter the author discusses in detail the various interpretations which may be put upon domatia. (1) They may be pathological, like galls; (2) they may be for catching insects; (3) they may have only an indirect connection with their tenants; (4) they may be of use to the plant as the dwellings of commensals. He adopts the last interpretation. He draws an interesting parallel, however, between galls and domatia, and is inclined to suppose that the domatia were first directly caused by the insects, but have gradually become inherent transmitted characteristics. The author gives a clear table, distinguish- ing the cecidia or galls due to “antagonistic symbiosis,” either plant or animal (phyto- and zoo-cecidia), and domatia due to “ mutual symbiosis,” either plant or animal (phyto- and zoo-domatia). Those due to plants are again subdivided into myco- and phyco-cecidia or -domatia. Myrmecophilous Plants.|—Herr A. N. Lundstrém observes that several species of Melampyrum are provided with dot-like nectariferous trichomes on their leaves and bracts. These attract large numbers of ants, which he believes are of service to the plant in the following way. ‘The seeds of these species bear an extraordinary resemblance to the larve of ants, even to the excrement-sac; and being mistaken for larve by the ants, are carried by them to their nests, where they germinate. Herr Lundstrém names also a number of myrmecophilous plants * Nov. Act. R. Soc. Scient. Upsala, xiii. (1887) pp. 1-72 (4 pls). See this Journal, 1887, p. 273. + Noy. Act. R. Soc. Scient. Upsala, xiii, (1887) pp. 77-88. 88 SUMMARY OF CURRENT RESEARCHES RELATING TO belonging to the Scandinavian flora, and describes the contrivance, not hitherto noticed, in the aspen. Humboldtia laurifolia as a Myrmecophilous Plant.*—Prof. F. O. Bower's description of this plant, a native of Ceylon, is now published in full. He ascribes the formation of the hollow channels in the stem and branches which the ants inhabit in the first place to rupture from tension; and believes that the ants only then fortuitously take posses- sion of them. He sees no evidence that the presence of the ants is of any advantage to the plant. A somewhat similar structure occurs in Clerodendron fistulosum n. sp. and Myristica myrmecophila n. sp., and in Nepenthes bicalcarata from North Borneo. Oxidation-process in Plants after death.—Herr J. Reinke + brings forward experimental evidence, furnished by Herr G. Brenstein, that after parts of plants have been completely killed by exposure for a considerable time to an atmosphere saturated with vapour of ether, the processes of oxidation and formation of carbonic acid still go on in them ; and that this is dependent on temperature even more in the dead than in the living plant. Herr W. Johannsen { objects to the validity of these experiments, that they were made to extend over too long a period. These processes cease on the death of the plant or part of the plant, but recommence after a time under the influence of bacteria. True intramolecular respira- tion will go on in an atmosphere destitute of oxygen, from the presence of a fermentative substance, while “ post-mortal” oxidation ceases at once in such an atmosphere. Retrogression in Oaks.s—Herr F. Kragan has followed up his previous “phyto-phylogenetic” studies by a study on the frequent occurrence of abnormal leaves on eaks. The species studied was Quercus sessiliflora Sm. His conclusions are as follows :—(1) The phenomena are in origin pathological; (2) the pathological state induces certain modes of growth dormant in normal states; (3) but those structures which develope symmetrically on affected branches and twigs, and unfold them- selves uniformly, can no longer be called pathological. It seems very probable (a) that the modes of growth evoked by the pathological state are retrogressive. In previous generations the plant had followed similar paths; and indeed, in geological periods with warmer tempe- rature, when the impulse which now evokes these “abnormal” leaves in summer, was constant. (b) Q. aquatica Walt., in N. America, is approximately in the state of the present Q. sessiliflora in the Miocene age, when it was still Q. tephrodes Ung. (c) By the study of such abnormal conditions much may be learned of phylogeny and relationship. Phenomenon analogous to Leaf-fall.|—Mr. F. W. Oliver points out that in Rubus australis, a plant in which the lamina is suppressed, the leaves being reduced to simple mid-ribs of the leaflets, a layer of phellogen is formed in the stem in the later part of the summer, out of the inner- most of the cortical layers, all of which are assimilative. By this means the rest of the assimilating cortex is cut off from the other tissues, and * Proc. Phil. Soc. Glasgow, xviii. (1887) pp. 320-6 (1 pl.). Cf. this Journal, 1887, p. 785. + Ber. Deutsch. Bot. Gesell., v. (1887) pp. 216-20. { Bot. Ztg., xlv. (1887) pp. 762-3. § SB. K. K. Akad. Wiss. Wien, xev. (1887) pp. 31-42. || Ann. of Bot., i. (1887) pp. 71-2. + ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 89 is cast off in scales during the second year. Fresh assimilating cortex is formed in the shoots of the current year. A somewhat similar process takes place in Casuarina. “Curl” of Peach-leaves.*—Miss Etta L. Knowles sums up briefly the action of Hxoascus deformans on peach-leaves in the following manner :— (1) A marked increase in width and thickness, accompanied by great distortion. (2) Great multiplication of cells, particularly of the palisade-cells and immediately adjacent parenchyma, by cell-division. (3) Thickening of the cell-walls and disappearauce of the inter- cellular spaces. (4) Diminution of cell-contents, which often are almost or wholly wanting. Plant Analysis as an Applied Science.j—In a useful lecture on this subject, Miss H. C. de 8. Abbott gives a résumé of the more important chemical tests used in discriminating the various substances found in vegetable tissues, and of the practical value of the results thus obtained. B. CRYPTOGAMIA. Arthur’s Report on Minnesota.t—The following is an enumeration of the number of species and varieties in each of the families of Crypto- gams mentioned in Arthur’s Report of Minnesota for 1886 :—Pterido- phyta 26. Bryophyta 42. Carpophyta 242. Oophyta 11. Zygo- phyta 45. Protophyta 28. The following new species are mentioned :—Among the Carpophyta, Puccinia halenie, P. ornata, Anthostoma flavo-viride, Nectria perforata, Ramularia variegata, Zygodesmus sublilacinus, Ciboria tabacina, Peziza (Dasys) borealis, and P. (Humaria) olivatra ; and among the Protophyta, Synchytrium Asari. Cryptogamia Vascularia. Germination of Ferns.s—Herr K. Goebel describes the germination of the spores of several little-known ferns. In Vittaria the first product is a filament which very soon divides into a plate of cells. Club-shaped bulbils are produced in large numbers on the prothallium, consisting of from six to nine cells, and placed upon peculiar semicylindrical sterigmata. Antheridia may be produced on the bulbils. The germination of the spores of Trichomanes was observed in T. maximum and diffusum. The prothallium is here filamentous; arche- gonia being produced at the ends, and antheridia at the middle of the filaments. Bulbils were also observed consisting of a single cell placed ona conical sterigma. Hymenophyllum has also a filamentous prothallium which produces gemmz borne on less distinct sterigmata; and the archegonia and antheridia are also described. Herr Goebel points out the parallelism between the development of * Bot. Gazette, xii. (1887) pp. 216-8. ¢ Journ. Franklin Inst., exxiy. (1887) pp. 1-33. $ Arthur, J. C., ‘Report of Botanical Work in Minnesota for the year 1886,’ 56 pp., St. Paul, 1887. § Ann. Jard. Bot. Buitenzorg, vii. (1887) pp. 74-119 (4 pls.). See Bot. Centralbl., xxxii. (1887) p. 170. 90 SUMMARY OF CURRENT RESEARCHES RELATING TO the Hymenophyllaceze and that of Mosses. He regards the primitive form of both to be a filiform protonema bearing directly sexual organs of both kinds; the original function of the leaves being simply to serve as a protecting envelope. The Hymenophyllacee would therefore be the archaic type of Ferns. Dehiscence of the Sporangium of Ferns.*— Miss F. M. Lyon describes the dehiscence of the sporangium of Adiantum pedatum as always taking place along a definite line across the side of the sporangium. This line is always determined by the presence of two narrow and elongated cells with lignified walls opposite the annulus and about mid- way between its end and the stalk, between which the fissure commences. These “ lip-cells,” the occurrence of which appears hitherto to have been overlooked, were observed also in a number of other species. The authoress suggests that their presence may have an important bearing on the causes which produce the dehiscence. Heterophyllous Ferns.;—Herr K. Goebel points out that the usual statement that in the heterophyllous species of Polypodium (P. Willde- nowii, rigidulum, and quercifolium), one form of frond is sterile and the other fertile, is incorrect ; both forms being fertile. The so-called fertile fronds are pinnatifid, long-stalked, and deep-green, and very soon die down to the rachis; the “sterile” fronds, on the other hand, are sessile, cordate, and convex below, so as to form an open “niche” above; they very soon lose their green colour, and wither away with the exception of a framework formed of the veins. The purpose of these leaves appears to be the collection of humus into which the roots of the fern penetrate, thus enabling them to obtain nutriment where otherwise it would be impossible. In Polypodium Heracleum, both functions, assimilation and the accumulation of humus, are performed by the same fronds, all having the same form with strongly dorsiventral structure; the base of the leaf forms the “niche,” the ribs of the frond the framework for the collection of humus. Leaves of the same kind occur in some epiphytic orchids, as Bolbophyllum Beccarii. The same explanation is offered of the heterophylly of the “ elk’s- horn fern,” Platycerium grande and alcicorne. The branched fronds serve for the purpose of assimilation, while the intermediate, sessile, unbranched, reniform fronds serve both to retain moisture, and to accumulate humus. At the base of these leaves is a strongly developed aquiferous tissue. Many epiphytic ferns, such as Drymoglossum, have similar receptacles for water. In Polypodium sinuosum and patelliferam, the hollow stem serves as an abode for ants; and the same is the case with the hollow pseudobulbs of some orchids. Organs of secretion occur in both kinds of fronds of P. quercifolium. Characeee. New Species of Characee.{—Dr. T. F. Allen describes and figures the following new species :—Nitella Muthnate from Muthnata Island in the Feejee group; Tolypella Macounti from Niagara river, and Nitelia Morongii from Nantucket. The Tolypella is especially noteworthy from * Bull. Torrey Bot. Club, xiv. (1887) pp. 180-3 (4 figs.). + Ann. Jard. Bot. Buitenzorg, vii. (1887) pp. 1-21 (1 pl.). See Bot. Centralbl., Xxxli. (1887) p. 165. { Bull. Torrey Bot, Club, xiv. (1887) pp. 211-5 (5 pls.). ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 9] the fact that the terminal joints of the fruiting rays are one-celled. No other species has such simple terminals; no species has so little fruit and such imperfectly formed “nests.” It is Nitella-like in its habit of growth, and slightly incrusted. Muscinee. Transpiration of the Sporophore of Mosses.*—Mr. J. R. Vaizey has confirmed by actual experiment his theory, previously enunciated on anatomical grounds, that the thin-walled strand of tissue in the sporo- gonium of mosses, to which he apples the term leptoxylon, is that which conducts the transpiration current up the seta to the apophysis, the organ of absorption and of assimilation and transpiration. The method adopted was to place the cut ends of the sporogonium in a drop of eosin, which was found to pass up the whole of the seta and enter the apophysis. The species experimented on were Polytrichum formosum and Splachnum sphezricum. Vegetative reproduction of a Moss.t—Herr H. Schulze describes a peculiar mode of vegetative reproduction in a variety of Hypnum (Harpidium) aduncum ; in the production of terminal buds at the ends of the stem and branches. They were usually surrounded by a few filiform paraphyses, and resembled in structure Schimper’s bulbils or gemmules. ; Sporogonium of Andreza and Sphagnum.{—Herr M. Waldner gives a complete account of the development of these two genera of mosses from the embryo to the mature sporogonium. New Sphagna.§—Dr. ©. Miller proposes the classification of the species of Sphagnum, which he reckons at about 120, under the following seven sub-genera, viz.:—(1) Platysphagnum (S. cymbifolia). Folia squamato-imbricata majuscula, apice rotundato-obtusata, apice plus minus eucullata. (2) Comatosphagnum (S. subsecunda). Folia dense conferta, ramulos plus minus julaceos sistentia, apice truncata exesa. (3) Aci- sphagnum (S. cuspidata). Folia plus minus squamoso-imbricata, laxe disposita, plus minus elongata, apice truncata exesa. (4) Malaco- sphagnum (S. rigida). Folia imbricata rigido-patula, apice truncata exesa. (5) Pycnosphagnum (8. acutifolia). Folia imbricata parva, ramulos tenuissimos sistentia, apice truncata exesa. (6) Acrosphagnum (S. mucronata). Folia imbricata ovato-mucronata pseudo-mucronata, apice vix bifida. (7) Acoccosphagnum (S. sericea). Folia parva imbricata sericea mucronata, fibris annularibus carentia. Of these subdivisions (6) belongs entirely to South Africa and Madagascar; (7) to the Sunda Isles. Dr. Miiller then describes as many as thirty new species of Sphagnum, nearly all from the southern hemisphere. Rabenhorst’s ‘Cryptogamic Flora of Germany’ (Musci).—The last two parts of this work (7 and 8), by Herr K. G. Limpricht, are still occupied by the Acrocarpe. The genus Campylopus is completed, and * Ann. of Bot., i. (1887) pp. 73-4. See this Journal, 1887, p. 122. + Bot. Centralbl., xxxi. (1887) pp. 382-4. t~ Waldner, M., ‘ Die Entwick. d. Sporogone v. Andrea u. Sphagnum,’ 25 pp. and 4 pls., Leipzig, 1887. See Bot. Ztg., xly. (1887) p. 725. § Flora, 1xx. (1887) pp. 403-22. 92 SUMMARY OF CURRENT RESEARCHES RELATING TO is followed by Dicranodontium, Metzleria, and Trematodon. The family Leucobryacere comprises the single species Leucobryum glaucum. The Fissidentacese comprise Fissidens with eighteen species, and the monotypic Pachyfissidens and Octodiceras; the Seligeriacee, Seligeria with five species, and Blindia, Trochobryum, and Stylostegium, with one each ; and the Campylosteliacezxe two species only, viz. one each of Brachydontium and Campylostelium. Then follow the Ditrichacez, including the genera Ceratodon, Trichodon, Ditrichum, and Distichium. Epiphytic Jungermanniex.*—Herr K. Goebel describes the con- trivances for storing up water in the epiphytic Jungermanniex of Java, which are numerous, growing especially on the leaves of ferns and flowering plants along with alge. The receptacles for water connected with the auricles are of three kinds :—(1) The two lobes of the same leaf are closely approximate, and form an organ the shape of a pouch or pitcher, as in Radula, Phragmicoma, and Lejeunia. In some species of Radula it is but feebly developed, most completely in Lejeunia. (2) The lower lobe of the leaf is concave on its morphologically upper side, and forms by itself the receptacle, as in Frullania and Polyotus. These receptacles are not formed if the supply of water is abundant, clearly showing their purpose. (8) The water-receptacle is formed out of a leaf and the lamella which springs from it, as in Gottschea and Physiotium. The chamber thus formed is often large and tubular, as in P. giganteum. They often form domiciles for insects; but there is no ground for regarding these Hepatice as insectivorous. The so-called “ tubular organs” of species of Physiotium are also receptacles for water. The epiphytic Jungermanniee are sometimes provided with special organs of attachment. Disc-like gemme were also found on species of Radula, Lejeunia, and other genera. Those of L. Goebeli spring from a single cell of the leaf. The circular gemme of Radula stand on a uni- cellular pedicel. Metzgeriopsis pusilla, epiphytic on the leaves of Ophioglossum pendulum, forms an interesting link between the thallose and foliose Hepatice. It consists of a small thallus branching monopodially, and composed of only a single layer of cells. It is propagated non-sexually by gemmez resembling those of Lejeunia, as well as by sexual organs, each female fertile shoot bearing only a single archegonium. There are no amphi- gastria. Production of Gemme by Fegatella.j— Herr G. Karsten describes the formation of gemmz on Fegatella conica, they not having been pre- viously observed in this genus of Hepatic. ‘They were obtained both in natural growth and on cultures in pots, under suitable conditions of moisture and temperature. The gemme originate from the midrib of the thallus, and either from the lowest layer of cells or the lowest but one when the lowest itself has died away. The cells rapidly become filled with starch and chlorophyll, and the gemma acquires a round form and dark-green colour. A great number of rhizoids are produced from its superficial cells. With or without a period of rest, the gemma developes into a new individual, the first cell-divisions being in the * Ann. Jard. Bot. Buitenzorg, vii. (1887) pp. 21-66 (8 pls.). See Bot. Centralbl., xxxii. (1887) p. 167. t Bot. Ztg., xlv. (1887) pp. 649-55 (1 pl.). ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 93 merismatic portions of the growing point at right angles to the longer axis of the gemma. Attempts to produce similar gemme in Preissia commutata and Reboulia hemispheerica were without result. Algee. Plasmolysis of Algze.*—Dr. J. M. Janse records the interesting fact that the protoplasm of the living vegetable cell is permeable to dilute solutions of mineral salts (potassium nitrate and sodium chloride) and of cane-sugar. The experiments were made both on a salt-water alga, Chetomorpha xrea, with which also Lomentaria, Ulva, and Dictyota agree in this respect, and on a fresh-water alga, Spirogyra nitida. In all these instances the plasmolysis, which had at first set up with the solutions named, completely disappeared after two hours. After four days the filaments had regained their previous turgidity ; the terminal cells being swollen to double their original size by the bulging of the transverse cell-walls, without any cell-division taking place. Choristocarpus tenellus.t—Herr F'. Hauck describes this very rare alga, gathered on Dasya elegans, on the island of St. Catherine, off the coast of Istria. The so-called sporangia with transverse septation he has determined to be gemme corresponding to those of Sphacelaria. One kind only of zoosporangium was found, the multilocular, on separate individuals. New Fresh-water Floridea.;j—Herr M. Mobius describes a hitherto undescribed fresh-water alga found growing on the leaves of Aneura pinnatifida. It consists of dichotomously branched filaments of a red, violet, or greenish colour, springing from cushion-like masses. Although presenting analogies to Chantransia, its systematic position cannot at present be ascertained. Cystocarp-like structures were observed, but their exact nature could not be determined. Lemanea.§—Herr F. Ketel corrects one or two points in Sirodot’s description of the anatomical structure of this genus of alge. The thallus grows by means of an apical cell, from which segments are cut off by walls placed at right angles to its direction of growth. Within each segment two walls, curved in the form of a watchglass, which lie in the direction of the growth in length, first of all separate two opposite lenticular cells. By two further transverse septa a ‘“ central cell” is formed, surrounded by peripheral cells. The central cell becomes a member of the central axis, the four peripheral cells develope into the “supporting cells” (“ramification cruciforme”); the hollow cylinder resulting from their further divisions. The thallus may therefore be regarded as composed of a central axis with whorls of four branches which coalesce into the cylinder; while in Batrachospermum we have free verticillate branching, and only the accessory lateral branches form a cortical layer applied to the central axis. ‘he ooblastema-filaments proceed directly from the impregnated oosphere ; Sirodot does not clearly * Bot. Centralbl., xxxii. (1887) pp. 21-6. + Hedwigia, xxvi. (1887) pp. 122-4 (1 pl.). t{ Versamml. Deutsch. Naturf. u. Aerzte, Wiesbaden, Sept. 21, 1887. Ber. Deutsch. Bot. Gesell., v. (1887) pp. lvi—lxiv. (1 pl.). § Ketel, F.. ‘Anatom. Unters. iib. d. Gattung Lemanea,’ Greifswald, 1887. See Bot. Ztg , xlv. (1887) p. 779. 94 SUMMARY OF CURRENT RESEARCHES RELATING TO distinguish between these fertile branches and the branches which occur in large numbers on the carpogonium-branch before impregnation, and which resemble paraphyses. Microspora.*—M. E. De Wildeman contends that this genus, formed by Thuret, should be again sunk in Conferva. The character on which the author relied for establishing the genus, the peculiar way in which the cell-wall behaves previous to the emission of zoospores, resembling the process called by Gay “encysting,”’ t is not a good generic character, but is rather a peculiar condition which occurs in a number of different genera of alge. Some points in Diatom-structure.{—From observations made with a 1/12 in. oil-immersion lens, Mr. 'T. F. Smith has come to different conclusions in some respects from those of Messrs. Nelson and Karop,§ as to the structure of the valve of Coscinodiscus asteromphalos. He objects to the term “ double structure,” if it implies that the two areolations are nearly on the same plane. As a matter of fact, each single dise of this diatom has three thicknesses of structure, each differing from the other. There is first the outer membrane, next a layer of hexagonal cells, and then an inner plate of so-called eye-spots. In C. centralis, what Nelson and Karop have figured as fine perforations are, according to Mr. Smith, little bosses standing out from the outer membrane. A similar structure is attributed by the author to Aulacodiscus Kittonii and Triceratium favus. He does not commit himself to an opinion whether the eye-spots have, in all cases, a closing membrane, but he thinks it clear that they have in some. In a later paper,|| Mr. Smith admits that the diatom described by him as Coscinodiscus centralis is not the same species as that referred to under this name by Nelson and Karop. Deep-sea Diatoms.f—Abbé Count F. Castracane adduces new evi- dence of the depth of the ocean at which diatoms can live, from an examination of the contents of the stomach of Echini and Holothuriz, dredged up from a depth of 2511 to 5274 metres. These contain the remains of diatoms belonging to the genera Synedra, Rhizosolenia, &c., in such a condition that the author contends they could only have been consumed in the living state. Fossil Marine Diatoms from New Zealand. **—Messrs. E. Grove and G. Sturt publish the results of their examination of a fossil marine diatomaceous deposit from Oamaru, Otago, New Zealand. A very large number of new species are described. Wolle’s ‘Fresh-water Alge of the United States.’ +{—This work is supplementary to the Rev. F. Wolle’s well-known ‘ Desmidiex of the United States, and comprises all the remaining families of fresh-water alge, except the diatoms. It includes also nine new plates of desmids. The Algex treated are arranged under three classes: Rhodophycee, * CR. Soc. R. Bot. Belgique, 1887, pp. 92-6. + See this Journal, 1887, p. 277. + Journ. Quek. Micr. Club, iii. (1887) pp. 125-30. § See this Journal, 1886, p. 661. || Tom. cit., pp. 163-6 (1 pl.). @ Atti Accad. Pontif. Nuovi Lincei, xxxviii. (1886) pp. 46-7. Cf. this Journal, 1885, p. 498. ** Journ. Quek. Micr. Club, iii. (1887) pp. 131-48 (5 pls.). ++ Wolle, Rev. F., ‘ Fresh-water Alge of the United States, exclusive of Dia- tomacee,’ 2 yols., 364 pp., and 151 pls., Bethlehem, Pa., 1887. ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 95 Chlorophyces, and Cyanophycex ; the first and third including each only one order, viz. Floridee and Schizosporez, while the Chlorophycez are again divided into four orders, Confervoide, Siphone, Protococcoider, and Zygospores. The author adopts Hansgirg’s view with regard to the polymorphism of algz, and regards all our present systems of classi- fication as only temporary. Lichenes. Gleeolichenes.*—Herr K. B. J. Forssell’s monograph of this new family of lichens is now published in detail. He defines the class as Ascolichenes with gonidia belonging to the Chroococcacer. The symbiosis between the two constituents of the lichen may be indifferent, antagonistic, or mutual. The algal constituent belongs to the genera Chroococcus, Gleocapsa, and Xanthocapsa, possibly also to Aphanocapsa, Gleothece, and Microcystis. The only kind of spore produced by the fungal element is endogenous (ascospores); stylospores have not been observed. The apothecia are either closed or open. The following twelve genera are described in detail, with their species :— Cryptothele, Pyrenopsis, Synalissa, Phylliscidium, Pyrenopsidium, Phylliscum, Col- lemopsidium, Enchylium, Psorotichia, Peccania, Anema, and Omphalaria. Gasterolichenes.t—Mr. G. Massee describes under this name a new section of lichens formed by the commensalism of a fungus belonging to the order Trichogastres of Gasterolichenes, with a unicellular alga. The first example is the fungus known as Hmericella variecolor Berk., in which the algal constituent is Palmella botryoides. The cells of this alga he describes as subglobose or broadly elliptical, varying from 20 to 39 » in longest diameter, and furnished with a very thick lamel- lose hyaline cell-wall. From the chlorophyllous portion of the cell a green unseptated filament passes through the cell-wall, and is joined at some distance to a similar filament from another cell, the two forming a common stem, on which several pairs of cells are supported on similar lateral bifurecating filaments. These pairs of cells originate from the fission of a single cell. The alga occupies interspaces in the loose peri- pheral portion of the base of the fungus, and also passes up into the loose texture of the peridium. ‘The tips of lateral branches of hyphe are frequently seen closely investing and even penetrating the algal cells. A second type of Gasterolichenes is furnished by the fungus described as Trichocoma paradoxa Jungh. Here the algal constituent belongs to the genus Botryococcus, and forms a stratum at the base of the capillitium. The colonies are generally invested with the hyphe of the fungus. To these Mr. Massee now adds a third hitherto undescribed species, T., leevispora. Action of Lichens on Rocks.{—Dr. J. Miiller makes an interesting note on the weathering action of lichens upon rocks. Little excavations containing the fructifications of lichens are often found on the surface of rocks, especially limestones. Several species of Polyblastia have the fructifications deeply buried, and it has been supposed that the lichen gradually ate its way in by the aid of acid secretion. If this were true, * Nov. Act. R. Soc. Scient. Upsala, xiii. (1887) pp. 1-118. See this Journal, 1886, p- 485. ¢ Phil. Trans., clxxviii. (1887) pp. 305-9 (1 pl.). + Arch. Sci. Phys. et Nat., xviii. (1887) pp. 490-1. Bull. Soc, Murithienne du Valais, 1887. 96 SUMMARY OF CURRENT RESEARCHES RELATING TO the comparatively large apothecia sometimes found beneath the surface ought to be connected with the exterior by some chimney-like tube. This is not the case. They appear to grow from the inside outwards, not from the outside inwards. The fact is that a large number of excessively fine gonidia-bearing hyphe insinuate themselves in the rock, and ramify under the outer pellicle of rock as the roots of grass in a meadow. The system can be demonstrated by dissolving away the rock in hydrochloric acid, which leaves the spreading hyphe and their gonidia intact. This internal thallus is of great importance as a silent factor in dynamical geology, aiding very powerfully the weathering of rock surface. Lichens on unusual substrata.*— Herren Hegetschweiler and Stizenberger give a list of fifteen species of Lichen gathered on serpen- tine, nine on the stem of the grape-vine (besides two mosses Orthotrichum affine and Amblystigium riparium), and eighteen on the deciduous bark of young plane trees. Fungi. Accumulation and Consumption of Glycogen by Fungi.t—Dr. L. Errera adduces further evidence of the fact that glycogen plays the same part in fungi that starch does in other plants. In young Ascomy- cetes (Peziza vesiculosa) the glycogen is distributed through the whole tissue, the hyphe and pseudoparenchyma being completely filled by it. As soon as the hymenium is developed the glycogen pours into it, and later is found at work entirely in the asci. When the fructification is ripe, the glycogen has again completely disappeared, reserve-substances, especially of an oily nature, being stored up in the ascospores. The same phenomenon of the disappearance of the glycogen takes place during the very rapid growth of the stalk of Phallus impudicus. The glycogen of fungi is not formed, like the starch of other plants, from the free carbon dioxide of the atmosphere, but out of previously existing organic carbon compounds, especially the products of decomposi- tion of other food materials. Function of Cystids.t—Dr. R. v. Wettstein has investigated the structure and function of those organs of Hymenomycetes known as cystids. Various functions, such as those of artheridia, have been ascribed to them. Brefeld showed that they develope (in Ooprinus stercorarius ) from rudimentary basidia, and have an external protective function in the development of spores. They are props to keep the lamelle apart. Wettstein has been led to corroborate and extend Brefeld’s conclu- sions. The cystids are homologous with basidia. Their systematic importance has been exaggerated. They are always closed. ‘There are two kinds: (a) with free, (b) with fixed extremities. The latter may be fixed to another cystid, or may have penetrated into the tissue of adjacent lamelle, or may have united with the palisades of other lamellx. As to function : (1) they force the lamelle apart, making room for spore-develop- ment; (2) they prevent the delicate membranous moist lamelle from adhering together; (8) they may also bind lamelle together. They seem definable as very passive overgrown non-reproductive basidia. * Flora, Ixx. (1887) pp. 430-1. + Versamml. Deutsch. Naturf. u. Aerzte, Wiesbaden, Sept. 21, 1887. Ber. Deutsch. Bot. Gesell., v. (1887) pp. Ixxiv.-viii. Cf. this Journal, 1886, p. 833. t+ SB. Akad. Wiss. Wien, xcvy. (1887) pp. 10-21 (1 pl.). ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 97 Rhizomorpha subcorticalis of Armillaria mellea.*—M. J. de Seynes states that, in the initial stage of its development, the Rhizomorpha sub- corticalis appears as a white fibrous membrane more or less flabelliform, and agrees with Leveille’s definition of the hymenoid mycelium of Armillaria mellea. The author further states that he has observed in certain cases a tendency of the extremity of the rhizomorph to divide into lobes, and these are easily detached from the wood on which the fungus is growing. In conclusion, the subject of these observations is described as a mixed organ representing not only a condensed membranous mycelium, but sterile, deformed, and flattened receptacles. A few lines are also added on its mode of phosphorescence, which is stated to be exclusively nocturnal. Uredinex.}—Herr P. Dietel enters into several points of comparative anatomy in the Uredinee. One of the more important features of varia- dion within the family is in the teleutospores, while very little variety is exhibited by the uredospores or xcidiospores. The ecidia of Gymno- sporangium differ from those of the other genera in not being saucer- or cup-shaped, but comparatively long flask-shaped structures. The greatest point of variability in the teleutospores is their size, and the number of cells of which they are composed, this varying even within the same genus. In addition to the normal bicellular teleutospores, unicellular spores often occur, which have been termed “ mesospores,” from an idea that they are intermediate structures between teleutospores and uredospores. Tulasne, on the other hand, regards them as having arisen by the abortion of the lower cell of the teleutospore, thus exhibiting the affinity of Puccinia with Uromyces, the latter being degraded repre- sentatives of the former. Herr Dietel, while agreeing with this view on the whole, thinks it more probable that Puccinia has sprung from Uromyces by progressive development. The teleutospores also vary greatly in their form; and this is some- times the case even in the same species, especially where it occurs on several different hosts. The occurrence, in certain species of Puccinia, of teleutospores consisting of three or more cells has been thought to indicate a transition to the genera Phragmidium and Triphragmium ; but the author considers that this is rendered improbable by the very different phenomena of germination exhibited by the spores of these two genera. In Puccinia germination takes place by a single pore at the upper end of each cell; in Phragmidium by several pores in the equa- torial zone of each cell. The nature of the surface of the outer mem- brane of the teleutospore is also variable, especially in Uromyces and Puccinia ; the two constituent spores may differ from one another in this respect, or may be alike. Great difference is also exhibited in the colour of the spores. The Uredinee are generally regarded as most nearly allied to the Ascomycetes; but the homology of the different kinds of spore is attended with difficulties. Schréter regarded the teleutospores as homo- logous to the asci. The frequent appearance of spermogonia without ecidia before the uredo-generation can only be explained by the abortion * Bull. Soc. Bot. France, xxxiv. (1887) pp. 286-7. + Bot. Centralbl., xxxii. (1887) pp. 54-6, 84-91, 118-21, 152-6, 182-6, 217-20, 246-50 (1 pl.). 1888. H 98 SUMMARY OF CURRENT RESEARCHES RELATING TO of a previously existing mcidio-generation; and from this it would appear to follow that the scidio-form, and not the teleuto-form, is the original one. The author thinks it must be assumed that originally one and the same mycelium had the power of producing both teleutospores and ecidiospores; and that the distinction of the two generations ori- ginated in the alternations of climate; and the occurrence or absence in any species of the uredo-generation depends, in the same way, on its adaptation to the climatal conditions in which it is found. The most essential difference between the Uredinew and the Ascomycetes lies in the capacity of the former to produce sporidia, which do not fail in any known species, and must therefore be regarded as the most essential member in the cycle of development. All three generations may occur on the same host in the course of a year, or they may be confined to different hosts. In the hetercecious species the particular host on which the teleuto-form or eecidio-form will develope depends in no way on its systematic position, but on the facilities presented for the spread of the spores. Autcecious Uredinee can hibernate in the uredo-form. In all probability it is the teleuto- spore-generation that has migrated from its original host to a different one. Grape-disease—Comothyrium diplodiella.*—M. E. Prillieux has come definitely to the conclusion that Comothyrium diplodiella is a true parasite, and not merely saprophytic. Professor Pirotta, of Rome, allowed ripe spores to germinate in spring-water, and infected perfectly healthy grapes with them. The disease showed itself in four to six days. M. Fréchon corroborated this, and M. Prillieux has also satisfied himself by experimental inoculation that the fungus is truly parasitic. New Disease of Lemons.}—Sig. G. Gasperini describes a new disease exceedingly destructive to the lemon-crop in Italy, spreading with very great rapidity, and entirely destroying the fruit, which it causes to fall, and to which it gives a nauseous smell. He finds it to be caused by the mycelium of several Hyphomycetous fun gi, of which the following species are described as new, and their diagnoses given, viz.:—Aspergillus violaceo-fuscus, A. elegans, and A. variabilis. On the surface of the lemons was also found a species of Saccharomyces, which he calls S. Citri, consisting of oval, elliptical, or cylindrical cells 8-6°5 p long by 1-2 p broad, united into colonies which branch in a variety of ways. They contained from one to three very minute spores, and were readily culti- vated on dilute sterilized lemon-juice. New Pythium.t—Herr W. Wabrlich proposes the name Pythiwm fecundum for a new saprophytic species found in a stream springing from the Rhone Glacier. It presents in some respects a transitional form between the Peronosporee and the Saprolegnieex. The zoosporangia are 2 p broad, 120-160 » long, and scarcely distinguishable from the ordinary hyphe ; the zoospores are reniform, 4 ~ wide by 6 p long, and with two cilia on their concave side. The oogonia are of two kinds; in those first formed each oogonium is impregnated by one or two antheridia formed in close proximity to the oogonium. The second kind are some- times produced on the same branch as the first, but later. These are * Comptes Rendus, ev. (1887) pp. 1037-8. + Atti Soc. Tose. Sci. Nat., viii. (1887) pp. 315-41. { Ber. Deutsch. Bot. Gesell., v. (1887) pp. 242-6 (1 pl.). ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 99 double the size, and break up into two or three daughter-cells, each of which is an oogonium capable of impregnation. When not impregnated, the oogonium puts out prolifications which develope into ordinary vegetative hyphe. Chytridiacea parasitic on Diatoms.*—Under the name LKctrogella Bacillariacearum Herr W. Zopf describes a parasite which attacks species of Synedra and Pinnularia. Its effect is first manifested by an alteration in the shape and position of the chlorophyll-bands. They recede from the walls, contract in direction of their length, and become closely applied to the parasites. At the same time the nucleus is dissolved and the protoplasm contracts. Later on, in consequence of the pressure exercised by the parasites, the valves fall asunder. The sporangial fructification of Ectrogeila determines its place among the Ancylistex; it bears the same relation to Ancylistes as Olpidiopsis to Myzocytium. __ Cohn’s ‘Cryptogamic Flora of Silesia.|—The last contribution to Herr J. Schroeter’s monograph of Silesian fungi in Cohn’s ‘ Cryptogamic Flora of Silesia’ is devoted to the orders Protomycetes, Ustilagine», Uredinei, and Auricularici. A full account is given of the life-history of fungi belonging to these orders. Protomycetes include the two genera Protomyces and Endogone. The Ustilaginew are divided into three families, viz.:—Ustilaginacei (Ustilago, Sphacelotheca, Schizonella, and Tolyposporium) ; Tilletiacei (Tilletia, Urocystis, Entyloma, Melanoteenium, Tuburcinia, Doassansia); and Thecaphorei (Schrevterta, Thecaphora, Sorosporium), with several doubtful genera. The Uredinei comprise five families, viz. :—Pucciniei (Uromyces, Puccinia); Phragmidiei (Trachy- spora, Triphragmium, Phragmidium) ; Endophylei (Endophyllum) ; Gym- nosporangiei (Gymnosporangium); and Melampsorei (Melampsora, Me- lampsorella, Calyptospora, Coleosporium, Chrysomyxa, and Cronartium. The Auriculariei comprise the single family Auriculariacei (Stypinella n. gen. and Platyglea n. gen.). The following new species are described :— Ustilago major, Uromyces alpinus, U. minor, Puccinia Cirsit lanceolati, P. Crepidis, P. tenuistipes, Platyglea fimicola, and P. effusa. Protophyta. Microchete.{—Under the name WM. striatula ? Abbé Hy describes a new species of this genus, found among Sphagnum in turf-bogs. It forms an interesting link of connection between the older species on which M. Thuret founded the genus, and the more recently discovered M. diplosiphon Gom. M. Hy agrees with Bornet in regarding Micro- chzete as belonging to the Scytonemacecex, of which it constitutes the most simple type without any appearance of branching. Vibrio from Nasal Mucus.§—Dr. E. Weibel finds that there occurs in the mucosa of the posterior nares a vibrio, the presence of which is not apparently associated with a pathological condition. The bacillus is curved, and about as thick as that of anthrax, the length varying from 2-5 times the thickness. The degree of curvature is very variable, there * Zopf, W., ‘Zur Kenntniss der Phycomyceten. See Mr. G. Karop in Journ. Quek. Micr. Club, iii. (1887) p. 115 (1 pl.). + Schroeter, J.. in Cohn’s Kryptogamen Flora v. Schlesien, Bd. iii. Lief. 3, Breslau, 1887. See Hedwigia, xxvi. (1887) p. 173. ¢ Morot’s Journ. de Bot. i. (1887) pp. 193-8 (3 figs.). § Centralbl. f. Bacteriol. u. Parasitenk., ii. (1887) pp. 465-9 (4 figs. of a pl.). H 2 100 SUMMARY OF CURRENT RESEARCHES RELATING TO being gradations from a semicircle down to a straight line. The bacilli are aggregated into groups, and do not form continuous threads. About individual rods an unstained periphery is evident, but the possession of a capsule is not conclusively demonstrable. Pure cultivations were obtained by breeding, first in bouillon, then in gelatin, and afterwards isolating on gelatin-plates. On the plates the colonies became visible on the third day, and by the fifth attained a diameter of 0°3 mm.; by the next day their size was nearly doubled. In tube cultivations the colonies spread along the inoculation track, there being no surface development and no liquefaction of the medium. In agar the develop- ment was similar but more luxuriant. On potato no growth occurred. The morphological variations are manifold and complicated, although the fundamental form is a bent rod. In bouillon it almost always occurs as single rods, the ends of which stain deeply, the central part remaining uncoloured. Such forms therefore simulate diplococci, and raise a suspicion of spore-formation. Cultivated in agar or gelatin, single rods occur, but most frequently the individual elements are united to form chains, which are most perfect in the agar. Staining is easily effected with gentian violet and decoloration by Gram’s iodine. Weak spirit (1:3) dissolves out the dye from the stained medium, and leaves the bacilli still coloured. The formation of spores could not be proved. In hanging drops only Brownian movements were perceived. The author has repeatedly made pure cultivations of the vibrio from his own nasal mucus, but declines to give a definite opinion as to its general frequency. Subcutaneous inoculations produced no effect on mice. Two kinds of Vibrios found in decomposing Hay Infusion.*—Dr. KE. Weibel obtained from rotting hay infusion two kinds of vibrio by means of the attenuation method. A needleful of the fluid was diluted with so much sterilized water that in each drop only a very few germs were included ; from this a series of test-tubes filled with sterilized hay infusion were inoculated. In two tubes vibrios predominated. From these gelatin-plate cultivations were made, and two kinds of vibrio successfully developed. These differed in size, and are distinguished as hay vibrio a and hay vibrio 8. The larger kind, vibrio a, is a bent rodlet about 3 ~ long; the thickness is about one-fifth of the length. Owing to the ends diminishing in thickness, a crescent-shaped form results, and in the ecntre of this is a bright spot. Two individuals fre- quently unite to produce an S-like form, more numerous combinations being less common; but such may appear after eight days’ cultivation in bouillon or agar. Vibrio B is about 2 pw long, and about as thick as the tubercle bacillus. _Double-comma forms are very frequent, and in some prepara- tions the rule. On gelatin plates the two kinds grow slowly, but a quicker than B. Colonies of a attain in three days a diameter of 0:2-0°3 mm., and in six days about 0°6 mm. Under a low power ( x 80) and with reflected light, they appear as circular yellowish-brown discs, and on the third or fourth day as dark rings round about a central point. The colonies of vibrio B never exceed 0°3 mm. in diameter. In neither case is the gelatin liquefied. In gelatin both kinds grow along the inoculation track, and also show a slight growth on the surface, but the whole of the surface is never overgrown. In agar the inoculation * Centralbl. f. Bacteriol. u. Parasitenk., ii, (1887) pp. 469-72 (2 figs. of a pl.). ZOOLOGY AND BOTANY, MICROSCOPY, ETO. 101 track is little affected, but over the surface development takes place copiously, vibrio a spreading in a dirty whitish-yellow layer, beneath which the agar mass for a depth of 1-2 mm. is clouded. Vibrio B produces a similar crust, but the underlay is dry, and it is impossible to remove a specimen without taking up also the agar substance. On potato both kinds thrive well. Vibrio a forms in two days a luxuriant slimy layer of a yellow-red colour, which gradually darkens to chocolate. Vibrio £ produces a thin dirty brownish-green overlay, which is removed for examination with difficulty. The potatoes breeding vibrio a develope a strong ammoniacal odour, but with vibrio 6 this occurs but slightly or not at all. Both stain well with anilin dyes, especially with gentian- violet. In hanging drops both varieties show lively movements. Phosphorescent Bacteria from Sea-water.*—Dr. O. Katz has isolated three groups of micro-organisms, which are capable of cultiva- tion in various nutrient media, and which by transference to marine animals (fish, crustaceans) and to sca-water produce phosphorescence. (1) Bacillus smaragdino-phosphorescens, obtained from dead marine fish, 1s a short thick rod about 1 » wide and about double as long as wide. The ends are rounded off. It is not motile or flagellated. When stained with anilins the peripheral parts only are dyed, a central spot or “ vacuole” remaining uncoloured. It grows in small colonies on gelatin without liquefying the medium. It developes best at a tem- perature of 20° C. or a little higher, and then emits a ‘“ wonderful emerald-green” light. Grown at 13-15° C. development is slower and the light is less intense. (2) Bacillus argenteo-phosphorescens was obtained from sea-water at Elizabeth Bay, Sydney. On gelatin, after having been mixed with ten drops of sea-water, there would appear, among a considerable number of other colonies, not more than two of these luminous colonies. It is a slender rod, tapering at the extremities and commonly slightly curved. It is about 2°5 » long, and about three times as long as broad. It is motile, but forms no filament. The best stains were anilin-fuchsin and anilin-gentian-violet. The colonies do not liquefy gelatin, but spread over it more than those of number 1. It grows best between 14° and 23° C., and within this range shows the greatest luminosity. The emitted light is of a mild silvery appearance. 3) Bacillus cyano-phosphorescens was obtained from sea-water at Little Bay, Sydney. It is a straight rod about 2°6 w long, and about 2% times as long as broad. The ends are rounded off. It is motile, and is often found as diplo-bacillus, but not often in chains. These are commonly bent, attaining here and there a considerable length. It stains well with alkaline methylin-blue, but a small central portion remains uncoloured. It grows rather slowly in and upon gelatin, which is gradually liquefied by it. It developes better on agar, where after a comparatively short time it forms a substantial greyish-white sticky layer. The optimum of growth and luminosity lies between 20° and 30° C., but a lower temperature is not unfavourable. The colour of the light emitted has a decidedly bluish tint. The intensity lies between those of I. and II. The author proposes to publish further details later. In some further remarks on the phosphorescent bacteria,t Dr. Katz describes three additional kinds. * Proc. Linn. Soc. N. 8. Wales, ii. (1887) pp. 331-6. + Abstr. Proc. Linn. Soc. N.S. Wales, 1887, p. v. 102 SUMMARY OF OURRENT RESEARCHES RELATING TO (1) Bacillus argenteo-phosphorescens liquefaciens, obtained from sea- water at Bondi; its cultures, liquefying gelatin, emit in the dark a silvery light, which, however, is the weakest of the six kinds hitherto found ; (2) Bacillus argenteo-phosphorescens I1., derived from a luminous piece of a small squid (Loligo), and, at the same time, from luminous pieces of the Sydney gar-fish (Hemirhamphus intermedius Cant., H. melanochir Cuy. and Val.) ; (3) Bacillus argenteo-phosphorescens IL1., from the squid already mentioned. Neither of the latter micro-organisms causes liquefaction of the gelatin. They give off in the dark a handsome silver light, much more intense than that of the first-mentioned, but resembling that of the previously exhibited Bacillus argenteo-phospho- rescens (now to be designated I.). From this latter Nos. II. and Ii. distinctly differ. Lectures on Bacteria.*—The second improved edition of Prof. A. De Bary’s Lectures on Bacteria has been translated into English by Mr. H. E. F. Garnsey, and revised by Prof. I. B. Balfour; it will be very useful as a general view of the subject to all who are interested in these organisms. * «Lectures on Bacteria. By A. De Bary. Authorised translation by Henry E. F. Garnsey. Revised by I. B. Balfour” Oxford, 1887. ZOOLOGY AND BOTANY, MIOROSOOPY, ETO. 103 MICROSCOPY. a. Instruments, Accessories, &c.* (1) Stands. Collins’s Aquarium Microscope.—Mr. ©. Collins’s Aquarium Micro- scope (fig. 1) differs from all other forms in that it is applied to the side of the aquarium itself. This is accomplished by making use of a sucker apparatus. The head of the sucker is shown on the left of the drawing, with an indiarubber ring surrounding a central piston. The ring is applied to the glass surface of the aquarium, and the air is exhausted by screwing round the head of the piston seen on the right. Two turns are sufficient to fasten the sucker securely. The rod to which the support of the body-tube is attached passes through the sucker-arm, and can be clamped at any height desired. Golfarelli’s Micrometric Microscope for Horologists—This Micro- scope (fig. 2), made by the “ Officina Galileo” of Florence, after the design of Prof. I. Golfarelli, is intended for the use of clock- and watch- makers, enabling them to ascertain, for instance, that the teeth of chrono- meter and duplex escapement wheels are regularly cut. The upper part of the Microscope is screwed to a metal stage 5 in. X 4 in., supported on four feet, and having a graduated scale on its front side. In a wide groove in the stage slides a metal plate, with four spring clips to hold the object examined. The clips can be variously applied in fourteen different holes. The plate is moved by a * This subdivision contains (1) Stands; (2) Eye-pieces and Objectives; (3) Illu- minating and other Apparatus; (4) Photomicrography; (5) Microscopical Optics and Manipulation ; (6) Miscellaneous. 104 SUMMARY OF OURRENT RESEARCHES RELATING TO fine screw, which extends beneath the stage for its whole length, and is actuated by the milled head on the right. To this is attached a graduated disc, which reads against a fixed index, the movable plate having also an index. Over the front of the objective is a plane mirror of polished silver, with a central aperture through which the object is Fic. 2. viewed. The mirror being inclined at 45°, reflects the light upon the object on the stage, which is always viewed as an opaque object. The mirror rotates in a collar socket to vary the illumination. ‘There is a fine-adjustment screw (usual Continental form) at the top of the pillar, and a screw eye-piece micrometer forms part of the body-tube. For levelling the instrument one of the feet has a screw by which it can be lengthened or shortened. Lenhossék’s Polymicroscope.—Dr. J. v. Lenhossék has applied the principle of the revolving stereoscope to the Microscope in a very ingenious manner. The instrument is shown in perspective in fig. 3, in profile in fig. 4, and in section in fig.5. The essential feature consists in an endless band M M (fig. 5) turning on the upper and lower axles K L, and carrying 60 ordinary 3 x 1 in. slides, N. The slides lie horizontally, but as each slide comes to the top it stands vertically, and the object is observed through the opening H, in the side of the box A, by the Micro- ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 105 scope I, which is necessarily of somewhat low power, and has a focal distance of 53 mm. The endless band is moved by two handles at the sides of the outer box, which turn the upper axle. The slides can be illuminated by direct light through the opening F, in the opposite side of the box, or by the mirror R, shown in figs. 8 and 4. The Microscope is focused by the milled head at g. The slides can be placed in position by raising the top of the box B (fig. 5), or if a more extensive inspection of the interior of the box is required both front E and back G (hinged at the bottom at e and g) can be turned away as shown in fig. 5. The manner of fixing the slides is shown in fig. 6, A from in front, B from above. aa in the one fig. and bb in the other are the two spring jaws which hold the slides firmly in position. A dise with four notches is attached to one end of the upper axle, and a spring falling into a notch, indicates when a slide is exactly vertical. An are-piece with rack and pinion (B ¢, fig. 4), enables the whole instrument to be inclined to suit the convenience of the observer. The lenses can be attached to a special stand, and used as an ordinary Microscope. With the Microscope Prof. Lenhossék sent a portfolio of manuscript 106 SUMMARY OF CURRENT RESEARCHES RELATING TO EU CH ty LNG CH ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 107 and drawings, giving the most elaborate and complete account that perhaps has ever been given of any Microscope.* Prof. Lenhossék recommends the Polymicroscope especially for a continuous series of objects. Dufet’s Polarizing Microscope.t—This instrument (figs. 7-9) was designed by M. H. Dufet to show the interference figures of crystalline fragments, and to allow of the accurate measurement of the axial angle for different colours of the spectrum. G, fig. 7, is the plate of crystal Fia. 8. Fic. 9. * Cf. also ‘Ein Polymikroskop von Dr. Joseph von Lenhoss¢k,’ 25 pp., 1 phot., and 2 pls., 8vo, Berlin, 1877 (from Virchow’s Arch. f. Pathol. Anat. u. Physiol., Ixx.). + Journ. de Physique, v. (1886) pp. 564-84. Bull. Soc. Franc. de Minéral., ix. (1886) pp. 275-81 (2 figs.), 108 SUMMARY OF CURRENT RESEARCHES RELATING TO the eye-piece r with cross wires; the analyser is at A. The image is much improved by the use of microscopic objectives (of which the principal focal surfaces are practically plane), instead of simple lenses. The instrument is focused by moving the objective I and then shifting the eye-piece. The apparatus for concentrating the light consists of a microscopic objective E placed behind a nicol. To use rays of any required refrangibility, a direct-vision spectroscope is employed. The collimator B is moved by a micrometer screw V with divided drum T. The rays, after traversing the prism C and the lens J, form a real spectrum at the principal focus of the objective E. The isochromatic curves are then projected upon the spectrum, and a movement of V brings the different colours in succession into the field; the graduation on the drum will, by previous experiment, give the exact wave-length of the light corresponding to any position of the collimator. Fig. 8 represents in 1/5 the natural size the apparatus used for the measurement of axial angles; it is practically that of von Lang. The crystal fragment is held in a spring clip with spherical and rectilinear adjust- ments, aud moves under a divided circle reading with verniers to 20", Measurements in oil can as usual be made by the help of the small stage ¢ below the crystal. This appa- ratus may also be used to mea- sure indices of refraction by the method of total reflection; for this purpose the spectroscope is removed, and the clip is replaced by the two prisms represented half-size in fig. 9, which inclose the section surrounded by a layer of some liquid having a higher refractive index than the section itself. Finally, this part of the apparatus may be used, like the similar Universal Apparatus of Groth, asa Wollaston goniometer. Duboscq’s Projection Micro- scope.*—M. Duboscq’s projection Microscope (fig. 10) is arranged to carry three objectives, two shown in the fig., the third being at the opposite side of the lantern. This enables different magnifying powers to be used by simply turning the lantern round and without having to screw and unscrew the objectives. Electric light is used for the illumination. * Stein, S. T., ‘Das Licht im Dienste wiss. Forschung,’ vy. (1887) pp. 303-5 (3 figs.). Also ‘Die Optische Projektions-Kunst im Dienste der exakten Wissen- schaften,’ 1887, pp. 94-6 (3 figs.). yl Via, ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 109 Campani’s Compound Microscopes.— With reference to the note on pp. 643-4,* we have since found that a figure of a nearly similar Microscope was published in the ‘ Acta Eruditorum, Lipse, 1686, Tab. x. (pp. 371-2), where it was designated “ Novum Microscopium Dn: losephi Campani, ejusque usus,’ the figure also showing the employment of the instrument for viewing transparent and opaque objects. This figure was reproduced in the ‘Opuscula omnia Actis Eruditorum Lipsiensibus inserta, &c.,’ tom. ii., Venetiis, 1740, p. 439. * See this Journal, 1887, p. 643. ie | 4 rofcopum Dn: Fosephs SEAR Ete =f “Novum Mic 110 SUMMARY OF CURRENT RESEARCHES RELATING TO Our fig. 11 is copied from the original. It will thus be seen that our conjecture as to the early date (ante 1665) of the construction, based upon the absence of a field-lens, may possibly need qualification in the face of the publication (apparently the first of this form of Microscope) in 1686. From various references we have met with, and notably from the paper ‘ Nvove inventioni di tubi ottici’ (a contribution to the ‘ Accademia Fisico-matematica, of Rome, in 1686, by—we believe—Ciampini, the then editor of the ‘Giornale de’ Letterati,’ of Rome) Campani’s Microscopes appear to have been well known at that date, so well known, indeed, that any resemblances to them in more recent models were at once noted. Attention may be called to the curious mixture of scales in the drawing. The large Microscope on the left is the same instrument as is represented by the two small ones in the centre and on the right. The artist, it will be seen, has introduced a diagram of an eye above the large Microscope, a proceeding which, although it looks very odd in such a picture, had the useful effect of checking the scale and preventing the instrument from being taken to be of the same proportions as the men who accompany it in the drawing. It will be re- membered that it was the blunder of an artist in substituting a man for an eye, that led to the ludicrous misinterpretations of Schott’s Microscopes on which we commented in this Journal, 1887, p.148. In a more recent visit to Italy than that referred to in our previous note on this subject, we met with the very early form of Microscope shown in our fig. 12. The body-tube is of cardboard covered with marbled paper, and slides in the split ring-socket on the top of the tripod for focusing. A draw- tube of cardboard carries an eye-piece with a field-lens—the lenses mounted in wood cells. The instrument is in the “ Museo di Fisica,” Florence, where apparently nothing definite is known of its origin. We are, however, able to assign the construction with considerable proba- bility to Campani from the fact that at the “ Conservatoire des Arts et Métiers,” Paris, there is a practically identical Microscope bearing the inscription, “ Giuseppe Campani in Roma 1673.” It is thus evident that Campani constructed eye-pieces with, and also without field- lenses. L., A. S.—Differential Screw Slow Motion—To Mr. Crisp. [Claim to have anticipated by sixteen or seventeen years Campbell’s differential screw fine-adjustment. Cf. this Journal, 1887, p. 324. | Engl. Mech., XLVI. (1887) p. 416. RovussELEeT, C.—On a small Portable Binocular Microscope and a Live-box. [Microscope not figured, Live-box, infra, p. 112.] Journ, Quek. Mier. Club, IIL, (1887) pp. 175-7 (1 fig.). ZOOLOGY AND BOTANY, MICROSCOPY, ETC. ad (2) Eye-pieces and Objectives. NeEuson, E. M.—On a new Eye-piece. (Cf. this Journal, 1887, p. 928.] Journ. Quek. Micr. Club, III. (1887) pp. 173-4 (1 fig.). PELLETAN, J.—Les Objectifs. (Objectives.) Contd. Journ. de Microgr., XI. (4887) pp. 546-9. (3) Illuminating and other Apparatus. Zeiss’ Iris Diaphragm.—Dr. C. Zeiss has designed an Iris diaphragm in which the aperture is approximately circular for all diameters. Fig. 15 shows the apparatus in its natural size with the six crescent- shaped metal plates, which form the aperture. These slide over one another by the handle on the right. The internal mechanism is shown in fig. 14; one end of the plates is pivoted on the upper plate of the diaphragm case, and at the free end is a straight prolongation which is Fre: 13. Fia. 14. Fia. 15. inserted between the raised pieces placed round the circumference of the second disc shown in fig. 15; when this disc is rotated by its handle the six plates turn on their pivots. With a turn of the handle to the left the aperture is reduced, and enlarged with one to the right. By means of the screw (fig. 13) the diaphragm may be fixed to the Abbe condenser and substituted for the ordinary diaphragms. It can be worked with the little finger of the left hand, so that the other fingers can move the slide while the right hand is available for focusing. We gather that Dr. A. Zimmermann, who describes the apparatus,* is not very familiar with the English and American forms of Beck, Wale, and others. He points out that Iris diaphragms are of advantage in drawing with the camera lucida. Edmonds’s Automatic Mica Stage. — The purpose of Mr. J. Edmonds’s apparatus is to rotate a mounted film of mica between the prisms of the polariscope and beneath the object exhibited in the Microscope, producing by the rotation of the mica alone all the colour effects usually obtained by revolving the polariscope by hand. As pointed out by * Zeitschr, f. Wiss. Mikr., iv. (1887) pp. 543-5 (3 figs.). 1 SUMMARY OF CURRENT RESEARCHES RELATING TO Dr. Carpenter, “The variety of tints given by a selenite film under polarized light is so greatly increased by the interposition of a rotating film of mica, that two selenites—red and blue—with a mica film, are found to give the entire series of colours obtainable from any number of selenite films, either separately or in combination with each other.” * The apparatus is contained in a flat box or case forming a loose stage intended to be laid upon the permanent stage of the Microscope, and the object under examination being placed upon it may be observed and adjusted, or changed from time to time, without disturbing the Microscope or its accessories. The automatic rotation is effected by a specially constructed train of wheelwork which, on being wound up, continues in action for an hour, and when set in motion requires no further attention, enabling the observer to watch the varying effects without touching the instrument. It can be used with any Microscope having polariscopic attachments, is self- contained, and removable at pleasure, and does not interfere with the substage appliances. The designer claims that “the beautiful and interesting phenomena observable in polarizing objects under various aspects, may, with the aid of this self-acting arrangement, be exhibited to a number of persons in suc- cession, with an ease and a readiness not attainable by any other means.” Rousselet’s Life-box.t—Mr. C. Rousselet describes a life-box which for pond-life he considers works better than any other contrivance of the kind he has seen. The old life-box, which has done duty for so long, has, in his opinion, the very great defect that the object placed thereon is totally out of reach of the substage condenser, and, therefore, incapable of being properly illuminated. Some years ago Mr. Swift made an improvement by fixing the glass plate, on which the object is placed, nearly flush with the plate of the life-box, as is shown in fig. 17. But this, however, introduced another defect, “that any objects placed in the box could be examined, over the Fic. 17. whole field, only with low powers, whilst with high powers only those objects placed near the centre could be reached. Now, it is very frequently desirable to examine an object with a high power after it has been found with a low ‘one, and we all know how very fond living * Carpenter on the Microscope, 6th ed., 1881, pp. 132-3. t Journ. Quek. Micr. Club, iii. (1887) pp. 176-7 (1 fig.). ZOOLOGY AND BOTANY, MICROSCOPY, ETC. aS creatures are of getting to the edge of the drop of water in which they are placed, and to shift them to the centre is frequently a very tedious work, and is often fatal to the animal.” To remedy this defect, Mr. Rousselet “had a life-box constructed in which the glass tablet is somewhat reduced in diameter, but the outer ring is enlarged sufficiently to allow any high power to focus to the very edge of the glass tablet, and the result is very satisfactory. An object lying anywhere in the life-box can be reached by the condenser from below, and by both low and high powers from above; besides which, it acts as a very good compressor, capable of fixing, without hurting, the smallest rotifers, and, when you know how to do it, it is also possible to get a rotifer in so small a drop of water that it is unable to swim out of the field of view of a 1/4 in. objective.” He has had it in constant use for animals of all sizes, from the smallest infusoria to tadpoles. Mr. Rousselet has also had a small screw compresser, made on the same principle; “it is very simple and effective, and allows of regulating the pressure to a nicety.” Large form of Abbe Camera Lucida.*—-Dr. Zeiss makes a form of this camera lucida with a larger mirror and a longer arm than the one first issued.t The larger form (only made to order) is recommended by Dr. P. Mayer. The advantage of it he considers to be that it enables the whole field of vision to be utilized without any perceptible distortion of the image, and it is thus especially useful in drawing comparatively large objects with low powers. With the smaller camera the whole field can be projected on the drawing-paper only by giving the mirror an inclination differing so much from the angle (45°) required for accurate drawing that the image is'more or less disproportioned. Dr. Mayer further says that “the Abbe camera is superior to that of Oberhiuser in two important particulars: it gives a much larger field of vision and better ight. Its construction does not admit of use with the Microscope- tube in a horizontal position. This is a defect which ought to be at once corrected. The Abbe cameras, especially the larger one, can be used to great advantage with the embryograph of His. It is only necessary to add to the stand a horizontal arm, to which the camera can be fastened.” May’s Apparatus for Marking Objects.t—Mr. R. Hitchcock, in reference to Schiefferdecker’s apparatus,§ calls to mind a “ much simpler, but no doubt quite as efficient device for the same purpose,” that he has used for years, made by Mr. May, of Philadelphia. It consists of a simple rod of brass about 1/4 in. in diameter, with a screw at the top that fits into the nose-piece in place of an objective. A tube fits loosely over this rod, bearing a diamond point below, slightly eccentric. This is turned by a milled collar, so as to scratch minute circles on the cover- glass. Simple Method of Warming and Cooling under the Microscope.||— Herr H. Dewitz describes a very simple apparatus for warming and cooling objects under the Microscope. It only cost 2s., and for many purposes proved entirely satisfactory. Take a round leaden box, 0:08 m. in diameter, 0:03 m. in height at * Amer. Natural., xxi. (1887) pp. 1040-3 (1 fig.). + Cf. this Journal, 1883, p. 278. t¢ Amer. Mon. Micr. Journ., viii. (1887) p. 207. § See this Journal, 1887, p. 468. || Arch. f. Mikr. Anat., xxx. (1887) pp. 666-8 (1 fig.). 1888. I 114 SUMMARY OF CURRENT RESEARCHES RELATING TO the middle ; suppose the lid cut away so as to leave an opening 6:08 m. in length and 0-023 m. in height. This opening is closed by soldering a piece of lead b in such a way that the box is divided into two com- municating portions, one c lower than the other d (fig. 18). On the floor and roof of the flatter half two opposite circular openings eare made. These are covered with a cemented glass. The whole is Fig. 18- arranged on a. metallic circle beneath so that the lower glass is not rubbed or injured by moving the apparatus on the stage. On the roof of the deeper half a large hole is made for pouring in water and inserting ice fragments. A smaller hole receives a thermo- meter. Finally, just above the floor of the higher portion, the end of a tube hk is inserted. The free end 7 of this tube, which is about the size of a goose-quill, is curved so that water cannot flow out. Before use, the apparatus is half-filled with water poured in by the large hole, air-bubbles under the glass are got rid of, and a drop of fluid medium containing the object to be observed is placed on the upper glass, and carefully covered in familiar fashion. The projecting tube is then warmed by a spirit-flame till the thermometer in & indicates the desired temperature. A glass should be placed below the free end to receive expelled drops. For cooling purposes the apparatus is filled a third full with water at the temperature of the room or higher, and ice particles are inserted at the opening g. An overflow can be emptied out, via the long tube, by inclining the Microscope and without disturbing the arrangements. The layer of water between the two glass plates is quite thin, so that the strength of the light is but slightly altered. Apparatus for determining Sensibility to Heat.*—An apparatus for the investigation of the heat sensibilities of the cockroach is described by Prof. V. Graber. A trough of tin is divided into two end chambers and a middle chamber whose floor is of wood, and which can be separated from the end chambers by sliding doors. All three are covered by sliding lids of glass or of tin at pleasure, and the whole is surrounded by water-baths, two lamps placed underneath these enabling the end chambers to be kept at temperatures differing by any wished amount. The lamps are prevented from interfering with each other’s action by a wooden block under the middle chamber, which serves also as a stand * Arch. f, d. Gesammt. Physiol. (Pfliiger), xli. (1887) pp. 241-3. ZOOLOGY AND BOTANY, MICROSCOPY, ETC. ls for the whole apparatus. In each chamber one thermometer takes the temperature of the air, while the bulb of another is imbedded in felting so as to give the temperature of the walls. (4) Photomicrography. Israel and Stenglein’s Photomicrographic Microscope.*— Dr. O. Israel’s photomicrographic apparatus (fig. 19) may be used either in a Fig. 19. Fia. 20. * Stenglein, M., and Schultz-Hencke, ‘ Anleitung zur Ausfiihrung mikrophoto- graphischer Arbeiten,’ 8vo, Berlin, 1887, pp. 4-12 (2 figs.), 14-6 (1 fig.). I 2 116 SUMMARY OF CURKENT RESEARCHES RELATING TO horizontal or a vertical position ; in the former, the iron frame to which it is attached is fixed upon a table, using an inclining Microscope; in the latter the instrument is supported as shown in the figure upon an iron stand, which runs upon wheels, but can be fixed in any position by means of the three screws F. The apparatus consists of two parts, the Microscope and the camera; V is the focusing screen, upon which the image is focused by means of the rod 6b b,, terminating in a toothed wheel b,, which works into a similar but larger toothed wheel R, occupying the place of the usual micrometer-screw. B is the light- proof connection between the camera and Microscope, and consists of a leather bag fixed to the Microscope by the ring r. The camera consists of the three mahogany frames K, K, Ks, united by the leather bellows B, B., which can be extended to the length of a metre; the focusing screen can be rotated about an axis A, perpendicular to the axis of the instrument. a is a screw spindle, placed close to b, by means of which the camera may be clamped in any desired position to its iron standard. When the apparatus is used in the vertical position the Microscope simply stands upon its iron base, and is fixed below the camera by means of a screw-clamp Sch, which grips its horseshoe stand. The size of the plates used with this apparatus is 15 x 15 cm. Fig. 20 represents the similar instrument of Herr M. Stenglein, which carries its own illuminating apparatus. For this purpose the height of the instrument is considerably increased ; a space of 66 em. at the lower end of the standard serves to carry the movable parts which constitute the illuminating apparatus, namely a plane mirror 20 cm. square Sp, a condenser of 10 cm. radius and 21 em. focal length L, a light-filter C, to secure monochromatic light, consisting of a vessel filled with ammoniacal solution of copper oxide, and Abbe’s illuminator; to these may also be added, if necessary, a diaphragm B, which is to be employed when electric light is used, and in this case the mirror is replaced by the electric lamp. To preserve the centering, the illumi- nator and the Microscope not only slide along the upright, but are provided with a slight lateral adjustment, and the apparatus is cen- tered by using the smallest diaphragm of the Abbe illuminator and a diaphragm of equal size, which is made to be attached to the con- denser. - Stegemann’s Photomicrographic Camera. — The instrument repre- sented in fig. 21, and devised by Herr A. Stegemann, corrects, it is claimed, a defect of the ordinary apparatus by supplying the means of adjusting the distance between the objective and the focusing screen, upon which depends the relative size of the photographic image, and by measuring this distance upon a fixed scale. A square pillar rising from an iron foot carries the camera, with the objective-frame and the focusing screen which slide upon it; the pillar is graduated, and by means of a vernier attached to the adjustment-screw of the camera gives the exact distance between objective and focusing screen. The apparatus can be used either to photograph objects in their natural size, in which case the object is placed on a glass plate fixed to the foot; or with the Microscope, which is then placed in the forked support which serves to carry the glass plate. In this instrument the stratum of liquid which is used as a light- filter for monochromatic light is contained in a vessel which slides into ZOOLOGY AND BOTANY, MICROSCOPY, ETO. ERG the case of the objective-frame close to the objective, so that all rays which reach the sensitive plate must of necessity have passed through the solution. Fig. 21. —— TET | | = 5 = YY \ SS D& Marktanner’s Photomicrographic Cameras.*—Herr T. Marktanner describes two photomicrographic cameras which he has devised. The first is made on the Gerlach system, and consists of a wooden chamber, not made to draw out, which is placed upon the body-tube. It is distinguished from the camera of Gerlach by tbe basal table, which is * Bull. Soc, Belg. Micr., xiii. (1887) pp. 188-91 (2 figs.). 118 SUMMARY OF CURRENT RESEARCHES RELATING TO made of two equal-sized plates united by a hinge. The upper plate forms the base of the camera, which is pyramidal in shape; the lower is provided with a brass tube, accurately centered, by which the camera is adapted to the tube. If the preliminary adjustment is made by means of rackwork, the brass tube may be an elastic cap which is fixed to the upper part of the Microscope by a screw clamp. To secure greater stability, it is better to apply this camera to a stand, with which the preliminary focusing is made by a sliding movement. In this case the use is recommended of a strong brass tube of the same size as the body-tube, ending in a screw-thread similar to that of the objectives. If it is desired to use objectives of Fic. 22, different screw-threads, it will be better to employ several brass bli tubes of 8 cm. length, which can vA slide into the tube fixed at the centre of the lower plate. This camera will be especially useful in obtaining plates which give the full views so useful as aids towards drawing. As the ampli- fication will never be more than 200 times, cardboard holders will be quite sufficient. The size of the plates is 6 em. by 6°5 cm., and they are made by cutting a plate of 13 cm. by 18 cm. into six parts. The slide for the transparent glass is made of cardboard ; the glass is covered with a fine net- work of lines. The hinge which unites the two basal plates enables the camera to be lowered beside the Microscope. This arrange- ment is very useful when the apochromatic objectives of Zeiss are used, and also with the pro- jection eye-pieces constructed for photomicrography. The eye- pieces can then be easily changed. This arrangement was formerly less necessary than now, for with the objectives then used, photo- graphs were almost always taken without the eye-piece. The second camera (fig. 22) is sufficient for all the purposes of photomicrography. It is similar to that of Nachet, from which it is only distinguished by the bellows, by a slide in the basal plate, and by a levelling apparatus formed of a plate of zine upon three screws. This camera can be used in the horizontal (fig. 23) as well as in the vertical position. In the former it draws out to 90 cm.; in the latter tv 50 cm. ‘he transparent glass is made as in the preceding camera. ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 119 If the projected image is exactly focused, it ought to be seen with the lens at the same time with the fine lines traced upon the glass. In this apparatus the size of the plates is 12 cm. by 16 cm., a size which is recognized as sufficient by all who have had experience in photo- micrography. Nelson’s Photomicrographic Focusing Screen.*—Mr. G. Smith, in reference to Mr. Nelson’s suggestion + for ruling the focusing screen with metrical and English scales, considers that if diamond lines are used they should be ruled horizontally and vertically about 5), in. apart ; but better still, every third line should be missed. The cross ruling thus forms a kind of plaid pattern, and any decided pattern materially assists the eye in keeping to the proper plane instead of seeking a focus on either side. The eye-piece must of course be first adjusted exactly to these lines for the operator’s eye. Another very simple and effective plan (applicable to other cameras too) is to rule diagonals in blacklead pencil across the ground glass, and over the centre cement a thin cover-glass, taking care to put there a few grains of dust, or say, cotton fibre. Both these plans he has used for many years, and can recommend both; with either it is easy to focus the darkest interior. NevuHautuss, R.—Anleitung zur Mikrophotographie fiir Aerzte, Botaniker, &c. (Guide to Photomicrography for Physicians, Botanists, &c.) 32 pp., 8vo, Berlin, 1887. STterRNBERG, G. M.—Photo-micrography in Medecine. Reference Handbook of the Medical Sciences (U.S.A.) 1887, pp. 647-58 (7 figs.). (5) Microscopical Optics and Manipulation. Histological Structures and the Diffraction Theory.—Hitherto the examples of the action of diffraction in microscopical vision have been almost entirely confined to diatoms, objects which more than any others are suited to illustrate the principles on which the theory is founded, * Eng. Mech., xlvi. (1887) p. 394. ¢ See this Journal, 1887, p. 1028. 120 SUMMARY OF CURRENT RESEARCHES RELATING TO viz. that in the case of minute objects which are less than a few wave- lengths in diameter the laws of geometrical optics no longer apply, that is, the structures are no longer imaged according to the laws which govern the delineation of objects observed with the naked eye, but that the delineation is dependent upon the rays which are diffracted by the object. The matter is, however, obviously of more importance to histo- logists than to the observers of diatoms. In the case of histological structures the conditions are, of course, much more complicated than with diatoms, but the principles remain the same, and if they are not taken into account very false deductions may be made. A notable instance of this was the case on which we commented in 1881,* where Mr. J. B. Hayeroft ¢ put forward an explanation of the appearances presented by muscle-fibre which, while an eminently simple one, was unfortunately entirely founded on the supposition that the fibres acted in the same manner as cylindrical threads of larger size. Prof, 8. Exner, who has recently investigated the question of muscle- fibre, has published an article on the subject, in the course of which he deals fully with the operation of diffraction on such structures. This article from the point of view we are now considering is a very interest- ing one, and we have translated his remarks without abridgment. In order that the subject may be fully understood, we have prefaced the translation by notes on (1) the appearances presented by air-bubbles and oil-globules, by solid and hollow fibres, and by depressions and elevations where the objects are larger than a few multiples of a wave- length, and (2) the appearances presented by Pleurosigma angulatum under different optical conditions. (1) Appearances presented by Air-bubbles and Oil-globules, by solid and hollow Fibres, and by Depressions and Elevations of relatively large size.{—The accompanying figs. 24 and 25 supplement those given at Air-bubbles under the Microscope. Focus, a below the centre (at the focal plane), 6 to the centre, c the same with oblique light stopped off. p. 743 of Vol. II. (1882), a in fig. 24 representing an air-bubble when the Microscope is focused below its centre (a being the image of a window bar), 6 when focused to the centre, and c the same with oblique * See this Journal, 1881, p. 964. t Proc. Roy. Soc. Lond., xxxi. (1881) pp. 360-79 (1 pl.). ¢ Cf. Dippel, L., ‘Das Mikroskop und seine Anwendung,’ 1867, pp. 313-4 (4 figs.), pp. 355-60 (9 figs.), and 2nd ed. 1882, pp. 822-4 (4 figs.), pp. 852-6 (6 figs.). ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 13 light stopped off. Fig. 25 represents an oil-globule, a with the focus on the margin, b somewhat higher, and ¢ at the focal plane of the bubble. Fie. 25. Oil-globules under the Microscope. Focus, a on the margin, > somewhat higher, c higher (at the focal plane). Solid fibres, fig. 26, in a medium of lower refractive index (as a glass thread in air or water) show a diffused moderately bright appearance A at medium focus; a bright central line B when the tube is Fic. 26. raised; and a dull appearance C A B when the tube is focused below the centre. The reverse of course takes place if the surrounding medium is of higher refractive index, as glass threads in mono- bromide of naphthalin or binio- dide of mercury and potassium. If, again, the fibre is surrounded by a fluid of about the same re- fractive power, as in the case of a glass thread in Canada balsam, it -will then have the appearance of a flat band. : z : ier Hollow fibres charged with oes ee ee wet air, fig. 27 (or a fine capillary tube of glass), present with medium focus nearly the same appearance as the solid fibres, from which they are only to be distinguished by the fact that at both edges the double outline of the section of their solid walls will be seen as in A. In other respects the appearances are reversed ; the raising of the objective giving a dull image C, whilst on sinking it we have the central bright lime B. Fine tubes in a denser substance produce the same effect as hollow fibres. Semi-cylindrical channels or furrows act as concave lenses, whether the hollow side is turned from or to the observer. The only distinction between the two positions is, that in the former case the tube must be focused lower than in the latter, in order to obtain the greatest degree of brilliancy in the central line. If instead of the hollow fibre, or capillary tube charged with air, one filled with a fluid is substituted, this produces the same effect as a solid fibre, provided the contained and the surrounding fluid are nearly the same, or if the former has a greater refractive power. Solid and hollow fibres can then only be distinguished from each other in the medium focus, showing the optical section of the solid walls. On filling with a 122 SUMMARY OF CURRENT RESEARCHES RELATING TO fluid similar to that surrounding the fibre, an effect is produced more or less similar to that of the air-charged fibre, for if the refractive power of the contained and the surrounding fluid is greater than that of the solid walls, the latter will appear Fig, 27. as hollow spaces in the stronger refracting medium, as would be the case with glass capillary tubes filled and surrounded with monobromide of naphthalin. If oblique illumination is employed instead of central, the appearances just described are not essentially altered; a dis- placement of the illuminated line to the one side or the other is simply produced, according as the mirror is moved out of the axis to the right or left. With objects which act as convex lenses it is generally displaced to the side of the object which is turned away from the source of light, and with objects acting as concave lenses to the side nearest to the light; and therefore, as the compound Microscope inverts, it will appear in the first case on that side of the image which is turned towards the mirror, and in the latter case away from it. The glass thread or the solid fibre will therefore show the line of light on the side turned towards the mirror, when the illumination falls obliquely and the tube is raised; hollow cylinders and furrows will show it, when the tube is lowered, on the side of the image which is turned away from the mirror. The division of light and Glass capillary tubes. Focus, A medium, B lower, C higher. Hig. 28: Fig. 29. A B A B | Glass threads with oblique light Glass capillary tubes with oblique incident from the right. Focus, light incident from the right. Focus, A high, B somewhat lower. A low, B a little lower. shadow will appear as in A, figs. 28 and 29. Ifamore medium focus is taken, the conditions are so far altered, that now half of the object is ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 123 in shadow, while the other half is illuminated as strongly or even stronger than the field B, figs. 28 and 29. If depressions either with spherical surfaces or furrowed or bowl- shaped (fig. 30) are found on the surface of a membrane, they produce the same effect as concave lenses, and show their greatest brightness when the tube is lowered. If, however, there are spherical, hemi- spherical, or semi-cylindrical elevations, they act as convex lenses and Bigs 30: iGesole Semi-cylindrical elevations or depressions. | Cylindrical elevations and depressions. show their greatest brilliancy when the tube is raised from a medium focus. If furrow-like depressions alternate with semi-cylindrical eleva- tions, the surface presenting a wavy appearance, the former appear bright when the tube is lowered, the latter when it is raised, and when the former show the highest degree of brilliancy the latter has a dull appearance (fig. 31). With wave-like membranes the result is somewhat different, since here both of the undulations, as well those which have their convex side towards the observer, as those with the concave side so turned, act as concave lenses. They therefore show their greatest brightness on lowering the objective, and the same differences in the extent of the lowering as in the case before mentioned of the semi-cylindrical tubes. From what has been said of glass threads and hollow cylinders filled with fluid, it follows that more and less strongly refracting (i.e. dense and less dense) parts of one and the same object, will act similarly to the cylindrical elevations or depressions of a membrane. In observing, therefore, in water the differences thus presented in the microscopical image, it is necessary, in order to decide whether these depressions or elevations are caused by variations in structure or in density, to change the fluids, and particularly to use such substances as possess a greater refractive power than the object under examination, whereby the image is either (in the first case) changed according to the altered conditions, or (in the latter case) is substantially unchanged. If the greatest brilliancy appears when the tube is lowered, we have to do with an elevation, but if when the tube is raised, it must be a depression. In order to facilitate the determination of the position of the tube, we can either start with a medium fucus, or the tube may be lowered from a point at which no distinct image of the object is obtained. Depressions are then first bright on a dark ground, elevations, on the contrary, dark on a bright ground, till after further lowering of the tube the image is exactly 124 SUMMARY OF CURRENT RESEARCHES RELATING TO reversed. For accuracy in the determination, the object must be in its natural condition, and must not have been disturbed by any changes in density, or by any previous preparation, drying, Xe. (2) Appearances presented by Pleurosigma angulatum under different optical conditions.—Hugo v. Mohl and Schacht regarded the markings as formed by three intersecting sets of lines; to Max Schultze and others they seemed to be six-sided depressions ; to some English microscopists they appeared to be six-sided elevations, while Schiff and Dippel recognized a chess-board pattern. Stein, Pelletan, and Kaiser have recently referred to round protuberances, while Dr. Flégel has proved, by means of transverse sections, that at any rate the upper surface of the valve (with the exception of the central rib and the edge) is to be regarded as flat, but that it is full of cavities between its upper and under surfaces. If we look more closely into Plewrosigma angulatum by the light of the diffraction theory, we obtain the following result :—Using purely central illumination, i.e. a very narrow illuminating pencil, if the numerical aperture of the objective is sufficiently large, and is at least 0:90 to 0°95, we have six spectra a,—a, (circle A, plate ILI. fig. 1), which are arranged regularly round the direct image of the source of light, while the six spectra of the second series o,—a, fall outside the aperture even with very large numerical aperture. If the aperture is so small that with purely central illumination no one of the six least deflected pencils is admitted, the valve appears to be without markings, while with a larger aperture of above 1°00 N.A. the three systems of striz I-III. (plate III. fig. 2) make their appearance at the same time, and according to the excess of the aperture above unity give rise to a fainter or more sharply defined pattern. Each one of these systems of striz can also be made visible with a numerical aperture of 0°50 when oblique light is used ; in that case two spectra a and a, or a and a, (circle B, plate {It figs) always fall within the aperture. They may also be obtained in the same way with objectives of greater numerical aperture when all the other spectra, with the exception of one of those mentioned, are excluded by suitable diaphragms. With an objective of 0:7 to 0:8 N.A. as soon as the light is oblique enough, three pencils are included, the direct and two diffracted pencils (circle C, plate III. fig. 1), and then the two sets of strie I. and II. intersecting at 60° are obtained. If the direct pencil is excluded and only two opposite spectra A; Ay—Ay As, My, Ug, allowed to operate, there appear in succession three new sets of strie IV—VI. which owing to the exclusion of a are bright upon a dark field ; and the strie are brought nearer to one another in the ratio of 2:1, so that they appear twice as fine as I.—III. though they coincide with the latter in direction. The systems of striz vii—ix. which are at right angles to the ordinary sets I-III., and of which the lines are closer together in the proportion 3: 1, are obtained in a bright field when with objectives of very large aperture, the spectra of the first series a,-a, are inter- cepted by suitable diaphragms, and the objective receives the direct pencil a together with one of the spectra of the second series such as ad,,aa,...aa; The striation 1X. can be obtained by aa, and aa, when oblique light is allowed to fall upon the central rib. The same sets of striae can be produced upon a dark field when, using central light and an objective of large numerical aperture, a and Journ. R. Micr. Soc., 1888, PL. ill. nt AMA eo iy HL nM (ih Wile - | {| ! Hi HH | } Hl | Hh Mh | | Pleurosigma angulatum. ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 125 all the other spectra are shut off with the exception of two belonging to the series a, a3, @,a,...4,a,. The striation IX. is then repeated twice by a, a, and a; a;. Since the distance of the spectra aa,,aa,... OF @, a3, A, d,...18 greater in the ratio 1: ¥ 3 than that of aa,,aa,... the lines of the strie VII.-IX. must be closer to one another than those of I-III. in the ratio 43:1. The new striations IV—IX. called into existence by the above arrangements possess the same sharpness of outline as those which have been long known, namely I.—III. The above appearances serve to explain the different views which have been held with regard to the structure of diatoms, when they are observed with different modes of illumination. Dry and water-immersion objectives of no great numerical aperture show the well-known hexagons (plate III. fig. 3) when the illumination is central and with a not very minute diaphragm, or when the illumination is oblique if e.g. a a, dz a3 -Or @ @, a; a, are operative. Large numerical aperture with central illumination gives bright circles arranged in lines which intersect at 60°, and between which with very sharply defining objectives (homogeneous- immersion for instance) dark spots are also visible (plate III. fig. 4). Oblique illumination and the action of a, a, a3, a, a; a;, with a numerical aperture up to 1-10 shows a chess-board pattern as described by Schiff and Dippel (plate III. fig.5). Very oblique illumination and the action of @ a, G3 a, OY 4a; 4, a; With objectives of very large numerical aperture give the peculiar figure first observed by Stephenson and Abbe, in which the bright rectangular spaces are traversed by a small dark line and are accompanied by dark markings equal to the first in size and lying above and below them (plate III. fig. 6). Other forms may be obtained on a bright or dark field by the use of various modes of illumination and of diaphragms which intercept certain spectra of the first and second series and only allow the remainder to operate. That the ordinary markings which are seen with an objective of large numerical aperture and with central illumination are more nearly related to the true structure than the other images, can only be concluded from conditions of their production, and not from the images themselves. These markings appear when the largest possible part of the total spectrum of the Pleurosigma valve is in operation, and as little as possible (i.e. only the furthest fainter pencils of the second and third series) is lost; while each of the other images is produced by a much smaller part of the total diffraction spectrum. For this reason it may be concluded that the former image is less dissimilar than the others from the image which corresponds to the complete diffraction action of the valve, and which is unattainable by any Microscope.* (3) Prof. Exner’s remarks on the Optical character of living Musele- jibres.;—Prof. 8. Exner employed his micro-refractometer { to determine the refraction and double refraction of living muscle-fibres, and to answer the question whether transversally-striated fibres have their refractive index increased or diminished during contraction. The paper, as we have above stated, is more particularly interesting to microscopists from the observations which the author makes on the application of the * Dippel’s Das Mikroskop, 1882, pp. 158-61 (6 figs.). + Arch. f. d. gesammt. Physiol. (Pfliiger), xl. (1887) pp. 360-98 (2 pls.). ~ Sce this Journal, 1886, p. 328. 126 SUMMARY OF CURRENT RESEARCHES RELATING TO diffraction theory of microscopical vision to the examination of such minute objects as muscle-fibre. In the first place, the examination by the instrument of muscle from the femur of Hydrophilus piceus showed, beyond a doubt, that the con- tracted portions of a fibre have a higher refractive index than the remainder ; but, on the other hand, Prof. Exner claims to have proved that this is only the case with abnormal contraction, whereas when the contraction is normal, no change is produced in the refractive power. The immersion fluid used to determine the index was either white of egg concentrated over sulphuric acid in the receiver of an air-pump, and treated with acetic acid, or the liquid obtained by pressure from the eye of an ox or sheep. The refractive index of the former can be raised to 1:4053, and that of the latter to 1:42-1:43. A number of trials with these fluids led to the result that the stationary living muscle of Hydro- philus has an index of refraction which varies slightly on either side of the value 1:°363, while the same muscle may have slightly different values in different parts. As regards what may be called the ordinary and extraordinary rays for light traversing the fibres in a direction perpendicular to their length, measurements of the indices in the sartorius muscle of a frog led to the approximate values n, = 1°368 for the ordinary ray, and n¢ = 1-370 for the extraordinary ray. When the screen of the micro-refractometer is placed with its edge at right angles to the length of the fibres, a peculiar striped appearance is produced, which the author explains as due to the obliquity of the layers constituting the fibre, so that a ray of light is deflected or not according as it does or does not pass through layers of varying refractive index. Now when the waves of contraction which traverse the living muscle of an insect isolated in an inactive fluid of equal or greater refractive index are examined with the micro-refractometer, the screen having its edge parallel to the Jength of the fibres, it is found that the contracted portions become dark on the side of the screen and light on the opposite side, in other words, the index of refraction in these parts is diminished ; if the index were increased, the first effect would be an illumination of the fibre as far as the sarcolemma, and this is never observed, On the other hand, the permanently contracted and transversally striated parts found in fibres which are still living, especially near the torn ends, do exhibit a marked increase of refractive power; these, however, are regarded by the author not as normal contractions but as a change which accompanies the death of such parts of the fibre ; they do not recover their previous character, because the muscular substance has been partially destroyed, and this is proved by three facts—(1) the permanently contracted parts are smaller than those of which the con- traction is normal. (2) the death of a fibre is accompanied by the emission of a certain amount of liquid, as may be proved by examining the fibre in liquid paraffin (refractive index = 1°4712), when the micro- refractometer indicates that the contracted portion is surrounded by a liquid of less refractive index than the paraffin ; (3) it is only necessary to examine a free fibre under the Microscope, when it will be found after a few hours to have contracted and to be surrounded by liquid, and a contracting portion may be occasionally seen during a few minutes to surround itself with a ring of liquid as it contracts. It may be concluded therefore that there is an absolute distinction to ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 1pyi be made between the normal living contractions and the permanent con- tractions which are accompanied by a partial destruction of the muscle- fibre, and that the latter only are marked by an increase of refractive power. So far we have given an abstract only of the author’s paper. His “Remarks on our Knowledge of the Structure of the Transversally Striated Muscle-fibres ” which follow, we translate in extenso. “It seems to me therefore that the very contradictory data con- cerning the anatomical relations of a muscle-fibre during contraction require revision. It will be asked why I do not undertake this revision. The answer is, that such a revision is not possible without an accurate knowledge of the relaxed muscle-fibre, and that I feel myself unable to form an opinion as to whether certain results of late investigations on this subject are reliable or not. I regard not only myself but others also provisionally as unable to form this opinion for reasons which will be explained in the following remarks. Where twenty years ago a distinction was only drawn between singly and doubly refracting substance in the muscle, there is now recognized a sequence of the parallel layers (using Rollett’s nomencla- ture) Z, E, N, J, Q, h, J, N, E; nine layers in place of two; these layers are conveniently described as of a thinness which approaches ‘ the limits of the perceptible.’ If we consider that the whole of geometrical optics, i. e. the recognized laws of the formation of images, only holds good so long as the relation between the magnitude of the object and the wave-length of light does not fall below a certain limit;* and if we consider, further, that the wave-length of light in air (e.g. for the line Cf) is 0°000589 mm., and in muscle-fibre (n = 1°363) is 0°000432 mm., and that these numbers are greater than the thickness of the single layers, we must ask ourselves whether these anatomical results have any value at all. To this it must be added that Abbe, the first living authority on the theory of the Microscope, says with regard to the diffraction-images produced by the transverse striation of the muscle-fibres, ‘The manifold changes in the character of the image’ (produced by the trans- verse striation) ‘explain to some extent the well-known difference between the observations of various investigators with regard to these appear- ances, but prove also the impossibility of acquiring any definite knowledge about their actual physical structure’ (i.e. of the fibres) ‘in the sense of the attempts which have hitherto been made.’ } Thanks to the investigations of the same physicist, we now know that the formation of a true microscopic image depends upon whether all those rays contribute to the formation of the image on the retina which are diffracted by the boundaries (whether sharply defined or gradual) between parts of the object of different refractive powers, or by inequali- ties of the object, &c. If this is not the case we may receive illusory images; the finer the structure which we attempt to resolve by the Microscope, the greater is the probability that a portion of the diffracted rays will not reach the eye. Beyond a certain limit of fineness this probability becomes a certainty, and Abbe concludes ‘ that no Microscope has ever shown, or ,will ever show, anything actually existing in the * Cf. Helmholtz, ‘‘ Ueber die Grenzen der Leistungsfahigkeit des Mikrokopes,” SB. Berliner Akad., 1873, p. 625. + According to Ditscheiner. ¢ Arch. f. Mikr. Anat., ix. (1873) p. 454. 128 SUMMARY OF CURRENT RESEARCHES RELATING TO object which cannot be clearly distinguished by a normal. eye with a sharp immersion amplification of 800, ‘lo many microscopists the physical deductions will perhaps be less accessible than the experiments which show that the lines of a microscopic grating are doubled when a portion of the diffracted rays are prevented from reaching the eye; that by screening off another part lines can be seen running in a direction different to those of the lines of the grating, &e. Even the microscopist who has no desire to work at the theory of theso phenomena must at least be made anxious by them, and his anxiety is the more justified by the fact that there is no criterion by which we can know whether some of the rays have been lost to the retina or not. It is this feeling of anxiety with which I am concerned. How many pages have been written upon the structure and the linear markings of Pleurosigma angulatum! We now know that various authors have seen the markings differently, and we know why this is so, and that we may perhaps learn the true structure in some other way, but never by simple microscopic observation as has been attempted. Are we not upon similar ground in the case of the muscle-fibres? In any case it seems to me that we must tread it with caution. Now it is this caution and this feeling of anxiety which I miss in the later investigations on muscle-fibres; although our knowledge of the relation between the diffraction phenomena and the microscopic image is old enough, I do not remember to have ever found in the literature of the subject a clear and definite expression which would indicate any fear of falling into the error which I have pointed out. Yet facts so glaring as those which I have adduced, and such authors as Helmholtz and Abbe, cannot be overlooked. There is a special group of diffraction phenomena to which I will draw attention. The rays which, traverse the object naturally interfere in the wide space between the retina, the Fig. 52, object, and (according to the usual optical mode of expression) beyond the latter. Let a b (fig. 32) be a plane wave-surface, eda small opaque particle. Ine will meet rays without difference of phase, which have passed c and d and have been diffracted at those points. If then the Microscope is focused upon e a bright spot is seen, As the ob- jective is moved towards cd, i.e. as it is ad- justed for successive points in the line ef which lie between e and c d, the conditions are the same for all these points until the rays de and ce have so great an inclination, that with the particular aperture in use they no longer contribute to the formation of the image. If the Microscope-tube is depressed until it is adjusted for a point below cd, the bright spot returns and is now due to the rays rf and q f which have no difference of phase. With regard to points lying on either side of the median line ef the case is different. If m is a point at which the diffracted rays cm and dm meet, with a difference of path equal to a half wave-length ch, they destroy one another ; e will * See infra as to the fear of similar dangers entertained by Heppner and Donitz. ZOOLOGY AND BOTANY, MICROSCOPY, ETO. 129 therefore be surrounded by a dark ring; all points which satisfy the same conditions as m and which lie in the plane of the figure belong to a hyperbola whose apex lies in ab; as the tube is raised the dark ring will therefore increase. According to the conditions e will be surrounded by a certain number of dark rings corresponding to differences of path, which are an unequal number of half wave-lengths, and between them will lie bright rings. These diffraction ) henomena may be well seen with particles of Indian ink in water when a round opening of 1 cm. in a screen before a gas- flame is used as illuminator; the same thing may also be seen with ordinary illumination. Certain interference-bands lie in the immediate neighbourhood of the object, and are seen when the Microscope is focused close to the object ; and when the latter has, as is the case with the muscle-fibres, a considerable thickness, the diffraction images may even lie inside the object, aud thereby considerably increase the danger of error. Now, as ‘has been said above, the image is no longer reliable when the object attains a certain minuteness, so that in such cases it may be uncertain whether the Microscope is focused on the object or on the diffraction appearances. As is well known, the different interpretations put by Engelmann and Meyer upon the process of contraction in muscle-fibres depend on the different modes of judging what is meant by the ‘true’ focal adjustment of the object.* In working with the Microscope we see every day examples of these diffraction images; a sufficiently minute drop of mastic emulsion has naturally a definite outline and a transparent interior, like a larger drop, but this cannot be seen; in general, what is seen is a dark point, or with a different focus a bright point surrounded by a dark circle. Whether the object consists of a transparent liquid or a black pigment we cannot say, since the diffraction phenomena are the same in the twocases. With a sufficiently fine thread a similar figure is produced. The practised microscopist, although he only sees the diffraction phenomena, and even in consequence of them, will realize the existence * Cf. Merkel in Arch. f. Mikr. Anat., ix. (1873) p. 299. Merkel here attempts to settle the question by examining the primitive fibrille in polarized light, and since the ordinary illumination gives no result he employs direct sunlight. I cannot regard this as satisfactory, for in this case the small angular size of the source of light introduces conditions peculiarly suitable for diffraction phenomena, In fact it is impossible to ignore the fact that if the double-refraction has not been essentially altered in the balsam preparations, and there is no reason to believe this to be the case, Merkel’s results cannot be attributed to this cause; a single fibrilla is too thin. If the fibrilla is only visible in blue light upon a dark field the difference of path of the two rays must amount to : of this light. According to Ketteler, for the line G in vacuum Av = 0:000430409 mm. So that with the above values of n for the ordinary and extraordinary rays in a living muscle-fibre Ao = 0:00031463 mm. Ae = 0°00031417 mm, Assuming for the fibrilla the considerable thickness 0°002 mm. it contains 6°356 waves of the ordinary and 6°366 waves of the extraordinary ray; that is, the differ- ence of path is only 1/100 of a wave-length ; and this is not in harmony with the effect described, 1888. K 130 SUMMARY OF CURRENT RESEARCHES RELATING TO of a small particle. But how is he to gain the practice to explain diffraction phenomena in objects of complicated structure, and which he cannot, like a drop of mastic, reproduce artificially? It is scarcely possible either as the result of practice, or on the basis of theoretical treatment, to arrive at a clear explanation of all the images produced by different focusing, thickness of fibre, illumination, &c. The conditions are too complicated, but I will endeavour to make the essential points more clear. Let ab (fig. 33) be the boundary of a muscle-fibre, and mg fn the visible portion of a disc of the same which has a different refractive index from that of the next disc. If A is a point outside the fibre, the intensity of vibration at A of a plane wave of light which traverses ab is, aceording to Huyghens’s principle of the elementary zones of spherical waves, the result of the interference of gh with qf, of fg with ef, of ef with de, of de with cd, and of similar portions on the other side which reach A. If the path from gh to A is a half wave-length smaller than that from hi to A, and similarly in the remaining parts, the result of the interference is the extinction of the portion of the wave which is the more remote from A g, and the rectilinear propagation of the ray g A. The shaded portions may represent those parts where wave-troughs reach A at the same moment at which wave-crests arrive from the unshaded parts. If the pencils whose inclination is that of 1 A, or of the rays beyond / A which are not represented in the figure, do not enter the Microscope, then the above-mentioned case of an incomplete image is realized, which is of course in the present example without signification, since no part of the structure is included. If the cylindrical form of the fibre is negleeted this method of treat- ment may be applied to any point g of a line which is perpendicular to the axis of the fibre, and Huyghens’s elementary zones become elementary stripes parallel to this line. Consider next the case (marked B in fig. 33) in which the point g falls on the boundary between two dises of different index. Let the shaded parts represent as before the wave-troughs which reach B, and the ZOOLOGY AND BOTANY, MICROSCOPY, ETC. ast unshaded parts the wave-crests; then the figure indicates the altered conditions as compared with the first figure for the case in which, corresponding to the different refractive indices of the two discs, the portion of the light-wave which has traversed one of them is retarded by an uneven number of half wave-lengths behind the other. It will be seen at once that gf and gh in their action on B cancel each other, as do also the other elementary strips, just as in the first case. Further, it will be seen that this extinction takes place for every point of the line independently of the distance g B, and that with an alteration in the thickness of the fibre a periodic alternation between light and partial darkness must take place. The case is different when we consider a point which is not at right angles to the bounding surface, e.g. C, fig. 383. The vis viva to be transferred from fh to C is neither cancelled as in the second case, nor weakened in the same degree as in the first case by the neighbouring elementary stripes, whose phase is _ shifted through a half wave-length, but it reaches C, so far as concerns the portion fg, in its full extent, the action of ef and gh being added with positive sign to that of fg, though each of the first is weakened to a certain extent, it is irue, by the slight action of de and ht While there- fore, the point B remains undisturbed, C receives an intensity of vibra- tion, and a ray travels in the direction »C. This corresponds to the first diffraction pencil, Supposing that the muscle disc mg fx were much smaller, and extended from f only to a point, e (not shown in the figure), between e and f, if this thin layer is to have any effect upon the microscopic image it must, at least, contribute a diffracted pencil to the production of the image. The smaller fo, the farther must C travel from C,, that the difference of path between the portions of the wave fe and fg may attaiu a half wave-length, and the larger, therefore, must be the angle made by the diffraction pencil with the perpendicular nf. When fo is nearly a half wave-length, then this angle is nearly a right angle, and we get the law discovered by Helmholtz, that microscopic delineation ceases when the detail to be observed diminishes to the size of a half wave- length, presupposing an aperture of the Microscope of 180°. In this case one, at least, of the pencils of light diffracted by the structural element still enters into the microscopic image. If we consider the boundary of the dise more closely, it is clear that there will be a similar interference upon the other side of f n. Here also there will be a ray in the direction p, C,. Now, the two r, : rays p C and p, C, have a difference of phase equal to Z Focusing, therefore, upon the point of intersection of these two rays, we shall see a dark line under the upper surface of the fibre. If we focus the inter- section of p C with the corresponding line r q from the other surface of the disc, a bright band must be visible, as will also be the case when the Microscope is focused on the point above the fibre in which Ane intersects the corresponding line (not shown) upon the other side. The phenomena here described bear some relation, on the one hand, to the interference phenomena of the so-called ‘ mixed scales’ discovered by Young, which are explained by the retardation of a part of the light- waves which traverse a medium of different refractive index from the rest; and, on the other hand, with the ‘lamellar diffraction phenomena’ K 2 132 SUMMARY OF OURRENT RESEARCHES RELATING TO more recently investigated experimentally by Quincke and theoretically by Jochmann.* The phenomena are, beyond comparison, more complicated in the muscle-fibres, as must be at once apparent if it is remembered that the conditions described do not depend upon a b being the surface of the fibre, so that the above treatment holds good for any plane within the fibre for which the portions of the wave that traverse the different discs have a difference of phase equal to ; and when it is remembered also that the phenomena must change with the thickness of the layer, that the source of light is not a point, but a bright surface (a portion of the sky or its image), that the light used is mixed light, &e. The case may also be made clear in the following way:—When a plane wave traverses discs of unequal refractive index, it acquires parallel ridges corresponding to the layers of smaller index, The problem then consists in the determination of the resultant of the inter- ference of the elementary waves proceeding from a surface of this form. Some years ago Heppner} suspected that a certain layer of the muscle-fibre, identical with Rollett’s N, does not in reality exist, but is confused through a reflex. Sachs{ and others opposed this idea. Dénitz § seems to have been the first who thought of diffraction phenomena as the explanation of certain striations. He was followed by Schafer, and Ranvier made experiments upon the diffraction spectra obtained from stationary and contracted fibres in which the transverse striations acted as a diffraction grating. I have, in the above remarks, raised the question whether, in the light of this optical treatment, the results of recent investigations have any value as regards the distinguishing of several layers in the musele- fibres where previously two alone were recognized, or whether we must, with Abbe, for ever despair of recognizing such minute details. My answer amounts to this, that without doubt the greater part of the recent results deserve complete trust. All those layers which have been distinguished, not only in the optical image, but also by maceration and staining experiments, are free from the suspicion of being only the impression of incomplete delineation. Rollett, who seems to have been thoroughly aware how slippery is the ground of simple microscopic examination, has recently, as I think, trodden the path here indicated with the best results. The same has been attempted, it is true, by many inquirers before him, but no one has worked in this direction with such a variety of methods or obtained such promising results. When for example the layer N under the action of acid behaves in an essentially different way from the layer Q, there can be no doubt that a distinction is here established. But the case is different with certain details, where one meets with the above-mentioned want of care against incomplete delineation, in consequence of which one can see even more than is really present. I may be here allowed to give examples; but I may first state that in the absence of a true criterion for a correct and complete representation of the object, the following may serve as a criterion. A detail of the microscopic image is to be regarded as * Cf. Verdet, ‘ Vorlesungen iiber die Wellentheorie des Lichtes,’ German transla- tion, by K. Exner, i. (1881). + Arch. f. Mikr. Anat., v. (1869). } Du Bois Reymond and Reichert’s Arch., 1872. § Ibid., 1871. ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 133 existing in the object when its character is not altered by an inclination of the incident pencil of light (oblique illumination). If the character is altered in passing from central to oblique illumination, we may con- clude that in the latter, diffracted rays enter the Microscope which were unable to do so in the first case. When this happens, it indicates that a complete representation is not obtained by central illumination, and it must be doubtful whether it is so by oblique illumination. We may obtain a good idea of the optical processes which form the basis of this rule by means of the Abbe diffraction plate. If any line- system of the plate be so focused that the central image of the whole diffraction spectrum visible in the focal plane of the objective lies in the axis of the Microscope (direct illumination), and one entire half of the dif- fraction spectra be then screened off by a suitable diaphragm (with the exception of the central image for which the semicircular diaphragm must have a piece cut away), the microscopic image will not suffer any essential change. It is also possible, as may be easily seen, to set the ‘mirror so obliquely (or to obtain oblique illumination by Abbe’s con- denser), that the rays which have not been diffracted still contribute to the microscopic image, the image of the source of light then falling at the margin of the diffraction phenomena visible through the tube. In this case still further diffracted rays may become visible in the diffraction image, and may contribute to the delineation if such rays are present to a considerable extent. I cannot help calling attention to two other possible sources of error. It is not impossible that the discs of unequal index of which the muscle-fibre is constructed, are not separated from one another by sharp boundaries, but the optical density may change gradually from one to another. Such layers have in fact been described. Now a dise in which the refractive index is a maximum or a minimum at the cenire, acts like a cylindrical lens upon light which enters it parallel to its plane ends (independently of the cylindrical surface). The parts of a wave surface which traverse layers of smaller index, travel more rapidly than those which have to traverse layers of greater index, so that there results a cylindrical curvature of the wave surface.* In this way focal lines may be produced which are parallel to the layers in the muscle; they need not be outside the fibres, but may lie within them; in the first case they alter their position as the thickness of the fibre increases, It is evident that stripes which are produced in this way, as well as those which result from diffraction, must undergo various changes if an alteration takes place in the refractive indices, owing to the separa- tion of a liquid from the muscle-fibre. Since such changes do take place during the life of the muscle, it is not a matter for surprise if the fibres which are still contracting change their appearance. LRollett has in fact described and figured a series of such changes, but whether they are due to the causes here indicated, I must, in the presence of such a number of possibilities, leave undecided. Mention has repeatedly been made of darker and lighter layers in the fibre, and Rollett, in treating of the transverse striations of the fibres, likes to give two figures beside one another, one taken with high, * Cf. S. Exner, ‘Ueb. Cylinder welche optische Bilder entwerfen.’ This Journal, 1886, p. 1062. 134 SUMMARY OF CURRENT RESEARCHES RELATING TO the other with deep focusing, which bear the same relation to one another as the positive and negative of a photograph. They show that we have here a case of an optical effect. There are, however, frequently to be found figures in which the dark appearance of the striations is to be regarded as a true darkness of the anatomical structure; not the ex- pression of diffraction, but an absorption of the light-rays. Sachs * says, ‘The dark colour of the contractile substance rather depends principally upon the opposition offered by the very dense gelatinous mass to the passage of light; the greater part of the incident light between o, and o; is absorbed.’ Sachs is here speaking of the fresh living muscle-fibre,t in which the doubly refracting substance, at least under ordinary conditions and with the ordinary adjustment, does in fact appear dark. I must, however, deny this and similar statements to the effect that there is anywhere in the living muscle-fibre a substance which ‘absorbs the greater part of the incident light.’ Al parts of the fibre which are not granular are rather to be regarded as absolutely transparent in layers of the thickness with which the Microscope is concerned, i.e. if there is an absorption it is not appreciable. The ‘dark layers’ which are not granular, and also, of course, the ‘bright layers, are always optical effects. If there were an appreciable absorption it would also be observed when the light travels parallel to the axis of the fibres. Since « reflection of the rays must take place where there are granules in the fibre, it is an open question whether light is absorbed by the granules. The second source of error, which seems to me to be too much over- looked, takes effect when the fibres are examined in polarized light; not every bright line which is seen between crossed nicols is necessarily to be regarded as the expression of a doubly refracting layer. The plane of polarization is also turned by diffraction, and it is impossible to say whether in this case the rotation of the plane of polarization does not also take place by refraction and reflection. In some fibres examined for this purpose I have found the maximum bright- ness from Q and Z between crossed nicols to be always in the same azimuth, which contradicts such an explanation of the layer Z which is generally regarded as doubly refracting. Finally, there is one remark which I cannot refrain from making. It is fully established, in my judgment, as I have said, that there are living muscle-fibres for which the old idea of composition by alternate layers of singly and doubly refracting substance does not hold good; several layers can be distinguished. On the other hand, however, we must not ignore the fact that living fibres are observed in which only two old layers can be seen with certainty, and that this is the more certain in proportion as the fibres (assumed to be living) are more fresh. It may well be asked what then is essential and typical in muscle- fibres. One may well hold the view that it is more natural to assume that in certain cases we fail to distinguish a part of the layers than to imagine an irregularity in the structure of the fibres. We must remember, however, that Rollett’s investigations did not in general establish a type of numerous layers, but that the image varies from one * Reichert and Du Bois Reymond’s Arch., 1872, p. 633. + This is not expressly stated, but follows from the fact that in the passage quoted he is opposing Heppner, who speaks expressly of the living fibre. Arch. f. Mikr. Anat., v. (1869) p. 139. ZOOLOGY AND BOTANY, MICROSCOPY, ETC. a species to another, and what is not to be overlooked, that it varices con- siderably during the survival and decay, and during the process of hardening. In one preparation of living muscle-fibre from Hydrophilus I saw fibres in which the dises Z and E were well developed, by the side of others in which the distinction could not be seen. With this want of constancy it seems to me to be dangerous to regard the fibre with nine layers as the type,* without granting that there also exist fibres with two layers. Iam rather inclined to see the type in the fibres with two layers, and to regard the appearance of more layers as something secondary.” Method of Representing and Calculating the Magnification of Microscopic Objects in the projected images.|—Dr. P. de Vescovi has published a paper under this title, which seems to us to contain a great many elementary facts and statements. Divested of these, the following extracts appear to contain the pith of the paper. The statement of the amplification rarely corresponds to the truth, and generally deviates widely from it, since the methods ordinarily used to calculate and to indicate the enlargement are defective, or at least fail in something. The amplifications given in the tables which are supplied with Microscopes are mostly obtained by multiplying the magnifying power of the eye-picce by that of the objective—an inexact method. More exact are those who give the system of lenses used, and the names of the makers of the Microscope; but in this case if one considers the factors (such as length of tube), which contribute to the variations in size of the image, the indication is still inexact; as it may easily happen that with a given’ eye-piece and objective, and upon the same instrument, different amplifications may be obtained either of the real or of the projected image. “'Po remove all uncertainty and possible difficulties, it is necessary that the explanation of every figure should give the following data :— (1) The eye-piece and objective used. (2) The maker of the Microscope. (3) The length of the tube. 4) The true dimensions of the object. (5) The ratio of the dimensions of the object to those of its projected image, or the amplification of the drawing. Example : Hye-piece 3. Objective AA Zeiss. Length of tube = 17 cm. Greater diameter of the object = 0°026 mm. Amplification of the drawing = 95.” Measurement of Magnifying-power of Objectives. [Replies to query by J. S. Hewitt, T. F. 8S, “ Practical,” E. M. Nelson, E. Holmes, “ Gamma Sigma,” J. D. M., and “ Decem.’”’] Engl. Mech., XLVI. (1887) pp. 325, 341-2 (2 figs.), 365 (1 fig.), and 417. * So far as I know, no one has done this. Different authors have rather founded different types which always, however, have a considerable number of layers. t Zool. Anzeig., x. (1887) pp. 197-200. 136 SUMMARY OF OURRENT RESEARCHES RELATING TO (6) Miscellaneous. Development of the Compound Microscope.*—In the course of Mr, KE. M. Nelson’s paper on this subject he makes the following remarks :— “Let me preface the few remarks I have to make on the Development of the Microscope, by pointing out to you the important place the Micro- scope holds in our social economy. Up to a very few years ago the education of the nation was confined merely to a knowledge of Greek and Roman mythology. This was the key-note given by our two Uni- versities, which as a natural consequence was followed up by the public schools, whose masters are all graduates of one of these Universities. The knowledge of a dead language depends more on an effort of memory than on a use of the reasoning faculty. As a development of the reasoning faculty is of vastly greater importance than the memory power, so dead languages are most unsuited for the training of the young. To educate according to its derivation, means to lead out; to educate a boy therefore, is to lead out his mind; in other words, to draw out something which is there. According to the popular notion it is to put in something which is not. The only way to procure growth in an organism is to supply it with food it can readily digest, so the only way to develope the brain is to supply it with digestible food. Further, as one man’s meat is another’s poison for the body, so also is it for the mind. But what have the great educators of our nation done but force every one through the same classical diet, to the exclusion of everything else? In doing so they have ruined thousands of minds by arresting the development of the reasoning faculty, and by filling them with what is, in most cases, indigestible matter. There is necessarily a certain percentage of minds to whom classical lore is a food capable of ready assimilation ; they consequently may be benefited by it, but we may assume the percentage is small. You will be asking what all this has to do with the Microscope. To which I reply, that I wish to see Liddell and Scott’s Lexicon dethroned, and the Microscope put in its place as a national educator. Of late a change has taken place. Since my schooldays, science has been in- troduced. This is the thin end of the wedge; let it by all means have full scope, and I have little doubt but that that science which was ridi- culed by the schoolmasters of my day, will eventually supplant the Olympian mythoiogy as a pabulum on which to feed the young mind. The Microscope and the telescope hold the same relation to science as a knife and fork do to beef. If science isa food for the mind, a little time devoted to the knife which makes it capable of assimilation will, I hope, not be in vain. Therefore, without further digression, I will at once pass to the instrument. The telescope, dealing as it does with extra- mundane things, cannot have the same interest for us as the Microscope. The one fact, that the Microscope has revealed the pestilence which has walked in darkness all these ages, is sufficient to place it above all other scientific instruments in importance. An unseen foe is a bad one to fight, but now that his lurking-place has been unmasked by the Micro- scope, we may look for some victories over our enemy. Have not some indeed been already gained ?” “* We have now come to a period when the Microscope object-glass was achromatized, and from this date spring the great improvements * Trans. Middlesex Nat. Hist. and Sci. Soc., 1886-7, pp. 103-11. ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 137 which have brought the instrument to its present state of perfection. It would, indeed, take several evenings to systematically examine the great number of forms which have been introduced since that time. It is my intentien, however, only to notice three, as most of the others, not being of any practical value, have speedily become obsolete. We need no diagrams of the three forms which have survived, as I have actual examples in the room. First there is this, which is known as the “ Hartnack,” or “Continental Model,” it is a lineal descendent of the ** Oberhauser.” I have little hesitation in saying that nine-tenths of all original microscopical work has been done by these Microscopes, but at the same time I maintain that that statement does not prove it to be the best model. It is a model which is incapable of doing critical work with low powers, and of working any high power at all. The reason why so many discoveries have been made with it is due to the fact that nine-tenths of the things discovered lie among low-power objects. Another point must be borne in mind, viz. that a quarter-inch lens uncritically used will as readily discover an object as a half-inch critically used. The interpretation of images with low powers is easy, and requires very little training; critical images, therefore, are not so essential. Most of the fine high-power work which has been carried on with these instruments has been erroneous, and has had to be corrected with other instruments. As time goes on, discoveries with the low powers become less and less possible, and instruments of greater precision will become necessary.” “The importance of a condenser cannot be over-estimated. I have always held that Microscopy begins with a condenser. An instrument however well designed and well constructed, if it has not a condenser, is nothing more than a magnifying glass, while on the other hand, a simple stand like this iron one of Powell’s, with a condenser, forms a very efficient Microscope.” ‘Student’s Handbook to the Microscope.’ *—This little book ful- fils its purpose in a very creditable manner, and will be a useful guide for a large number of Microscope owners. It is a decided advance on the author’s previous venture, ‘My Microscope, the publication of which was, we thought, to be regretted. Even in these days it is, we suppose, hopeless to expect the question of aperture to be dealt with without a mistake, and therefore we find on p. 37, the statement that among the drawbacks to an excess of aperture is “a loss of defining power, that is distinctness of the image.” This arises from an entire misunderstanding of the principles of aperture. The larger the aperture, the less the penetrating power, or the power of seeing a given depth of the object with the same focus. But the definition of the particular plane, whatever its depth, which is seen by the large aperture is not in any way impaired; in fact the definition of what is seen is more complete and perfect with the “high angle” objective than with one of smaller aperture. ‘Microscopical Advances.” t—‘“ T. F. §.,” writing on one of a series of articles under this heading by Dr. G. W. Royston-Pigott, * A Quekett Club-man, ‘The Student’s Handbook to the Microscope. A Practical Guide to its Selection and Management,’ vii. and 72 pp. (80 figs.) 8vo, London, 1887. + Engl. Mech., xlvi. (1888) p. 435. 1388 SUMMARY OF CURRENT RESEARCHES RELATING TO points out that he has mixed up the “ villi” on butterfly seales—which point to real structure—with the old vexed question of the beading of the Lepisma and Podura scale, “ discrediting the whole thing with those who have knowledge of the subject, and giving utterly false impressions to those who have not.” Having carefully examined many scales of Lepisma with a fine 1/12 oil-immersion by Swift and Son, “'T. F. 8.” is prepared positively to state that there is not the slightest existence of beads in any of them, although it is easy to see what caused the appearance of beads to Dr. Pigott with the dry 1/16 in. which he used. “ Please remember,” T. F. 8. writes, “that it is a dry glass against an oil-immersion, and [ need not tell any expert microscopist that if certain appearances which present themselves with a narrow aperture of the objective vanish when another of larger aperture is screwed on, that of itself is sufficient to disprove the existence of the apparent structure. “ Now for the real structure. The scale itself is composed of two membranes, in one of which is imbedded the longitudinal ribs; the other is corrugated, and the corrugations cross the longitudinal ribs at an oblique angle, giving under a low power the appearance of spines. Between the two membranes, and over the whole scale, is a net-like looking structure, perforated in all directions, and where this also crosses the oblique corrugations there is the appearance of beads. This appearance of beading, however, is confined to the sides, and not even Dr. Pigott himself could conjure any appearance of beading out of the centre, and in the drawing he has confined himself to the side only. Some of the small scales have only small straight hairs between the long ribs, and here it is easy to produce beautiful beads by using the smallest hole in the diaphragm of the condenser ; but they all disappear on producing more light. On the Podura scale I have not been able to produce the slightest appearance of beading, although I have tried very hard todo so. The “villi” in the butterfly and moth scales stand on quite a different footing, and answer the purpose of keeping the two membranes more or less apart; but even here I can see no evidence of isolated beading. I can see them (the villi) on any scale with a dry 1/6 in. and 1/8 in.; but here the evidence is confirmed tenfold by substituting an oil-immersion 1/12 in.” ‘“‘The Microscope and Kidney Disease.”—-Most readers of news- papers are by this time sufficiently on their guard against the insidious paragraphs to be found at the bottoms of columns, the titles of which appear to promise a very interesting piece of news, but which ultimately end in an advertisement of some nostrum sold by the advertiser; such, for instance, as the “ False Swain and Deluded Spinster,” which in the last few lines is discovered to be an advertisement of a hair restorer. A particularly flagrant example of this trap for the unwary was presented by the ‘ Norfolk News’ of the 24th December last. The paragraph was not at the bottom but at the top of the column, and it was not printed in the usual smaller type, but in similar type to that used elsewhere in the paper. Being headed in capitals ‘Tue Micro- scopr,” and “THE MANY Puzziine Secrets REVEALED BY THIS WONDER- FuL Instrument,” we naturally proceeded to read it with much interest, and that our readers may be able to participate in the feelings with which we followed the development of the atrocious nonsense thus + ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 159 heralded we print it here, with the exception of the advertiscr’s name, for which we have substituted “Smith.” “No medical man of skill and ability considers his study at the present time complete unless it contains a first-class Microscope. This wonderful instrument by its marvellous power makes clear to our eyes a world of which, prior to its invention, we knew nothing. Its introduc- tion into medicine is only of late years, and has been mainly brought about by the competition of practitioners in their endeavour to find some aid that would enable them to detect the presence of disease when hidden or masked; to diagnose with greater accuracy, and so secure that prominence in their profession upon which their fame and emolu- ments rest. But its use has been more particularly applied to the examining of the fluids of the body to determine the state of the kidneys, and to decide if the latter are in a state of disease, and, if so, its stage. It has already been the means of saving many a life in fore- shadowing the advent of that stealthy and fatal disease to which Dr. Richard Bright gave his name, and which prior to the introduction of ‘Smith’s Cure’ was always regarded as incurable. In all the history of the Microscope its use was never so prevalent, its study never prosecuted with so much vigour, as it is to-day ; and science through its means is ever revealing something fresh and new in relation to its powers. For instance, a noted physician and German scholar has recently discovered that by its aid the presence of a tumour forming in the system can be detected, and if certain appearances are visible it is proof positive that the tumour or growth is of a malignant character. Uric acid, which is a rank poison, is one of the substances which arise from destructive waste of our body, and must be thrown off daily or we die. Now before we understood the Microscope it was impossible by any means at our command to know what was being passed out of our body, or from whence it came; and one great benefit which this instrument has con- ferred upon humanity is in the relief of headaches, malaise, indisposi- tion, and other diseases, which are now known to be caused by the retention of uric acid in the body. When an analysis of the fluid is made by a micro-chemical examination this substance can be traced in its proper quantity, and when the proper remedy is applied relief is soon secured, the cure being effected almost immediately. .. . As we said before, medical science has been unable to cope with this disease, and neither homeeopathics nor allopathics are prepared with a cure for deranged kidneys; and all the world has long since recognized, and many medical men who are without bias and without prejudice. liberal minded, and anxious to cure, admit and prescribe ‘Smith’s Cure’ as a specific for all diseases of the kidneys. .. . ‘Smith’s Cure,’ like the Microscope, was found out by a layman outside the medical code. The universal testimony of our friends and neighbours shows it to be alone the remedy for all diseases of the kidneys, their prevention and cure. Their statements are sufficient explanation and endorsement of its extraordinary growth, and conclusive proof that it is perhaps the most munificent remedy known to the medical world since the Microscope revealed to us the all-important nature of the organs which this medicine is specifically designed to benefit.” Although from one point of view it may not be very complimentary, yet we must express a hope that the editor of the ‘ Norfolk News’ when 140 SUMMARY OF CURRENT RESEARCHES RELATING TO he inserted this advertisement really believed that he was imparting to his fellow countrymen a sound and valuable piece of microscopical information. “‘Quriosities of Microscopical Literature.’—In the last volume of the Journal, p. 830, we had occasion to comment upon a paper by Mr. H. Morland, in which a fundamental point of microscopical optics was the subject of an extraordinary misapprehension. In the last number of the publication in which the original paper appeared, we find the following entry : *— “ Mr. Morland read a reply to a criticism in the Royal Microscopical « Society’s Journal for the current month on his paper on ‘ Mounting “* Media so far as they relate to Diatoms.’ ” Neither the reply nor even an abstract of it is, however, printed, and no communication has reached us as to the nature of it. This is the funniest way of dealing with a “reply ” that we can recall; it is framed somewhat on the principle of Lecch’s celebrated cartoon of Lord John Russell chalking “ No Popery ” on Cardinal Wiseman’s door, and- then running away ! Bary, A. de, Hon. F.R.M.S. Obituary Notice. Atheneum, 1888, Jan. 28th, pp. 118-9. Nature, XX XVII. pp. 297-9. Dancer, J. B., Death of. [“‘ The death is announced of Mr. John Benjamin Dancer, a Manchester optician, to whom many important inventions are due. Mr. Dancer was born in London in the year 1812. He settled in Manchester in 1835, and soon made his mark in scientific circles. He was elected a member of the Literary and Philosophical Society, and a Fellow of the Royal Astronomical Society. He was the first to suggest the application of photography in connection with the magic lantern, and he followed it up by other improvements. He also con- structed the optical chromatic fountain, an idea which has since been further developed at South Kensington, and Old Trafford, Manchester. Mr. Dancer’s services in connection with electricity and photography were of a valuable and important nature. Further, Dr. Joule states that the first thermometer made in England with any pretensions to accuracy was constructed ky the deceased. He was also successful in producing Microscopes which, while fully equal to the requirements of original research, were within reach of working-men naturalists. During the later years of his life Mr. Dancer's pecuniary circumstances were of a straitened character, and he also suffered from the terrible affliction of total blindness.’’] Times, 7th December, 1887. EpmuNDs, J.—Theory of the Microscope—Nageli and Schwendener. Engl. Mech., XLVI. (1887) p. 365. Errera, L.—La Micrographie a l’Exposition de Wiesbade. (Microscopy at the Wiesbaden Exhibition.) Bull. Soc. Belg. Micr., X1V. (1887) pp. 22-35. Ewett, M. D.—A Manual of Medical Jurisprudence for the use of Students at Law and of Medicine. [Contains chapters on the part which the Microscope may play in determining medico-legal questions. ] 414 pp., 12mo, Boston, 1887. Feu, G. E.—Exhibition of “Letter 0 occupying space of 1/1,000,000 in. magnified 3200 times.” Amer. Mon. Micr. Journ., VIII. (1887) p. 209. Hitrcucock, R.—Reminiscences and notes on recent progress. Amer. Mon. Micr. Journ., VIII. (1887) pp. 205-7. Mayall, J., Jun.—Conferences sur le Microscope. (Lectures on the Microscope.) Contd. { Zransl. of the Cantor Lectures. ] Journ. de Microgr., XI. (1887) pp. 544-6 (6 figs.). * Journ. Quek. Micr. Club, iii. (1887) p. 197. ZOOLOGY AND BOTANY, MICROSCOPY, ETO. 141 MocInvrirg, S. J.—Another Eveniny at the Royal Microscopical Society. [Deseription of the first Conversazione of this Session. } Sci.-Gossip, 1888, pp. 19-20. Netson, E. M.—The Microscope—Nageli and Schwendener—English Translation, 1887. Engl. Mech., XLVI. (1887) pp. 325, 364-5 (2 figs.), 393-4. Also comments by “ Practical,” who finds it “ far too abstruse to be of practical value to the general body of microscopists” (Jbid., p. 341), and reply by Dr. J. Edmunds (Jbid., p. 365)—‘ A Fellow of the Royal Astronomical Society,” who prefers Heath’s ‘Geometrical Optics’ (Zbid., p. 390).—Review by Dr. W. H. Dallinger (Nature, XXX VIL. pp. 171-3). Reichert, C.—Directions for using the Microscope. Transl. by A. Frazer. [In the Translator’s Preface acknowledgments are made to “Mr. A. Schulze (Fellow of the Royal Micro-copical Society).” No such name appears, however, in the Society’s List of Fellows. ] 12 pp. and 2 figs., 8vo, Edinburgh, 1887, Royston-Picort, G. W.—Microscopical Advances. XXIX., XXX. (Butterfly dust; bars, villi, and bacilli; latticed and beaded ribs. ] Engl. Mech., XLVI. (1887) pp. 357, 379-80 (4 figs.). Vorcer, C. M—The Meeting of the American Society of Microscopists. Amer. Mon. Micr. Journ., VIII. (1887) pp. 207-9. Waterhouse, G. R., Hon. F.R.M.S8. Obituary Notice. Atheneum, 1888, January 28th, p. 119. B. Technique.* (1) Collecting Objects, including Culture Processes. Cultivation of Saccharomycetes.t—Some fermentation experiments with which Mr. W. E. Stone has been engaged required the application of pure yeast, free from other organisms capable of producing fermenta- tion, and the following was the method of separation and cultivation employed :— A few drops of fresh beer-yeast were shaken in a test-tube with sterilized gelatin, which had been melted and cooled again until it was barely fluid. This flowed upon sterilized plates gave in twenty-four hours, at ordinary room temperature, a great number of colonies of Schizomycetes and Saccharomycetes, from which, with the aid of an ordinary dissecting Microscope, it was easy to inoculate new cultures. The gelatin was of ordinary composition in daily use in the laboratory, viz. 10 per cent. gelatin, 10 per cent. grape sugar, Liebig’s “ Fleisch Extract” added to give a yellowish-brown colour, and neutralized with sodium carbonate. Such a mixture is solid at 25° C. For further culture the isolated gelatin-plate colonies were inocu- lated into sterilized solutions consisting of an extract made by boiling 200 grams of yeast in a litre of water, filtering, and adding 10 per cent. of grape-sugar. In such a solution an inoculation of a few yeast-cells usually increased in from twenty-four to forty-eight hours sufficiently to cover the sides and bottom of an ordinary 200 c.cm. flask with a thick white sediment. The cultures were most strong and active at the end of forty-eight hours. The supernatant fluid was then poured off, leaving the yeast deposit comparatively dry, 20 c.cm. of sterilized water added, and in this condition transfer to the sugar solution undergoing observa- tion was easy by means of a pipette. By this method, and the use of the extract of yeast as a nutritive solution, pure cultures were repeatedly * This subdivision contains (1) Collecting Objects, including Culture Pro- cesses; (2) Preparing Objects; (3) Cutting, including Imbedding and Microtomes ; (4) Staining and Injecting; (5) Mounting, including slides, preservative fluids, &c. ; (6) Miscellaneous. + Bot. Gazette, xii. (1887) pp. 270-1. 142 SUMMARY OF CURRENT RESEARCHES RELATING TO obtained which excited as active a fermentation as the fresh yeast from the breweries, a result not always obtained by the use of artificial nutritive solutions. The original gelatin plate-cultures, on account of their rapid growth, were useless after thirty-six hours, and to avoid a constant renewal of the proccss, as well as the introduction of different species of Saccharomycetes, inoculations were made into gelatin tubes. The cultures thus obtained produced characteristic, elegant, ivory- white colonies of 3-6 mm. in diameter, and then further development ceased. In this state they retained their vitality, and were constantly referred to as a source of inoculating material for two months. Probably they remained vigorous much longer, as Saccharomycetes are well known to do, but at this time the author’s need of them came to an end. Improvement in the method of preparing Blood-serum for use in Bacteriology.*—Dr. A. C. Abbot fills a large vessel, which can be her- metically sealed, with blood taken directly from the neck of an animal, with the usual antiseptic precautions. It is then quickly closed and allowed to stand for 15-20 minutes until coagulation takes place; a sterilized glass rod is then introduced in order to break up any adhesion of the surface to the glass vessel. The vessel is then placed in a cooler temperature which should not be too low lest coagulation be interrupted. In 24-36 hours the serum is withdrawn with a pipette, and placed in a vessel closed with cotton wool. The latter is then packed in ice for at least three days in order to allow the coloured particles to subside. The clear part of the serum is then transferred in quantities of 60-75 c.cm. to sterilized flasks of 100 ¢.cm. contents. Discontinuous sterilization is then begun and continued for an hour a day for six consecutive days. For this, the temperature should never be higher than 64° C., nor lower than 58° C.; for at higher temperatures the serum loses its transparency, and at a lower one the microbes are not destroyed. Thus prepared, serum has been kept for a whole year in the laboratory of the Johns- Hopkins University. Improved method for cultivating Micro-organisms on Potatoes.|— Dr. O. Katz recommends the following procedure for cultivating micro- organisms on potato, which he has found to give satisfactory results, especially in cultivations from dejecta of typhoid patients. Test-tubes, 10-5 cm. high and 2°5 cm. in diameter, are plugged with cotton-wool and then sterilized in the usual manner. Potato slices cut out of medium-sized, oval-shaped, perfectly healthy potatoes, and about 1 em. thick, are placed with forceps in the test-tubes, to the width of which they are made to fit. The tubes are then sterilized again at 212° F. There is no fear of desiccation of the potato surfaces, as after boiling in the steam sterilizer, there is sufficient fluid at the bottom of the tube tc keep the contents moist for a considerable time at a temperature from 20°-25° C. (68°-77° F.). At higher temperatures the development of micro-organisms is so much accelerated that there is no danger of desic- cation, but if there should be any fear of its occurrence, the cotton-wool plug may be covered with an indiarubber cap. In practice both sides of the potato are inoculated either from the same or from different colonies. * Medical News, 1887, i. p. 207. + Proc. Linn. Soc. N. S. Wales, ii. (1887) pp. 187-90 (2 figs.). ZOOLOGY AND BOTANY, MICROSCOPY, ETO. 143 Method of preparing Potatoes for Bacterial Cultures.*—In order to meet the objections raised by E. Esmarch to the ordinary method of potato cultivation, Mr. M. Bolton, as he could not procure the Esmarch ceils in America, adopted the following method in place of that proposed by Esmarch. In test-tubes 43 in. to 5 in. long, of 1 in. or more in diameter, were accurately adapted pieces of potato 2-3 in. long. The skins having been removed, the potatoes were cut up in an ordinary apple-corer. It was found advisable that one end of the potato-pieces should be cut obliquely, so as to offer as large a surface as possible, as in agar or serum tubes. At the bottom of the tube a drop of water is placed in order to prevent the potato from drying up. The tube is then carefully sterilized by steam. Cultivation-bottle.;—Dr. H. Wilfarth uses, instead of the ordinary plate, for separating different kinds of bacteria, a flat flask of thin glass, , much like an ordinary brandy bottle. The sides are round, parallel to one another, about 2-24 cm. apart, and run pyriformly to a neck about 16-18 mm. wide, and sloping obliquely upwards. The neck is closed with a cotton-wool plug. The sterilized medium having been introduced and the inoculation made, the flask is laid on the flat side, and for microscopical examination under moderate powers it is turned over so that the gelatin layer is uppermost. For liquefying colonies and for agar cultivations the bent neck of the flask renders it inconvenient for removing colonies for inoculation. The flask is filled by means of a separating-funnel, which only allows a certain quantity to flow in at a time. Collecting and Cleaning Diatoms.{—Mr. K. M. Cunningham, who states that he has been able to demonstrate 300 distinct species of diatoms from the immediate neighbourhood of Mobile, says that the first requisite in the preparation of marine diatoms is to secure a quantity of mud, and the subsequent treatment as pursued by the writer is as follows : Take at least half a pound of hard or soft mud to begin on, and soften it into a uniform liquid paste, and to hasten and assist its liquidity, add about a teaspoonful of aqua ammonia, which liquid will be useful in the initial steps of cleaning, as it cuts and dissolves slimy and gelatinous impurities, and cleans the sand-grains, and enables the bulk of the material to be cleaned to settle quickly and compactly, as well as having distinct lubricating properties. Next transfer the liquid mud to a suitable vessel of tin or china of at least six or more inches in diameter, and not over 5 or 6 in. deep; put therein as much liquid mud as will fill 1 in. in depth, and fill up the vessel with clean water, and stir rapidly the contents to liberate the flocculent matter from the heavier contents. After allowing the contents to settle for ten minutes, with a piece of rubber tubing, at least 18 in. in length, siphon off the water to within 1/2 or 3/4 in. of the bottom of the vessel, renew the water, and then stir quickly, and after five minutes again siphon off the water to within 1/2 in. of the bottom. The sediment left is transferred to any shallow tin or other vessel for con- venience. * Medical News, 1887, i. p. 318. + Deutsch. Med. Wochenschr., 1887, No. 28. t Microscope, vii. (1887) pp. 331-6. 144 SUMMARY OF CURRENT RESEARCHES RELATING TO The next step is to place in a shallow concave glass used by photo- eraphers for crystal photographs, size about 4 by 6 in., a shallow layer of the diatomaceous mud, and, adding water, gently gig the glass to and fro, making the waves run from end to end, and tilting the off or front end. This manipulation forces the large and small sand-grains to densely cake and pack together, and at the same time forces to the sur- face a large percentage of the diatoms, and most of the vegetable débris. After a few moments of gigging, the surface fluid is gently poured off, and caught in a separate settling vessel, and the heavier sand dropped into a waste receptacle. It may here be observed that a very small percentage of matter would be the outcome of the first manipulation, and that the bulk of the material was removed from the crystal glass as rejected sand. It can generally be relied upon that what is left on the sigeine-glass would not do to manipulate again, and the diatoms must be looked for in the light, coherent, flocculent, vegetable débris that floated over in the first removal of the surface fluid. Repeat substantially the same manipulation until the whole of the mud has been gone through, and in the little that is left of the original half-pound the coveted gems will be found, or do not exist. The next step is to deal with what has been saved in the various partial concentrations, transferring all of it to the crystal glass, adding clean water, and gigging it again several times in succession to remove additional sand, and to get a further concentration of the desirable material. An occasional wet test under the Microscope will show whether the indications of diatoms are good. If so, the material is then transferred to a small holder with a spherical bottom, so that it may quickly settle, and with a rubber bulb pipette all water is carefully removed. Should there appear to be about 1/2 in. deep of material as the result of all previous manipulation, add to it an equal bulk of sulphuric acid, intimately mix, and by the aid of the pipette transfer it to a 1/2 or 3/4 in. diameter glass test-tube of about six inches length; boil for fifteen minutes over a candle or spirit- lamp: in that time it is probable that all organic matter will be reduced or carbonized. At this juncture add carefully, a drop at a time, several drops of nitric acid, and boil continuously for ten minutes longer, when it will soon be noted that the blackness is discharged, transparency restored to the boiling fluid, a partial or complete bleaching of the material having occurred, together with a remarkable reduction in volume. If there have not been a complete reduction of all vegetable or other organic matter, it may be necessary to add a few drops more of sulphuric acid and boil it a while longer. Should the preparation at any time not yield satisfactorily to the bleaching process, pour out the contents in a spherical-bottom vessel, and allow time to settle; pipette off the acid, and add a fresh quantity of sulphuric acid, and boil a few moments, and finally add a few more drops of nitric acid to oxidize the remainder of the carbonized substances. All acid-boiling processes should be conducted in an open fireplace if practicable, so that the irritating gases may pass up the chimney. The above apparently long or double boiling process is rarely required, but must be resorted to if the organic material to be reduced is refractory. Where boiling first in sulphuric acid, and later adding nitric acid, is applied to the cleaning of all diatom gatherings not badly mixed with sand or vegetable débris, or is applied to pure gatherings, it acts very rapidly, giving promptly a snowy-white cleaning of the diatoms. In ZOOLOGY AND BOTANY, MICROSCOPY, ETC, 145 case of the marine or fresh-water diatoms, a final bleaching may be accomplished by pouring the diatoms, while still in acid, into a shallow and contracted glass or china saucer, and adding thereto a few drops of Darby’s prophylactic fluid, which actively effervesces and liberates the bleaching gas. While the boiling alone, first in sulphuric acid and later adding some nitric acid will be sufficient, yet a greater whiteness is produced by the addition of the prophylactic fluid as a bleaching substance. The boiling process above described dispenses with the addition during the cleaning of any powdered crystalline salts, and is also operated with a minimum of acid fluids, and to purify the diatoms from acids, it is merely necessary to allow the preparation to settle a few minutes and carefully draw off the bulk of the acid and allow the diatoms to settle in shallow china saucers, 1/2 in. preferably; draw off and change the water after one minute intervals, and repeat for four changes. A trial test made on a slide, dried over a flame, will show that ‘all acid has been removed from the diatoms. At this stage there is a rich concentration of the diatoms, but included therein some sand-grains and flocculent soil; the flocculent matter is removed by repeated shakings and settlings through a few inches in depth of clean water at three minutes intervals, until when tested under the Microscope a satisfactory appearance is reached. The acid-cleaned diatoms are again transferred to the crystal gigging-glass and water added, and then very gently gigged for a final concentration of the diatomaceous forms and a further portion of fine sand removed. The finishing touch to the cleaning for concentration of the forms is done by placing a small quantity of the acid-cleaned and concentrated diatoms into a concave black or dark glass, such as is used in tourists’ eye-glasses, and the contents gently oscillated from side to side and to and fro, when the diatoms will be found richly aggregated on the centre of the containing glass. The glass is then tilted and the diatoms removed by the gentle suction of a pipette, the dark glass enabling the mass of diatoms to be distinguished from the fine grains of sand adherent to the bottom of the glass. In lieu of the dark concave eye-glass, a deep bull’s-eye watch-crystal makes a good substitute for the final act of concentration. Diatoms are also richly concentrated from sand by simply spreading the containing fluid over either a six-inch square of smooth or ground glass, and gently gigging it while tilting it in the direction of one of the corners and allowing the fluid to run off into a proper receptacle. A large percentage of the sand-grains remain in situ, or adherent to the glass surface. The author refrains from alluding to boiling in alkaline solutions to neutralize traces of acids as he has not found it desirable or necessary to do so; nor does he refer to flannel or silk strainers for the final cleaning and separation of diatoms. Bircu, H.—UVeber Ziichtung von Spaltpilzen in gefarbten Nahrmedien. (On the cultivation of Schizomycetes in coloured media.) Tagebl. 60. Versamml. Deutsch. Naturforscher u, Aerzte, 1887, pp. 275-7. Raskin, M.—Zur Ziichtung der pathogenen Mikroorganismen auf aus Milch bereiteten festen und durchsichtigen Nahrboden. (On the cultivation of patho- genic micro-organisms on solid and transparent media prepared from milk.) St. Petersb, Med. Wochenschr,., 1887, pp. 357-60. 1888. L 146 SUMMARY OF CURRENT RESEARCHES RELATING TO (2) Preparing Objects. Preparing Ova of Amphibia.*—Dr. O. Schulze places the ova of amphibia (the investment derived from the oviduct having been removed) for twenty-four hours ii chrom-osmium-acetic acid, or in chrom-acetie acid, and then washes them well with distilled water. At this point they are available for surface study. They are next immersed every twenty-four hours in spirit of 50, 70, 85, and 95 per cent., the latter being changed several times. Next in turpentine for one to two hours, according to the size of the ova. ‘They are then transferred to paraffin (50°), whereof they have sufficiently imbibed in a half to one hour. It is noted that the time given must be carefully observed. The sections were fixed to the slide with some thin adhesive, and then after evapora- tion of the water treated in the ordinary way. Borax-carmine was used as the stain, and decoloration effected with acidulated 70 per cent. spirit (5 drops HCI to 100 ¢.cm.). By frequent change of this the yolk-granules were decolorized, and only the chromatic substance remained red, Chrom-osmium-acetic acid cannot be used for fixing substances lying centrally in the egg. Preparing Testicle for observing Nuclear Fission.t—Dr. W. Flem- ming’s recent examination of cells was made on the testicle. The organ was very rapidly teased out on a slide, and the fixative dropped over it. Chrom-acetic-csmic acid five times diluted or Brass’s mixture for Protozoa, used rather strong, were the media employed for fixing. The prepara- tion haying been repeatedly wetted with this fixative was transferred to a moist chamber for several hours; the preparation was thereby hardened on the slide, and bore washing with a gentle stream of water for half an hour. Staining was performed by dropping on a safranin or gentian solu- tion, and then allowing the slide to stand in the moist chamber for some hours. The preparation was then washed, and dehydrated with absolute alcohol, to which a trace of hydrochloric acid was added if the osmium mixture had been used for hardening. The advantages of this method are that the cells lie pretty close together, and are often very beautifully stained. On the other hand, the nuclear figures may be destroyed by the teasing, and the contents of various cysts are so commingled that the various stages of fission cannot be compared. For making sections the testicles were placed in strong osmic acid. Then prolonged and careful saturation with celloidin, for the capsule after hardening in osmic acid is penetrable with difficulty. Sections were stained with gentian or safranin. Hematoxylin was fairly successful, but the nuclear staining was rather dull. Removal of the celloidin improved the clearness of the pictures. For this purpose the section was first treated with bergamot, and this having been removed by drainage and bibulous paper, was replaced by oil of cloves, which gradually dissolved the celloidin. Then dammar. Before cutting, the lobule of the testicle was examined for evidence of nuclear fission; if found it would be present in the other lobules. Demonstrating Cell-granules.t—Dr. R. Altmann demonstrates cell- granules in the following manner :—The parafiin sections, stuck on mica- scales with alcohol in which a little gun-cotton is dissolved, are freed * Zeitschr. f. Wiss. Zool., vi. (1887) pp. 177-226 (3 pls.). + Arch. f. Mikr, Anat., xxix. (1887) pp. 389-463 (4 pls.). { ‘Studien tiber die Zelle,’ 1886, Heft 1, 53 pp., 1 pl. ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 147 from the paraffin by means of xylol and alcohol, and then stained for about three minutes in a solution of acid-fuchsin (10 grm. of the dry stain dissolved in 66 grm. of water and 33 c.cm. of absolute alcohol added), and afterwards differentiated in a solution of picric acid (10 grm. picric acid, 150 e.em. absolute alcohol, 300 c.cm. water). Over-action of the picric acid is prevented by the absolute alcohol. From the spirit the sections are transferred to bergamot oil and xylol. The mica-scale is not detrimental beneath the cover-glass, provided the preparation lies above it. Thus stained, the cell-granules are to be examined with oil- immersion lenses, weak ocular, and a powerful illumination, For demonstrating the granules by means of this staining process, fixation methods which the author is to describe in future are necessary. Methods of Preparing Muscle for investigation.*—Mr. C. F. Marshall, in his investigations into the distribution of striped and un- striped muscle (see this Journal, 1887, p. 935), chiefly made use of Melland’s method of gold-staining. The gold stains and renders evident the intracellular network of most cells, and especially the network of the striped muscle-cells. Melland’s method consists in placing the muscle in 1 per cent. acetic acid for a few seconds; then in 1 per cent. gold chloride for thirty minutes, and then in formic acid (25 per cent.) for twenty-four or forty-eight hours in the dark. For more delicate organ- isms, such as Hydra or Daphnia, and the heart muscle of invertebrates, one hour’s immersion in formic acid, exposed to strong sunlight, is the best treatment, as longer immersion in formic acid may lead to disintegra- tion of the tissues. Control preparations were made with osmic acid. In many cases the examination of fresh tissues was useless ; the special action of the gold-staining is to soften the fibre and so swell it out, while at the same time staining the network. With regard to this reagent, it is to be noted that the results obtained are somewhat un- certain ; care must be taken with the time of action of the acetic acid. Permanent Preparations of Tissues treated with Potassium Hydrate.t—Mr. B. L. Oviatt uses a solution of potassium hydrate of from 36-40 per cent. (potassium hydrate 40 grams, water 60°00); then this is replaced by a saturated aqueous solution of potassium acetate. Then add the staining agent, and then glycerin as a permanent medium. Heart muscle treated in this way five months ago is as perfect as ever. Preparing Sections of Bone.{—Dr. G. Chiaragi decalcified a strip of quite fresh bone (bird) in picro-nitric acid diluted with two volumes of distilled water and then placed it in spirit of increasing strength. The sections were then immersed for some minutes in a 1 per cent. solution of eosin and afterwards washed in a 3 per cent. hydrate of potash solution. The eosin stained the bone-cells and their processes, the rest of the bone being uncoloured. In order to fix the eosin, the sections were washed in a 1 per cent. alum solution. The sections were mounted in the alum solution. Method of investigating Cristatella.s —Herr M. Verworn gives an account of his methods of working with Cristatella. The colonies were treated with 10 per cent. chloral hydrate solution for the purpose of * Quart. Journ. Micr. Sci., xxxviii. (1887) pp. 81-2. + St. Louis Med. and Surg. Journ., liii. (1887) p. 289. t Bull. Soc. Cult. Sci. Med. Siena, iv. (1886) Nos. 8 and 9. § Zeitschr. f. Wiss. Zool., xlvi. (1887) pp. 100-1. ee 148 SUMMARY OF CURRENT RESEAROHES RELATING TO obtaining the polyps in an extended condition ; they were put directly from the water into the solution, when the separate individuals generally contracted. But in a short time they gradually extended themselves again, and soon became insensible. In some cases chloral hydrate was added by drops. They were then put into a saturated solution of sublimate; after being for ten minutes in this, they were washed in water for half an-hour and then preserved in alcohol. The best preparations were thus obtained, and this method was distinctly preferable to killing them directly by alcohol or with osmic acid. Borax-carmine (with a small quantity of acetic acid) gave the best staining results, the preparations being subsequently treated with 70 per cent. alcohol and a few drops of hydrochloric acid. In the in- vestigation of the living animals, F. E. Schulze’s horizontal Microscope was found to be of great service. Methods of studying Development of Eye of Crangon.* — Dr. J. S. Kingsley, in his investigations, hardened his eggs by Perenyi’s fluid, followed by alcohol of increasing strengths; this is a process which works well with almost all arthropod tissues. In most cases they were stained entire with Grenacher’s alum-carmine, but sometimes Grenacher’s borax-carmine or Kleinenberg’s hematoxylin was used. In later stages, when the deposition of pigment in the eye interfered with clear vision, the eggs were cut into sections, which were fixed to the slide with Mayer’s albumen fixative. After melting the paraffin and allowing the sections to drop into the adhesive mixture, the imbedding material was dissolved in turpentine, and this was washed away with 95 per cent. alcohol. The sections were then covered with a mixture of equal parts of 95 per cent. alcohol and nitric acid, and after ten to fifteen minutes. the pigment was removed. The slide was next washed with strong alcohol, and the sections stained deeply with Kleinenberg’s hematoxylin, the excess being removed with acid alcohol in the usual manner. The sections were then mounted in balsam. Preparation of Ascaris megalocephala.t — Prof. O. Zacharias, believing that the conjugation of male and female chromatin elements must be a very rapid process, was naturally led to distrust the slow fixing methods hitherto practised, and sought for a better. Fresh females were laid ona piece of wadding damped with 3 per cent. salt solution, covered with another of the same, put under a bell-glass, and incubated at 20° R, for two or three hours. Polar body formation and segmentation are thus stimulated. The separated organs are then placed in a fixing medium, the period being varied according to the age of the different regions of ova, and according to the character of the host. The youngest ova were only exposed for 5—7 minutes, the oldest for at least 25. After fixing in a mixture of acids (not yet disclosed), the ova were removed for 2-3 hours to absolute alcohol, and then placed in weaker spirit. Schneider’s acetic carmine, and acidified aqueous solution of methyl-green, were also used. The ova were cleared in two volumes of glycerin to one of water. Preparing Tape-worms for the Museum and the Microscope,t— Mr. J. M. Stedman fills a hypodermic, or other syringe possessing a fine * Journ. of Morphology, i. (1887) p. 49. + Arch. f. Mikr. Anat., xxx. (1887) pp. 111-82 (3 pls.). Cf. supra, p. 43. } St. Louis Med. and Surg. Journal, liii. (1887) p. 291. ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 149 sharp canula, with fine injecting mass, then the canula is inserted in the generative cloaca or opening of the vagina, thus cutting the excretory canal. If the canula is inserted the proper distance, the entire caudal portion of the water-vascular or excretory system can be injected. The injecting mass does not flow towards the head on account of the opposing valves. For the museum nothing further is done, except to wash the worm with water and suspend it in a bottle of 75 per cent. glycerin, to which has been added a tew drops of acetic acid. The worm will soon clear up and show all the structures with the greatest clearness. For microscopical preparations, one and a half or two segments, after treatment as above, are mounted on a slide in a cell of glycerin jelly. For the most satisfactory microscopical preparations, the ovaries and uteri, as well as the excretory system, should be injected. This is accomplished by first injecting the excretory system with one colour as described above, and then by employing another colour and forcing the canula further into the worm than when injecting the excretory system. Segments so injected may be preserved in glycerin jelly, or after gradual dehydration, in Canada balsam. Uninjected segments may be hardened in Miiller’s or Ehrlich’s fluid, and then in alcohol, and made into serial sections to show the finer structural details. Methods of studying Sphyranura.*—Prof. R. Ramsay Wright and Mr. A. B. Macallum found that specimens of Sphyranura were rarely too large to prevent complete study in the fresh condition. The most completely satisfactory reagent was Flemming’s chrom-osmic- acetic mixture: an example being placed in water sufficient to cover it, a drop of the reagent was placed beside that in which the worm lies and the two were allowed to mingle, with the result that in five or ten seconds death, but not complete fixation, occurs. The greater part of the fluid being drained away the worm was gently straightened out with a needle, and a second drop of the reagent added for two or three minutes. The specimen must now be transferred to a larger quantity of the reagent, in which it must remain for thitty minutes, and it must then be passed through various strengths of aleohol from 30 to 90 per cent. Lang’s Planarian fluid, and solutions containing picric acid cause shrinkage, Delage’s osmic carmine has no advantage over Flemming’s fluid. The process of imbedding used was the chloroform-paraffin method, the substitution of chloroform for turpentine having been found to obviate shrinkage of some of the delicate cells. Alum-cochineal was most satisfactory for staining specimens én toto. Histology of Echinoderms.j—In making his observations on the minute anatomy of Echinoderms (see supra, p. 53), Dr. O. Hamann found that Flemming’s chrom-osmic-acetic acid mixture was useful with the organs attached to the body-wall. With young and small animals chromic acid was used. Urchins preserved in strong alcohol were decalcified by placing small pieces in a 0°3 per cent. solution for a day, and washing them for twelve hours; these preparations took well the hematoxylin-stain. The pedicellaria were either decalcified and cut, or were cut after treatment with Flemming’s solution. The staining reagents used were, generally, carmine solutions; in the examination of glandular organs the anilin colours were useful. After treatment with * Journ. of Morphology, i. (1887) pp. 4-6. t Jenaische Zcitschr. f. Naturwiss., xxi. (1887) pp. 88-9. 150 SUMMARY OF CURRENT RESEARCHES RELATING TO absolute alcohol the preparations were clearcd with bergamot oil or xylol, imbedded in paraffin, which was removed by xylol, and put up in Canada balsam to which xylol had been added. Xylol is to be preferred to such fluids as turpentine or chloroform. Preparing Moulds.*—Mr. E. B. Wilson considers that although it is well known that the study of moulds may be greatly facilitated by following their development in gelatin films, or other solid substrata, spread on glass slides, yet that the value of the method for classes in elementary biology has not been sufliciently recognized. He therefore calls attention to the following application of the method, as simple and practical, and especially as affording a ready means of making very clear and beautiful permanent preparations. The spores are sown with a needle-point in films, consisting of a modification of Pasteur’s or Mayer’s fluid (with pepsin) thickened with Iceland moss. In this medium moulds grow freely in the moist-chamber. They may be examined either fresh or after treatment with iodine, which scarcely colours the substratum. For the purpose of making permanent preparations the culture-slides are transferred directly from the moist-chamber to a saturated solution of eosin in 95 per cent. alcohol, a fluid by which the moulds are at once fixed and stained. After twenty-four hours (or, preferably, three or four days), the pre- parations are washed in 95 per cent. alcohol until the colour nearly dis- appears from the substratum, cleared with oil of cloves, and mounted in balsam. All stages may thus be prepared. The mycelia, conidia, &c., appear of an intense red colour, while the substratum is scarcely stained. Alcoholic fuchsin may be used instead of eosin, though inferior to it; but other dyes (of which a considerable number have been tested) colour the substratum uniformly with the moulds, and are therefore useless. Eosin preparations made more than a year ago do not yet show the slightest alteration of colour. The best results have thus far been obtained with Penicillium, Eurotium, and certain parasitic forms. Mucor gives less satisfactory preparations, since it is always more or less shrunken by the alcohol. Fair preparations of yeast may be made by mixing it with the liquefied medium and spreading the medium on glass slides, which, after solidification of the films, are placed in the eosin solution, as in the case of mould-cultures. For preparing the cultures, Pasteur’s or Mayer’s fluid, with pepsin (see Huxley and Martin’s ‘ Practical Biology ’), but not containing more than 5 per cent. of sugar, is heated with Iceland moss until the mixture attains such a consistency that it will just solidify when cold (fifteen to thirty minutes). It is then filtered by means of a hot filter into small glass flasks, which are afterwards plugged with cotton-wool, and steri- lized at 65° to 70° C. by the ordinary method. When required for use the mass is liquefied by gentle heat, poured on the slides, and allowed to solidify. ‘The spores are sown by a needle-point, touched once to a mass of spores, and thereupon drawn across several films in succession, the spores being thus scattered along the track of the needle, and more or less completely isolated. Care must be taken that the quantity of sugar be not too great. The films should be tolerably thick, and the atmosphere of the moist-chamber such that the films neither dry nor liquefy. * Amer, Natural., xxi. (1887) pp. 207-8. ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 151 Technique of Bacteria.*—M. Kunstler reports that either the vapour of osmic acid or the concentrated acid is a good fixing reagent for Bacteria. To show the flagella of Spirillum tenue it is necessary to mix a drop of osmic acid with a drop of the water containing the microbe, and to allow of a quarter of an hour’s evaporation. Having covered it witha slip, a very small drop of a saturated solution of “noir Collin” is added near the middle of the four sides. The preparation is then carefully closed with wax, so as to prevent any evaporation. After some eight to fifteen hours the Spirilla become intensely coloured, and the flagella may be seen with moderate powers. At the extremity of the microbes there are four to six flagella. If, in addition to the “noir Collin,” we add a little chromic acid, the body of Spirillum tenue presents a vacuolated, reticular, or areolated structure; the areole often contain granules. These appearances are best seen in specimens which are about to divide. In the other process of reproduction, M. Kunstler thinks the term of monosporous cysts to be preferable to that of spores. Good results are “got by the use of a concentrated solution of hematoxylin, to which a little glycerin and chromic acid have been added. In some cases traces of potash are preferable to chromic acid. (3) Cutting, including Imbedding. Myrtle-wax Imbedding Process.;—Prof. W. H. Seaman says that Mr. J. H. Blackburn, in attempting to carry out the Reeves process of mounting,t{ failed entirely to get satisfactory results with what was sold to him by the local druggists as myrtle-wax, which he desired to try on the suggestion of Dr. Miller. On returning the wax, and stating that there must be some other substance called myrtle-wax, he received an article that gave perfect satisfaction, so much so, indeed, that he found it better than paraffin, and substituted it for that. Having been furnished with specimens, a short examination of its fusing point, &c., showed that it was the Japan wax obtained from the Rhus succedanea, now an exten- sive article of commerce. This substance is very peculiar in its great latent heat, giving it a wide range between the fusing and solidifying points. It solidifies without wrinkles, and sticks close to an imbedded object, qualities that render it especially valuable to the section-cutter. It is not strictly a wax at all, but a fat, since it consists chiefly of palmitic acid, and is capable of saponification. Mr. Blackburn showed whole brains saturated with it so perfectly, and preserved so naturally, except colour, that there seemed no reason why they could not be employed as models for class demonstration. To all appearances at the present time they are permanent. The substance may easily be obtained from the wholesale druggists. Homogeneous Paraffin.s—Dr. G. A. Piersol says that much has been written regarding the necessity of having paraffin of the right con- sistence to insure success in cutting ribbon sections, but the desirability of having it homogeneous has been but little emphasized. The selection of a pure paraffin, freedom from turpentine or chloroform used in im- bedding, and a very rapid cooling after the tissue is arranged, appear to be the essential conditions for securing this desirable character to the * Comptes Rendus, cv. (1886) pp. 684-5. t+ Queen’s Mier. Bulletin, iv. (1887) pp. 33-4. ¢ See this Journal, 1887, p. 1048. § Amer. Mon. Mier. Journ., viii. (1887) p. 159. 152 SUMMARY OF CURRENT RESEARCHES RELATING TO imbedding mass. With a homogencous paraffin it is surprising to see with what wide latitudes as to melting-point the chains of sections will come off. Schiefferdecker’s Microtome for cutting under alcohol.*—Dr. P. Schiefferdecker’s improved microtome (fig. 54) is now provided with an arrangement for cutting under spirit, as well as for raising the knife- carrier and automatically raising the preparation. There are, besides, numerous practical improvements, but the principle of the instrument is unchanged. The angle of the slideway and the weight of the slide itself are more favourable. Any slipping of the band from the wheel is now prevented, and the handle can be placed in any desired position. On drawing out the slide, the band can be so fastened that it always remains in the proper position. Bending of the metal parts owing to refractory preparations is obviated, and the knife-guard is now so arranged that the pressure on the knife is as small as possible. In the illustration the arrangement for raising the knife is not seen, as it is covered by the pan. In a very simple way the knife-carrier is raised any required height merely by the crank action when the slide is drawn backwards. As the knife requires to be raised a shorter distance for paraffin preparations than for unim- bedded ones, the arrangement for raising it is so effected that this action can be made at any desired position of the slideway. The position of the preparation is automatically altered, also, in a very simple manner. A bar, which in its turn is moved by the crank, is set in motion bya toothed wheel acting upon a micrometer screw. Upon this bar is fixed a plate for regulating the amount or distance of raising. Expressed in fractions these amounts are 0:°005, 0°01, &., to 0°05 mm. For most cases these are sufficient, but if any other size be required the automatic arrangement may be dispensed with, and the preparation raised by turn- ing the milled head of the micrometer screw with the hand. Of course any other denominator than 200 can be used for the fraction. For the automatic motion of the micrometer screw a new striking mechanism has been constructed, and this is found to be more effective than the catch arrangement. The immersion apparatus is a flat quadrangular pan, in the bottom of which, and just above the preparation-clamp, is a circular hole for the preparation to pass through. The clamp, with the screws necessary for the two turns, is placed within a cylinder, the upper edge of which, by means of a short and wide caoutchouc tube, is united with a projecting rim running round the hole in the bottom of the pan, so that, when the spirit fills the pan and cylinder, the preparation always lies in the alcohol, and yet can be pushed up and down with the cylinder without difficulty. The screws which alter the clamp are turned with keys. The knife, which has a straight handle, is fastened by means of two screws to a thick metal-piece (the connecting-piece), and this in its turn is united by screws with the plate of the knife-carrier. The connecting-piece, to the under surface of which the knife is fastened, passes over the pan in such a way that it projects into the spirit. Unpernuiut, H. M. J.—Section-cutting applied to Insects. Sci.-Gossip, 1888, pp. 1-4. * Zeitschr. f. Wiss. Mikr., iv. (1887) pp. 340-3 (1 fig.). ZOOLOGY AND BOTANY, MICROSCOPY, ETC. “TOHOOTY UAINO YNILLAO WOT AMKOLOWOIP, § VAMWOACUAAAALHOS FE “OL 154 SUMMARY OF CURRENT RESEARCHES RELATING TO (4) Staining and Injecting. Methods for Pathological Investigations.*—Dr. V. Babes uses a strong watery solution of safranin by dissolving the dye in distilled water to which 2 per cent. anilin oil is added. The mixture is then heated to about 60° C. and filtered while warm. The solution stains in about one minute; the sections are then passed through alcohol and oil of cloves and mounted in balsam. Hardening with Flemming’s fluid is suitable for this method. According to the author this stain colours calcareous infiltration a red-violet, and is especially suitable for tissues containing bacteria. The use of this safranin is also adapted for demonstrating certain pathological changes. For this purpose the tissues are thoroughly stained with safranin and are then placed for a minute in Gram’s iodine solution. After passing through spirit and being mounted in balsam the colour is withdrawn, except from certain elements. For example, parts infiltrated with chalk and such as have undergone a colloid change remained stained. The iodo-safranin treatment is especially valuable for staining the club-shaped elements of the Actinomyces. 'The pus or the crushed Actinomyces is dried rapidly on a cover-glass and treated with anilin safranin for twenty-four hours, decolorized with the iodine solution, and mounted after dehydration and clearing up in clove oil. The author also recommends a neutral anilin stain made up of a mix- ture of basic and acid anilins. This neutral stain consists of equal parts of acid fuchsin, methyl-green and orange, and is made by mixing 125 c.cm. of a saturated watery orange solution with 125 c.cm. of a saturated solu- tion of acid fuchsin dissolved in 20 per cent. alcohol; to this 75 e.cm. of absolute alcohol and 125 c.cm. of a saturated watery solution of methyl-green are then added gradually. The sections are left in this staining fluid for half an hour, then washed and treated with alcohol and bergamot oil. In sections thus treated the blood-corpuscles are orange-yellow, the nuclei of the polynucleated leucocytes green, and their cell-substance deep violet, the cell-substance of the eosinophilous cells blackish-brown. Staining of Ossification Preparations.;—Dr. H. Klaatsch remarks that it is advantageous to possess a simple and reliable method for demonstrating the process of ossification to classes, for showing students the remains of cartilage in the newly-formed osseous tissue, and for distinguishing the difference between periosteal and cartilaginous ossi- fication. ; These objects may be attained by staining with logwood and decoloriz- ing with picric acid. Grenacher’s or Bohmer’s hematoxylin may be used. Overstaining is of no advantage, but if it occur the section must be left for a longer time than usual in the picric acid. Students leave their sections overnight in a watchglass ina mixture of a little aq. destil. plus 6 drops of Bohmer’s hematoxylin and 3 drops of glycerin. After being washed in distilled water the sections are transferred to a saturated solution of picric acid until they assume a yellowish-brown colour. They are next placed in glacial acetic acid for about half a minute, and are then washed in distilled water until the yellow colour is no longer * Virchow’s Arch. f. Pathol. Anat. u. Hist., ev. (1886) pp. 511-26 (1 pl.). } Zeitschr. f. Wiss. Mikr., iv. (1887) pp. 214-5. ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 155 given off. They are then dehydrated, cleared up, and mounted in Canada balsam. The preparations show the epiphysial cartilage to be of a dull pale blue, while the remains of the cartilage between the lines of ossification is of a deep blue colour. The newly-formed bone stains yellow, and the blood-vessels have a brownish hue. The permanence of the stain seems fairly good, as the author possesses specimens made six months ago which haye undergone no perceptible change. A modification of the foregoing method is also given. Instead of with hematoxylin the sections are deeply stained with methyl-violet and de- colorized with picric acid until the blue colour is no longer given off. After being mounted in Canada balsam the sections look green to the naked eye. The cartilage remains, even to their least ramifications, are stained deeply blue and surrounded by yellow layers of bone. In the periosteal region the young bone-cells are of a greenish colour. The epiphysial cartilage is pale yellow. In this modification the histological details are wanting, and it is chiefly useful for demonstrating the difference between periosteum and cartilage ossification under low powers. Staining the Elastic Fibres of the Skin.*—Dr. K. Herxheimer hardens his preparations in Miiller’s fluid; his method will, however, give good pictures after spirit, picric acid, and the chrom-osmic-acetic acid mixture. The sections should not be more than 0:2 mm. thick. They are stuck on with celloidin, and then stained for three to five minutes with hematoxylin (1 ¢.cm. hematoxylin, 20 ¢c.em. alcohol ab- solute, 20 c.cm. H°O, 1 e.cm. lithium carbonate), but other watery solu- tions may be used. The sections are then treated for five to twenty seconds with chloride of iron solution. This last step requires some care. Mount in balsam. ‘The elastic fibres stain a bluish-black or black, while the surrounding tissue is grey or bluish. By longer action of the iron, so that the connective tissue is quite decolorized and a part of the elastic fibres slightly pale, a contrast stain with carmine or Bruns- wick brown may be used with advantage. The method can be em- ployed for staining the nervous system; for this two hours are required. Instead of hematoxylin the author also uses anilin water gentian-violet. Staining Nerve-terminations with Chloride of Gold.j—Dr. G. Boecardi recommends the reduction of objects impregnated by Ranvier’s or Loéwit’s gold chloride method to be done with oxalic acid of 0:10 per cent., or of 0:°25-0°30 per cent. Another favourable reduction fluid consists of 5 c.cm. pure formic acid, 1 c.cm. oxalic acid of 1 per cent. and 25 c.cm. aq. destil. Pieces impregnated with gold chloride are to remain in this fluid in the dark not longer than 2 to 4 hours. Demonstrating the Membrane of the Bordered Pits in Coniferee.{— Dr. A. Zimmerman states that this membrane only requires staining for its demonstration, and that hematoxylin is the best dye for the purpose ; Bismarck-brown and gentian-violet are also capable of staining this tissue, but are inferior to logwood. Material which has been preserved in alcohol is to be preferred. The sections are placed in Béhmer’s hematoxylin for 2-5 minutes only, as a longer time stains the rest of the membrane, and it is advisable to * Fortschr. d. Med., iv. (1886) pp. 785-9. + Alboni Lavori eseg. nell’ Istit. Fisiol. Napoli, 1886, Fase. 1, pp. 27-9. + Zeitsch, f. Wiss. Mikr., iv. (1887) pp. 216-7. 156 SUMMARY OF CURRENT RESEARCHES RELATING TO stain the cell-nuclei and the investing membrane of the bordered pit only. The preparation is then washed in water, dehydrated in alcohol, and cleared up in oil of cloves. Clearing up acts very beneficially, because the optical effect produced by the curvature of the pit is diminished. The reaction of the bordered pit membrane to dyes undoubtedly shows that it differs in its chemical and physical relation from the rest of the membrane substance. The circumstance that membranes of the cambium cells and the membranes consisting chiefly of pure cellulose stain deeply with hematoxylin might lead to the conclusion that in the pit membrane we have to deal with a pure cellulose. This, however, is contradicted by the fact that it stains deep red with phloroglucin and hydrochloric acid. Staining Diatoms.*—Prof. O. Drude discusses the method of staining diatoms as a suitable means for obtaining proper microscopical prep.ra- tions. The methods which merely preserve the siliceous valves, and which at one time was the only object aimed at, have since Ptitzer’s systematic classification (cf. Hanstein’s ‘ Beitriige’ and Schenk’s ‘ Hand- buch der Botanik,’ ii. p. 403) have been recognized and adopted, no longer suffice, and must give way to a method which clearly shows and permanently retains in the microscopical preparation, the cell-nucleus and the endochrome-plates. Such a method was communicated by Pfitzer four years ago,t and has been employed by the author with great advantage. It consists in staining the fresh material with picronigrosin: to a saturated watery solution of picric acid is added as much of a saturated watery solution of nigrosin as causes the mixture to assume a deep olive-green hue. This solution is poured over the fresh Bacillariz, or the rotting leaves, stems, &c., of water plants on which they are found are placed in test- tubes filled with the picronigrosin solution. The first kills and fixes, the latter stains, the nucleus most strongly, less so the endochrome- plates, and very faintly the thin layer of protoplasm. The stained valves are best mounted in balsam, after having been thoroughly washed with spirit, then dehydrated with absolute alcohol, and cleared up in oil of cloves. Thus are obtained very useful prepara- tions which show beautifully the nucleus and nuclear fission, and also the endochrome plates which formerly soon lost colour or altered in form and position. Glycerin may be also used for mounting. Stained Yeast-preparations.j—Dr. P. Lindner states that the behaviour of yeast-cells to dyes is the same as occurs in Bacteria. If yeast-cells dried on cover-glasses be placed in solutions of methylen- blue, gentian-violet, fuchsin, Bismarck-brown, &c., they greedily pick up the dye. If the preparation be over-stained the mistake is easily obviated either by prolonged washing with distilled water, or by the application of spirituous or slightly acidulated water. The spores too behave in a manner similar to the resting spores of Bacteria. They are stained with difficulty ; if this, however, take place, it is extremely per- manent. For example, if they be stained with fuchsin, they may be washed for a long time, without being decolorized, while everything except the spores quickly loses its colour. In order to stain the mother and the sporeless cells e.g. blue, it is merely needful to immerse the * SB. u. Abh. Naturwiss. Gesell. Isis, 1887, pp. 8-9. + See this Journal, 1883, p. 445. t Wochenschr. f. Brauerei, 1887, p. 775. ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 157 preparation in a solution of some blue dye. The red spores do not take up the blue pigment at all, while everything else is stained deeply blue. Staining Lepra and Tubercle Bacilli.*—Dr. F. Wesener makes another reply to Prof. Baumgartner’s criticisms on the methods for dis- tinguishing between leprosy and tubercle bacilli. Throughout the con- troversy, no new facts have been adduced, and the gist of the whole seems to be that the one learned stainer prefers his own method to that of the other. They both seem to agree that tubercle, like leprosy bacilli, can be stained with simple solutions of fuchsin and methyl- violet; that there are, however, certain gradual differences between them, the leprosy bacilli taking up the stain somewhat more easily than the tubercle bacilli. Dr. Wesener distinguishes his position from that of Baumgartner by insisting that these gradual differences are very fluctuating, and not always constant, and on this ground that they are insufficient for a reliable diagnosis: the two methods given by Baum- gartner for sections are specially unreliable. As both these learned dyers have admitted that other data besides those of various stains (in so many words, it must be known beforehand which is tubercle and which leprosy tissue) are necessary for a certain diagnosis, it must be acknowleged that the main point in the con- troversy is one which requires special mental acuteness for its compre- hension. Specificness of the Tubercle Bacillus Stain.j—It is well known that Bienstock and Gottstein demonstrated the fact that certain non- pathogenic bacilli which stain in the ordinary way with anilin dyes could be so altered that they were able to be stained in the same way as tubercle bacillus. To effect this they were bred in agar-gelatin medium, to which about 20 per cent. of fat was added. Dr. A. W. Grigorjew has now tested Bienstock’s conclusion, according to which tubercle bacilli owe their peculiar staining property to an investment of fatty matter, which prevents the decolorizing action of acids. The author cultivated in fatty media (1-20 per cent.) Bacillus anthracis, B. subtilis, Clostridium buty- ricum, Bacterium termo, Staphylococcus aureus, and S. albus. All these cultivations gave similar results. Bacteria lying in the fat stained as tubercle bacilli; those above or in islets free from fat stained in the usual way. Again, if the former class were acted on by potash, alcohol, or ether, their power of assuming the specific stain vanished, and they coloured in the usual way. The author further points to the significance which the mixing of a little fat with the bacteria on the cover-glass has, In this case the specific nature of the stain is lost. In this way it is even possible to impart the specific tubercle stain to a streak of albumen, and the author concludes that his experiments justify him in disbelieving Bienstock’s explanation, and in supporting the existing theory as to the staining of tubercle bacilli. New Staining Fluid.{—Mr. J. W. Roosevelt recommends an iron stain, consisting of 20 drops of a saturated solution of iron sulphate, * Centralbl. f. Bacteriol. u. Parasitenk., ii. (1887) pp. 131-5. + Ruskaja Medizina, 1886, Nos. 42 and 43. Cf. Zeitschr. f. Wiss. Mikr., iv. (1887) pp. 251-2. { New York Patholog. Soc., 9th March, 1887. Cf. Medical Record, ii. (1887) p. 84. 158 SUMMARY OF CURRENT RESEARCHES RELATING TO 30 grams water, and 15-20 drops pyrogallic acid. The preparation assumes a brownish-grey colour. It is specially suitable for photo- micrographic purposes, because, when united with albuminous tissues, it undergoes no further change. Benda’s Modified Copper-hematoxylin.*—Dr. G. A. Piersol calls attention to the excellence of this reagent; though the method is troublesome the results amply repay where a careful study of cells under high powers is proposed. Tissues treated with chromic acid or Flemming’s solution stain readily, as well as do those hardened in alcohol or any other of the usual fluids. For careful examination, staining after cutting is advised; the sections on the slide or cover are placed for 8-12 hours in an almost saturated solution of cupric acetate (to which a few drops of acetic acid may be added) in the oven at 50° C., washed a few minutes in two changes of distilled water, and stained with 10 per cent. alcoholic solution of hematoxylin until very dark blue; transferred directly to hydrochloric acid solution (1:350), where they remain until bleached to a straw tint; after being rinsed in water they are placed in fresh copper solution until again blue. Should the sections be too dark they may be again bleached in the acid and passed through the copper solution as before ; if too pale they are placed again in the hematoxylin and carried through the solution as at first. The advantages of the method are certainty of good results after chromic acid, control of the intensity and ease of correcting faults of the stain, and above all, the excellent results. While the colour is less brilliant than the usual alum-hematoxylin stainings, the crisp, sharply- defined pictures furnished leave little to be desired, and to those seeking a precise and reliable stain after Flemming’s solution this method is confidently recommended. Since the hematoxylin with care and occasional filtering may be repeatedly used, and as the copper solution is readily prepared and inexpensive, the method will be found economical and by no means as complicated in practice as on paper. Action of Staining.t|—Dr. M. C. Dekhuyzen holds, in opposition to Griesbach,t that staining is rather a physical process, as in the majority of cases only molecular combinations take place. He classifies the tissues (material hardened in 96° alcohol) as follows :—Mucin, primitive cartilage capsules (Ranvier), gland cells of fundus, cells of pyloric glands, Neumann’s pericellular substance in cartilage, an imperfectly known constituent of nerve, and Henle’s layer of the internal sheath of the hair-root are basophile, that is, possess an inclination for basic and a disinclination for acid dyes. The “acidophilous” constituents of tissues show the opposite behaviour, protoplasm especially, in covering cells (“ Belegzellen”) and in the lunules of Gianuzzi, connective-tissue bundles, elastin, decalcified bone, muscle, axis-cylinder, the peripheral layer of cartilage where the cells are flattened, and the secondary capsules of Ranvier which lie immediately upon the cartilage cells. Chromo- philia is the property which both classes may have in common, although it is more marked in one of them. Chromatin and eleidin are chromo- philous, and both have a preference for basic dyes. * Amer. Mon. Micr. Journ., viii. (1887) pp. 153-5. + Med. Centralbl., 1886, No. 51, pp. 931-2, and No. 52, pp. 945-7. t See this Journal, 1887, p. 1058. ZOOLOGY AND BOTANY, MIOROSCOPY, ETC. 159 Modification of Schiefferdecker’s Celloidin Corrosion Mass.*—Dr. F’. Hochstetter has devised a modification of Schiefferdecker’s celloidin corrosion mass, whereby crumbling of the mass and any brittleness after the addition of a large quantity of dye are prevented. It is recommended to mix washed porcelain earth (kaolin) with celloidin. The porcelain earth is rubbed up with ether, to which cobalt blue, chrome yellow, or cinnabar is added. To this celloidin of the consistence of honey is added. The quantity of the kaolin to be used depends on the size of the vessel to be filled. If the whole distribution area of a vessel is to be injected, the syringe should at first be filled with a thin injection mass containing less porcelain; afterwards a thicker mass should be used. Teichmann’s screw-syringe is the most suitable instrument for the purpose. A small quantity of pure ether is first injected ; this done the mass is squirted in, at first pretty quickly, but afterwards more slowly, and the pressure of the piston-rod is kept up until the mass begins to set in the large vessels. This method may be ‘advantageously employed for demonstrating the vessels in bone or those lying immediately upon it, but for “ parenchymatous” organs this mass is not to be recommended. ‘The preparations are macerated in the cold, bleached, &c. HamittTon, D. J.—Method of combining Weigert’s Hematoxylin-Copper Stain for Nerve-fibre with the use of the Freezing Microtome. Journ. of Anat., XXI. (1887) p. 444. LigutTon, W. R.—Notes on Staining Vegetable Tissues. [Cut a fresh green stem and place the newly cut end in one of the usual staining solutions. The colouring matter will gradually be absorbed and distributed through the tissues. ] Amer. Mon. Micr. Journ., VIII. (4887) pp. 194-5. WaAssERzUG, E.—Principaux procédes de Coloration des Bacteries. (Principal processes of staining Bacteria.) Journ, de Bot., I. (1887) pp. 299-803, 321-4. (5) Mounting, including Slides, Preservative Fluids, &c. Fixing Sections.;—Of the three fixatives now in general use— shellac, collodion, and albumen—shellac is considered the best for objects coloured in toto. The carbolic-acid shellac introduced by Dr. P. Mayer has been found to be unreliable in some respects. Carbolic acid warm is injurious to some tissues, e.g. the dermis of vertebrates. The alcoholic solution is a perfectly harmless fixative. The method of using, now described by Dr. Mayer, and which differs in important points from the one prescribed by Giesbrecht, is as follows :— (a) The object-slide, heated to about 50° C., is coated with shellac in the usual manner, by drawing a glass rod wet with the solution once or twice over its surface. As soon as the slide is cool and the film of shellac hard and no longer sticky, the sections are arranged dry, and then gently pressed down by means of an elastic spatula (horn or metal) until they lie flat and smooth on the slide. (b) Expose the slide thus prepared to the vapour of ether. For this purpose the slide may be placed in a glass cylinder of suitable size, and closely stoppered. The cylinder is placed in a horizontal position, or, at * Anat. Anzeig., 1886, pp. 51-2. t Internat. Monatsschr. f. Anat. u. Physiol., iv. (1887) Heft 2. Cf. Amer. Natural., xxi. (1887) pp. 1040-1, and this Journal, 1887, p. 853, where the author’s name was omitted through the note being separated from others in printing. 160 SUMMARY OF CURRENT RESEARCHES RELATING TO least, so inclined that the slide lies wholly above the ether. The saturation of the sections will be sufficiently complete in about half a minute. (c) The slide is next to be warmed in the water-bath in order to evaporate the ether. The paraffin is then removed, and the mounting completed in the usual manner. It is best to use balsam dissolved in turpentine or benzole rather than in chloroform, as the latter softens the shellac, and thus often loosens the sections. One great advantage of this method of using shellac is that it permits of arranging and flattening the sections on the slide. Ordinarily sections are placed while the adhesive coating is soft, and must then lie as they fall. With reference to collodion, Dr. Mayer remarks that it depends entirely upon the quality of the gun-cotton employed whether the sections bear well treatment with alcohol and aqueous fluids. When sections are to be stained on the slide, the albumen-fixative is preferred to collodion. The mixture is prepared as follows:—White of egg, 50 grm.; glycerin, 50 grm.; sodium salicylate, 1 grm. These in- gredients are mixed and thoroughly shaken together, then filtered and kept in a well-cleaned bottle. Dr. Mayer has kept this mixture three years in a good condition. Other antiseptics have proved far less efficient than salicylate of sodium. Substitute for Clearing.*—Dr. G. A. Piersol says that clearing with oil of cloves or other oil can be omitted where the sections are thin, especially when numerous and fixed to the slide or cover. If the sections be thoroughly dehydrated in strong or absolute alcohol, they may be mounted directly in balsam. The slide with the dehydrated section is removed from the absolute alcohol, hastily drained, a drop of balsam added, and the clean cover which is for a moment held over the flame is applied, when the slide is gently warmed over the lamp. 'There may be cloudiness at first towards the edges of the cover, but in a few minutes (with large sections somewhat longer) this all disappears. After a night in the oven at 40° C. these slides come out with covers so firmly fixed, that oil-immersions may be used and the covers cleaned with little fear of shifting. Mounting in Canada Balsam by the Exposure Method.j—It has been a matter of surprise to Mr. G. H. Bryan that amongst the various methods of preparing microscopical slides, the so-called “ exposure” method (due to Mr. A. C. Cole) of mounting in Canada balsam or other gum-resins, in which the balsam is partially dried before the cover is finally placed on the slide, has received so little notice, and he therefure desires to call attention to the advantages of this process for mounting almost all classes of objects, and also to describe a slight modification of it, by which means such arranged objects as sections in series, the various parts of an insect or other groups of objects may be mounted in balsam without difficulty. The following is a brief outline of the exposure method :—Breathe thoroughly on a glass slip, and on it drop three clean covers, which will thus adhere temporarily to the slip, or, if preferable, each may be let fall * Amer. Mon. Micr. Journ., viii. (1887) p. 155. { Scientif. Enquirer, ii. (1887) pp. 184-6. ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 161 on the tiniest drop of water. On each cover let an object be arranged in a moderately convex drop of balsam, extending to but not over the edge of the cover. Then put the specimens away for the balsam to dry for at least twelve hours in a dust-proof box. When the covers have been exposed long enough, they may be turned over on to warmed slides, but must not themselves be warmed first. The danger of large air-bubbles is diminished by placing or smearing a little fresh balsam on the slide, and this must be done if there is not enough balsam on the cover. If possible, the cover should be held in a pair of forceps and lowered horizontally over the slip, not on one side first. It is then less liable to tilt, and the fresh balsam is squeezed out symmetrically round the edge on pressing the cover down, and can mostly be at once taken off with a knife, and the slide then cleaned with spirit, the part under the middle of the cover being filled with the exposed balsam, which is generally firm enough to keep from slipping. An any case, the small amount of soft balsam around the edge will soon dry after the rough scraping, thus avoiding the long waiting required before cleaning slides mounted in the usual way. For mounting arranged objects, we may proceed as follows :—-The cover being stuck by breathing to a slip as before, the objects are all neatly arranged on it in the layer of balsam, which should not be too thick. The cover must now be exposed till the balsam is nearly or quite hard—a weck’s exposure or longer may be requisite. The covers must be turned over on to a cold slip into a drop of soft balsam and pressed down, the objects being fixed in their places on the cover by the hardened balsam, which is undisturbed. Scrape off the superfluous soft balsam, and put away to dry. The streaky appearance due to the two densities of balsam will soon disappear. The author has tried the above methods with great success for mounting whole insects, and parts of insects, under pressure. For preparing whole insects for mounting, it is best to soak in potash, wash in water with a few drops of acetic acid, flatten out with two pieces of glass, which are tied together while the specimen is soaked for a further period in acidulated water, then in alcohol. Untie the glasses, float the insect on to a cover-glass and take it out, drain off superfluous alcohol, lay the cover on a slip, add a drop of clove-oil, which will permeate the object, and the alcohol will mostly evaporate in half an hour or more. Most of the superfluous clove-oil may then be drawn off with a pointed tube and the balsam applied. Parts of insects may be lifted from the alcohol into a vessel containing clove-oil, and afterwards taken out and laid out in the balsam on the cover. In this way he has mounted twelve parts of a honey-bee neatly grouped on one cover, and several other “type” slides, and he thinks it will be found that these methods remove the chief difficulties of mounting in balsam, and especially of mounting arranged slides. Burruam, T. H.—{Arranging Slides.] Engl. Mech., XLYI. (1887) pp. 396-7. (6) Miscellaneous. Dissecting Dish.*—The following is taken from one of a series of articles on “the Naturalist’s Laboratory” in course of publication in the journal noted at foot. * Kuowledge, xi. (1887) pp. 278-9 (1 fig.). 1888. M 162 SUMMARY OF CURRENT RESEARCHES RELATING TO The dissecting dish, as its name implies, is useful for animals of small size only, such as earthworms, snails, frogs, &e. Although an ordinary pie-dish can be, and has largely been, used for this purpose, it is unquestionably a very imperfect article. Let us take, for example, a frog: to learn its anatomy thoroughly, several days of work should be spent upon its dissection. The dish should be filled to the depth Kia. 35. ce, cover; d, body of dish; p, bed of paraffin. of about 15 in. with a suitable mixture of paraffin wax and hog’s lard, melted together at a low temperature, and poured, whilst still fluid, but on the verge of becoming solid, into the dish; this will prevent any marked after shrinkage. The animal should next be fastened upon the paraffin when solid, with pins, and covered, or partially covered, with dilute spirit. After a day or two, when some critical portion is about to be examined, the student often finds, to his chagrin, that the liquid around his dissection has insinuated itself between the sides of the dish and the edges of the paraffin bed, by an almost imperceptible shrinkage of the latter, sufficient, however, to render it so unsteady as to preclude the possibility of work except with the utmost difficulty. To obviate any such mishaps, the (anonymous) author has devised a dish, shown in section at fig. 35. It may be oval or oblong (preferably the latter) in shape; its sides slope upwards and inwards, and thus effectually prevent the bed of paraffin from shifting or floating during the dissection. The upper rim of the dish should be indented, so as to admit of a cover which will not easily slip off. Both dish and cover may be made of earthenware, of indurated wood, or the new paper bottle material invented by Mr. H. L. Thomas. Artificial Serum for Computation of Blood-corpuscles.*—M. Mayet finds that the disadvantages of deformation, &c., which attend the use of all the liquids employed in the computation of the number of blood- corpuscles, may be avoided by using an artificial serum of the following composition :—distilled water, 100 gr.; pure anhydrous neutral phos- phate of sodium 2 gr.; and cane-sugar to raise the density to 1085. The form of the elements is preserved ; the density, slight viscosity, and the presence of a neutral alkaline salt secure uniform distribution of the elements ; the differences of level avoided in a less dense medium are of little importance; by altering the focus the leucocytes appear quite distinct as brilliant bodies. * Comptes Rendus, cy. (1887) pp. 943-4. ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 1638 Reeves’s Water-bath and Oven.—The arrangement of Dr. Reeves’s apparatus sufficiently appears from fig. 36. It is heated by a gas- burner, or placed over a coal-oil flame. Fic. 36. Doty’s Balsam Bottle.—Most of the methods for the manipulation of Canada balsam are open, it is said, to the objections of inconvenience, wastefulness and slowness which Mr. Doty’s bottle, fig. 37, is intended to obviate. Fie. 37. The reservoir B is a turnip-shaped bulb, through the stopper C of which passes a wire R. One end of the wire is then bent into a ring for the finger, and the other is tapered and ground into the lower end of the stem of the bulb, thus forming a valve V. In preparing for use, first put a small quantity of the solvent S, which is used to dilute the balsam, into the bottle D, being careful that not enough is used to touch the valve; remove the wire and stopper from the bulb and close the valve end; fill the bulb with balsam diluted so as to flow or drop freely, and replace the wire and stopper. The advantages of the bottle are:—The bulb can be taken from the bottle and operated with one hand; the balsam is always ready to flow and will not harden at the exit of the bulb; the flow can be perfectly controlled; it may be operated continuously ; it is cleanly and durable ; the balsam being delivered from the lower end of the tube is free trom bubbles, and being always protected is free from dust. Eternod’s Apparatus for stretching Membranes.* — Professor A. Eternod’s apparatus for stretching membranes consists of a nest of rings * Zeitschr. f. Wiss. Mikr., iv. (1887) pp. 89-41 (2 figs. ). 164 SUMMARY OF CURRENT RESEARCHES RELATING TO (fig. 388), each of which is slightly conical (fig. 39), so that the one fits into its neighbour very easily. The upper side has a bevelled edge c, Which prevents too extended a contact of the membrane with the inner ring when the membrane is stretched. The rings are made of vulcanite, a substance which is not attacked by the ordinary reagents, such as spirit, Miiller’s fluid, acids, &c. When stretched on these rings, the object M— mesentery, epiplasm, &ce.—may be placed beneath the Microscope and subjected to stains or fixative or other reagents, such as nitrate of silver. Determination of the Number of Trichine or other Animal Parasites in Meat.*—This is thus effected by Prof. H. Gage:—After meat has been found to be infested with parasites, if it is desired to determine the number in a kilogram, pound, or any other weight, a section of the meat is made with some sharp instrument, and the thick- ness of the section is measured by placing it between two cover-glasses whose thickness is known, and then, after pressing the cover-glasses quite firmly together, measuring the entire thickness. The thickness of the section of meat is then easily determined by subtracting the thickness of the cover-glasses from the number representing the thickness of the cover-glasses and the meat. ‘The sections may be from 0-1 to 0:3 mm. in thickness. Remove the upper or eye-lens of the ocular of the Microscope, and place on the diaphragm a piece of paper in which a small square opening has been made, thus converting the diaphragmatic opening from a round to a square one. Replace the lens, and by the aid of a stage micrometer determine the value of one side of the square field thus made. The opening need not, of course, be square, but it is much easier for most persons to determine the area of a square than a cirele— hence a square is recommended. Put the section of meat under the Microscope and count the number of parasites in the field, moving the specimen and making twenty or more counts, in order to get an average which shall fairly represent the number of parasites in one field. Find the cubic contents of one field by multiplying the thickness of the section by the number representing the value of the sides of the square field. From this compute the number of parasites in an entire cubic centimetre. Divide this number by the specific gravity of muscle (1-058), and the result will give the number of parasites in one gram of the meat. From this the number in one kilogram may be obtained by simply adding three cyphers (multiplying by 1000), or in one pound avoirdupois by multiplying by 453,593, which is the number of grains in one pound. ‘The following is an example : — The thickness of the section was 0°27 mm., and the value of the square field as seen in the ocular was 1°5 mm. The average number of Trichine seen in this field in twenty observations of different portions of the meat was three. The cubic contents of the field was 0°27 x 2°5 x 1:5 = 0°6075 cub. mm. If 0:6075 cub. mm. contains three Trichine, one cub. mm. will contain 4°038 of them, and a cubic centimetre or gram would contain 1000 times as much, or 4938 Trichinz, providing it weighed only as much as distilled water at 60° F. But as muscle weighs * St. Louis Med. and Surg. Journal, liii. (1887) pp. 289-91. . ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 165 for) ler) “I -3 in one gram, or 4667-300 in a kilogram, or 4667°3 x 453-593 1-058 as compared to water, the true number would be 4987 x 1-058 = 2,117,054 in one pound avoirdupois. Models in Metal of Microscopical Preparations.*—Prof. E. Selenka prepares metal models from microscopical preparations in the following way :—To obtain a plaster representation of the brain of a vertebrate embryo, the outlines of the head, the external and internal boundary lines of the brain are drawn on paper from the specimen with a camera lucida. According to the size of the separate sections, every second, third, or fourth section is selected, the drawings are numbered, and then carefully stuck on cardboard of the necessary thickness; the reverse side of the cardboard is covered with glue. The separate figures are then carefully cut out. Small strips for joining must of course be left in the brain. The different layers of cardboard are then glued together in their proper order, and thus a case model of the head is obtained. Any gaps or seams on the surface are filled in with plaster of Paris, and then the hollow model, which is open behind, is filled with Wood’s metal heated to about 75° C. When cool the cardboard is softened in lukewarm water and then stripped off. The model is next cut in two with a fret- saw and the internal surface of the brain freed from the cardboard. Unevenness of the surface and holes are easily got rid of with a heated needle or knife, or by touching up with a stick of Wood’s metal which has been softened at a gas jet. It is necessary to leave vent-holes in the cardboard model. New Reagent for Albuminoids.,—Dr. M. Kronfeld proposes a new test for the presence of albuminous substances, viz. allowan (= mesoxa- lylurea). This substance forms crystals which are readily soluble either in water or alcohol. From a hoé solution there are deposited small permanent crystals with 1 equivalent of water; the larger crystals which are obtained from a warm solution deliquesce in the air. Solutions of alloxan produce, with albuminoids, and with some of the products of its decomposition, a red colour, which passes into purple, with an unpleasant odour. The reaction is obtained with tyrosin, very intense with aspara~ ginic acid and with asparagin; apparently with all those compounds which contain in their molecules the group CH,.CH(NH.).CO,H. Solutions of albuminoids give the reaction more slowly than when in the solid form. In order to be certain of success it is necessary to operate in the cold, and to exclude as much as possible the presence of ammonia; solutions in alcohol, water, or in caustic soda may be used. Free acids prevent the reaction. The endosperm of seeds, which contains aleurone and spherocrystals, is very convenient for experimenting with the alloxan-reaction. White's Elementary Microscopical Manipulation.t — Whilst it might be thought that the ground was already fully occupied for works on microscopical manipulation, Mr. T. Charters White’s excellent little book will be found to meet a distinct want. More extensive treatises of course exist, but this, in the words of the author, “is designed with the aim of affording the youngest beginner such directions for preparing * SB. Physiol. Med. Soc. Erlangen, 1886, Heft 18. + SB. K. Akad. Wiss. Wien, xciv. (1887) p. 135. { White, T. C., ‘A Manual of Elementary Microscopical Manipulation for the use of Amateurs,’ iii. and 104 pp., 1 pl. and 6 figs. S8vo, London, 1887. 166 SUMMARY OF CURRENT RESEARCHES, ETO. objects of interest and instruction in an elementary but at the same time such a complete manner that, be he the merest tyro, he may grasp their details and work out his studies with the most satisfactory results.” Brun, J.—Notes sur la Microscopie technique appliquee a l’histoire naturelle. (Notes on microscopicai technique applied to natural history.) Arch, Sci. Phys. et Nat., XVII. (1887) p. 146. Journ. de Microgr., XI. (1887) p. 178. Harris and Powpnr.—Manual for the Physiological Laboratory. 4th ed., 266 pp. and figs., 8vo, Paris, 1887. HWircucock, R.—The Biological Examination of Water. III. Amer. Mon. Mier. Journ., VIII. (1887) pp. 203-5. Mruuer, M. N.—Practical Microscopy. 217 pp. and 126 figs., 8vo, New York, 1887. fOsporn, H. L.J]—Microscope in Medecine. Amer, Mon. Micr. Journ., VIL. (1887) p. 217. Prerson, G. A.—Laboratory Jottings. [Fixing reagents (chromic acid the best). Benda’s modified copper-heema- toxylin (supra, p. 158), Celloidin v. Paraffin. Homogeneous paraffin (supra, p. 151). Dispensing with clearing (supra, p. 160).] Aimer. Mon. Micr. Journ., VIII. (1887) pp. 153-5, Strasburger, E.—Mieroscopic Botany. A Manual of the Microscope in Vegetable Histology. TZransl. by A. B. Hervey. [Translation of ‘Das Kleine Botanische Practicum.’ } 382 pp., 8vo, Boston, 1887. Tayutor, T.—The Crystallography of Butter and other Fats. IV. Amer. Mon. Micr. Journ., VIL. (1887) p. 226 (2 pls.). ZinGueER, E.—Die Technik der histologischen Untersuchung pathologisch-anato- mischer Praparate. (The technique of the histological investigation of patho- logico-anatomical preparations.) 8vo, Jena, 1857. ZuN«", A.—Cours de microscopie médicale et pharmaceutique. (Course of medical and pharmaceutical microscopy.) Moniteur du Praticien, 11. (1887) pp. 125 and 158. @ 167 ) PROCEEDINGS OF THE SOCIETY. Meetine or 147TH December, 1887, ar Kine’s Cottrcr, Stranp, W.C., THE PresIDENT (THE Rev. Dr, Dauiincer, F.R.S.) ix roe Cuarr. The Minutes of the meeting of 9th November last were read and confirmed, and were signed by the President. The List of Donations (exclusive of exchanges and reprints) received since the last meeting was submitted, and the thanks of the Society given to the donors. From Dallinger, Rev. W. H., LLD., F.R.S., The Creator, and what we may know of the method of Creation. 388 pp. (Svo, London, LISI) “ao “eee = a. oo Be S30 ot) og eo, GG 4 oc The Author. Mr. Crisp read to the meeting the preface to Dr, Dallinger’s book. The President said, that although it would not be imparting any- thing new to the Fellows to remark upon the fact of the removal by death of Mr. Bolton since their last meeting, he thought it was fitting to make public allusion to the fact in that room. Microscopists generally were greatly indebted to him for the measures which he had adopted to enable them to study a great variety of living objects. His friends moved the Government to grant him a small pension for the services he had rendered to science, but unfortunately he only lived to enjoy it for a very short period. Both as individuals and as a Society they would record his death with sorrow. Mr. J. Mayall, jun., described two Microscopes by Jaubert, one of which had been described in the Journal for 1887, p. 632, and the other had not yet been described. Mr. Michael said that, a short time since, his relative, Mr. W. H. Michael, who was an excellent chemist, drew his attention to the Olewm Rhodit as being a substance very likely to prove advantageous as a substitute for oil of cloves in cases where this was usually employed in the preparation of objects for mounting. He had tried it for a few months, and it had given results sufiiciently satisfactory to induce him to bring it to the notice of the Society. “Rhodium oil,’ as it was commonly called, was supplied by chemists who sometimes thought it had to do in some way with the metal Rhodium. It was, however, obtained from Rhodium Radix—Rhodium being a thorny shrub growing in the Canary Isles. The oil was prepared by distillation, and was used for two widely distinct purposes. Firstly, the refined quality was largely used in this country by perfumers, as diluted attar of roses; and secondly, the commoner kind was used by rat-catchers on the Continent for the purpose of attracting rats, which were said to have a great partiality for it. Its value for mounting purposes was suggested to him on account of its being an oil of high penetrating power, and at the same time not being volatile. He had used it for about two months on Acari, 168 PROCEEDINGS OF THE SOCIETY. and found that it had three great advantages. First, when a delicate object had been prepared in spirit and was afterwards transferred to oil of cloves it usually shrank back in a degree that was often detrimental : Rhodium oil did not cause it to do this. Second, when a very delicate object with small passages had been in oil of cloves it was often found that the oil of cloves ran out quicker than the balsam ran in, resulting in an appearance as if air had got into the tissues: this was avoided by the use of Rhodium oi]. Third, an object could be transferred direct to this oil from water or dilute acetic acid without the necessity of passing it through spirit. It gave as good results as oil of cloves, and rendered mounting in the last named respect a somewhat less trouble- some process. Mr. Karop inquired if Mr. Michael had tried it upon anything else than insect preparations? It seemed to him somewhat strange that an essential oil should be miscible with water. Mr. Michael said he had tried it upon a few other objects, but had not much histological work to try it upon at present. He found that it did not produce any milkiness in objects transferred to it from water. Mr. Suffolk asked if it was easily procurable ? Mr. Michael said he thought it could be got at almost any chemist’s, especially such as supplied materials to perfumers; but the finer quality should be asked for. The President said he was not yet able to give any practical account of the piece of apparatus which he held in his hand, but he thought the Fellows present would be interested to know that it was the first condenser made with the new German glass. It had a numerical aperture of 1:4, working at the same distance as the achromatic conden- ser also made by Messrs. Powell & Lealand, but this was also practically apochromatic. He had not yet had the pleasure of trying it, but he hoped to be able to do so in a very short time. Mr. T. B. Rosseter’s paper “On the Generative Organs of Ostra- coda” was read by Prof. Bell. Prof. Bell said, with regard to the question of motion in the sperma- tozoa, he did not think that the observations were really out of agree- ment with Prof. Huxley, who probably meant that there was no active movement. Of course, if there were absolutely no movement, it was tolerably certain that at no distant period the race would become extinct, so that by the expression, “ totally deprived of mobility,” he supposed was meant that they had not the same activity as that of the flagellate forms. Mr. Michael thought it was a fact that no motion could be made out in the case of several of the Arthropods. Mr. Campbell said in his paper that he could not detect any motion in the spermatozoa of some of the spiders, and he had himself found the same thing in the case of some of the Acari. Prof. Bell thought that the only cases in which flagellate spermato- zoa occurred were in the Scorpions and in Limulus. Prof. Stewart supposed it was rather a lapsus linguze on the part of Prof. Bell when he said the flagellate spermatozoa were rare amongst these classes, because amongst the insects they found them to be all—or PROCEEDINGS OF THE SOCIETY. 169 nearly all—flagellate. Again also, as to the remark about the inactivity of the spermatozooids being comparative, he thought the difficulty was hardly so great as imagined. Supposing the fertilizing spermatozoa to be absolutely motionless, he did not see why the race should on that account become extinct, because in this case they had an instance of true copulation, in which these bodies were introduced completely within the passage of the female organ, and it was quite conceivable that by the contraction of its walls they might be eventually brought into contact with the ovum. In the other case mentioned it might be that an ame- biform action was subsequently taken on, because it seemed that a ray or burr-like form was in itself practically unfit to be carried up the duct of the female. Mr. A. W. Bennett said that in the case of one very large class of plants—the Floridee—the spermatozoa were entirely devoid of the power of motion. Prof. Bell pointed out that the amceboid motions in the case of the higher Crustacea had been noticed by a Russian observer. Mr. W. M. Maskell’s paper, “ Note on Micrasterias americana Ralts and its varieties,’ was read by Mr. Crisp (supra, p. 7). Mr. A. W. Bennett said that this paper struck him as being one of very great interest ; but to those who had given up the idea of fixity of species it was a matter of arrangement whether they regarded them as different, or as varieties of the same species. The genus Micrasterias was one of the most interesting of the Desmidiez, because of the com- paratively large size and great beauty of many of the forms. The author spoke of the great advantage which would accrue from a mono- graph of the Desmidiex, but he thought if they had a complete mono- graph of only Micrasterias it would be of inestimable value. One of the whole group would be a matter of such enormous labour that it could hardly be hoped for. He could completely corroborate what the author said as to the very great variety of forms which existed in individuals of the same species. He thought this paper was a contribution to science, for which the Society ought to be grateful. The following Instruments, Objects, &c., were exhibited :— Mr. Bolton :—Canthocamptus minutus. Mr. Burgess :—Carterina spiculotesta Carter, Raine Island, Torres Strait. Mr. Crisp :—Jaubert’s Microscopes (2). Mr. Guimaraens :—Diatoms from Sysran, Government of Simbirsk, Russia (a new deposit). Mr. Michael :—Specimen of Mounting Medium in which Ol. Rhodii had been used. New Fellows:—The following were elected Ordinary Fellows :— Messrs. C. Spence Bate, F.R.S., W. Laurence Gadd, F.C.S., and Rev. Thomas 8. King. 1888. N 170 PROCEEDINGS OF THE SOCIETY. Meeting or llrn January, 1888, ar Krine’s Cottece, Stranp, W.C., THE Presipent (tHE Rey. Dr. Daxuinerr, ¥.R.S.) In THE CHAIR The Minutes of the meeting of 14th December last were read and confirmed, and were signed by the President. The List of Donations (exclusive of exchanges and reprints) received since the last meeting was submitted, and the thanks of the Society given to the donors. From M‘Coy, F., Prodromus of the Zoology of Victoria. Decades 1-14. The Government 8vo, Melbourne, 1878-87 5 A ea Fie of Victoria. The President said that since their last meeting the death had oc- eurred of Dr. Arthur Farre, F.R.S., who was formerly Professor of Obstetrics in King’s College and a Physician Extraordinary to the Queen, and who was also one of the first supporters of the Society (elected in 1840) at a time when it held a position very different from that which it occupied at the present day. He was one of those who had actively assisted in bringing microscopy to its present condition of prominence, and his death would be recorded with sorrow. Mr. Crisp also referred to the death of Mr. Lettsom, formerly a Fellow of the Society, and who was specially interested in the optical questions connected with the Microscope. The death of Mr. Dancer had also taken place, who, although not known to them as an attendant at the meetings, had in former years done much useful work in con- nection with microscopy. Mr. Crisp read the list of nominations for Officers and Council for the ensuing year, to be elected at the Annual Meeting in February. Mr. J. J. Vezey and Mr. W. W. Reeves were elected Auditors of the Treasurer’s accounts. Mr. Crisp gave notice, on behalf of the Council, of the alterations in the Bye Laws which it was intended to present to the Annual Meeting for adoption. In consequence of alterations made from time to time in certain of the Bye Laws, the wording of others required revision in order to make them consistent, and some additions had also appeared to be advisable. The nature of the proposed alterations was then explained to the meeting, and the proof of the Bye Laws as amended was laid on the table. Prof. Stewart exhibited a specimen of a Lamellibranchiate shell which he said possessed some peculiar features of a very interesting character, and which, although often figured, were not generally known to biologists at large. In some of the Mollusca the individuals were moncecious, but in those where the sexes were separate the female shell was usually larger than the male and also differed considerably in shape, » as shown by the drawings of each, which he made upon the board. In the genus T’hecalia the female shell exhibited a peculiarity which was quite unique; this genus contained only two species, of which con- PROCEEDINGS OF THE SOCIETY. nL7Al camerata was the one to which the specimen shown belonged. As age advanced the mantle became folded back upon itself in a very curious manner, and simultaneously with this there occurred a similar infolding of the contiguous portions of the shell, by which two depressions were produced, forming a fusiform chamber when the two valves came together. In this cavity the embryonic shells were to be found. In the specimens exhibited this chamber was well seen, although with few exceptions the embryos had been removed. Edmonds’s Automatic Mica Stage, rotating by clockwork, was exhi- bited and described. It had been devised by Mr. John Edmonds, of Hockley, formerly President of the Birmingham Microscopical Society (supra, p. 111). Mr. Crisp said that, though having by experience become wary as to ‘small-type paragraphs appearing at the bottom of newspaper columns having marvellous headings, but found at the end to be advertisements (such as “ A False Swain and a Deluded Spinster,” which advocated a hair nostrum ), he was taken in by an article which was placed at the head of a column and had attracted his attention by the reference to ‘“‘ The Micro- scope” and “The many puzzling secrets revealed by this wonderful instrument.” On reading it the article was found to be an ingeniously worded advertisement of a wonderful “cure.” It was the first time that he had seen the Microscope thus made use of by advertisers as a victim (supra, p. 188). Mr. A. W. Bennett gave a résumé of his paper on “ Fresh-water Algz of the English Lake District. II. With descriptions of a new genus and five new species,’ in continuation of his previous communication on the same subject (supra, p. 1). The President said Mr. Bennett’s paper was a most important contri- bution to their knowledge of a subject which he had made so specially his own. Only one who was a master of this branch of science could recognize the new species in this manner, not only amongst British organisms, but also in the case of foreign forms. Dr. G. Gulliver read a paper on Pelomyxa palustris (supra, p. 11). Prof. Stewart thought that the Fellows were much to be congratu- lated upon the information which they had received in this paper. The practice of staining in the course of the examination of these lowly organisms had long been employed in rendering the nucleus of the cell more distinct ; but, so far as he was aware, this was the first occasion in which, in addition to staining, sections had een made. There were of course many instances in which this could not be done with advan- tage ; but in the case before them, in consequence of the large size of the organism, section-cutting had been possible, and the results had been so encouraging, that he hoped it would be applied in other cases also. If they took a Pelomyxa they would see on a front view a large creature very much like an Ameba, and also like it, containing masses of granules, which moved forward along those portions of the creature which were extended in the direction in which it intended to move. If they looked at it edgeways, they would see no difference between the endoplasm and the exoplasm, so long as they looked at it in the ordinary way, but if it was stained the granulated structure was at once revealed. 172 PROCEEDINGS OF THE SOCIETY. The appearance of the nucleus of the cell would lead to the notion that such cells might perhaps be swarm-spores; careful observation would, however, be necessary to establish this as a fact. As regarded classifica- tion, he should not be surprised if it ultimately turned out that these organisms had a nearer relation to the true Heliozoa than to the more lowly Amebe. The President expressed the thanks of the meeting to Dr. Gulliver for his paper, and also to Prof. Stewart for his remarks upon the subject. He thought that if one of the tendencies of fifteen or twenty years ago had been to conclude that there was no structure in low organisms of the type of that before them, it was equally certain that the tendency of the present day was to show that there was structure throughout. This was not yet established ; but even yet, if it should appear that the endosare was without structure, it was still certain that the ectosare was shown to be full of structure. Mr. E, M. Nelson handed round for inspection two photographic positives, one of Amphipleura pellucida and the other of a kind of fungus growth which attacked calcareous sand as described by Mr. J. G. Waller in the ‘ Journal of the Quekett Microscopical Club’ (vol. i. p. 345). This object presented some photographic difficulty because of its non-actinic colour. With regard to the other, he might remark that, in resolving diatoms with oblique light, it was essential to decide whether they in- tended to focus upon the real surface or upon the optical image produced in a higher plane, in consequence of the double nature of the structure of the valve. In the latter case, they would obtain a result such as he exhibited, which was a photograph of the optical image, and not of the real diatom. He also exhibited the focusing screen for use in the micro- camera which he described at the previous meeting of the Society. Mr. Nelson also called attention to a curious optical effect, for which at present he was unable to account. In a flat box he had placed a glass positive of Amphipleura pellucida, which was viewed as a trans- parency through a piece of tube fitted at right angles to the surface. If this was looked at when held towards a surface of light, such as an opal lamp-shade or a “ sun-light ” gas-burner, the black lines appeared to be slightly smaller than the white lines; but if it was turned towards a small light at a distance, then the black lines appeared very large, and the white ones were reduced to mere threads. The scale of the photo- graph showed that the effect was not due to the operation of the first diffraction spectrum; and it was still more curious to note that in the case of another positive taken from the same negative, and upon the same scale, this optical illusion was not observed. The following Instruments, Objects, &c., were exhibited :— Mr. Crisp :—Edmonds’s Mica Stage. Dr. G. Gulliver :—Pelomyzxa palustris. Mr. Nelson :—Photomicrographs. Diffraction effect of Amphipleura pellucida. Prof. Stewart :—Thecalia concamerata. New Fellows:—The following were elected Ordinary Fellows :— Messrs. H. Williams Case, Hahnemann Epps, Thomas W. Kirk, and F. Raymond. The Journal is issued on the second Wednesday of February, April, June, August, October, and December. . ay ice al 1888. Part 2. APRIL. i pee Bee JOURNAL OF THE ROYAL MICROSCOPICAL SOCIETY: - CONTAINING ITS TRANSACTIONS AND PROCEEDINGS, AND A SUMMARY OF CURRENT RESEARCHES RELATING TO ZOO LOGS AINE DD: BOT AN (principally Invertebrata and Cryptogamia), MICROSCOPY, 8c. 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.S., Lecturer on Botany at St. Thomas's Hospital, Professor of Comparative Anatomy in Ki ing’s College, JOHN MAYALL, Joy. F.ZS., R. G. HEBB, M.A,, M.D. (Cantad.), AND J. ARTHUR THOMSON, M.A., Lecturer on Zoology in the School of Medicine, Edinburgh, FELLOWS OF THE SOCIETY, WILLIAMS & NORGATE, \ De - LONDON AND EDINBURGH. PRINTED BY WM. CLOWES AND SONS, LIMITED,] [STAMFORD STREET AND CHARING CROSS. CONTENTS. —_—_—_—- TRANSAOTIONS OF THE SooInTY— IV.—On tur Tyrer or A New onper or Foner. By George Massee, PR MS (Plate TV) 2 G82 ve see V.—Tux Presipent’s Appress. By the Rev. W. H. Dallinger, UE Da Bias Lie QUO.) 56 3s ee, Siva ted Clhae SUMMARY OF CURRENT RESEAROHES. ZOOLOGY. A. VERTEBRATA :—Embryology, Histology, and General. a. Embryology. Betionor, G.—Polar Globule of Mammalian Ovum ., Ryver, J. A.—Vestiges of Zonary Decidua in Mouse oi Usxow, N.—Development of Blood-vascular System of the Chick HaAswetyi, W. A.—Development of Hmu seve ce newt Scuanz, F.—Fate of the Blastopore in Amphibiang .. ss «s Fieumine, W.—Spermatogenesis of Salamander so vs on es Brooz, G.—Germinal Layers in Teleostet .. so ss ee ee Fusaril, R.—Segmentation of Teleostean Ova DEA Soe neue eens fe Cunnincuam, J. T.—Eggs and Larve of Teleosteans.. 1. +» ZircLer, H. 0.—Origin of Blood in Teleostet .. ee se ae lees J. T.—Ova of Bdellostoma .. is Manrcacct, rar hei of Movement on Developing “Eggs. - Hatscuex, B.—Significance of Sexual Reproduction .. .. + Dermer, W.—Inheritance of Acquired Characters .. 2. ae WiepersHeimm, R.—Ancestry of Man 4. se ce tte Weismann, A.—Degeneration.. .. «esa a we B. Histology. NANsEN, F'.—Histological Elements ef the Central Nervous System Bampesz, C. Van—Artificial Deformations of the Nucleus .. ees P.—Structure of Nerve-fibre .. .. < Foi, F.—Structure of Red Blood-corpuscles .. Hauuipurton, W. D.—Hemoglobin Crystals of Rodents’ Blood B. INVERTEBRATA. Duranp, W. F.—Parasites of Teredo navalis 14 see we Innor, O. E.—Fauna of Mosses «. os on ne oe oa Mollusca. Fou, H. ee ake Structure of Muscles of Molluscs .. oe ScHIEMENZ, P.—Ingestion of Water in Lamellibranche, Gastropods, ‘and Peeropods a. Cephalopoda. Barner, F. A.—Growth of Cephalopod Shells .. + «ses y. Gastropoda. Korner, R.—Form and Development of Spermatozoa in Murex SaLensky, M.—Development of Vermetus .. .. Seesee Bouvier, E. L.—Anatomy and Affinities of Ampullaria ae Scuimgewitsou, W.—Development of Heart of Pulmonate Mollusca Frwxes, J. W.—Sucker on Fin of Pterotrachea ..- 1. «5. ee oe PAGE 173 177 186 186 187 187 189 189 189 191 191 192 192 193 193 193 193 194 194 196 197 198 198 199. 199 199 199 200 200 208 ei 204 204 205 (3) §. Lamellibranchiata. Apirny, I.—Histology of Najadz .. Molluscoida. a. Tunicata. BENEDEN, E. a ee Tanvena es aes Douixy, C. S.— Histology of Salpa B: Polyzoa. Herpman, W. A.—Reproductive Organs of ee gale Forrrinerr, A .—Anatomy of Pedicellina Arthropoda. Parren, W.—Eyes.of Arthropods .. «+ a, Insecta. Ravi, O. v yaa ae Sensory Organs of Insects.. —.. Kytrret, A.—Salivary glands of Insects Pees M‘Coox, H. C.—Sense of Direction in Formica rufa FRICKEN, V.—Respiration of Hydrophilus.. .. SzLvatico, S.—Aorta of Bombyx mort .. Rascurgn, E. W.—Larva of Culex . : CuoLoprovsky, N,.—Some Species of Chermes 8. Myriopoda. Hearucors, F, G.—Post-embryonic Development of Julus 6. Arachnida. PuaTEAv, F.—Vision in Arachnids ey a Respiration of Arachnida WacnER, V.—fegeneration of Lost Parts M'‘Coox, H. C.—Age and Habits of American Tarantula .. ZACHARIAS, O.— Distribution of Arachnida .. e. Crustacea. pena P.— Excretion in Brachyurous Crustacea Rawitz, B.—Green Gland of Crayfish .. .. 1 — « Garp, A., & J. Bonnrer—The Bopyridz a5 Two New Genera of “Epicarida Cuavs, C. Se oricinaks and the Philichthydz Nusspaum, M.—First Changes in Fecundated Ovwm o of Lepas a Vermes, a, Annelida. Scam M.—Development of Annelids .6 6s an we Bourne, A. G.—Vascular System of Hirudinea.. .. »- BrvUNoTTE, C. —Structure of the Eye of Branchiomma .. Vespovsky, F.—Larval and Definite Excretory Systems in Lumbricide .. Bepparp, F, E.—Reproductive Organs of Moniligaster ., 2 ” So-called Prone Glands of Oligochzta Roux, L.—-Histology of Pachydrilus enchytrzoides +. Benuam, W. B-—New Earthworm ieee Mryer, E.—Organization of Annelids .. Joveux-Larruie, J.—Nervous System Me Chatopterus Valencinit agen J.—Polygordius .. .. 8. Nemathelminthes, Lrg, A. DOLEBS Soperierogatiees in Chetognatha ., °°. a aie .—Life-history of Gordius Vitor, A.—Development and Specific Determination ¢ ee Gordié Bos, J. Rirzema—Natural History of Tylenchus PAGE 205 206 207 208 208 209 210 211 212 212 212 212 213 213 214 214 215 215 215 216 216 216 217 217 218 218 219 219 220 227 221 222 », 222 222 225 225 — 227 228 228 229 eee) y: Platyhelminthes. PAGR Montez, R.—Tenia nana Ss Bee ae or foal pyr cea Re Bdlcrkk to rea a Tuma, I.—Some European Triclades See Gee Sg ie Re RSM tig Osetia A area 5. Incertee Sedis, Hoop, reptiles clei annulata .. Be RES Ut ani en rae eee Nansen, F'.—Nervous System of Myzostoma.. APP Mauch eRe R ALE Memo Echinodermata. Bury, H.— Development of Antedon rosacea é aft Sib a Po ep aoc ara ea ca ar Groom, T. T.—New Features in Pelanechinus corallanus wok Cock wR ee SR Sarasin, Pi & F.—Budding im Star-fishes 1. 66 ee be eee ce nee RBS Semon, R.—Mediterranean Synaptide@ .. 6. ose we eee eee ne ue | 288 Celenterata. page C.—Cladonemidx mer ay Ce hae Tey eet Ante ew Ne Lewy, J—Hydra .. READE eas Sama ten Pas tet Ne Cone Ye PP Frwxkes, J. W.—Are there Deep- Sea Medusee 2 dn, PE agg teas Sara ge, wel Hickson, 8. J.—Sea-cells and Development of Millepora .. 1 4s ae ewe 286 Nicnotson, H. A.—Structure and Affinities of Parkeria .. 4. 1 te oe ae 287 MARENZELLER, E. voN—Growth of Flabellum =... 02 ee wees ee DBT Sruper, T.—Classification of Aleyonaria .. .. ee ee ete tne we DBT Grima, J: A.—Norse Alcyonaria 4. see oe ne oe te ne ee we ae 239 Porifera. TorsENntT, E.—So-called Peripheral Prolongations of ne SEC A ae aa THomson, J. ARTHUR—Structure of Suberites 1. 6. su te te we ae we 289. Protozoa. GreENwoop, M.—Digestion in Rhizopods .. «+ ne ee ty te ee ane 240 Grassi, B.—Protozoa Parasitic in Man Wee SUMO ke USI ob oak FL Ee hae ee ZACHARIAS, O.—Psorospermiuwm Haeckeli —.. Be ap ae Muti) bak ek aoa Daweon, J; W:—Hoxoon: Canadense® aii eo ad ee og ges ae. pb oda ton eee BOTANY. A. GENERAL, including the Anatomy and Physiology of the Phanerogamia. a. Anatomy. (1) Cell-structure and Protoplasm. Moorr, 8S. Le M.—Influence of Light upon Protoplasmic eee ge ae: Gh come Went, F. A. F. C.—Nuclear and Cell. Division Anse Re de 7 3) Wicanp, A.—Crystal-plastids Seep m ad wigs ete ekece ee Boxorny, T.—Separation of silver by active Anan Pa ETT eee Cie et (2) Other Cell-contents (including Secretions). Moors, 8S. Le M.—Epidermal Chlorophyll .. 4. 24 eu ee we oa DED es Cugin1, G.—Fluorescence of Chlorophyll... icch paw ae Saat oe we 245” Maccniati, L.—Preparation of Pure Chlorophyll tee sec aa wig awa ee Lorw, O., & T. Boxorny—Presence be active Albumin tn the Cell-sap eae eee Zorr, W. _Fibrosin, anew cell-content .. .. 2. on aww dae nk veoh eae Mouiscn, H H.—Secretion from the Roots .. .. dy Cope aaa! PaLLADIN, W.—Formation of organic acids in the growing parts of “plants RC nites 4-9) JOHANNSEN—Localization of Emulsin in Almonds... a piprer eee Hitec ta Fra) a (8) Structure of aeons ! InuicH, E.—Development of Stomata .. ss se ne te te te te wwe D4 Pratt, E Papen a a ote nd DIUM 29 Ga ee be oe a ata ee Gee ee Krasser, F.—Split Xylem in Clematis .. «. ahi uae Nes eee Scoudntanp, 8.—Apical meristem of the roots of Pontederiaccee .. ret aber rie or ho re 9 (4) Structure of Organs. PAGE _ Prrorra, R. Asana Alaa of Gelsominer (Jasminer) .. .» +e ee owe 249 Mastort, R .—Salt-excreting glands of Tamariscinez 249 Koen, L.—Organs for the absorption of vegetable food-material by plants containing chlorophyll .. -s. Gorissen: ek 249 Sapion, LECLERC pu—-Haustoria of the Rhinanthece and Santalacee .. 250 Trecuen, P. Van—Structure of the root and arrangement of the rootlets in Centro- lepidex, Eriocaulex, Juncex, Mayacex, and Xyridew.. +» ss ee an we DBL Geminate Root-hairs .. we iawe toe. Sine Snes eet Ook Marriroto, 0, & L. Buscattont—Root-tubercles of Leguininose = Peay 11) F Wanp, H. Mansuatt—Tubercular Swellings on the Roots of Vicia Faba.. os ol BAuprnt, T. A.—Emergences on the Roots of Seaiicabied Re ee Spi lee lem: we ee Coroms, G.—Stipules .. Sa GEE ig. tak ee AR AOR OT os, oso mA ea areutes LOM Dirz, R.-—Vernation of Leaves Rhee ment eee WE aS Nes SES awe A Va SG Ot naa Toe KRONFELD, M.—Double Leaves .. ROI ece SAN teres WPS eee es EAT ee enile leaflets of Staphylea pinata Tia et neey re See eer Hurn, B.—Clinging-Planis .. .. .. BG toas etree denied Flee OS. Krasser, F.—Heterophylly .. .. saree tint a0) Svaees ar Wiepatreeies. TOO Wicanp, A.—Colours of Leaves and Porte ee eae ng OR ReEicuHe,- K.—Anatomy of the Floral Axis... 40) ee oe ee te swe we 204 Hunstow, G.— Comparative Anatomy of Flowers Saher Wel oo an nse he cD De.pino, F.—Floral Nectary of Symphoricarpus.. 2. 6» 00 ee wn oe ne 288 Opens, A.—Fruit of Borraginez .. eee a Peek RAS Conte Pike Ne RES Pie Srapr, O.— Explosive Fruits of Alstreemeria daarvel SPUR eH ees. a ea LOO B. Physiology. (1) Reproduction and Germination. Nrcoorra, L.—Pollination of Serapias .. . eS. HST SI OR oe eT 256 Rozn, E.— Pollination in Zannichellia palustris Uae ee Bee cee eon ea seee S815 Nosse, F'.—Production of Sex und phenomena of Crossing Serge lesen omens ee JorDAN, K. F.—Physiological Organography of Flowers .. .. sso» we” 256 Rorre, R. A.—Bigeneric Orchid Hybrids... .. wat eee nba ree Sealy eae Cae. HERE, O—— Germenanton of 2 UNS 320k aes Ona tse oe bho OF as ee he ep LEO. (2) Nutrition and Growth (including Movements of Fluids), DancGearp, P. A.—Importance of the Mode of Nutrition as a means of Distinction between Animals and Vegetables .. EPA TSR ea etd ee rere WAY | Unuitzscu, P. G.—-Growth af the Leaf- “stalk See pres, ete atest OOS Bower, F. O.—Modes of Climbing in the genus Calamus... ae sleet psees eet “ROO Krevster, U.— Assimilation and Respiration of Plants .. .s .. 2. se +» 258 WInrsneEr, s. Pep ei of Atmospheric Movement on Transpiration.. .. .. .. 259 Burcerstern, A —— Literature.of- Pranspiration® 1.28.5 ise ane ew 8 ee Se OD. (3) Irritability. Pasnew J.—Movements of Irritation .. UG esd nat sex ba SeeDe Mernan, T.—Irritability of the Stamens of Echinocactue . Bo Oates sean anoles kena er OE (4) Chemical Changes (including Respiration and Fermentation), Lawes, J. B.—Sources of the Nitrogen of Vegetation .. .. +s «os 0 «« 261 B. CRYPTOGAMIA. Cryptogamia Vascularia. GorsBeL, K.—Conversion of Fertile into Sterile Fronds... se 22 «0 se o» 261 Bower, F. O.—Formation of Gemmez in Trichomanes sss sews ae we 262 BAKER, G. —Enterosora ee ee ae oe oe oe oe oe oe oe 262 Trevs, M.—Life-history of Lycopodium was Sree ener ee pie aid aa aM roe ane ae _ Bucutien, O.—Prothallium of Equisetum .. nos) Cae ke SON NR and gee DO “Reyavir, B.—Leaves of Sigillaria and Lepidodendron RE Pe Ma tee Tite teay «| C68) Muscinesx. Vaizey, J, R.—Absorption of ee and its igen to the apse sites of the Celt- wall in Mosses ~.. . Sco RPRE CORN BOT DERE SgEE Purizert—Peristome of Mosses rl piaia eet ed Ph Motes halal dahl ame Santo, C.—Hybrid Mosses nh EN WS REE asiee pak One oe ened MassALoNnao, ‘G.—Distribution of Hepation wo hia 8? te Saye ial Nn Gas gee a a Alges. ; Scuirr, F.—Phycophein.. La NOs eG DEBRAY, F.— Development of the Thallus of certain Age AP Mair pce Sa ae. as | Outver, F, W.—Sieve-tubes in the Laminaries Sab Dat ee Ma en Tso Lacernem, G.— Development of Confervacess 4. 4 ne 4 we ine ee Hanserme,. Ai—Algological Studies 0 ode ee Sn lea toen flaebee) wey ce Sood pee RAUWENHOF®, No. Wo P-Spheropled 6 0g ope Sei en be tee dn we ae WiILpEMAN, BH. DE—Ulothriacrenulata:.. 26> ee ot ae eh ee ey ee ab Porrmr, M. C.—Alga epiphytic on a Tortoise ayes a Sontrr, F.—ormation of Auxospores in Diatoma .. ve ee wee Fungi. Frank, B.—New Forms of Mycorhiza .. fake telat aay ee R. von—Abnormal Fructi ification of Agaricus procerus Spaie A Morini, F.—Sexuality of Ustilaginex .. Se earecesyy », Germination of the Spores in Ustilago ay Su a TieGHEM, P. Van—New Genera of Ascomycetes, Oleina and Podocapsa sea ZvuKAL, H.—Asci.of Penicillium erustaceum ., pecan Rotugrt, W.—Formation of Sporangia and Spores i in the Saprolegniez .. ve ScuNerzLER, J. B—Infection of a Frog-tadpole a a Ma seree Iiness, M., & C. Fiscu—Hlaphomyces .. .. ee RI BRUNCHORS?, J == Cabbage Herne ee cite Ie ok eee Uo eRe See ae Steal eas OD 5 Ee OLNO UU OUB YS go isin. se. Pe OBI we We ee ke Rome RogrNson, B. L.—Taphrina .. RPGS gs: NM TT PE VuILuemin, P.—Disease affecting Cherry and Phum-trees lata 6 alae i eae Harz, C. eee PPO ONE Nae aera ewe a eel reg KCtenaa) nokeae ROSPRUD,: He —Bunge Of Penance ake sa ewes ieee eS ea te res Protophyta. Scorn, ie H.—Nucleus in Oscillaria and Tolypothrix PCT eee rng tiipax titect Fae Borzi, A.—Microchete .. Binier, A.— Life-history and Morphological Variations of Bacterium Laminaria Tomascuer, A., & A. Hansairc—Bacillus muralis s,s. ++ ve one 2 Buswip, O-= Bacteria in Hailstones SEN veg Sed aa Fiscuer, B.—Phosphorescent Bacillus «. Kirasato, 8.—Spirillum concentricum, a new species from decomposing blood MICROSCOPY. a Instruments, Accessories, &c. (1) Stands. Wiuurams, G. H.—Bausch and Lomb Optical Co.’s Petr he ag Eee (Fig. 40)... me Spies CZAPSEI, S.—Bamberg’s Spherometer Microscope (Fig. “AD ee ee Sagat CN Nea GaALuaAnpD-Mason’s (R.) Microphotoscope (Figs. 42-44) © 2. 50 nee eee (2) Bye-pieces and Objectives. GunpLach, 8.—Apochromatie Objectives «se ve we ten CueEaP Objectives Ske eT S ape panier be vey sy hen sen ee ae he (3) INuminating and other Apparatus. BREFELD, O.—Geissler’s Culture Tubes (Fig. sai Gas and Moist Chambers (Figs. 46-55)... Eger eins oe a 6 “i «i MAuuarp, E.—Bertrand’s Refractometer vis ee PETS LEHMANN, O sat dae pie for Microphysical Investigations teeo ks PAGE 263 263 264 264 be) (4) Photomicrography. Leumany, O.—Photomicrography of Chemical Preparations... + - NeunHaus’s (R.) Photomicrographic Camera (Fig. 56) «1 es ek tee STELN’S ss T.) “ Large Photomicroscope” (Fig. 57) 2.0 2. ee ee thee Troan, A., & O. Wirr—Photomicrographs of STIS Ces Mente toe 15! 115,692 125,404 152,397 1:19 = 126° 58!|°103°--2' 114,728 124,359 151,128 1:18 ie 125°: 73" | 1019:50! 113, 764 123,314 149, 857 ite beg es 123° 13’ | 100° 38’ 112,799 122,269 148,588 1°16 as L219 96"4<. 992-29! 111,835 121,224 147,317 1°15 es 119° 41’ | 98°20’ 110,872 120,179 146,048 1:14 re TASS Oh OTS LY 109,907 119,134 144,777 1:13 vs 4IGS 20") 296°. 72! 108,943 118,089 143,508 1:12 - 114° 44’| 94° 55’ 107,979 117,044 142,237 1:11 os 113° -.9"|-* 93° 47’ 107,015 115,999 140,968 1:10 a 111° 36") — 92°.48’ 106,051 114,954 139,698 1:09 & 110°. -5! | -.91° 88? 105,087 113,909 138 ,428 1-08 A 108° 36’| 90° 34’ 104,123 112, 864 137,158 1:07 ‘ 107° 8’ | 89° 30’ 103,159 111,819 135,888 1:06 és 105° 42’ 88° 27’ 102,195 110,774 134,618 1°05 ws 104° 16’ | 87° 24’ 101,231 109,729 183,348 1-04 et 102° 53’ | 86° 21’ 100,266 108,684 132,078 1:03 as 101° 30’ | 85° 19’ 99,302 107,639 130,808 1:02 Se 100° 10’ | 84° 18’ 98,338 106,593 129,538 1:01 98° 50’ | 83° 17' 97,374 105,548 128,268 1:00 180° 0’ 97223 | 82° TP 96,410 104,503 126,998 0:99 163° 48’ 96° 12’ | 81° 17’ 95,446 103,458 125,728 0:98 157°: -2’ =| . 94°. 5677 = 80°17’ 94,482 102,413 124,458 0-97 151° 52’ 93° 40’| 79° 18’ 93,518 101,368 123,188 ‘0-96 147° 29' 92° 24'| 78° 20’ 92,554 100,323 121,918 0°95 148° 36’ 919 10% |. 779-22! 91,590 99,278 120,648 0:94 140° 6’ 89° 56’| 76° 24’ 90,625 98, 233 119,378 0°93 136° 52’ 88° 44’| (75° 27° 89,661 97,188 118,108 0:92 133° 51’ 87° 32'| ‘74° 30’ 88,697 96,143 116,838 0:‘91 131° 0’ 86° 20’| 73°. 33’ 87,733 95,098 115,568 0:SO 128° 19° 85° 10’| 72° 36’ 86,769 94,053 114,298 0:89 125° 45’ 8490! 1 7 19-A0! 85,805 93,008 113,028 _ 0°88 || 123° 17’ 82°. 51’} 70° -44’ $4,841 91,963 111,758 ED sty age be a> . Numerical Aperture. (m sin w= a.) APERTURE TABLE—continued. Corresponding Angle (2 w) for Air (n = 1°00). 120° 118° 116° 114° 112° 110° 108° 106° 104° 102° 100° 98° 97° 95° 2 93° 92° 90° 88° 87° 85° 84° 82° 81° 79° 78° 76° 75° 73° 72° 70° 69° 68° 66° 65° € 64° 62° 61° 60° 57° Ao 53° 52° 492, he 44° 42° 40° 39° 37° 34° 32° 30° 28° 27° 25° 23° 55’ 38’ 25’ 17’ 12’ 10’ 10’ 16’ 22’ 26’ | Water (m = 1°33). 81° 42’ 80°. 34’ Homogeneous immersion (m = 1°52). 69° 49° White Light. Line E.) Line F.) 83,877 90,918 82,913 89,873 81,949 88,828 80,984 87,783 80,020 86,738 79,056 85,693 78,092 84,648 77,128 83,603 76,164 82,558 75,200 81,513 74,236 80,468 73,272 79,423 72,308 78,378 71,343 717 333 70,379 76,288 69,415 75,242 68,451 74,197 67,487 73,152 66,523 72,107 65,559 71,062 64,595 70,017 63,631 68,972 62,667 67,927 61,702 66,882 60,738 65,837 59,774 64,792 98,810 63,747 57,846 62,702 56,881 61,657 55,918 60,612 54,954 59,567 53,990 98,522 53,026 57,477 52,061 56,432 51,097 55,387 50,133 54,342 49,169 53, 297 48,205 52, 252 46,277 00, 162 44 349 48,072 43,385 47,026 42,420 45,981 40 , 492 43,891 38,564 41,801 36,636 39,711 34,708 37,621 33,744 36,576 32,779 35, 531 30,851 33,441 28,923 81,351 26,995 29,261 25,067 27,171 24,103 26,126 23,138 25,081 21,210 22,991 19,282 20,901 17,354 18,811 15,426 16,721 14,462 15,676 13,498 14,630 11,570 12,540 9,641 10,450 7,713 8,360 5,785 6,270 4,821 5,225 Monochromatic (Blue) Light. (A = 0°5269 p, | (A = 0°4861 pu, | Photography. (A= 074000 p, near Line h.) 110,488 109,218 107,948 106,678 105,408 104,138 102 , 868 101,598 100,328 99,058 97,788 96,518 95,248 93,979 92,709 91,439 90,169 88,899 87, 629 86,359 85,089 83,819 82,549 81,279 80,009 78,739 17,469 76,199 74,929 73,659 72,389 71,119 69,849 68,579 67,309 66,039 64,769 63,499 60,959 58,419 57,149 55,879 53,339 50,799 48 259 45,719 44449 43,179 40,639 38,099 35,559 33,019 31,749 30,479 27,940 25,400 22,860 20,320 19,050 17,780 15,240 12,700 10,160 7,620 6,350 Limit of Resolving Power, in Lines to an Inch.f Pene- Piiluminating} trating Power, (a®.) ‘757 *740 *723 *706 “689 *672 *656 DAWA PRO WWD NNNNNNNNPNW NH HE HEE Ee Eee eee EP ee ee ee ee et ee ee ee St ee ee eee fea 3 “ D a] Power. (-) 68, CORNHILL, LONDON, E.C. ( 10 ) GREATLY REDUCED PRICES OBJECT-GLASSES MANUFACTURED BY R. & J. BECK, PRICES OF BEST ACHROMATIC OBJECT-GLASSES. No. Focal length. 100 | 4 inches 101 | 8 inches 102 | 3 inches 108 | 2 inches 106 | 2 inch . 107 | 2 inch 108 | 3 inch 109 | +4, inch 110 | +, ine “ 111 | } inch LES) Laneh-3 113 | tinch . 114 | 3, imm. APPLICABLE TO ALL INSTRUMENTS MADE WITH THE UNIVERSAL SorEw. Linear magnifying-power, with ro-inch body-tube and eye-pieces. Angle of aper- Price. ture, about No. 1,| No. 2. 8 Pome Spaih p | 9 110 0 10 16 30 Zz | AB Shs] m/s 10 110 0. 17 | 210 0 } id Pee de Be 23 210 O 30 48 go 2) 2:8 8) el cel oe 45 210 01] 100} 160] 300 65 4 0 O} 125 | 200}| 375 95 5 O O|} 150} 240] 450 75 810 OQ | 200} 320]. 600 120 410 0} 250! 400) 750 130 5 0 O}| 400 |. 640 |. 12900 180 5 5 O|} 500) 800 | 1500 180 8 0.0 | ~750 | 1200 | 2250 180 10 O O |} 1000 | 1600 | 3000 160. | 20 0 O | 2000 | 3200 | 6000 ECONOMIC ACHROMATIC OBJECT-GLASSES, No. 3.|No. 4.| No. 5. LT, No. 150 Focal length. 3 inches 2 inches linch . Zinch .. ¢inch .. Zdinch .. Zinch .. zs 1mm. aper- ture, about Price. Eecigs st i" 4 | co plate, covered over so as to form a box, into which the preparation is slipped. From the front of the plate projects a flat double arm, also of * Queen’s Mier. Bull., v. (1888) p. 5. + Arch. de Physiol., viii. (1886) pp. 271-3 (1 fig.). ZOOLOGY AND BOTANY, MICROSCOPY, ETO. 489 metal. The end of the arm is expanded in order to be more readily heated. The sides of the hot chamber or box are of unequal thickness, the side farthest from the arm being the thicker, in order that the temperature of the side from which the arm projects and that of the opposite side may be about equal. This is shown by putting little pieces of paraffin on the top of the box, for they melt at almost the same time. A thermometer is placed within the chamber to mark the temperature, and this may be made to rise more or less quickly, ac- cording as the expanded end of the arm is more or less heated, and thus the temperature be kept fairly equable. If, however, a constant temperature be necessary, the author advises the use of M. Vignal’s hot stage. The one described, however, is much more simple, and quite suitable for most purposes. The instrument may also be used for cooling down preparations by using methyl chloride on the expansion at the end of the arm. Hallstén’s “ Compressorium.”*—Dr. K. Hiillstén apologetically calls his apparatus a compressorium for want of a better name, for its main use is intended to safeguard the face of the objective from the deposit of vapour while examining the circulation of S the blood, e.g. in the chick. It may, Fig. 79. however, be used as a compressorium for flattening out or exerting equal pressure upon the parts of a specimen. The apparatus (fig. 79) consists of a cylindrical brass tube H, which surrounds the objective and carries the cover-glass D so that watery vapour is prevented from reaching the objective or face of the lens. R is a ring into which the upper end of the brass tube is screwed. This ring is screwed in between the body-tube T' and the objec- tive O. The cover-glass DD is fixed to the lower end of the compressorium tube by an alcoholic shellac solution. When in use the tube can be screwed down so that the cover- glass penetrates within the examining fluid and comes in contact with the blastoderm, and observation is unhindered by the presence of vapour. When the apparatus acts as a compressorium, the action is effected by merely screwing or pushing the tube down upon the object. Hardy’s Growing Slide.—Mr. J. D. Hardy writes :—“ The absolutely necessary qualities of a growing slide are that there should be a perfectly free current, that the water supply should be pure or devoid of any extraneous matter, and that the object should be observable at any time. To carry out these desiderata I use apparatus shown in fig. 80 consisting of the old ‘animalcule box’ of 1} in. in diameter. At the upper part of the raised cylinder a small vertical slit is made half-way down. On the opposite side a hole is drilled in the bottom of the groove which runs round the central glass disc. A hole is drilled in the side of the cap about half-way down, so that when the cap is pressed close down the * Zeitschr. f. Biol., xxii. (1886) pp. 404-7 (1 fig.). 490 SUMMARY OF CURRENT RESEARCHES RELATING TO hole is below the bottom of the slit. The compressor is now inverted, and a bottle or tube, made to fit watertight, and having a small hole in the side at the bottom, is inserted in the well. The hole in the bottle and that in the bottom of the groove are plugged with cotton-wool, either loosely or tight, according as the flow of water is desired. The water flows through the hole in the bottle, and then through that in the bottom of the groove, and so between the glass covers containing the object, passing out through the slit and the hole in the cap. The flow can be so regulated that it may take either a day or an hour to empty the bottle, which will contain about one fluid ounce. The cotton-wool plugs com- pletely stop any foreign substance passing. When observation is re- quired, the bottle being removed, the water will remain in the life-box, or it may be at once rendered watertight by turning the hole in the cap away from the slit.” Schieck’s Microscope Lamps.—Herr J. W. Schieck has devised the lamps shown in figs. 81-4. Fic. 82. The pecularity of the two former (which differ only in their mounting) is the metal shade and reflector, which is shaped as shown in the figs. ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 491 with a condensing lens in the lower end. The two latter have a hinged shade which can be placed in different positions in front of the lens according to the illumination required. Gerlach’s Embryoscope.* —The embryoscope, devised by Dr. L. Gerlach, supplies a great and long-felt desideratum in experimental embryology. It is a mechanism for closing hermetically a circular opening, made with a trepan, in the shell of the hen’s egg; and it serves the purpose of a window, through which the living embryo may be directly observed, and its development followed from day to day. The instrument consists of two parts:—-(1) A mounting-ring to be firmly cemented to the egg-shell. (2) A key-piece with glass front, which screws into the ring and closes it air-tight. Fig. 85 represents the embryoscope in perspective, and fig. 86 in section. ‘The metallic mounting-ring is 1} mm. thick, and has a lumen 2 cm.in diameter, The lower edge Ar is bevelled and saddle-shaped so as to fit the equatorial surface of the egg, while the upper edge is flat. From the outer surface of the ring two square-cornered bars Z project in opposite directions. On its inner surface, a little above the lower edge, is a diaphragm Md with an opening 13 mm. in diameter. Rest- ing upon this diaphragm, and correspoading with it in size and shape, is a second diaphragm of thin wax-cloth Wd, which serves as a packing- washer for the key-piece. The key-piece of the embryoscope consists of a low metallic cylin- der, closed by a disc of glass G, which represents the window that is to cover the artificial opening in the shell. The upper part of the cylinder expands peripherally to form a rim witha milled edge Vs. This rim has two notches E opposite each other, into which fit the arms of a small wrench, by the aid of which the key-piece can be tightly screwed down. * Anat, Anzeig., ii. (1887) p. 583 (2 figs.). 492 SUMMARY OF CURRENT RESEARCHES RELATING TO There is also a short, narrow vertical canal Vo or vont, the lower end of which must open in the middle of the key-piece ring. The accessory apparatus required in the use of the embryoscope consist of (1) a trepan; (2) a guide-ring for the same; (3) a motallic fork ; and (4) the key or wrench before mentioned. Fia. 86. The trepan is a thin metallic cylinder, 2 to 24 em. long, the lower end of which is toothed, while the upper part is fluted and serves as the handle. The diameter of the trepan is a trifle smaller than that of the opening of the diaphragm. The object of this is to leave a very narrow zone of shell, covered with shellac, inside the inner edge of the diaphragm. The guide-ring for the trepan has the same construction as the key- piece, except that it has no glass disc. It serves to steady as well as guide the trepan during the process of cutting. The fork has two notches at the ends of its prongs fitted to receive the two bars of the mounting-ring. When adjusted to the bars, the fork serves as a means of holding the embryoscope securely while screwing or unscrewing the key-piece. The wrench, the use of which has already been explained, is similar in construction to the wrench used for mathematical instruments. The mounting-ring is fastened to the egg by means of a cement con- sisting of two parts of wax and three parts of colophonium. The cement is hard and brittle at the ordinary room-temperature, but becomes soft and kneadable when held in the hand for a few moments. After warming the mounting-ring over a gas or a spirit-lamp, a roll of the softened cement is pressed into the space which must be completely filled between the lower face of the diaphragm and the lower edge of the rmg. As soon as the ring becomes sufficiently cool, it is pressed firmly to the equatorial surface of the egg, and the excess of the still soft cement, which is thus forced outward and inward beneath the ring, ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 493 should be removed before it becomes brittle by the aid of a small, sharp- pointed blade. In order to avoid injuring the blastoderm, which might occur if the hot ring were fastened to the shell directly over it, it is best to fix the ring to the side rather than the top of the egg. After the ring has been securely fixed and the superfluous cement removed, the exposed edges of the remaining cement seen beneath the lower edge of the ring and the inner edge of the diaphragm, must be covered with a coat of an alcoholic solution of yellow shellac. This may be applied with a small brush, care being taken to cover the cement completely, and as little of the egg-shell as possible. After the shellac has dried, a process which is completed in twelve to fourteen hours in the open air and in six hours in the incubator, the shell may be trepanned. Antiseptic precautions are required in opening the egg. An oblong porcelain trough or glass dish is first filled with a 3 per cent. solution of carbolic acid, and in this are placed the instruments to be used in the operation: a glass rod, a medium-sized brush, small shears, forceps, the trepan, and the guide-ring. Before using, these instruments are dried with carbolized cotton, and after using, returned to the dish of carbolic acid. After washing the hands in dilute sublimate, or carbolic acid, a perfectly fresh egg is painted with the 3 per cent. solution of carbolic acid, and then dried with carbolized cotton. The small end of the egg-shell is then cut out with the shears, and the thick white poured with the aid of the glass rod into a clean dish, leaving the yolk and the thinner white in the shell. The white is to be used in screwing in the key-piece, and must therefore always be prepared beforehand. After these preparations, the egg to which the mounting-ring has been cemented is disinfected in the manner above described, and placed in an egg-carrier with the ring uppermost. 'The inside of the ring is then brushed with carbolic acid, which is shaken out after one or two minutes, and replaced by a 1/2 per cent. solution of common salt, which is also allowed to remain from one to two minutes, and then completely removed by means of carbolized cotton. The guide-ring is now screwed in, and the egg trepanned from the side in order to avoid injuring the blastoderm. 'The egg is next placed with its opening upward, and the guide-ring removed. When the trepan is withdrawn, the excised piece of shell often comes with it, and sometimes the underlying shell- membrane. If this is not the case, the two pieces must be removed separately by the aid of the pincers. Care must, of course, be taken not to injure the biastoderm and the zona pellucida. The thin white, which was left with the yolk in the shell, is allowed to flow over the glass rod upon the exposed blastoderm until the ring is filled, care being taken to avoid air-bubbles. The wax-cloth diaphragm is next taken from the dish of carbolic acid, dried in blotting-paper, drawn through the thick white, and inserted in the ring in close contact with the metallic diaphragm, and then the key-piece, previously washed with carbolic acid, and dried with carbolized cotton, is slowly screwed down. The superfluous white is thus slowly forced out through the vent Vo, until the key-piece reaches the diaphragm and closes the vent. Finally, when the strength of the hand is no longer sufficient, the egg with its embryoscope is placed in the metallic fork, and the wrench applied, until with this means it is no longer possible to turn the key-piece farther. 494 SUMMARY OF CURRENT RESEARCHES RELATING TO The process of trepanning and inserting the key-piece is somewhat more complicated in the case of eggs that have already been incubated, as the egg and the fluids employed must be kept warm. A water-bath is required, consisting of a low tin box, filled with water, and provided with covered apartments for the reception of the egg, the thin white, the carbolic acid, and the salt solution, which are in this way maintained at a proper temperature. In other respects, the mode of procedure is exactly the same as given above. The key-piece may be removed as often as desired, provided the above precautions are taken each time in inserting it. If the key-piece is unscrewed by means of the fork and wrench, it must, of course, be washed in the warm carbolic acid, and the vent cleared by the intro- duction of a wire. The egg must be placed in the incubator with the embryoscope on one side. If it is placed upward the respiration of the embryo is hindered. The embryoscope can be turned up at any moment, and kept upright for five minutes at a time without injury to the embryo. With a little practice the whole process of arming an egg with the embryoscope may be completed in from six to eight minutes. The embryoscope is well adapted for purposes of class-demonstra- tion, for investigating the growth of the various parts of the embryo, and the physiological processes during embryonic life, as the action of the heart, movements of the body, &c. It is indispensable to the study of the effects of external agents upon the embryos of warm-blooded animals, and must be of great service where it is required to determine the precise stage of development before removing the embryo from the egg. It has been found useful in studying the formation of double embryos. Fenestrated eggs have been successfully incubated up to the thirteenth day, and it is probable that, under favourable conditions, the embryos of such eggs would reach maturity. On the fifth day it is still easy to bring the embryos under the window. On the sixth and seventh days it is more difficult. At this period the change in the position of the embryo, which requires from five to ten minutes, should take place in the incubator. After the eighth day the embryo cannot be brought under the window. If it be necessary to determine whether such an egg or an older one still lives, we have only to leave the egg for several hours in the incubator with the window directed upwards a little, after which, by strong reflected light, one may readily see the blood circulating through the channels of the vascular area.* Curtis, J. 8.—The Quantitative Determination of Silver by means of the Micro- scope. [Describes a “ micrometer measuring apparatus,” consisting of a Microscope with a vertical and two horizontal cross hairs and a mechanical stage. ] 6th Ann. Rep. U.S. Geol. Survey, 1885, pp. 823-52 (1 pl. and 2 figs.). MataAssez, L.—Sur quelques nouveaux Appareils. II. Hemochromométre perfec- tionné. (On some new apparatus. II. Improved hemochromometer.) Arch. de Piysiol., VIII, (1886) pp. 261-8 (2 figs.). Ney, O.—Magnesiumlampen. (Magnesium lamps.) [The magnesium ribbon is unrolled from a wheel at the back of the apparatus, and there is a patent adjustment for the burner which remoyes the ash by means of a clockwork motion with brushes, rollers, revolving discs, or some such mechanism. Three kinds are figured, one representing the lamp in the form in which it can be used directly with suitable lenses or mirrors for > * Cf. Dr. C. O. Whitman in Amer. Natural., xxii. (1888) pp. 186-90 (2 figs.). ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 495 general purposes of illumination. A second, in which it is shown as applied for projecting microscopic objects, &e.; it is claimed that as an illuminator for this purpose it is far superior to petroleum lamps as being free from smell and from excessive heat, and at the same time more brilliant. The third is a special form for photographic illumination. ] Central-Ztg. f. Optik u. Mech., 1X. (1888) p. 82 (8 figs.). Puurricn, C.—Ein neues Refractometer, besonders zum Gebrauch fiir Chemiker eingerichtet. (A new refractometer, specially intended for the use of chemists.) Zeitschr. f. Instrumentenk., VIII. (1888) pp. 47-53 (2 figs.). SpirertT.—UVeber das Auer’sche Gasgliihlicht. (On the Auer incandescent gas burner.) [Recommendation of the Auer von Welsbach light (known in England as the Welsbach) for microscopical observations, examination of the nose, ear, &c.] SB. Physik,-Med. Gesell, Wiirzburg, 1887, pp. 11-3. (4) Photomicrography. Cross, C. F., E. J. Bevan, C. M. Kine, E. Joynson, and G. WatTt.—Report on Indian Fibres and Fibrous Substances exhibited at the Colonial and Indian Exhibition, 1886. [Contains a description of the photomicrographic apparatus and the method of working, pp. 13-6, 1 fig.] viii. and 71 pp., 5 pls. of photomicr., 8vo, London, 1887. {Manton, W. P., and others. ]|—Photomicrography. [Urging that the “ helpful devices and methods” of workers should be “ written up and published for the general good, and not held secret for individual benefit.” | The Microscope, VIII. (1888) p. 89. NeE.Lson, E. M.—On the Formation of Diatom Structure. {In exhibiting some photomicrographic positives of diatoms, Mr. Nelson said, “I believe we are on the verge of a new departure in the field of micro- scopical work, viz. illustration by means of lantern pictures from photo- micrographic positives.’ | Journ. Quek. Micr. Civb, IIL. (1888) pp. 201-2 (1 pl. of photomicr.). (5) Microscopical Optics and Manipulation. Learning to see with the Microscope.*—Mr. E. B. Poulton, in a review of the new edition of Huxley and Martin’s ‘ Course of Elemen- tary Instruction in Practical Biology, writes on this subject as follows :— “The most striking thing in the revised form of ‘ Practical Biology’ is the reversal of the old arrangement, so that the student is now led to begin with a vertebrate type, and from this to work his way down to the lowest forms of life, and from these again upwards to a type of the flowering plants. There is little doubt that such a change will be met by conflicting criticisms. I believe, however, that the majority of those who have had the widest experience of biological teaching, and espe- cially those who have instructed students in the first use of the Micro- scope, will heartily agree with Prof. Huxley’s defence of the alteration in the preface to the revised edition. “The process by which the student first learns to see with the Microscope is almost like the education of a new sense-organ suddenly conferred upon a mature organism. We know that under such circum- stances it would be a very long time before the impressions conveyed by the new organ could be harmonized with the well-known experiences resulting from the stimulation of other organs. Accustomed to judge of the shapes of objects by their appearance in three dimensions, the student is suddenly provided with a field of vision in which shapes have * Nature, xxxviil. (1888) pp. 505-6. 496 SUMMARY OF OURRENT RESEARCHES RELATING TO to be nearly always inferred from the appearance of solid three-dimen- sioned objects when seen under conditions which prevent them from being examined in more than two dimensions at any one time. For it is a long time before the student can accustom himself, by focusing at suc- cessive depths, and by making the most of the limited third dimensions of depth which the high powers of the Microscope provide, to judge accurately of the forms of objects. And the novel conditions under which a student sees with a Microscope effectually prevent him from making the best of the impressions he receives. Thus, if the section of a solid object presented the appearance of a circle 1 inch in diameter, and if two other sections at right angles to each other and to the first section presented the appearance of a rectangular figure 3 feet by 1 inch, nearly every one would readily infer that the shape was that of a cylinder 3 feet long by 1 inch in diameter. But precisely similar data when presented in the field of the Microscope, do not readily lead the student to any definite conclusions as to the forms of objects, and in reality a long course of discipline is necessary in order to make him form any clear conception of the actual shape of the object at which he is lcoking. “‘T therefore think that it is expedient to begin the course of biologi- cal teaching with organisms which only require the use of a Microscope for the investigation of part of their structure, and thus to gradually work downwards to the minutest organisms, in which the whole investi- gation depends upon high microscopic powers. Thus the gradual training in the use. of the Microscope will proceed parallel with its gradually increasing necessity.” Cover-correction.—Herr C. Reichert considers* that the “im- portance of ‘ cover-correction’ by means of a screw collar is not so great as it once was, because, in the first place, it is now possible to readily obtain cover-glasses of a definite thickness, and, in the next place, because all good Microscopes are now provided with a draw-tube. In all high-class instruments, the draw-tube forms an important part, and is less intended to increase the magnification than to correct for the difference in the thickness of the cover-glasses. By means of varying the length of the tube, we are able to produce an effect upon the image similar to that which is the result of making the back lenses approach or recede from the front lenses of the objective. The effect due to varying the tube-length is noticeable in an objective such as No. 5, which has a focal length of about 1/16 in., and is more marked as the power of the objective increases. For example, if an objective having a focal distance of about 1/10 in. be corrected for a cover-glass 0:17 mm. thick, when the tube is half drawn out, it may, by shortening the tube, be made suitable for cover-glasses having a thickness of 0:25 mm. to 0°30 mm.; and if the tube be fully drawn out, the objective will then be suitable for cover-glasses from 0°14 to 9°12 mm. “ Those commencing microscopical studies should make themselves familiar with the influence exerted by the varying length of the tube, and this may conveniently be done by studying a delicate test-object, such as Pleurosigma angulatum, when the tube is extended or shortened in the manner already described.” * Reichert, C., ‘Directions for using the Microscope,’ translated by A. Frazer. 8vo, Edinburgh, 1887, 12 pp. (2 figs.). ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 497 On this point we will observe that the student will find his range of experience much increased by varying the position of the mirror so as to make the illumination more or less oblique. The differences between the positions of the draw-tube required to obtain the more perfect definition will thus be much more plainly appreciable by the untrained eye, and he will thus learn to discriminate at a glance when he is obtaining the best images his objectives will produce. Further, this method of practice should also be adopted in con- junction with the correction-collar of the objective, which should be turned slowly from end to end of its range in one direction, and then ir the other whilst following the varying focus by the other hand on the fine-adjustment. The eye and the hand will thus be trained to the skilful employment of the Microscope, a matter which has been far too much neglected hitherto. It is a subject of common observation by opticians that the great majority of Microscopists have no practical training in the use of a , correction-adjustment in improving the quality of the image under varying conditions of the illumination and with different thicknesses of cover-glass. Through neglect of such points the student drifts into regarding the correction-adjustment as useless ; hence, he too frequently contents himself with mediocre definition, when his Microscope is capable of superior work if only properly handled. Adjusting an Objective for the Thickness of the Cover-glass.— In a description of their “ National” Microscope, Messrs. R. and J. Beck give directions for adjusting an objective, which are conveniently arranged Fic. 87. fe ru oe mali i hath i re rt i oe a : curtx hsascesenpca te et nt e4 YER I este 5 OE . ~y RAITT EG “| CARS Cote mere it Sigs Wy ala for the use of the student microscopist, and with these they give the following figures showing the appearance of a Podura scale when (fig. 87) 1888. 2M 498 SUMMARY OF CURRENT RESEARCHES RELATING TO the adjustment of the object-glass is correct ; the effect (fig. 88) produced on each side of the exact focus; and the way (fig. 89) in which the markings individually divide when all the adjustments are correct, and when the focus is altered the least possible amount only each way. Figs. 90 and 91 show the two appearances on one and the other side of the best focus when the adjustment is incorrect; fig. 92 showing the appearance of the same at its best focus. Villi on the Scales of Butterflies and Moths.—Dr. G. W. Royston- Pigott considers * that the resolution of these difficult objects is a capi- tal introduction to the study of the minute structure of discase germs, and he can consequently strongly commend it to the attention of micro- scopists who have neglected this department of natural history. Many of the villi in butterfly and moth scales are pawn-shaped, possessing a base and a spherical summit. This form was the first one discovered, with exceeding difficulty, on the scales of the Red Admiral butterfly. The scales of Amathusia Horsfeldii gave clearer indications, but their extreme delicacy permits of no pressure being applied, as it fluttens and distorts them. After seven years’ prosecution of the re- search he was rewarded with finding an entirely new vein, which has proved very rich in material, in moths of the Zygena tribe. Occasion- ally they are seen to lie flat upon the basic membrane, and to be con- nected by cross ramifications, interlacing in an extraordinary manner. At other times the bases of the villi are ciliated, forming reticulations, resembling ancient hieroglyphics or archaic writing. Their thickness varies from 1/60,000 to 1/120,000 in., and their length is sometimes prodigious. The villi principally observed at present take the following forms :— i. Beaded villi; ii. Embossed villi; iii. Pillar villi; iv. Ciliated villi; v. Connected villi; vi. Banana or Bunched villi; vii. Spinous villi; and viii. Tall villi. Out of about 400 preparations (dry mounts) of scales obtained from all parts of the world, the author selects a few which with good object- glasses give, he considers, some startling results. Only a brief abstract is, however, given of the appearances. Mr. T. F. Smith considers ¢ that some of the appearances described in the paper are due to the villi being seen out of focus. In his view they are in between the two membranes of which the scales are com- posed, their use being to keep the two surfaces of the scale-apart, and they are longer or shorter according to whether the surfaces are more or less rounded. He had seen some of the appearances, but only by taking too deep a focus. ‘As for the beading, he had never seen it, and he was strongly inclined to the belief that it arose from Dr. Pigott’s methods being in some way at fault. He believed from what he had read that Dr. Pigott worked with a very small aperture, and if any one wanted to produce false appearances they could not go a better way to work ; by using the lowest aperture of the condenser the same effects could be produced. With regard to Dr. Pigott’s test rings, he knew that appearance perfectly well; but it was again a false effect due to the results of using too small an aperture.” Mr. Smith also shows t that “some very respectable beads” may be * Journ. Quek. Micr. Club, iii. (1888) pp. 205-7. + Ibid., pp. 234-5. t Ibid., p. 204. ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 499 developed by using the smallest aperture of the condenser, but that they instantly vanish when the light is restored. There can be very little doubt that Mr. Smith is right in his criti- cism, and that it is Dr. Pigott’s defective methods of manipulation that have led him astray in this matter. New Appearances in Podura Scale.*—Mr. T. F. Smith calls atten- tion to what he considers to be a new appearance of the Podura scale not yet recorded. In place of the optician’s appearance of the scale, with the exclamation marks, blue or red, according to the corrections of the glass, and with a light streak in the middle, more or less extended as the aperture is larger or smaller, the usual markings had vanished, and in their stead “the whole scale was studded with very slender spines with round heads, and the pointed ends stuck into the scale like a lot of pins stuck loosely and anyhow into a paper, and instead of being blue or red were a pure white.” At first he thought there were two sides to the scale, and that this was the wrong one, but he found that the scale was tight against the cover, and that all the scales so placed had the same appearance. Since then he has examined many scales on several slides, and is “now strongly of opinion that the note of exclamation markings are spurious, and that the light streak is the true appearance, which has hitherto been seen with the darker outline on each from taking too deep a focus. It is a well-known fact that an oil-immersion objective works only with its full aperture when an object mounted dry is well on the cover, and this in itself should be sufficient evidence that the appearance the object presents, under these circumstances, is the truer one. Then, again, the pin-like looking spines are not more than half the diameter of the exclamation marks, and the image is always at its smallest when in focus; never larger.” Another fact which guides the author in his estimation of the structure is the observation of a hair with small pro- jecting spines. ‘‘ Here was structure of which there could be no doubt, and the same point of the correction-collar that gave the sharpest image of this hair gave also the sharpest image of the spines on the scale. Still another proof. To bring the note of exclamation marks out well requires a deal of management of the light, and they are best seen with the smallest apertures of the condenser; but no amount of light will obliterate the new ones or prevent them from standing out sharply from the general blaze.” “New Glass just made in Sweden.”—We have received from a con- siderable number of correspondents cuttings from various newspapers describing this “new glass.” As will be seen it is a revival of the paragraphs to which we called attention in the last volume of this Journal, pp. 155 and 321. What is the cause of this recrudescence we do not at all know, but it has apparently been disseminated all over England, as our cuttings come from London papers, local country papers, religious papers, &ce. The paragraphs are the most outrageous piece of rubbish ever pub- lished, and while of course editors can’t be expected to know everything, they might surely get to know enough to avoid putting in such asinine statements as these. “Perhaps the most wonderful thing that has been discovered of late * Journ. Quek. Mier. Club, iii. (1888) pp. 203-4. 2m 2 500 SUMMARY OF CURRENT RESEARCHES RELATING TO is the new glass which hast just been made in Sweden. The revolution ‘ which this new refractor is destined to make is almost inconceivable, if it is true, as is positively alleged, that, while the highest power of an old-fashioned microscopic lens reveals only the one four-hundred- thousandth part of an inch, this new glass will enable us to distinguish one two-hundred-and-four-million-seven-hundred-thousandth part of an mens 7 “« A new kind of glass, which is to revolutionize scientific investiga- tion, has been invented in Sweden. Ordinary glass is composed of six ingredients, but this compound contains no less than fourteen, chief among the new substances employed being phosphorus and boron. For microscopic purposes the power claimed for this Swedish glass is almost incredible. One 400,000th of an inch can be distinguished by the strongest lens at present, but the new glass will, it is said, reveal the 204,700,000th part of an inch. If the Swedish invention at all ap- proaches what is promised for it, its importance can hardly be exagger- ated, but the very moderate performance of the so-called ‘ unbreakable glass’ invented a few years ago, may warn us to be somewhat sceptical in regard to new wonders in the way of glass.” T Curiosities of the Senses. [‘‘ According to a memoir communicated to the Biological Society of Paris by M. Mathias Duval, and reported in the Siecle, it is not advantageous when looking through a telescope with one eye to close the other, but rather the contrary. We have not succeeded in verifying this observation with the Microscope.” } Scientif. News, I. (1888) p. 372. Cz[apsKk1i, S.]—Bemerkungen iiber Prof. Abbe’s Abhandlung: Die Vergrésserung einer Linse oder eines Linsensystems. (Remarks on Prot. Abbe’s paper: The magnifying power of a lens or a lens-system.) [Criticism of the papers of Prof. Abbe and Prof. Giltay in this Journal, 1884, p. 348, and 1885, p. 960. “For practical microscopists to adopt Abbe’s definition for ordinary use seems to me not only purposeless, but at no time desirable. On the other hand, for scientific purposes in theoretical discussions relating to the magnifying power of an optical apparatus, the stricter definition of Abbe will be of value; and even in Giltay’s point of view, the number which represents the magnifying power is subjective, and applies only to an eye which sees an object best at the distance of 25 cm., but is different for another length of vision. The arbitrary character of the measure which Giltay raises as an objection to Abbe cannot be supported as an argument against his definition, for it is common to all magnitudes expressed in so-called absolute units. ] Zeitschr. f. Instrumentenk., VIII. (1888) pp. 104-5. D., M. T.—Microscopical Drawings. [Device for drawing with the Microscope :—“ Take a small portion of the silvering from the back of a mirror, about 1/16 in. in diameter (there must be a thick coating of paint on the back of the amalgam to support it, or it will not break off). This small reflector is to be mounted with cement on the edge of a piece of watch-spring at the proper angle. ‘The spring is bent round and fixed to a brass tube fitting over the eye-piece, so that the reflector stands about 1/4 in. from the eye-lens and central with it. On looking into it the object on the stage of the Microscope is seen, and appears to be pro- jected on to the paper spread below. I believe that steel mirrors are used for the same purpose; but the amalgam has a very good surface, costs nothing, and can be renewed in a very short time, It is better than the ‘neutral glass plate,’ ”’] Engl. Mech., XLVI. (1888) p. 170. * Essex local paper. + Christian World, 1888, April 19. ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 501 Hopexinson, A.—On the Diffraction of Microscopic Objects in Relation to the Resolving Power of Objectives. Proc. Manch. Lit. and Phil. Soc., XX V. (1886) pp. 263-7 (5 figs.) and pp. 223 and 271-2. J Ames, F. L.—Nobert’s Bands. St. Lowis Med. and Surg. Journ., LIV. (1888) pp. 166-7. L., A. S.—Powers of Eye-pieces. [Table of the powers of the eye-pieces of different makers as deduced from the total magnification with the 1 in. objective.”’] Engl. Mech., XUVII. (1888) p. 146. Quxren, J. W.—Apparent and Actual Size of Field, Magnifying Power, &c. Queen’s Micr, Bulletin, V. (1888) pp. 1-2. 5 $ General Hints on the use and care of the Microscope. The Microscope, VIII. (1888) pp. 4-5. Royston-Picort, G. W.—Microscopical Advances. XXXV., XXXVI. [Researches in High Power Definition. Interference lines, circles, and dots. Attenuated lines, circles and dots. ] Engl. Mech., XLVIL. (1888) pp. 187 (2 figs.), 226-7 (2 figs.). Wiener, O.—[Measuring Thin Films.] (In an exhaustive paper upon methods of measuring thin films, Otto Wiener makes certain measurements of the thickness of a film of silver which can just be perceived by the eye, and arrives at the conclusion that 0°2 millionths of a millimetre is an upper limit of the diameter of a silver molecule.” } The Microscope, VIII. (1888) p. 93, from Scientific American. Zecu, P.—Elementare Behandlung von Linsensystemen. (Elementary treatment of lens-systems.) 8vo, Tiibingen, 1887. (6) Miscellaneous. Heather’s ‘Mathematical Instruments.’—It is really a disgrace to all concerned—publishers and editor—that this book with a title-page of 1888,* should have been published. It is inconceivable that any intelligent grown-up person should not have known that the extracts we print below are an anachronism in this year 1888 or even in the year 1848. Imagine, for instance, describing any Microscope of this date as having the “ amplifying lens” of the old makers. “The compound or achromatic Microscope consists of four lenses and a diaphragm, placed in the following order: the object-lens, the diaphragm, the amplifying lens, so-called because it amplifies or enlarges the field of view, the field-lens, and the eye-lens. The relations between the focal lengths and intervals of the lenses, and the distance of the diaphragm from the object-lenses are determined so that the combination may be achromatic, aplanatic, and free from spherical con- fusion. The field-lens and eye-lens form what is called the eye-piece, and the object-lens and amplifying-lens form, or tend to form, an enlarged image of the object in the focus of the eye-piece, which image is viewed through the eye-piece” (p. 79). The following paragraph is also deserving of note :— “The best Microscopes are constructed with compound object-lenses, which are both achromatic and aplanatic, and by this means the aperture, and consequently the quantity of light, is much increased. Good compound lenses possessing the required properties have been formed of a concave lens of flint glass placed between two convex lenses, one of crown glass and the other of Dutch plate” (p. 79). * Heather, J. F., ‘A Treatise on Mathematical Instruments, their construction, adjustment, testing, and use concisely explained.’ 14th ed., revised, with additions by A. T. Walmisley. 8vo, London, 1888. 502 SUMMARY OF CURRENT RESEARCHES RELATING TO The above is followed by a whole page on “the Reflecting Micro- scope,’ no such a Microscope having been made certainly since 1840. Micromillimetre.*-—Prof. A. W. Riicker observing that the word micromillimetre is used as equivalent to the thousandth of a millimetre, and being told that it is now commonly employed by biologists, and especially by botanists, with that meaning, protests against such a use of the word. As he thinks it would be very unfortunate if the same word were habitually used in different senses by students of different branches of science, he points out that, according to the definitions of the C.G.S. system, a micromillimetre is the millionth of a millimetre. In the well-known report of the Committee of the British Association for the “Selection and Nomenclature of Dynamical and Electrical Units,” it is laid down that the prefixes mega and micro are to be em- ployed “for multiplication and division by a million.” ‘This ruling has been generally accepted not only by scientific men, but also by those engaged in commerce. Megohm and microfarad are terms which are used in contracts, and are universally understood to mean a million ohms and a millionth of a farad respectively. It will be hopeless, he thinks, to try to introduce scientific systems of measurement into the affairs of daily life if scientific men themselves disregard the rules on which those systems are framed. It would also, in his view, be particularly confusing if the micro- millimetre were wrongly used by microscopists. In its proper sense it is the most convenient unit in which to express molecular magnitudes. It has been employed for that purpose by Sir William Thomson and others in England, and also by physicists abroad. If the micromillimetre of the microscopist is 1000 times too large, all sorts of mistakes will be rife as to the relative dimensions of molecules and of the smallest objects visible with the Microscope. The proper name for the thousandth of a millimetre (j) is, in his view, the micrométre, and though the similarity of this word to microméter is no doubt a drawback, it is not likely that confusion could often arise between them. He therefore begs respectfully to suggest that botanists should bring their nomenclature of units of length into conformity with the definitions of the C.G.S. system. Otherwise there will be a permanent confusion between the micrometre (w) and the micromillimetre (yp). On the other hand, Mr. H. J. Chaney suggests t “that even the de- nomination ‘micrométre’ may be hardly acceptable to scientific workers. The denomination for the measure of the one-thousandth of a millimetre (4), or 0°000001 metre, is ‘micron,’ and not ‘ micrometre.’ “ For the ‘micron’ we have the authority of the ‘ Comité International des Poids et Mesures.’ One shudders at the thought of the confusion likely to arise when computers are required to deal with both micro- metre-units and microméter-divisions. “The Comité International have also recommended the use of the following metric denominations for minute measurements :— Denomination. Symbol. Equivalent. Micron aces ee = | O00 millimetre: Microgramme .. y . .. 0:°001 milligramme. Milliitre .. .. amlo:. . “OrgOl iitre: Microlitre 2s. ~.. ~Av .. +. 0000001 (htre.* * Nature, xxxvil. (1888) pp. 388-9. + Ibid., p. 488. ZOOLOGY AND BOTANY, MICROSCOPY, ETO. 503 Mr. A. D’Abbadie also writes* to say that “here” (presumably Paris), micron is currently used to express the 1/1000 mm.; while Mr. R. B. Hayward proposes f a new nomenclature which would convert the micro-millimetre into a “ hexametret.” The Council of the Society having considered the question raised by Prof. Riicker, decided, as announced at the April Meeting, that the term micron should in future be used in this Journal and in the official pro- ceedings of the Society, in place of micro-millimetre. It was felt that the term micrometre from its similarity to micrometer (especially in French) was unsuitable. American Society of Microscopists—Columbus, Ohio, Meeting, 1888. The Microscope, VIII. (1888) pp. 117-8. Bonn, G. M. (Kditor).—Standards of Length and their practical application. A résumé covering the methods employed for the production of standard gauges to insure uniformity and interchangeability in every department of manufactures, including the reports of Prof. W. A. Rogers; the Committee on Standards and Gauges, American Society of Mechanical Engineers; the Committee of the Master Car-Builders’ Association; and including also the Report of the Special Committee appointed by the Franklin Institute, April 1864. [Describes and figures the Rogers-Bond Universal Comparator. ] iv. and 180 pp. and 31 figs., 8vo, Hartford, Conn., U.S.A., 1887. Calcutta Microscopical Society. The Microscope, VIIL. (1888) pp. 89-90. DaLLinGcerR, W. H.—Least and simplest forms of Life. (Three lectures at the Royal Institution. | Scientif. News, I. (1888) pp. 282, 306, 378. East London Microscopical Society. [Report of meeting. ] Engl. Mech., XLVII. (1888) p. 142. Micuaer., A. D.—Parasitism. [Presidential Address.to Quekett Microscopical Club. ] Journ. Quek. Micr, Club, III. (1888) pp. 208-24. M‘Intrire, S. J.—The Quekett Microscopical Club. [Report on soirée of 9th March. ] Sci.-Gossip, 1888, p. 92. Postal Microscopical Society. [Suggestion for the formation of “ circles” for “ work either of a general or a specific character.” Journ, of Micr., I. (1888) pp. 118-20. QuimsBy, B. F.—[Widening the Scope of Microscopical Societies. ] The Microscope, VIII. (1888) pp. 125-6. ScuroperR, H.—Aufforderung der Griindung eines Instituts, um die grossen Ent- deckungen der neuesten Zeit in der Astronomie, Astrophysik, Optik und Mikroskopie Allen zuganglich zu machen. (Suggestion for the establishment of an Institute to make accessible to all the great discoveries of recent times in Astronomy, Astronomical Physics, Optics, and Microscopy.) Central-Ztg. f. Optik u. Mech., 1X. (1888) pp. 85-9 (5 figs.). 8B. Technique.t{ (1) Collecting Objects, including Culture Processes. Alkaline Egg-albumen as a Medium for Bacteria Cultivation.§ — Dr. J. Tarchanoff and Dr. Kolessnikoff find that if hens’ eggs with their shells be placed in 5 to 10 per cent. solution of hydrate of potash for * Nature, xxxvii. (1888) p. 438. t Ibid., pp. 437-8. ¢ This subdivision contains (1) Collecting Objects, including Culture Pro- cesses; (2) Preparing Objects; (3) Cutting, including Imbedding and Microtomes; (4) Staining and Injecting; (5) Mounting, including slides, preservative fluids, &c.; (6) Miscellaneous. § Russkaja Medicina, No. 11, 1887, p. 191. Cf. Zeitschr. f. Wiss. Mikr., iv. (1887) pp. 405-6. 504 SUMMARY OF CURRENT RESEARCHES RELATING TO from four to fourteen days, the albumen undergoes a change of consist- ence. By the fourth day it is fluid and transparent; from the fifth to the fourteenth it is transparent but firm, gelatinous and yellowish. Both modifications can be produced in a steam sterilizer either alone or in combination with gelatin (3 to 10 per cent. half-fluid) or agar agar (1 per cent. firm). For testing the utility of this medium for cultivation purposes the author’s three combinations of alkali albuminate were (1) Bouillon albuminate: Albumen of eggs having lain four days in 10 per cent. KHO solution, and water added to make a 10 per cent. solution which was steam sterilized in the usual way for three days, and then put in test-tubes or Pasteur’s “ Matras” and again sterilized. (2) Syrup alkali albuminate: Albumen having been four days in KHO was diluted one- half with water, placed in test-tubes, and sterilized in the usual way. (3) Firm albuminate (a) Sterilized: Half-fluid albumen of four days’ standing was poured in test-tubes and steam sterilized at 105° for some minutes to one hour on one or three days. It resuited that albumen after fifteen minutes’ sterilization became opalescent-whitish, but was always transparent. On repeated or protracted sterilization it hardened and became of a yellowish-orange colour. (b) Unsterilized: Hard transparent hen’s egg albumen of fourteen days’ standing in 10 per cent. KHO was cut up into thin plates and treated like potato cultivations. On these three media various bacteria were sown. Bacillus anthracis grew very well on the bouillon albuminate; on No. 2 and 3 it was slower in starting. The cultivations were all pathogenic. Spirochzte cholere asiatice and Prior-Finkler grew just as well as on their ordinary media. Although the latter fluidified No. 2 and No. 3 albuminates, the colonies were not characteristic. Bacillus tuberculosis and Mallei grew well, as did also Bacillus subtilis, prodigiosus, Micrococcus ruber Fliigge, Sarcina flava, and orange. The authors lay stress on the simplicity of the production, the transparency and the cultural utility of this new medium for the most different kinds of bacteria. They anticipate that it will eventually supplant the ordinary gelatin, agar, and serum media. Fatty Matters in Cultivation Media.*—Sig. L. Manfredi reports his experiments with cultivation media containing fatty matters. The results were that whenever the fatty constituent (as in broths) reached one-third of the total amount, the bacillus of anthrax failed to thrive, and that when it passed that proportion, the cultivation became exceedingly feeble, totally ceasing before two-thirds was reached. This is given as a matter of precaution to those who experiment with fatty broths, &c. It has, however, a value beyond this, viz. that with the decreasing vitality of the specific microbes, their virus is attenuated, and that, consequently, by using a certain amount of fatty matter in the pure cultures, the virus may be correspondingly attenuated. Collecting Microscopic Algz. [Take waxed paper (from cakes of soap, &e.), and punch holes slightly smaller than the largest covers; then wrap the paper about the slides in such a way as to bring the holes in the middle on each slide. On suspending the slides good mounts can be obtained. Surround it with a ring, place on another slip or coyer-glass, and it is ready for observation.’ ] Scientif. Enquirer, IL. (1888) p. 68. * St. Louis Med. and Surg. Journ., liv. (1888) p. 97, from Giorn. Internat. ZOOLOGY AND BOTANY, MICROSCOPY, ETO. 505 Eyre&, J.—Pond Dredging and Collecting. [For more delicate work or for use in ponds, &e., comparatively free from weeds, a large-sized test-tube might be substituted for the bottle, and should be fastened to a short thin length of bamboo as follows :— Take a 6 in. length of caoutchoue tubing, and make a cross cut three-quarters through, at about an inch from one end; then another at right angles to the first along the other 5 inches; the result is a short piece of tube with a 5 in. slip of gutta- percha. The tube is slipped over the end of the rod, and the free end of the flap is pushed between the rod and the tubing, the test-tube placed in the loop so formed, and the strip drawn tight and fastened off.’’] Sci.-Gossip, 1888, p. 69. RovussELet, C.—Pond Dredging and Collecting. [Hints on collecting Infusoria, Rotifera, and Polyzoa, the result of my expe- rience in this interesting pursuit.’’] Sci.-Gossip, 1888, pp. 54-5. (2) Preparing Objects. Demonstrating Nuclein and Plastin.*—Dr. H. Zacharias in discuss- ing the properties and mode of origin of nuclein and plastin, remarks that both substances are undissolved when the cells are treated with artificial gastric juice. Under the action of gastric juice, or of 0:2-0°3 per cent. hydrochloric acid, parts containing nuclein present a sharply defined appearance, while bodies which contain plastin but no tiuclein swell up and grow pale. Nuclein swells up in 10 per cent. salt solution, in solution of soda and in dilute caustic potash. Plastin, on the contrary, does not swell up in 10 per cent. salt solution, and is only soluble with difficulty in alkalies. Both are soluble in concentrated hydrochloric acid, but in a mixture of 4 vols. HCl to 3 vols. H,O the nuclein only dis- appears. When fresh, bodies containing nuclein swell up in distilled water. Long preservation in spirit is detrimental to these reactions. Nuclein takes up pigments with avidity, but this property is in no way confined to parts containing nuclein. All the cell protoplasm becomes stained by the prolonged action of pigment. It cannot therefore be con- cluded that nuclein is present because the nucleus becomes stained, but if it do not, it may be inferred that it is absent or present in smal] quantity. Substances with the foregoing properties have hitherto only been demonstrated in the cell-nuclei; plastin, on the other hand, is a con- stituent of the whole cell-plasma. The existence of nuclein in bottom yeast, in Phycochromacez, milk, and yolk-corpuscles of animal ova appears to clash with the former statement. In the two last cases the substance in question differs in its reactions from nuclein. The author found it both in germinating and in bottom yeast. By extracting germinating yeast with ether alcohol, then soaking in water, and staining with Grenacher’s hematoxylin, the cell-nuclei are rendered evident. The action of the digestion-fluid failed to demonstrate the nucleus ; but in bottom yeast the nucleus was found to contain nuclein. Bottom yeast extracted with alcohol ether, digested, and then placed in a 0°3 per cent. salt solution for 24 hours, showed in the bright swollen-up plasma residue corpuscles of irregular shape, and with the characteristic bright- ness of nuclein, By adding pure strong hydrochlorie acid the corpuscles lose the brightness, the plasma becomes clearer, and then disappears along with the corpuscles. A 10 per cent. salt solution acting on digested material which has been extracted with alcohol-ether causes the corpuscles to swell up while the rest of the plasma remains well defined * Bot. Ztg., xlv. (1887) pp. 282-8, 297-304, 313-9, 329-37, 345-56, 361-72, 377-88 (1 pl.). 506 SUMMARY OF CURRENT RESEARCHES RELATING TO and unswollen. In Phycochromaces the nucleus was demonstrated in Tolypothriz, ZBgagropila, and Oscillaria sp.; it was best shown by digesting the fresh filament, then extracting with ether-alcohol and examining in a 0°38 per cent. salt solution. The author also treats of the resting and active condition of the nucleus, and the cells taking part in reproduction. Preparation of Nerve-cells and Peripheral Ganglia.*—Anna Kot- larewsky employed in her researches on the spinal ganglia, and on the Gasserian ganglion four different hardening methods. (1) Hardening in acids: 8 per cent. nitric acid; half per cent. chromic acid; 1 per cent. osmic acid; 1 per cent. picric acid, and Flemming’s mixture. The preparations were imbedded in celloidin, or paraffin. Next to freshly examined cells, the picric acid was found to produce the best effect. Flemming’s mixture had an unfavourable action on the shape of the cells. In all the preparations hardened in acids, the outline of the cells was sharp; the cell-body took stains well, but the nucleus only slightly, though the nucleoli were well coloured. (2) Hardening in acid salts (Miiller’s solution). (8) Hardening in neutral media (neutral acetate of lead and spirit): Cells inthe preparations treated with 10 per cent. solution of acetate of lead showed excellent fixation ; hardening in spirit was less favourable. (4) Hardening in alkaline media: Basie acetate of lead and ammoniacal chloride of silver (1 per cent.) were used. Both solutions penetrated only slowly, so that the superficial layers could be used. The depth to which the hardening medium had pene- trated was determined by treating the sections with hydric sulphide or bichromate of potash. The hardened objects were variously stained. (1) With metals: Osmice acid used for preparations hardened in Miiller’s fluid effected no remarkable differentiation of the nervous elements. After-treatment with ammoniacal silver solution (reduction being effected in an incu- bator) gave a better result. In this way good pictures were obtained in 24 hours ; the preparations, however, did not keep. (2) With nuclear stains: these affected the bodies of the nerve-cells more than the nuclei, the corpuscles in the latter behaving in a way similar to the cell-body. Gentian-violet and hematoxylin stained the granula of the body of the cell ; carmine in neutral solution did not. Merkel’s staining method gave favourable results for differentiating the chromophilous and chromo- phobous cells. (3) Dyes were used which do not stain the nucleus; eosin, fuchsin, nigrosin. Of these, nigrosin produced in the lead pre- parations interesting pictures, the dye having stained the protoplasm, a reticulated appearance was imparted to the cell-body. In the lead preparations, eosin stained the nucleus pretty dark, and the cell-body of the nerve-cells diffusely. Methylen-blue was examined by dissolving it in 0-7 per cent. salt solution, and injecting it into the spinal lymph-sac or abdominal cavity of a frog. Some time after the injection the ganglia were removed as quickly as possible, and examined in salt solution or glycerin. The cells were stained in about one or two hours. Methemoglobin Crystals.t—According to Dr. W. D. Halliburton the following is an easy way to obtain these crystals :-— Defibrinate a few cubic centimetres of the blood of a rat, guinea-pig, * MT. Naturf. Gesell. Bern, 1887, pp. 3-23. + St. Louis Med. and Surg. Journ., liv. (1888) p. 96. ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 507 or squirrel, and add to it a few drops of amy] nitrite and shake violently for a minute or two, or until the nitrite assumes a chocolate colour. A drop of this is withdrawn with a pipette, and placed on a slide, the cover-glass being applied immediately. In a few moments the methe- moglobin crystals will begin to form. By sealing the edge of the cover- glass, the crystals will remain unchanged a very long time. Preparation of Brains and other Organs.*—Prof. M. Flesch pre- pares brains for permanent preservation in the dry condition in the following simple manner :— After having been hardened in spirit, the preparations are first placed in a mixture of equal parts of glycerin, alcohol, and water, and afterwards into pure glycerin. To both fluids sublimate is added in the proportion of 1 to 3000. Bone and cartilage may, without previous hardening, be placed in the first solution and then changed to the second. The time of the treatment depends on the size of the object. A human brain should lie about four weeks in spirit (if placed upon cotton-wool 10-12 cm. thick, it is not necessary to change the spirit, nor to turn the brain so often), then for three weeks in each of the two solutions. The rest of the treatment consists in removing the super- fluous glycerin by placing the specimens to drain upon a layer of blotting-paper supported on cotton-wool, and they are finally put up in a similar way and covered over with a glass-topped cardboard case. The cost of the method is small, since both solutions can be used repeatedly. Preparing Radule of small species of Gastropoda.j—Mr. C. HE. Beecher kills the organisms by boiling or immersion in alcohol, and then extracts the animals from their shells by drawing them out with a mounted needle or hook, and, in the larger species the head is cut off and the remainder of the animal rejected. In the minute species the shell may be removed with hydrochloric acid. Hither process may be employed upou shells which contain the dried remains of the animals. The specimens are then placed in a small porcelain crucible con- taining water in a sand-bath over a Bunsen burner. After boiling a short while, a small piece of caustic potash is added and the boiling continued until the tissues have become disintegrated. The boiling is then stopped to prevent the thin membrane upon which the lingual teeth are situated from being attacked. After removal from the burner, water is added, and the undissolved material allowed to precipitate. The fluid is then removed by means ofa pipette, or by decantation, and fresh water added, and this last procedure repeated until the potash and light flocculent material are eliminated. The residue is then washed in a flat-bottomed dish or large watch-crystal, and the radule removed on needles to a vessel containing a small amount of water. In case the radul are very small, the material is transferred drop by drop with a pipette, and examined under a 1-inch objective ; the Microscope should be furnished with an erector. The radule are thus easily detected and removed. | A drop of strong chromic acid is added to the specimens, and in from one to two minutes the teeth on the radule are stained a light yellow or amber colour. After washing out the chromic acid, the specimens are dehydrated in the usual way, and after removing. the alcohol with a * MT. Naturforsch. Gesell. Bern, 1887, pp. xiii—xiv, + Journ. New York Micr. Soc., iv. (1888) pp. 7-11. 508 SUMMARY OF CURRENT RESEARCHES RELATING TO pipette, absorbent paper, and partial evaporation, oil of cloves is added, and the specimen mounted in balsam. ‘l'he lingual membranes will be found more or less coiled, and usually attached to the jaws. It is desirable to have the membrane flattened out, with the dentiferous side uppermost, and dissociated from the jaws. Some species have a large strong jaw, which, if left with the lingual membrane, will raise the cover so far above the denticles as to prevent the use of high powers. It is therefore necessary to unfold the radula and remove the jaw. Having provided a clean glass slide on the turntable, the specimen is taken from the clove oil and centered on the slide. The radula is then easily unrolled with needles under a Microscope provided with an erector, and the jaw removed. Replaced on the turntable, a thin cover-glass is imposed and centered. This should be done before the balsam is added, as it prevents the specimen from again becoming coiled or displaced. A drop of balsam in benzol is put adjacent to the edge of the cover, and the slide held an instant over a gas-burner or spirit-lamp, which will cause the balsam to flow under the cover. Haeckel, E., Das System der Medusen. Erster "Theil. x. and 360 pp. ‘and 40 pls. (4to, Jena, 1879) .. .. db. OE » Hertwig, R., Zur Histologie der Radiolarien. Untersuchung iiber den Bau und die Entwicklung der Sphaerozoiden und Thalassicolliden. 91 pp. and 5 pls. (4to, Leipzig, 1876) . 9» Jurine, L., Histoire des Monocles, qui se trouvent aux environs de Geneve. xvi. and 258 pp. and 22 pls. Ce, Geneve, 1820) Soul ace rome’ | etobects » Lardner, D., Optics. Handbook of Natural Philosophy. xvi. and 432 pp. "and 289 figs. (8vo, London, 1856) .. . ” Laurent, P., Etudes Physiologiques sur les Animalcules des In- fusions. Végétales, comparés aux organes élémentaires des Végétaux. 2 vols. (4to, Nancy, 1854-58) .. a Leydig, F., Naturgeschichte der Daphniden (Crustacea Clado- cera). 252 pp. - and 10 pls. (4to, Tiibingen, 1860) ale “5 Liljeborg, W., De Crustaceis ex Ordinibus Tribus: Cladocera, Ostracoda et Copepoda, in Scania occurrentibus. xv. and 222 pp. and 26 pls. (8vo, Lund, 1853) . 9 Pallas, P. S., Elenchus Zoophytorum. 451. pp. (8vo, Hage j Comitum, 1766) .. = Roumeguere, C., Cr yptogamie Ilustrée, ou Histoire des Familles Naturelles des Plantes Acotylédones d’Europe. Famille des Lichens. 73 pp. and 187 figs. (4to, Paris, 1868) Ac » » Famille des Champignons. 164 PP- and 567 figs. (4to, Paris, 1870) .. ae ” Slides of Aulacodiscus orientalis and Biddulphia echinata D. sp. .- Mr. Kitton. Photomicrographs (12) . . . So ka se oe) eB asheanen: Mr. Crisp said that he had received a letter from the President, in which he expressed the great regret which he felt at being still obliged to remain at home, the accident to his knee necessitating his confinement to one floor of his house. PROCEEDINGS OF THE SOCIETY, a5) Mr. J. Mayall, jun., described a somewhat remarkable instrument from Mr. Crisp’s collection, which he thought most persons would at first sight be inclined to mistake for one of the old forms of reflecting telescope, but which was really a Microscope, dating probably from the commencement of the present century. It bore the name of Adams as the inventor, and seemed to be a combination of an ordinary compound Microscope and a projection Microscope, to be illuminated by a lamp, or possibly by sunlight, though he scarcely inclined to the idea that this was intended because the body had no movement in azimuth, but only in altitude. The apparatus belonging to it was of an elaborate kind, comprising various arrangements for carrying objectives of different foci, also a spring stage and a very complicated stage on which opaque objects could be viewed. There was a circular ground-glass screen for receiving projection images, which fitted in a slot in the body-tube. The instrument was evidently intended as a type of a first-class Micro- scope of its day, both from the complexity of the design, and from the care and finish bestowed on the workmanship. He had not yet been able to meet with any description or figure of it. Mr. C. Curties exhibited two photomicrographs by Dr. Roderick Zeiss, of Jena, viz. :— Amphipleura pellucida x 2000 partly resolved into beads, taken with an apochromatic 3-0 mm. N.A. 1°40 oil-immersion objective. Pleurosigma angulatum x 4900 taken with an apochromatic 2:0 mm. N.A. 1°30 oil-immersion objective. Mr. J. Mayall, jun., considered these photomicrographs would bear comparison with any they had yet seen. It would be remembered that about a year ago they received some from Dr. Van Heurck, of Antwerp, and Dr. Millar at the time called attention to the one of P. angulatum in comparison with a transparent photograph by Nachet, of Paris, which had been in the possession of the Society since 1867. In the case of these now exhibited there was distinct progress shown; in that of Pleurosigma angulatum the features were beautifully defined and the curious diffraction effects were well shown. The object itself was not a difficult thing to photograph, but, with a power as high as that used (x 4900), to make a good picture was not an easy matter. The photo- graph of Amphipleura pellucida showed the striations partly resolved into beads, but in this case the resolution did not come out so clearly as in the photograph by Dr. Van Heurck; whether this beaded appearance was real or whether it was the effect of improper illumination, as Mr. Nelson alleged it to be, was a question which he must leave to others to decide. During a visit to Antwerp, Dr. Van Heurck showed it to him by means of the electric light ; therefore he had no doubt as to its being seen. But it was worth mentioning that Dr. Zeiss used an electric arc lamp in his experiments, and this method of illumination was so unsteady—never two moments alike—and it altered the image so frequently, that he doubted very much the possibility of getting the finest effects by means of it. On the other hand, Dr. Zeiss had every possible appliance at his command which could contribute to success. He had concrete floors in his atelier, so as to ensure freedom from vibration ; and he had also the pick of the fine lenses produced at his works, so that if he could not produce good photographs, it was difficult to say who could. 526 PROCEEDINGS OF THE SOCIETY. Mr. Ingpen asked if Mr. Mayall considered that the appearance of beading was due simply to the intermittence of the are light and nothing else ? Mr. Mayall could not say exactly to what it was due, but he thought unsteadiness in the light was not the sole cause, because he had seen it with the incandescent electric lamp—which was what Dr. Van Heurck used—and this was one of the steadiest lights known. He had also seen it with the oxyhydrogen light, and with sunlight he had seen it very well indeed. Whether it was a false impression or not was another matter. Mr. Crisp said that at the last meeting Prof. Stewart referred to some slides said to be mounted in “ Suffolk,” and that Mr. Suffolk, who was present, whilst disclaiming all knowledge of the matter, thought it might possibly be something which he had at some time or other recom- mended. Since then they had received a letter from Mr. J. W. Gooch, giving the explanation that an old friend of his who lived in the county of Suffolk invented this medium, but would never divulge the secret of its composition, and when any one pressed him as to what the slides were mounted in, he used to reply that “they were mounted in Suffolk.” Hence the term came to be applied as if it was the name of the medium. Mr. Crisp referred to Prof. Riicker’s suggestions in ‘ Nature,’ with reference to the use of the term “micromillimetre,” and reported that the Council, after some consideration of the subject, had ultimately deter- mined to recommend the abandonment of “ micromillimetre,” and the use of the term “ micron” to indicate the 1/1000th part of a millimetre (supra, p. 502). Mr. A. Meates’s paper “On a new Mounting Medinm of High Refrac- tive Index” was read by Mr. Ingpen, who said that Mr. Meates would be pleased to correspond with any Fellow who might be interested in the subject, or he would be glad to assist them in mounting any difficult diatoms in this medium (supra, p. 519). Mr. Crisp read a letter from Mr. Julien Deby, explaining the process of obtaining photomicrographs employed by Messrs. Truan y Luard and O. Witt, who stated that when an amplification of 500 diameters was required, the best results were obtained by making a negative of 100 diameters with a low power, which could then be enlarged to 500 on by an ordinary photographic copying process. (Ante, . 295. i Mr. T. C. White said he had already tried that plan, but it required the original photograph to be so remarkably sharp that very few persons were likely to succeed in doing it to their satisfaction. Mr. Crisp inquired whether any one present had any experience of the advantage to be obtained by photographing an object x 100 and then enlarging it x 5? Mr. T. C. White said he would himself much rather take it with the higher magnification at once. The Chairman asked if taking it upon the larger scale would not inyolve an inconvenient loss of light. Mr. T. C. White said they certainly would lose light, but that only PROCEEDINGS OF THE SOCIETY. 527 meant that a longer exposure would be required to get the same effect. He had not done anything himself with a greater amplification than x 200, but up to that magnification he had not found a want of light to present any difficulty, in fact, he thought the mistake most often made was that of having too much light thrown into the objective. In practice he found it frequently necessary to cut off some of the light in order to prevent the details of the picture from being blurred by too much glare. Mr. J. Mayall, jun., said he had made a great many experiments in this direction with high powers from x 200 up to x 1000 cr more, and he might say that his experience went to show that the difficulty of getting good results with high magnifications direct from the object was considerable, especially where a long exposure was required. In such cases the risk of vibration was so great that very few photographs taken in that way were successful. Even Dr. Woodward, who had such pre- cautions taken as concrete floors to his workroom, frequently experienced the difficulty arising from this cause. Mr. Mayall also referred to instances of the improper use of the condenser, which was either not placed correctly, or not centered, or the light was not properly focused ; whereas to produce good results the object must be evenly illuminated. The Chairman said that few persons were so well able to give an authoritative opinion on this subject as Mr. Mayall, so that they were much interested to hear the remarks which had fallen from him, As regarded high-power work, there could be no doubt that the centering of the condenser was a very important consideration, but he thought it was possible that where an object was photographed under a low power there might be some advantage indirectly gained by an unequal illumina- tion, and that appearances would result which might help them in some way to form an estimate of the real form. It might in reality be an imperfection, but it might, notwithstanding, have some practical utility. Mr. Mayall said doubtless every kind of illumination might be said to contribute more or Jess to the accurate interpretation of images seen in the Microscope. In cases, however, where an unequal illumination was thought desirable, there were recognized methods of obtaining such illumination. There were central stops, and a great variety of movable stops, that could be used at pleasure either alone or in combination with diaphragms of different sizes; the employment of such means was most important to enable the observer to interpret structure, especially, too, as he could record exactly the method employed, so that his results could be repeated by himself or others. But the unequal illumination which he observed in a great many photomicrographs submitted to the Society was due to imperfect adjustment of the condenser, imperfect adjustment due in most cases to want of training in the skilful employment of the Microscope and accessory apparatus. Such unequal illumination of the field of the Microscope was, for the most part, not an effect deliberately sought for by the microscopist, but was obtained hap-hazard, without any systematic manipulation capable of being recorded and repeated. It was this unskilful microscopy which he hoped to see remedied; for when it came to be combined with inferior technical photography, which he regretted to say was far too often the case, then the results were by no means admirable. It should surely be an essential part of the train- ing of a microscopist to be able to centre and otherwise adjust his con- denser and regulate the illumination; such matters were the A BC of 528 PROCEEDINGS OF THE SOCIETY. microscopy. If, further, it were desired to apply photography to the Microscope, the microscopist should either master the technicalities of photography, or call in trained assistance in that department. He thought it was hardly treating the Society fairly to submit to their notice photomicrographs which showed neither skilful manipulation with the Microscope nor passably good photography. Several of the photomicro- graphs recently received from America seemed to him extremely defec- tive ; they evidenced utter want of training in the management of the Microscope, selection of the object, &c., while as to the photography, it was simply beneath criticism ; the negatives were all over-exposed or under-exposed, over-developed or under-developed. He must, however, admit that the prints were well burnished ; that was their one redeeming point. Mr. T. ©. White said he could quite endorse Mr. Mayall’s opinion as to the necessity for strictly centering the condenser ; if this was not done, they would get half the field in shade and the other half in light. It must be properly centered and then moved back until they got an equal illumination all over, and this was equally necessary, whether they worked with high powers or low. It was also quite a matter of common experience that most of the photographs they saw were like those which had been handed round, some being very much under- exposed, and some over-exposed. Mr. J. D. Hardy said there were two considerations of importance in the suggestions made for improving a photograph by taking it first with a low power and afterwards enlarging it. In photographing a Floscule under a high power he should want more time and more light, but by using a low power first he took much less time over the process, and thus got a perfect image; whereas if a longer time had been required, the Floscule might have moved meanwhile, and so spoilt the result. Also the effects of vibration in taking a large image would be reduced so much by taking a low-power image first, that he thought a great advan- tage would be gained on that account. Mr. J. Mayall, jun., said that, as regarded the subject of the original communication, he thought there was both truth and untruth in the recommendation. Where a power of x 100 was enough to show the structure of the object, then he would say do as the authors recommended ; but if it needed a power of x 500 to reveal the structure, then it was of no use whatever to photograph with x 100 and afterwards enlarge to x 500. Mr. Crisp called attention to Galland-Mason’s “ Microphotoscope,” and read extracts from the inventor’s patent specification. (Ante, p. 281.) Mr. Kitton’s communication was read describing a new species of Biddulphia (B. echinata) from Fiji, specimens of which were shown under Microscopes in the room. (Supra, p. 466.) Dr. R. H. Ward’s report on his examination of Fasoldt’s plates of ruled lines was read, in which he showed that the maker himself was in reality unable to see more lines to the inch than the Abbe theory allowed should be visible. (Ante, p. 298.) PROCEEDINGS OF THE SOCIETY. 529 The following Instruments, Objects, &c., were exhibited :— Mr. Bolton :—Dendrosoma radians. Mr. Crisp :—Adams’s large Microscope. Mr. Kitton :—Biddulphia echinata n. sp. Mr. A. Meates :—Navicula rhomboides mounted in new medium. Mr. J. B. Shearer :—Photomicrographs of various microscopic objects. Dr. R. Zeiss:—Photomicrographs of Amphipleura pellucida and Pleurosigma angulatum. New Fellows.——The following were elected Ordinary Fellows :— Messrs. Thomas W. Cave, M.R.C.V.S., John Dimsdale, John H. Mummery, M.R.C.S., George Pearce, William H. Pratt, Adolf Schulze, A. Norman Tate, F.LC., F.C.S., Frederick W. Thompson, and Rey. H. Armstrong Hall. Prof. G. Govi, Prof. Sven Lovén, and Prof. R. Virchow were elected Honorary Fellows. Meetine or 9TH May, 1888, at Kine’s Cottece, Stranp, W.C., Tur Presipent (Dr. C. T. Hopson) 1n tHe CuHarr. The Minutes of the meeting of 11th April last were read and confirmed, and were signed by the President. The List of Donations (exclusive of exchanges and reprints) received since the last meeting was submitted, and the thanks of the Society given to the donors. : Cross, C. F., E. J. Bevan, & C. M. King, Report on Indian Fibres From and Fibrous Substances. vi. and 71 pp. and 5 pls. (8vo, London, 1887) .. EP Ae bit k= BiG AAO po? . Ore eict The Authors. The President said that on the occasion of his taking the chair for the first time, he desired, before beginning the business of the evening, to thank the Fellows very heartily for the honour which they had done him in electing him their President. He confessed that when he heard the news it filled him with a kind of fearful joy, because Dr. Dallinger’s great services during the four years he had held the office had been so conspicuous as to add a distinction to the position which made it difficult to approach, much less to emulate. But whatever, under the circum- stances, his own failings and shortcomings might prove to be, he could assure them that he should not fail in trying to do his best. Mr. Crisp exhibited a form of camera lucida by M. Dumaige, of Paris, fitted in a box with a cover, which, when closed, kept the prism and mirror free from dust. Also, by the same maker, an adapter with spiral springs for rapidly changing objectives, and a portable Microscope in ae the foot and stage were in one piece (supra, pp. 476, 487, and 488). Dr. Kibbler exhibited and described a new stand and camera, which, he believed, would be found very useful for photomicrography. It had been made to his design by Mr. Bailey, his idea being that it was best 1888. 20 530 PROCEEDINGS OF THE SOCIETY. not to take negatives upon a large plate, but on a quarter-plate first and afterwards to enlarge the pictures from the original negatives. Speci- mens of such enlargements were also exhibited enlarged about nine times from the originals. The great advantage of this method was in the amount of light gained for the purpose of focusing. If a good sharp picture was produced, the gelatin plate would admit of consider- able enlargement up to the point where the grain began to show. This quarter-plate size was also the proper one for lantern slides, which were so much in request at the present time for purposes of demonstration. In the ordinary forms of stand the diaphragm plate is placed immediately below the stage; but, for photographic purposes, this was, in his ex- perience, entirely useless, because it only cut off the edge of the field without either improving definition or correcting spherical aberration. In practice, he had found that by removing the diaphragm plate a certain distance from the object it then ceased to cut off the field and began to reduce the light and to improve the penetration and definition. Opticians, he knew, were inclined to doubt whether this arrangement would do what he claimed for it; but he could only say that, with a good light he could easily show that such was the fact. In cases where high powers were used this answered very well; but it would not work, how- ever, with low powers unless the diaphragm plate was removed to a distance too great to be convenient in practice. He had now, therefore, devised the plan of introducing a short 15 in. condenser behind the stage, and about 3 in. in front of the diaphragm plate, in this way throw- ing it out of focus. The effect of this was that the same improvement in penetration and definition was obtained, but on a much shorter dis- tance. The use of the diaphragm was of the utmost importance in photography where the most perfect focusing and definition were required. Attention was also called to a method of clamping the object in position when the focus had been obtained; also to a plan for obtaining a fine-adjustment by means of a tangent screw. Mr. Beck said he did not usually like criticizing matters of that sort, because he was one of those who had great doubts as to the value of photographic images produced by the Microscope. Photography might produce what was seen by the eye; but in many cases they were frightful distortions. If they looked at the photograph shown of the proboscis of the blow-fly, they would see that it showed every hair as being double, an effect which he considered was due to the removal of the diaphragm having caused distortion by diffraction. If a diaphragm was of any use at all it was to cut off certain rays which caused indis- tinctness of focus, or to cut off the central rays, so that the circumferen- tial rays could be used alone, and the object in photography should be to get rid of all those inaccuracies which a diaphragm, when it was properly used, would get rid of. He did not wish to criticize the apparatus before them, which seemed to be beautifully made, except that he thought there was rather an inconvenient distance to stretch out in order to reach the focusing screw. Mr. Teasdale said he had practised photography more or less for the last thirty years, and had never found it necessary to pay the slightest regard to the diaphragm, although he might have occasionally used a temporary one. In the case of photomicrography, the place for it was certainly behind the lens. The chief difficulty in focusing was due to want of light. Focusing should always be done with as much light as PROCEEDINGS OF THE SOCIETY. 531 possible, and then having used the whole aperture, the light should afterwards be reduced to sharpen the object. To insure success, ex- tremely accurate focusing was necessary, and to obtain this it was well to put a plate on with some object mounted upon it—say, some diatoms. This was easily obtained by pouring a little water containing diatoms upon the glass and letting it evaporate, when the diatoms would be left adhering to the glass ; then focus and get an acrial image. He quite agreed as to the value of the quarter-plate size. It was undoubtedly the most useful for lantern plates and for enlargements, and he entirely concurred as to the benefit to be obtained from taking negatives first on a smaller scale and enlarging afterwards; but he had very decided opinions as to the uselessness of diaphragms behind the object. Dr. Kibbler said as regarded the hairs he could only say that the image of the object when seen on the ground glass appeared very much worse than in the photograph, each hair showing as if composed of three _or four. The photograph was not taken with a small diaphragm. It had an exposure of ten minutes with an ordinary paraffin lamp. If he had a good light he could demonstrate to any one in the room the use of the diaphragm plate in improving the image when used in the way he had described. With small objects like blood-discs diffraction images appeared, Mr. Crisp said that since their last meeting various London and provincial papers had published a most astounding piece of rubbish in reference to an alleged “new glass just made in Sweden.” Many of the Fellows and others had forwarded cuttings to the Society (supra, p. 499). Mr. Crisp also called attention to the fact that the 14th (1888) edition of Heather’s ‘Mathematical Instruments’ had been issued, with the description of the Microscope which was given in the first edition unaltered and uncorrected. In particular, it is made to appear that the “amplifying lens” of bygone days is, with the eye-lens, field-lens, and objective, an essential part of a compound Microscope, while a whole page is devoted to the reflecting Microscope, none of which have been made since 1840 (supra, p. 501). Mr. Mills’s note on “ A Sponge with Stelliform Spicules” was read by Prof. Bell. Mr. Crisp referred to some comments which had recently been made in America upon the advantages of the method of tilting the stage of the Microscope as a means of obtaining a very economical and simple fine- adjustment. This idea was not by any means new, as might be seen by an examination of the various Microscopes upon the table, in each of which it had been carried out in a different way (supra, p. 478). Mr. J. Mayall, jun., said his main objection to this form of fine- adjustment was that for high powers it was not possible to properly use a condenser. Focusing by tilting the stage not only involved the move- ment of the object in relation to the objective, but also in relation to the substage condenser. Under such circumstances he thought it was hardly possible to carry on a delicate microscopical investigation satisfactorily. Mr. Beck said that to allow the stage to move in any direction except parallel to its plane, at once destroyed all delicate effects. Let them take such an object as a Podura scale, and they would find that if they 582 PROCEEDINGS OF THE SOCIETY. moved the stage in any degree, however slightly, which was not parallel, the appearance of it would be materially altered. Anything which interfered with the parallel position of the stage must be destructive of true definition. Mr. J. Mayall, jun., said he agreed very much with Mr. Beck in the remarks which he had made; but he thought if they took objection to the movement upon the ground stated, they must take objection also to the ‘‘ Bausch and Lomb” fine-adjustment, where the body-tube was hung on two parallel pieces of clock-spring, and which he assumed was a movement in are, although it did not alter the relation of the object to the condenser. Mr. Beck said that the movement was a parallel movement and not a tilting movement. The Bausch and Lomb arrangement was not the same thing at all as the other, because the same parallelism was main- tained, whereas in the tilting pattern they had the optical axis thrown out of line perpendicular to the object. Mr. J. Mayall, jun., said that as he understood it, the Bausch and Lomb movement compelled them to see a different portion of the surface of the object with every change of the focal adjustment. Mr. Beck repeated that although this was so, parallelism was main- tained. Some discussion took place as to whether the movement of the tube was not in reality in arc; but it was ultimately conceded that Mr. Beck’s view was correct. Dr. A.C. Stokes’s paper on “ New Infusoria Flagellata from American Fresh Waters,” containing descriptions of twenty new species, was read by Prof. Bell (post). Messrs. H. W. Burrows, ©. D. Sherborn, and G. Bailey’s paper on “The Foraminifera of the Red Chalk” was also read by Prof. Bell (ante, p. 383). Mr. Karop called attention to the recent investigations by Dr. W. Pfeffer, on what he termed the “ chemotaxic ” movements of Bacteria, Flagellata, and Volvocinee, meaning by “chemotaxis” the phenomenon exhibited by these organisms in the presence of certain substances which attracted or dispersed them according to the nature of the stimulant material. A given substance may act upon one organism, but not upon another—e. g dextrin excites Bacterium termo to an extraordinary degree, but not Spirillum. Prof. Bell called attention to a paper recently published by Mr. Wray, giving an account of the structure of a feather. ».The following Instruments, Objects, &c, were exhibited :— Mr. Bailey :—Photomicroscope. Mr. Bolton :—Mastigocerca elongata and M. rattus. Mr. Crisp:—Dumaige’s Portable Microscope, Objective Adapter, and Camera Lucida. Mr. H. Mills :—Heteromeyenia radiospiculata n.sp. New Fellows:—The following were elected Ordinary Fellows :— Messrs. William Cash, F.G.S., Henry C. Corke, Thomas W. Johnson, M.D., and William Penman, Assoc. M.I.C.E. 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