in ee ee re on i Sate ee ren soe MEME Sinhe >: Ot Ne tiaa ke Ree tc Rixe ketene to ~ Stee Be WS Tidvases ota gt pte tate Soe he) Tat ees eee OT Os Behe CaaS OSA Sap ORR setae pode BaF Sa hee ihe A van ws Mae mnerehe, S FOR THE PEOPLE FOR EDVCATION FOR SCIENCE LIBRARY OF THE AMERICAN MUSEUM OF NATURAL HISTORY QUARTERLY JOURNAL OF MICROSCOPICAL SCIENCE: EDITED BY EDWIN LANKESTER, M.D.- WR.S3- iss AND ® GEORGE BUSK, F.R.C.S.E., F.R.S., Sxc. LS. VOLUME I.—New Senizs. GRith dllusirations on Wood and Stone. LONDON: JOHN CHURCHILL, NEW BURLINGTON STREET. 186], Fexil). “neta ‘ ae rv | . NUEUN, WAOTHANA (ei ja Re aa RINT ARCA UCN Mn) - : ] - * g . ~ ; bs ¥ a lnrnJ3n (Of ff 2g AL OU UO ~Ciff- / | / 3 : { ‘see < ans >" +. 3 =" e ' ; . « J . # . - > — ORIGINAL COMMUNICATIONS. On the Marine Diatomacem of NorTHUMBERLAND, with a Description of SeverAL New Species. By Arruvur ‘Scorr Donkin, M.D., L.R.C.S. Edin., Lecturer on Medical Jurisprudence in the Newcastle-on-Tyne Col- lege of Medicine, in connection with the University of Durham. In my previous communication* on this subject, I believe I was the first to pomt out to observers, that in many locali- ties on the sands of the open shore, marine Diatomacez, in a living state, can be collected in great abundance; and several to whom I have sent slides, or gatherings, have had oppor- tunities of judging of their richness and purity; amongst whom I may mention my friends, Dr. Greville, Mr. Roper, and Mr. Okeden. Since the publication of my former con- tribution, the ample experience of three consecutive sum- mers has led me to arrive at the conclusion, that the presence of Diatomacez on the sandy beach of still bays is not an accidental occurrence, or the result of peculiarities of season ; but, on the contrary, that such localities are the natural habi- tat of the free species belonging to this highly interesting class of microscopic organisms, and that, in such localities, these species are annually, during the spring and summer months, generated in surprising abundance. But my observations have led me to infer that certain conditions are essential to their propagation on the open shore. These are— 1, a clean sandy beach; 2, a still or calm condition of the water by which this beach is washed; 3, a certain degree of warmth in the sand. On the first of these conditions I may remark, that mud seems to be inimical to the propagation of free marine species ; for in muddy localities, otherwise favorable to their propagation, they are either entirely absent or very thinly scattered over the surface. As to the second condition, they are never found on such portions of the beach as are subject * «Trans. Micr. Soc. London,’ vol. vi, p. 34, new series. VOL. I, NEW SER. A 2 DONKIN, ON DIATOMACEZ. in ordinary weather to the influence of breakers, but only in sheltered quiet nooks, where the tide creeps up and retires again without producing waves, which, beating against the surface of the sand, soon dissipate its tiny occupants. For this reason, the collector may traverse miles of the shore otherwise suitable, without observing a single specimen, until he arrives at some sheltered cove, such, for example, as serves to protect the boats of the fishermen from the violence of the storm. In such favoured spots, the furrows left on the sand by the receding tide will be found to be covered by a chesnut or olive coloured stratum of Diatomacee, which may be collected in the manner described in my former paper. It is necessary to add, that these habitats should not be visited by the collector, except during the con- tinuance of calm weather, as immediately after a storm all traces of Diatomacez will have disappeared. 'The third con- dition, however, seems to be as necessary as the other two ; consequently, Diatomacez are only observed on the beach between the latter part of April to the begining of Sep- tember, as a general rule, when not only the stillness of the sea, but the warmth which the sands acquire from the direct rays of the sun during ebb-tide, favours their propagation. From September to April, the low temperature and the waves of winter prevent their development and aggregation. I will only here remark, on the propagation of the Dia- tomaceze, that although it has not been shown that they form gonidia, yet I have reason to believe that gonidia, m the form of sézl or resting spores, are the sources from which the new crop originates on the beach each successive spring. This opinion I have formed from the following facts. First, amongst the myriads of specimens of marine Diatomaceze I have examined in the living state, I have never observed the process of conjugation. Secondly, Ihave, as a general rule, found the same species luxuriating in the same circum- scribed locality (extending, in many cases, over only a few square yards) which yielded it in the previous summer. The presence of a particular form, year after year, in the same spot, would therefore appear to be due to the propagating cause, remaining buried in the sand during the winter, through the course of which not a diatom is to be found. Were the crop of each succeeding spring due to the subdivision of a single frustule, or of a few, accidently left by the tides, the same locality would produce, in all probability, widely different forms each returning season. I may mention as a fact of some importance, that I have generally found the species most commonly met with on the DONKIN, ON DIATOMACES. 3 beach, arranged in distinct zones, in the lower of which (that near the low water margin) the Toxonidee, Pl. lanceo- latum, Pl. falceatum, N. lyra, N. forcipata, S&c., occur abundantly. In the upper zone, or that near high-water mark, the predominant forms are Cocconeis excentrica, N. palpebralis, Amphiprora pusilla, Ep. marina, Nitz. virgata, Nitz. spathulata, &c.; in the middle zone, A. arenaria, N. granulata, N. humerosa, N. Clepsydra, N. Northumbrica, N. truncata, &e., are abundant. Before proceeding to describe the new species which I am about to introduce, I consider it necessary to make a few observations in defence of some of those already published in my previous contribution. Professor Walker Arnott has asserted that the two species forming my new genus Towxo- nidea, T. Gregoriana and T. insignis, are mere twisted or distorted conditions of Pleurosigmata, the former of Pl. angulatum, the latter of Pl. estuaru or Pl. lanceolatum, Dr. Arnott observes,* ‘“ In Pleurosigma I have seen no instance in which the living frustule is twisted” * * * “the S.V. is sigmoid with the median line nearly equidistant from the two sides; but after the valves are detached from the connecting zone, they often become slightly twisted, and as they cannot then present a flat surface to the eye, the me- dian line appears to approach nearer to the one margin than the other.* ‘This is a confession and explanation of views, on the part of Dr. Arnott, in itself fatal to his hypothesis; for it shows that the twisting or distortion, which he avers the Toxonidee have been subjected to, is not a vital change found in the living frustule, but is the result of boiling in acid, and of drying the valve on glass slides. To prove the inaccuracy of this assertion, I have only to observe, that I have examined numberless specimens of both Tox. Grego- riana and imsignis in a living state, moving in their native element ; and that the shape of the valve, and the relative position of all its parts, in each species, is exactly that repre- sented by me in my description+ and figures of them. To my own testimony I may be allowed to add that of my friend, Dr. Greville, to whom I sent a living gathering, abounding in these species. In nearly all the very numerous gathermgs I have, from time to time, made on the Nor- _ thumbrian shore during the last four summers, I have found ‘the Toxonidez in some localities in great abundance, and in all they preserve a remarkable uniformity of contour and markings. Pl. angulatum, on the contrary, is not a shore * € Micr. Journal,’ vol. vi, p. 199. _ ‘Trans. Micr. Soc. Lond.,’ vol. vi, p. 19, new series. 4 DONKIN, ON DIATOMACE, diatom, as I have ascertained by ample experience in searching after living forms. It is not even a marine species, its habitat being the brackish water of the tidal estuaries, where it occurs abundantly. On the open shore, free from the influence of streams, its occurrence is very rare and accidental. Pl. lanceolatum Dr. Arnott considers to be “a form of Pl. estuarii, Sm., peculiar to clean sand.’’—‘ Micr. Jour.,’ vol. vi, p. 197). “These two forms,” he says, “ have not been sufficiently isolated to permit any positive deduction to be drawn.” This reads somewhat paradoxical; but I must reply, first, that Pl. lanceolatum is a very much larger form than Pl. estuarii, and has not apiculate extremities; the colour of the valve is rich salmon, while that of the latter is bluish inclining to purple; secondly, that both are found in the typical state developed under the same conditions in the same localities, on the surface of the clean sandy beach ; and thirdly, that I have gathered each form singly in separate localities. Dr. Arnott seems to found his opinion of the identity of these two species on the assertion of Professor Smith, that Pl. estuarit is frequently “ direct.” It is pos- sible, however, that Professor Smith has confounded the two forms together. Some observers have objected to Epithemia marina, that it is a Nitzschia; but with this opinion I cannot agree: it has neither the compressed frustule nor the keeled valve of that genus ; on the contrary, its valve is inflated, and I have been able to detect on it a median line with central and terminal nodules, which is best seen in dry specimens, when the ventral surface of the F. V. is carefully brought mto focus under a high power and good illumination. These charac- ters of the valve, taken in connection with the ornamented appearance of the hoop, would prove the species in question to belong either to the genus Amphora or to be a member of a new genus; to the one or the other of which, it and the following closely allied forms, Nitzschia virgata, Roper, Nitz. Amphioxys, Sm., and Nitz. vivax, Sm., ought to be referred. In all of these the striz are punctate. In the first two sections of the following list, I have in- cluded all the species enumerated under Sections I and II of my former paper. Section 1.—Species described in Professor Smith’s Synopsis, - a. Brackish Water Species. Epithemia Musculus, Kutz. Epithemia Constricta, De Westermanii, Bréb. Kutz. Amphora affinis, Kutz. 2) DONKIN, ON Campylodiscus parvulus, Sm. Surirella lata, Sm. » Gepma, Sm. » fastuosa. Ehr. » Brightwelli, Sm. » ovata, Sm. meena, Sm; Tryblionella marginata, Sm. S punctata, Sm. m acuminata, Sm. Nitzschia sigma, Sm. is bilobata, Sm. Navicula convexa, Sm. » Jennerii, Sm. ss Westu, Sm. » punctulata, Sm. oF pusilla, Sm. 53 Amphisbena, var., Sm. DIATOMACE®. 5 Navicula elegans, Sm. Pinnularia peregrina, Ehr. Stauroneis crucicula, Sm. Pleurosigma distortum, Sm. oy fasciola, Sm. ¥ litorale, Sm. 58 Hippocampus, Sm. a Balticum, Sm. - guadratum, Sm. angulatum, Sm. St ynedra tabulata, Sm. » gracilis, Sm. Amphiprora alata, Kutz. Ne constricta, Khr. vitrea, Sm. Amphipleura sigmoidea, Sm. 6. Salt-water Species. Cocconeis scutellum, Ehr. », diaphana, Sm. Kupodiscus crassus, Sy. :, JSulvus, Ehr. Actinocyclus undulatus, Kitz. Coscinodiscus radiatus, Ehr. 4 excentricus, Ehr. concinnus, Sm. Triceratium favus, Ehr. Campylodiscus Hodgsonii, Ss m. Fy Ralfsii, Sm. clypeus, Ehr. rare. Nitzschia spathula, De Bréb. by ereversa, Sm. », Closterium, Sm. Synedra superba, Kiitz. Navicula liber, Sm. » pygmea, Sm. » Smithii, De Bréb. »» humerosa, De Bréb. x, Crabro, Ehr. Navicula didyma, Kitz. », palpebralis, De Bréb, » Lyra. Ehr. » Kennedyu, Sm. » retusa. De Bréb. Pinnularia Cyprinus, Ehr. 33 distans, Sm. a directa, Sm. Stauroneis pulchella, Sm. var. pl. 19, fig. 1948. Pleurosigma transversale, De Bréb. ad Nubecula, Sm., rare. 5 formosum, Sm. y elongatum, Sm. Ld delicatulum, Sm. ns strigosum, Sm. estuarii, Sm. Doryphora Boeckii, Sm. Amphitetras antediluvianum, Ehr. Biddulphia aurita, De Bréb. 3 Baileyui, Sm. 6 DONKIN, ON DIATOMACEA. Biddulphia rhombus, Sm. Grammatophora marina, 4 turgida, Sym. id Kiitz. Gomphonema marina, Sim. serpeptina, Kitz. Achnanthes brevipes, Ag. Melosira nummuloides, Kiitz. nm subsessilis, Kiitz. Orthosira marina, Sm. Rhabdonema arcuatum, Kiitz. Isthmia enervis, Ehr. 3 minutum, Kitz. Schizonema cruciger, Sm. SECTION II.—Species discovered since the publication of Professor Smith’s Synopsis. Eupodiscus sparsus, Greg. ‘Trans. Micr. Soe. vol. vy, pl. 1, fig. 47). Eupodiscus tesselatus, Roper. (Micr. Journal, vol. vi, pl. iu, fig. 1). . Coscinodiscus concavus, Ehr. (Greg. in Trans. Royal Soc. Edin. vol. xxi, part iv, pl. 2, fig. 47). . Coscinodiscus nitidus, Greg. (Trans. Royal Soc. Edin. vol. xxi, part iv, pl. 2, fig. 45). Coscinodiscus ovalis, Roper. (Micr. Journal, vol. vi, pl, 3, fig. 4). Amphiprora plicata, Greg. (Trans. Royal Soc. Edin, yol. Xx1, part iv, pl. 4, fig. 57). Amphiprora complera, Greg. (Trans. Royal Soc. Edin. yol. xxi, part iv, pl. 4, fig. 62.) Amphiprora maxima, Greg. (Trans. Royal Soe. Edin. vol. xxi, part iv, pl. 4, fig. 61). Amphiprora pusilla, Greg. (Trans. Royal Soc. Edin. vol. xxi, part iv, pl. 4, fig. 56). Amphora Grevilliana, Greg. (Trans. Royal Soc. Edin. vol. xxi, part iv, pl. 5, fig. 90). Amphora cymbifera, Greg. (Trans. Royal Soc. Edin. vol. Xxi, part iv, pl. 6, fig. 97). Amphora robusta, Greg. (Trans. Royal Soc. Edin. vol. Xxi, part iv, pl. 4, fig. 79). Amphora levis, Greg, (Trans. Royal Soc. Edin. vol. xxi, part iv, pl. 4, fig. 74). Amphora levissima, Greg. (Trans. Royal Soc. Edin. vol. XX1, part iv, pl. 4, fig. 72). Navicula granulata, De Bréb. (Trans. Micr. Soe. Lond. vol. vi, pl. 3, fig. 19. Navicula clavata, Greg. (Trans. Micr. Soc. Lond. vol. iv, pl..5, fig. 17). Navicula angulosa, Greg. (Trans. Micr. Soc. vol. iy, pl. 5, fig. 8). Navicula rectangulata, Greg. (Trans. Royal Soc. Edin. vol. xxi, pl. 1, fig. 7). 7 DONKIN, ON DIATOMACE®. i Navicula nitescens, Greg. (Trans. Royal Soc. Edin. vol. xxi, part iv, pl. 1, fig. 16). _ Navicula formosa, Greg. (Trans. Micr. Soe. Lond. vol. iv, pl. 5, fig. 6). Navicula rhombica, Greg. Trans. Micr. Soc. Lond. vol. iv, pl. 5, fig. 1). NW. libellus, of the same author, is obviously a variety of this form (see Trans. Royal Soc. Edin. vol. xxi, part iv, pl. 6, fig. 101). Navicula forcipata, Grey. (Micr. Jour. vol. vii, pl. 6, figs. 10 and 11). Nitzschia virgata, Roper. (Mier. Jour. vol. vi, pl. 3, fig. 6). Tistien decora, West. (Trans. Micr. Soc. vol. vil, pl. 7, fig. 15). This form I gathered in abundance at Cresswell, so long ago as June, 1857. That is long before Mr. West or Mr. Atthey were aware that Diatomaceze were to be found on the beach there. It is horny, and not siliceous in its struc- ture, and will therefore not bear boiling in acid. From the above list I have excluded the following forms contained in the corresponding section of my former paper: Navicula latissima, Greg., a variety of N. granulata; N. Max- ima, Greg. identical with N. liber ; N. Barclayana, Greg. a large form of N. palpebralis ; Amphiprora lepidoptera, Greg., which I. inserted erroneously ; and Cocconeis distans, Greg., of which I have only seen an imperfect specimen. Section III.—Species new to Britain, 1. Hupodiscus tenellus, De Bréb. (Fig. 16). (Diatom. Marin. du Littoral de Cherbourg,” memoires de la Société Impériale des Sciences Naturelles de Cherbourg, tome ii, 1854). Disc colourless, slightly convex, granular ; granules monili- form, arranged in convergent lines; surface of disc divided into eight compartments by eight equidistant lines of coarser granules, reaching near to the centre ; lines on either side of these interrupted a short distance from the margin; pseudo- nodule marginal. _ Of this form De Brébisson justly remarks : “L’ouverture marginale de cette espéce délicate est si peu distincte, et se confond tellement avec les granules, qu’il serait permis de douter qu’elle appartint ace genre, si la struc- ture non celluleuse et la disposition de ses granules n’obli- geaient a l’y rapporter.” Section I1V.—New Species. 1. Pleurosigma falcatum, n. sp. (PL. I, fig. 1) —Form of frus- 8 DONKIN, ON DIATOMACE. tule linear on S. V.; on F. V. falcate, or gently arcuate. V. pale straw colour, on 8. V., narrow, linear, slightly sigmoid ; extremities rounded; median line strongly sigmoid; on F. V. twisted laterally and falcate. Length from -0060" to -0070", breadth of 8S. V. about -0006" ; strize oblique, fine. The peculiar form of this singular species is owing to the entire frustule being twisted laterally on its long axis, and to its beimg curved in the form of anarc. The frustule has, therefore, one valve curved forward, and convex on its outer surface ; the other bent backwards, and concave in its outer surface. The peculiar lateral twisting of the valve is well seen in its F. V. (fig. 1, c). When examined in the living state, this species has all the appearance of a Towxonidea, between which genus and the Pleurosigmata it forms a connecting link; it is, however, a genuine Pleurosigma, in which the twisting and curvature of the frustule are natural and not accidental conditions. To examine the entire frustule in a prepared state, the material must be macerated in alcohol and ether, and afterwards roasted on a thin glass cover. Hab. Cresswell and Boulmar Bay; plentiful, June to Sep- tember, 1858 and 1859. 2. Navicula Trevelyana,* un. sp. (fig. 2).—Form on F. V. elongated quadrangular, constricted laterally ; on S. V. linear, extremities rounded, margins slightly bulging out near the extremities and middle; valve exceedingly convex, inflated, with large orbicular unstriated space around central nodule ; median line curved ; striz coarse, costate, strongly convergent around central nodule, strongly divergent near extremities. Length, from 0040" to 0050”; breadth of S. V. about 0008”. This beautiful species I have found in gatherings with N. rectangulata, Greg., to which it is closely allied, but twice as large, and widely different in specific characters. Hab. Cresswell and Duridge Bay. May, June, and July, 1857, 1858, and 1859. (L.< >) 3. Navicula clepsydra,+ n. sp:-—Form on F. V. elongated * Dedicated to Sir Walter Calverley Trevelyan, Bart., Wallington, Northumberland. t I have placed this species, as well as the new species of Navicule with costate striz, described in this contribution, in the genus Vavicula, because I believe the genera Stauroneis, Ehr., and Pinnularia, Ehr., to be merely sections of the genus Vavicula, and the characters on which they are estab- lished of a purely specific nature. Even the late Prof. Smith did not adhere strictly to the definition of these two genera, as given by Ehrenberg, for we find in the ‘ Synopsis’ that he places in the genus Pinnularia species which have the features of Stauroneis, i.e., P. divergens, P. interrupta, and P. Stauronei-formis. In like manner Pinnularia Johnsonit, Sm., is a Navienla in the acceptation of Ehrenberg. DONKIN, ON DIATOMACE. 9 quadrangular, constricted laterally; S.V. linear elliptical, extremities rounded; valve convex, compressed laterally, with an imperfectly orbicular stauros not reaching to the margin ; striz coarse, moniliform, monile irregular elongated. Length, from -0025” to :0350” ; breadth, from :0008” to -0010’. This species I have named from the hourglass-shaped out- line of the F. V.; it is a very abundant littoral form, being present in the greater number of gatherings I have made from time to time on the Northumbrian shore; it is very little subject to variation in outline and striation ; and though closely allied to Stauroneis pulchella, it differs from that species in being a much smaller form, in the outline of the F.V., m the much greater convexity of the valve, in its striation, and size and shape of the stauros. The var. of S. pulchella, figured by Professor Smith (‘ Synop.,’ vol. i, pl. xix, fig. 194, 5), is common on the Northumbrian shore, and seems to take the place of the typical form, which is rare. Hab. Cresswell, Druridge Bay, Tynemouth; coast of Normandy, De Brébisson. (fi °4 , 4. Navicula truncata, n. sp.—Form on F. V. rectangular, constricted laterally, angles truncated. On S. V. narrow, linear elliptical; extremities subacute ; valve convex, com- pressed laterally; strie costate, coarse, parallel, reaching nearly to the median line. Length, from :0025” to :0035”; breadth of 8. V. about :0005”. Hab. Boulmar Bay, Druridge Bay, Cresswell, Tyne- mouth, abundant. Frith of Clyde, the late Professor Gregory. (hK0,.S 5. Navicula Northwnbrica, n. sp.—Form on F. V. broad, quadrangular, with gently rounded angles, and slightly con- stricted laterally ; striz delicate, moniliform ; those opposite and on either side of central nodule coarse and opaque, forming a dark bar, extending from nodule towards the margin of valve; valve highly convex, and compressed laterally,-from the margins towards the median line, into a keel. 8S.V. narrow, lanceolate acute. Length, from 0018" to -0030"; breadth of F.V., from :0012” to -0018”, of 8. V. :0004”. The delicate moniliform striz and opaque line opposite the central nodules, as seen on the F. V., readily distinguish this form from its allies. The narrow acute S. V. is also very remarkable; for, owing to the valve being so strongly compressed and convex, its margins and median line cannot be brought into focus at the same time with a 1-in. or a VOL. I.—NEW SER. B 10 DONKIN, ON DIATOMACEX. 1 objective; so that the striz can only be examined on the Hab. Very abundant on the Northumbrian shore, in several localities, from May to September, 1857, 1858, and 1859. Coast of Normandy, De Brébisson. 6. Navicula hyalina, nu. sp. (fig. 6).— Form on §.V. gracefully elliptical, valve colourless, median line bordered on either side by an opaque, shadowy line, broad, gradually widening on either side of central nodule, and suddenly con- tracting near termina] nodules. Strize very fine and delicate, probably 75 in ‘0001’. The gracefully elliptical outline, hyalie appearance of the valve,’ and its striation, more delicate than most of the finely marked Pleurosigmata, sufficiently distinguish this species from any of the marine Navicule with which I am acquainted. Itis a severe test-object for the best objectives below a one-eighth inch focus. Hab. Cresswell and Boulmar Bay, from July to September, 1858 and 1859. (Eig .T) 7. Navicula cruciformis, n. sp.—Form on F. V. oblong, constricted laterally, extremities truncate. 8. V. linear elliptical ; valve convex, compressed laterally, colour brown ; striz costate, about 35 in ‘001’, reaching to median line, absent from centre, so as to leave a stauros reaching to the margin. Length, about ‘0030"; breadth of 8. V. -0006”. The marine habitat alone, independent of structural pecu- liarities, distinguishes this species at once from N. Brébissonit, Kiitz. (N. Stauroneiformis, Sm.), which is often gathered at very high altitudes, and which it somewhat resembles in its general appearance. Hab. Boulmar Bay and Cresswell, abundant. CO 4% vy 8. Navicula arenaria, n. sp.— Form on F.V. oblong, extremities truncate ; on 8. V. narrow, lanceolate, acute ; strize costate, coarse, slightly convergent opposite central nodule, reaching to the median line; length from -0012” to 0012”. This small form is the most abundant of the littoral species with which I am acquainted, with the exception of N. gregaria, the next form to be described, which, however, _ is more restricted to certain localities. Hab. Boulmar Bay, Druridge Bay, Cresswell, Lyne Mouth, Newbiggin, Tynemouth. cci< .\0) 9. Navicula gregaria, nu. sp—Form on §S. V. broadly lanceolate, apiculate ; strize obscure. This exceedingly minute form is very abundant in localities where small streams pass over the sandy beach into the sea, DONKIN, ON DIATOMACEA. dl] below the high-water level. In such situation it is therefore covered with fresh water for a short period during ebb tide, and with salt water for several hours during the flow. It is not, however, confined to the beach, but forms an olive stratum on the surface of the piers, stones, and piles of our harbours, between the high and low water level, and may be looked upon as the species which occurs in most abundance on our coasts. In the gatherings I have made of this species I have observed that all the specimens, in a very short space of time, congregated and adhered around any extraneous matter present in the gathering, and that the groups thus formed adhered with wonderful tenacity. This phenomenon I have frequently observed under the microscope, and have been astonished to observe numberless individuals simultaneously directing their course towards the same object, as if controlled by an in- fluence higher than physical force, to which alone the move- ments of the Diatomacez have been referred by many ob- servers. Hab. Chibburn mouth, Druridge Bay, Lyne Mouth, Blyth Harbour, Tynemouth. F:2, LO, Amphora ocellata, Nn. sp. a ae on F. V. broad, rectangular, extremities very slightly rounded, colourless ; hoop on dorsal surface transversely and very delicately striated ; valve inflated, finely striated, with a broad, hyaline band extending across it from posterior margin to central nodule; central nodule indefinite, marginal. Length, about 0028” ; breadth, about :0014”. The hyaline, transverse band gives rise to an opaque, eye- shaped spot on each margin of the frustule, when seen on the F.V. From a comparison of specimens of both forms, I feel satisfied that this species is distinct from A. levis, Greg. (‘Trans. R. Soc. Edin.,’ vol. xxi, part iv, pl. iv, fig. 74). (£ )<,)4 11. Amphora naviculacea, nu. sp.—Form on F.V.rectangular; angles slightly rounded, valve highly convex, median line gently curved; striz on dorsal or outer half of valve continuous, and nearly parallel; an inner or ventral half coarser, inter- rupted, and absent opposite central nodule, strongly divergent on either side of it, and strongly convergent near terminal nodules. Length, from 0030” to °0035’ ; breadth of F. V. about ‘0011. This species strongly resembles a Navicula in its F.V., though the want of symmetry of the valve on either side of the median line, even observable in this view of the frustule, easily determines its generic position. Hab. Cresswell, common, May, 1858. 12 DONKIN, ON, DIATOMACES. 12. Amphora lineolata, n. sp—Form on F. V. nearly rectangular, slightly convex laterally. Hoop with several longitudinal plice, finely striated transversely ; valve slightly convex, arcuate on dorsal and linear on ventral margin, with delicate transverse striz ; median line gently curved. Length, about ‘0030; breadth of F. V. :0012”. Hab. Cresswell and Druridge Bay, May to August, 1857 and 1858. SystEePHaniA, Hhr. “Frustules orbicular; disc cellulose, neither septate nor radiate, with an external circlet of spines or an erect mem- brane on the disc, not on the margin; cellules in parallel rows. ‘The spines are subalate, and not unlike the peristome of amoss.” (Pritchard’s ‘ Infusoria,’ 4to edition, p. 832.) Such are the characters given by Ehrenberg to a genus of which he has described three species, namely, S. aculeata, distinguished by its few spines (12 to 15) and coarse cellules S. corona, with numerous spines (40 to 50) and finer cellules; (about 11 in ‘001”) ; and S. diadema, with numerous incurved spines and still finer cellules (about 13 in -001"). These three species have only been found, hitherto, in a fossil state im the Bermuda earth. (er <. 144) 13. Systephania Anglica, n. sp.—Valve circular, finely punctate; punctze excentric; spines about nineteen, acute, and curved about the margin of the valve. Diameter, from “0012” to :0015”. I am glad to be able to add this most curious form to the list of British species; it is the only living representative of the genus hitherto discovered, and from the description above given it will be perceived it differs from S. aculeata, S. corona, and S. diadema in the number and nature of its spines and the minuteness of its areole. These are only visible, as ex- centric lines of puncte, with a superior English one-fifth or one-eighth objective, and suitable illumination, and would, therefore, have been perfectly invisible by the glasses used by Ehrenberg. Hab. Cresswell, May and June, 1858. Although this species is rare, I have examined several specimens from this locality. DONKIN; ON DIATOMACES, 13 Drurivei,* noy. gen., Donkin. Filament free, compressed, of two (or few?) frustules ; frustules oblong or elliptical, geminate by the persistence of the connecting membrane; valve compressed, elliptical, punctate, siliceous throughout. This new genus I have established to refer to it a species whose characters cannot be reconciled either to the genus Podosira, in which the filament is attached, the frustule spherical or cylindrical, and the valve hemispherical, with an absence of silex fromits apex ; or to Melosira, in which the filament is composed of numerous cylindrical frustules, with hemispherical valves. { (..,,¢ 14. Druridgia geminata, n:sp.—Filament of two frustules ; cingulum transparent, delicate; frustule on F. V. oblong, with rounded angles, approaching to elliptical, brown when dry; hoop absent, or restricted to a mere line; valve com- pressed, on S. V. elliptical, mimutely and obscurely punctate. Length, from -0007” to 0016"; breadth, -0004”. In the living state the endochrome presents a large, dark, circular spot at each angle of the filament. In the previous number of this Journal Mr. West has described and figured (vol. vii, Pl. VII, fig. 11) a form, under the name of Podosira ? compressa, which seems, from his description, to be identical with Druridgia gemi- nata; if so, Mr. West has represented the puncta to be much coarser and more scattered and distinct than they ought to be. So much so, that I feel assured that specimens could not be identified by his figure. Mr. West states that his P. compressa and Atheya decora were found in Druridge Bay and at Cresswell by Mr. Athey, of West Cramlington, from whom he derived his materials. Concerning the publi- cation of these two forms by Mr. West, I think it just to observe that he was well aware, from a call he made me in December, 1859, that I had in my possession a large number of new MSS. species, discovered by me at Cresswell and other localities on the Northumbrian shore, all of which I intended shortly to publish, and only a few of which I had time to show to him on that occasion. Now, bearing this fact in remembrance, I hold that Mr. West, before publishmg the two species in question,. ought to have inquired whether they were amongst the number of MSS. species. If he had done so, I would have in- formed him that I discovered them both at Cresswell, * From Druridge, Northumberland. 14 DONKIN, ON DIATOMACEZ. so long ago as the month of June, 1857, at a time, in short, when neither Mr. Athey nor any one else in this country knew that marine diatoms were to be found on the sands in such localities. Navicula retusa, De Bréb. (fig. 17).—Form on F. V. oblong, angles rounded, constricted in the middle; S. V. linear, nar- row, extremities rounded. Valve convex near the margin ; striz parallel, costate, subdistant, short, not reaching to the median line, shortest opposite the central nodule; me- dian line delicate; middle third of valve hyaline. Length, from 0020” to 0025”; breadth, about 0004”. Concerning this form, much confusion prevails amongst observers. I have-thought it necessary to give a figure of it, to show more clearly the points of difference between it and N. truncata and N. Northumbrica, to which it is closely allied. The description I have above given of N. retusa corresponds with that of Prof. Smith, given in the appendix +o the ‘ Synopsis,’ and also with the description of the S. V. given by De Brébisson ; it differs from its nearest allies, especially in the linear outline of its S. V., in its short thick striz, cut short at a considerable distance from the median line, so that the middle third of the valve is hyaline. The F. V. figured by De Brébisson (‘ Diat. Litt. de Cherl.,’ fig. 6) be- longs to a different species—to N. truncata—although his delineation of the S. V. is correct in outline. What the late Professor Smith meant by N. pectinalis, Bréb., is now somewhat uncertain. According to Professor Arnott, it was unknown to De Brébisson (‘ Microscopical Journal,’ vol. vii, p. 177); its strie, according to Smith’s description, are 16 in ‘001’, and therefore as coarse as those of WN. retusa, but much coarser than those of N. truncata and N. Northumbrica. Professor Arnott, how- ever, appears to be acquainted with N. pectinalis, and would confer a benefit on the science by describing and figuring it. ($58 15. Amphiprora fulva, n. sp., Donkin (‘ Trans. Micro. Soc. Lond.,’ n. sp., vol. vi, Pl. III, fig. 48)—Form on F. VY. oblong, extremities rounded, gradually and deeply constricted in the middle; S. V. narrow, lanceolate, apiculate; valve slightly alate, compressed laterally ; median line straight ; striz transverse, fine, probably 60 in -001”’; dry valve of a rich salmon colour. Length, from ‘0050" to -0055”. In my previous contribution (op. cit.), I described and figured the F. V. of this species as that of Pl. lanceolatum ; but I have since discovered that, in doing so, I have com- mitted an error, and use the present opportunity of correct- HICKS, ON GONIDIA OF LICHENS. 15 ing it. The F. V. of Pl. lanceolatum is that of a typical member of the genus, and is, therefore, not constricted in the middle. Hab. Cresswell and Druridge Bay, plentiful. -Conrrisurions to the knowledge of the Devutopment of the Gonrp1a of Licuens, in relation to the UNICELLULAR Aucz. By J. Braxton Hicks, M.D.,Lonp., F.LS. Fasciculus II. CLADONIA. In the former fasciculus I endeavoured to show that the green cell-srowth everywhere covering trees, walls, palings, &e., which was commonly called “ Chlorococcus,” and ranked as an alga, was really, as had been suspected by some botanists, the gonidia of lichens, which, for an inde- finite time, continuing to undergo segmentation, ultimately extended over considerable surfaces. I also showed that the lichen-gonidium and the chlorococcus-gonidium both went through the same changes of segmentation, and ultimately, by the production of a fibre, became a sortdium, within which, again, certain conditions of segmentation went on till it became a thallus in miniature. I mentioned that, though these were the changes common to the generality of lichens, yet that there were some notable exceptions, one of the most remarkable being that found in the subject of the present contribution. Although the following remarks have reference princi- pally to Cladonia pywxidata, yet it must not be supposed that the changes are confined to it, for I have found them in at least two other species; besides which, as will be again noticed, they are to be found in other lichens of a different genus. JI had proceeded some way with these observations when I had the pleasure of reading a communication on the same subject in the ‘ Botanische Zeitung’ (January 5th, 1855), by J. Sachs, accompanied by figures, in which he pomts out the origin of Gleocapsa from Cladonia pyaxidata. He has noticed it as proceeding from the ends of the felted fibres on the surface of the thallus. My observations go further than 16 HICKS, ON. GONIDIA OF LICHENS. his, and also point out that it arises from within the sori- dium, and that, under varied circumstances, the changes which the lichen-gonidium undergoes are far more diversi- fied than has been hitherto suspected. If we observe carefully the gonidia on Cladonia pyxidata, we find them, generally at least, passing through the seg- mental stage in the same way as those of Parmelia, for instance, and in the same way as in Chlorococcus ;* and to proceed, in course of time, to the formation of soridia, by similar stages; and this holds if this lichen be growing in a dry position, or during a hot or dry season; but should the weather become damp, or the plant grow in a moist situa- tion, or be removed to one, then the changes which form the basis of this fasciculus appear very constantly. I have noticed it in specimens from so many parts of the south of England, that it may, without hesitation, be said to bea normal condition. To observe the early changes it will be necessary to break up the soridium by pressure, or otherwise; after a time the contents escape from one side of the soridium, or break up the whole simultaneously. The first change observable is, that some of the segments be- come enveloped by a layer of mucus, inside of which subdivi- sion still further proceeds, the portions in most cases possess- ing, after a little time, each a separate mucous envelope. This is shown in Plate II, at figs. 4, 6, 7. Thus, we have all the elements of a Gleocapsa (Kiitzing) growth. At first, com- monly, the subdivision is maintained on the binary plan, which may continue for some time, as at fig. 7. Frequently the quaternary plan prevails, as at fig. 10. After a while the subdivisions become separated, each with a mucous layer, as in the smaller cells at fig. 8, the process of segmentation being arrested. Again, in some the mucous envelope of the original cell does not dissolve away while segmentation proceeds within, so that many of the Gleocapsiform cells have from one to three common envelopes (fig. 11, a, a, fig. 14, a, a, &c. &c). A condition being thus produced similar to Hassall’s Hematococcus rupestris (Gleocapsa polydermatica, Kiutzing). In the same mass—the produce of the Cladonia- soridia—will be found every variety of subdivision, each form constituting a mass of a greater or smaller extent; generally, I may observe, (and this is a point worthy of notice,) but not always indiscriminately mingled, as if a particular kind having once commenced, it would, cireum- * See Fasciculus I, ‘ Microscopical Journal,’ Oct., 1860. HICKS, ON GONIDTA OF LICHENS. 17 stances continuing the same, procced in the same direction for an unlimited time. Mingled with the above, we find some large cells, gene- rally globular, sometimes however oval (mother cells), with- out any mucous coat, which contain a number of very small, green cells (fig. 8, b,c). When these are set free by the bursting open of the mother cell-wall, they gradually become surrounded with a mucous envelope, and then appear as the other Gleocapsa-forms above noticed. These may produce ultimately mother cells, or may go on to any of the other forms. They are shown at fig. 8, d, fig. 9, 6, in different conditions of growth. The oval mother cells sometimes are developed early, as seen at fig. 5, 6. They may be solitary, as fig. 11, 6, enveloped with a mucous layer, or even two layers, as at fig. 11, c; or combined within a common enve- lope, in groups of from two to twelve, or even more, as shown at fig. 9, a. The contents of these cells, on dispersion, become like those of the naked, round mother cells at fig. 8, d. When the soridia undergoing this transformation are placed in water, the mucous envelope becomes much increased in diameter, the cells become more numerous and smaller, and assume the appearance of Hematococcus alpestris (frus- trulosus, Hassall (fig. 15). It proceeds sometimes to such extreme division that the process seems almost indefinite, and the results resemble Hematococcus theriacus and minu- tissimus, Hass. (fig. 16, a). Segmentation here goes on in various ways, as seen in figs. 15, 16. The proportion the mucous coat bears to the cell is exceedingly variable, as shown in fig. 15. Another result of this process is the formation of a group of large, oval cells, precisely similar to Palmoglea, Kiitzing (Cylindrocystis, Meach., Coccochloris, Hass.), each of oe being surrounded by a mucous layer. At first, they are con- tained in a common, firm mucous envelope, of a purplish- brown colour, which, at first, extends between the various cells, as shown at fig. 12. The groups vary in number, from two to sixteen, or perhaps more. After a time, the outer purple coating breaks up, or dissolves away, and the con- tained Palmoglee escape, and segmentation proceeds as in- the above cases (fig. 14, 6, b). Each of the oval cells oes one or two distinct nuclei, as in Palmoglea Brébissonii. After they have remained in water some time they assume the appearance represented at fig. 13, a, b,c, where the chlorophyll contents have acquired a round ‘form, but of smaller size. These cells agree in every 18 HICKS, ON GONIDIA OF LICHENS. particular with the marks of the genus Coccochloris, Has- sall, and seem visually identical with C. Brébissonii. 1 have not had any opportunity of testing whether they, like it, possess the property of conjugating ; it is an imteresting question for future investigators; nor is such a process hy any means impossible, when it is remembered that it is merely an act of fusion, not of impregnation. It will be seen that the mass (“ frond”) is at first definite, but becomes indefinite as soon as the common envelope is broken up or dissolved. After this these Palmoglzea-cells may multiply as Palmoglee, till a large mass is formed, and then, circumstances changing, the cell-development proceeds in one of the other modes, which will account for the mass fre- quently possessing more or less of a uniform character through- out its whole extent. I have seen cells precisely similar to these amongst aquatic alge, and which are possibly of the same origin. I say possibly because, from observations in other directions, I have good reason to believe that other vegetable organisms do, in some of their phases, form masses of Gleocapsa-like cells. What other changes take place under varying circumstances in the Cladonia-gonidium it is impossible to say, but I am disposed to consider that by no means have all been noticed. Nor are they confined to Cladonia alone; I have found all the early changes sparingly in Lecanora, Parmelia, and one or two others: also the Palmoglea-growth in Parmelia ; and it is very probable that future observations may extend it to many others, for I shall, in a future contribution, show that there is considerable tendency in the gonidium to vary in other directions than those just mentioned. The next point I wish to remark upon is, that about and amongst these masses of Gleocapsa, Palmoglea, &c., fine fibres are to be found (tubular, jointed occasionally, and branching), which dip in between the component masses and cells, as I have drawn in figs. 11, 14.c, 17 a,and 18; such have also been noticed to exist in the masses classed under Palmellacez, and supposed by Thwaites* and others to belong to the cells. Under the belief that the Palmellacez were distinct alge, their existence was very inexplicable, and their connection doubted. From the above remarks, however, the matter will, I think, be very easy of solution, for, as I noticed in the former fasciculus, the branches of the fibre of the soridium passed inwards, between the segments of the soridium. Now, when the Gleocapsa-formation takes place, these fibres (pro- * *Annals of Natural History,’ Second Series, vol. iii, pp, 241, 243. HICKS, ON GONIDIA OF LICHENS. 19 bably under the influence of the same moisture) elongate, be- come more delicate, and as the soridium breaks up they become detached, whilst their origin is rendered obscure. I have seen them gradually become very delicate, and dipping between the mucous covering of the Palmoglea-form cells in almost every specimen. This, I think, clears up the mystery hanging over these delicate fibres, which have been a source of much dis- putation amongst some of our best observers in this branch. If the reader will refer to my former contribution on this subject, he will observe that it was remarked that the *Chlorococcus” of any given neighbourhood varied very constantly with the prevalent lichen of that spot, and this remark applies peculiarly to localities where Cladonia prevails. If any old wall where Cladonia is growing be observed care- fully, it will be found that where the Chlorococcus has gone on to the formation of soridia (provided the weather be damp and moderately warm) that all the changes mentioned above are taking place within the latter. It will be seen that, sooner or later, over a considerable surface originally covered by Chlo- rococcus, the latter has been supplanted by a Palmella-form of growth, forming broad patches of a gelatinous “frond,” and these growths proceeding rapidly, the stratum soon acquires considerable thickness. By comparing and tracing the formation of the Cladonia-gonidium, and its spreading away from the parent lichen to form a Chlorococcus, and by noting the subsequent changes it undergoes till it forms a broad patch of a Palmella-form growth, I conceive it will readily be conceded by any one taking the pains to observe that the origin of the latter so-called alga is as above described. What are the required changes of circumstances which tend to direct cell-growth into this or that form of subdivision is still mexplicable ; it suffices here to state a palpable con- dition ; but whatever changes of form and appearance they may undergo, I have no doubt, from numerous observations, that even these Gleocapse, &c., do, by the condensation or desiccation of the mucous sheath and by the enlargement of the green cell, ultimately revert to the form of the original gonidium from which they arose. Perhaps the best example in support of the above remarks is to be found on the podetia of Cladonia pyxidata, where, by watching from time to time the gonidia as they appear on the surface, the whole process may be observed. It may also be noticed at one and the same time on different parts of the podetia ; for in the scyphus, or cup, are found the Chlorococcus stage and soridia; half-way down, the Gleocapsa stage; and 20 HICKS, ON GONIDIA OF LICHENS. at the base will be seen the latter changing into a small thallus—a squamule. I have kept patches of Chlorococcus from the neighbour- hood of Cladonia on the bark of trees and under glass till soridia appeared, and then it became in every respect a mass of Gleocapsa. I have never found Cladonia pyxidata without it, except in very dry situations ; but when they were removed to a moist atmosphere the Gleocapsa appeared. The Chloro- coccus from heathery places, where Cladonia alone grew, always produced the same results. Besides the origin of Gleocapsa, Palmoglea, Sorospora, &c., from the soridia, and besides the mode set forth by H. Sachs, there is another way in which the above organisms spring from Cladonia. In this latter the whole of the goni- dial layer of the thallus sometimes becomes converted imto them ; the finest masses of Palmoglea I have met with came from this source. In this condition the mucous layer of the cells is at first of small thickness, and more or less angular by mutual compression (being much as is seen in Palmella cruenta, only of a green colour), but as segmentation proceeds they overcome the resistance, expand, and become more globular. The resulting forms are then as I have above de- scribed as arising from the soridia. In some I have noticed a condition precisely like that of Hassall’s Coccochloris variabilis. When all the gonidia of a thallus assume the Gleocapsa change the separate masses of each variety are of larger extent, but they even then are so blended as to preclude any doubt as to their common origin. In Plate I, fig. 18, 1 have shown a portion of these masses. The felted fibres are more or less mingled with the Gleo- capsa and other forms, and their presence m a mass of unknown origin will indicate its parentage. It will be readily seen from the above observations that these facts have an important bearing upon the independent existence of many of the unicellular alge. In the accompanying plate will be observed almost every form of what has formerly been called Hematococcus, Agardh, and more recently Gleocapsa, Kiitzing. All these forms have been named as distinct species, but how unsatisfactorily so I leave the best observers to testify. If it be a fact, as appears to me very evident, that all these forms can and do arise from one cell, then their existence as distinct species and genera is at an end, and in this I go further than Sachs, and consider that we must exclude Coccochloris, Spv. (Palmoglea, Kiitzing), (for the growth found after immersion or in very damp situations pos- HICKS, ON GONIDIA OF LICHENS. 21 sesses every character of that genus), and Sorospora virescens, Hassall (Microhaloa, Kiitzing). Distinctions drawn from a defined or undefined condi- tion, either at first or subsequently, of the mucous portion of the mass, I hold, as the result of numerous observations, to be valueless as a specific character, and the same may be said of the persistence of the parent mucous envelope to the second or third generation, such as forms the character of Hemaiococcus, Agardh (Gleocapsa polydermatica, Kut- zing), for in the plate accompanying this paper, and in that illustrating Sachs’ paper,* every variety may be seen so inti- mately blended, that one can, by no possibility, deny their common origin. Whether Palmoglea Brébissonii, which may be frequently seen conjugating, be identical with the Cladonia-Palmoglea, requires further observation to determine. The remainder of the British species of Palmoglea or Coccochloris can certainly be produced from Cladonia. Nor doI consider the size of the cell of any importance as a specific character. From the re- marks I have already made, and which I repeat here, it may be noticed, that the size of cells in a state of subdivision, how- ever produced, depends on the rapidity of the segmentary process compared with that of the growth of the individual cell. When the former process is very active, then the resulting produce is small; but when it proceeds slowly, then the individual cells are larger, and continue to grow (so long as the segmentary process is kept in abeyance) till they arrive at full maturity. As far as my researches have extended, the following forms, hitherto distinguished as species, have been observed to spring from the soridium of Cladonia pyxidata : HASSALL. KUTZING. Hematococcus rupestris. Gleocapsa polydermatica. a granosus. bs granosa. Er alpestris. a frustulosus ? 35 arenarius. fi binalis. 3 Surfuraceus. A lividus ? e eruginosus. 3 eruginosa. 53 theriacus. * Op. cit. 22 HICKS, ON GONIDIA OF LICHENS. HASSALL. KUTZING. Hematecoccus vulgaris. Gleocapsa vulgaris (Chloro- coccus vulgare, Greville). a microsporus. a montana. 7 minutissimus. as confluens. Coccochloris protuberans. Palmoglea. 5 variabilis. os muscicola, ivy hyalina. pe depressa. eA rivularis. a Grevillit. as obscura. Brébissonii ? Sorospor a@ virescens. Microhaloa. And if we regard those similar forms of a red colour as merely a winter ‘condition of those of green colour, which is now pretty well certain, then we must “add to the above list, probably, Palmella cruenta, Hassall ; Hematococcus insignis and sanguineus, Hassall; and some forms of Protococcus nivalis, Hassall. Itis very possible that, as observations extend, other lichen- gonidia may be found, yielding explanations of the life- history of many kindred forms. At the same time, because we have shown that the lichen-gonidium can produce Gleocapsa, Palmoglea, &c., it is not hence, by any means, intended to be asserted that such is their sole origin ; on the contrary, there can be little doubt but that other vegetable growths are, during certain vegetating processes, capable of giving rise to very similar cells. In either case, it seems we can no longer assign them that position they have hitherto held as separate existences; but they must fall before the extended study of the life-history of plants into the rank of but one of the many alternations which, it becomes more evident every day, many families of the vegetable kingdom periodically pass through. The relation of the lichen-gonidium to Nostoc and its allies will form the basis of Fasciculus ITT. RAINEY, ON CARBONATE OF LIME GLOBULES, 28 Some further Exprriments and Opservations on the Mont of Formation and CoaLescence of Carponate oF Lime Guosutes, and the DevELopMENT of SHELL-TIssuES. By G. Rainry, M.R.C.S., Lecturer and Demonstrator of Microscopical and Surgical Anatomy at St. Thomas’s Hospital. As I believe it is generally admitted, especially by those who have examined my specimens of carbonate of lime, as it occurs in shell-tissues, and compared them with the analogous artificial forms, that both are formed in the same manner ; and as in this case the experimental investigation of the arti- ficial process will furnish the best clue to a precise and certain knowledge of the natural one, by showing more clearly how much is due to physical agency, I have been anxious to ex- tend and improve my former process for obtaining the globular form of carbonate of lime by making the conditions more like the natural ones, and by so performing the experiments that the changes, which the carbonate undergoes in its pas- sage from an apparently amorphous state to large globules, may, as they are taking place, allow of being examined by the microscope. The process about to be described is the same in principle as that given in the “ Transactions of the Microscopical So- ciety,’ published in the ‘ Quarterly Journal of Microscopic Science’ for January, 1858. It consists in employing a very shallow cell, open at both ends, for the decomposition of the salts of lime contained in gum-arabic by subcarbonate of potash. This cell is made by cementing two ledges of thin glass, about two inches in length and a quarter of an inch in width, placed parallel with one another, to a microscope-slide, and placing upon them a thin glass cover, fixed in its place by thick gold-size. At one of the ends of this cell a very thick and clear solution of gum-arabic is to be introduced by capillary attraction, sutficient in quantity almost to fill it, and at the other a small quantity of still denser solution of gum, saturated with subcarbonate of potash, sufficient, with the first solution, entirely to fill the cell. The alkaline solution should be sufficient to fill about a fifth of it. The excess of gum is then to be removed from each end, after which they are to be closed up by very thick gold-size, or some similar cement. ‘The cell thus charged should be kept in a horizontal position, and examined by the microscope as occasion may require. The rapidity with which the globules will be formed, 24 RAINEY, ON CARBONATE OF LIME GLOBULES. and afterwards increase in size, will depend upon the densi- ties of the solutions. If they are not very dense, globular particles will be apparent in a few hours; but if they are as thick as they can be, to admit of being attracted into the cell, the carbonate will remain in an amorphous state for a week or two. The best results are produced when the solu- tions are as thick as possible. In this case the globules will go on gradually increasing in diameter for four or five months, and I have no doubt but the experiment might be so per- formed that this period would be greatly prolonged, as it will depend upon the relative proportions of the simple and alka- line solutions of gum, so that the globules would keep growing so long as there is any simple solution to furnish the earthy carbonate, and alkaline solution to decompose the salts of lime it contains. At first, the globules increase rapidly, but afterwards slowly, and ultimately they acquire even a larger size than those formed according to the first process. The great advantage of this mode of experimenting is that, by the employment of the micrometer, the progressive changes taking place in the form and shape of the globules can be accurately measured. And, besides, such experiments require but little time, and may be said to be attended with no ex- pense. The mechanical conditions, also, under which these globules are produced resemble more those in sheli-tissues. I may add, that the solutions ought to be made perfectly clear by repeatedly filtering; if not sufficiently thick, they must be further inspissated. On a careful examination of the contents of these cells as above prepared, the first appearance is that of a cloudiness of the fluid in the cell where the solu- tions are in the act of mixing, which, if the solutions are very dense, remain so for several days, after which it becomes slightly granular; if, on the contrary, a thin solution of gum is employed, minute globules and dumb-bells appear in a few hours. The same amorphous condition of the carbonate with gum is obtained by mixing intimately strong alkaline and simple solutions of gum together, and filtermg the mixture through blotting-paper. After four times filtering, I have found amorphous matter in the filtered fluid, which afterwards passes into globules and dumb-bells; but globules formed in this manner do not increase much, but remain small, and nearly all about the same size. The globules which form on the part of the floor of the cell covered with amorphous deposit have in their centre a quan- tity, more or less abundant, of granular, amorphous matter, sometimes surrounded by a granular layer or two (see Plate 1V, fig. 1). As these globules increase, the amorphous RAINEY, ON CARBONATE OF LIME GLOBULES. 25 deposit around them partially disappears, leaving only minute crystals of oxalate of lime. The disappearance of this matter is best seen by examining it from time to time where it exists between two globules, and noticing particu- larly the amount of diminution during stated intervals. As the globules increase in size the crystals also increase, but more slowly than the globules, so that one part of this amorphous matter appears to be attracted by crystals, and another by the globules, a fact which seems to indicate that each has a kind of specific attraction, exerted at sensible distances. As the globules get larger, the carbonate which their surface receives is clear, being probably now the fresh carbonate attracted by them, without first collecting in suf- ficient quantity to appear in an amorphous shape. See fig. 2, which shows two globules, with the amorphous matter between them, and. fig. 3, the same two globules examined a week later, from between which all this matter has disappeared. During this interval both globules had increased in diameter. If globules form where there is no amorphous matter, as on the cover of the cell, they have no granular matter in the centre, but are clear throughout. In some cases, a portion of the granular matter remains attached to the floor of the cell, without passing into globules or dumb-bells. The form of the globules is very much influ- enced by that of the surface of the glass. If this be rendered rough, and thus the points of attraction be increased, the number of globules will be increased accordingly, but their size diminished ; but if the surface be coated with shell-lac, a repellent action will be exerted upon the solution of gum, and globules of a larger size will result ; lastly, if the car- bonate be formed only in very small quantities, it will be attracted by the glass in minute but separate globules, and the interstices between them becoming gradually filled up by subsequent additions, a film of coalesced globules will be formed, covering the surface of the slide, similar to some forms of shell-tissue. All the appearances above described are best seen when the solutions of gum are as thick as possible, in which case, as before stated, the time required for their production will be slow. I have not noticed in those globules which have an amorphous nucleus that this nucleus has, in three or four months, suffered any visible change, either in size or appearance. In some globules the central part is made up of an aggregation of small globules, whilst the peripheral one is more or less clear and lami- nated, as represented in fig. 4. These bear a strong re- semblance to the otolithes of small fishes in an early stage of. VOL. I1.—NEW SER. Cc 26 RAINEY, ON CARBONATE OF LIME GLOBULES. development. See fig. 5, which is a representation of the otolithe of a young stickleback, and fig. 6 of one from a very small whitebait. These bodies are formed by the deposition of carbonate of lime in small sacs, which car- bonate seems to go through the same changes of form as in shells, but I have not found the globules presenting so well- defined a cross under polarized light as in some forms of shell. With respect to the manner in which the calcareous globules, in the artificial process, acquire their increase of size and become coalesced into one mass, I may notice that the explanation given in my first paper is founded on a theoretical error, which more accurate experiments and more careful observations have since enabled me to correct. In ny first method of obtaining the globules of carbonate of lime with gum, the different changes which these bodies underwent being produced in bottles, were entirely out of the reach of direct observation, and therefore the manner in which these forms were produced must be, to some extent, a matter of inference. The larger must either have resulted from the incorporation of smaller ones, as globules of a liquid would unite, or they must grow by addition to the surface. The various appearances which they assumed, especially those of the dumb-bell forms, seemed to be best accounted for on the first hypothesis ; and as certain lenticular calcare- ous bodies occurring in the scales of fishes, similar to the glo- bules of carbonate found in the incipient stage of shell-growth, had been described as undergoing a process of complete fusion or incorporation, I adopted this hypothesis in respect to the artificial products, as appearing to me to be the right one. However, Dr. Gladstone, on examining some specimens which I showed to him, considered that these globules were produced according to the super-position theory, and Mr. Warrington and Mr. Brooke, who saw them afterwards, were of the same opinion. As I had great confidence in their opinions on this subject, and as my only wish was to know the truth, and, moreover, as I considered, in experiments so completely phy- sical and chemical, and admitting so easily of being brought within the reach of direct observation, certainty upon this point was attainable, and no doubt need remain respecting it, I proceeded to perform the series of experiments above detailed, which I will now briefly apply in explanation of the manner in which the calcareous globules acquire an increase of size, according to the super-position hypothesis. Though these experiments, so far as this point goes, may not show anything new, yet they will have the advantage of removing all doubt as to the manner in which the analogous RAINEY, ON CARBONATE OF LIME GLOBULES. 27 forms of carbonate of lime are produced in organized bodies, to which the same decisive mode of testing this fact could not be so easily applied; and in physiological science posi- tive, experimental evidence is especially needed. In merely describing the different characters of the calcareous globules in the glass cells before alluded to, this subject has been anticipated, and therefore it only remains to show, by the measurement of these globules during their growth, how their increase of diameter and their coalescence takes place. Two globules attached to the floor of a cell containing the two solutions of gum, in which decomposition and the formation of carbonate of lime were slowly going on, were measured by means of the micrometer eye-piece on the 27th of August, 1860, and their distance apart accurately deter- mined, which was 5245 of an inch, that is, four spaces between the lines of the micrometer, each space being 5, of an inch. On the 29th instant, the interval had become dimin- ished 5,5 of an inch, and the diameter of the globules increased accordingly. On September 10th, it had dimin- ished another 3315, of an inch, with a proportionate increase of the globules; 52,, of an inch were now left, which were gradually filled up between the present time and the 27th of November, when the globules had acquired such an increase of size as to be incontact. Similar measurements were made of other globules, with a like result, and the experiment is so easily performed that any one can, without either much trou- ble or sacrifice of time, verify its correctness. As the inter- val between two or more globules is in progress of being filled up, none of the particles of the carbonate of lime which are being added to their surface are visible, and the surface itself appears perfectly smooth and sharply defined. These obser- vations are best made on the globules which form on the cover of the cell, these being more clear than those on the floor, and if the cover be sufficiently thin, a lens of 4 or +4, of an inch focus can be employed in the examination. The invisibility of the increments which these globules receive during the time ordinarily employed in the examination of any minute part of an object, supposing that time to be one minute, will admit of an obvious explanation, on considering the entire space between two globules, divided by the number of minutes contained in the time required to fill it up, and the extreme minuteness of each of these divisions. In the above experiment, a space equal to >,/;5 of an inch was filled up im seventy-eight days ; hence the size of the particle added to each globule in one minute would be more than the two- hundred millioneth of an inch in diameter. This would be 28 RAINEY, ON CARBONATE OF LIME GLOBULES. on the supposition that the increments which each globule received in equal spaces of time are equal, but as the filling in of this space takes place more slowly as the globules in these experiments get nearer together, the degree of minute- ness of the particles in question would far exceed that above mentioned. In this case, their size, when the globules were on the point of actual contact, would be several thousand times smaller than that of the smallest particle of matter visible by any known power of the microscope. But how- ever small these particles are, they have, doubtless, a defi- nite size, otherwise the surface of the increasing globules would, most probably, not be so sharply defined, but gradually shaded off. Besides, it can be shown, by dissolving out the earthy component, and leaving the gum one, that the layer of a globule last formed is the densest. For this purpose, it is only necessary to put the slides on which these globules have been deposited into a solution of gum, which, either being itself an acid or from the free acid it contains, gradually dissolves out all the carbonate with efferves- cence, and leaves the gum-element insoluble, and more or less of the form of the original globule, this depending very much upon the relative quantity of gum in com- bination with the earthy matter. Hence the globules which have been made in a strong solution of gum are the best for demonstrating this fact, and those made in the bottles according to the first process are necessary for this experiment. The gum-constituent, thus prepared, presents under the microscope the appearance of a nucleated cell ; but that which appears to be a nucleus is rather a vacuity, and in these globules, when examined by the microscope by polarized light, in which the carbonate is only partially re- moved, the central part is generally dark, without having a cross, showing either a very small quantity or a total absence of the carbonate of lime. In many globules thus treated the exterior gum-layer appears quite like a dense husk, enclosing the parts within. These gum-residua, being insoluble, can be kept in glycerine, but if any of the carbonate had been left in them it becomes gradually removed. I have noticed in my paper on the dental tissues the same fact taking place in the calcareous globules of a delicate film of calcifying oyster-shell. Now, two facts are obvious from these expe- riments—one is, that the particles of gum and carbonate of lime are combined in these globules in inconceivably minute quantities ; and the other, that the gum becomes insoluble in water. In these respects, gum in plants bears an analogy to albumen in animals. With respect to the globular form RAINEY, ON CARBONATE OF LIME GLOBULES. — 29 of carbonate of lime, I may state that I am perfectly aware that there are other cases in which carbonate of lime may be made to take the globular form. In this respect it seems to be a compound like salicine, asparagine, and some others, in which the force causing the crystalline form is feeble, and there- ‘fore easily overcome by that which causes particles to become globular ; but this does not in the least affect the fact of car- bonate of lime, when formed ina sufliciently strong solution of gum or albumen, becoming globular, or its applicability to the organism in which this compound.is produced, as experi- ment shows that it is in such a state of combination as this that it occurs in organic tissues. To show the effect which gum has in determining the form of carbonate of lime, slides were put into bottles containing the same alkaline solution, which in all was as much inspissated as possible to be fluid, but the simple solution of gum was of different densities in each bottle. The slides were removed from the solutions in about four weeks. ‘The carbonate on those which had been in the densest solution was all either in globules or dumb- bells. There were no crystals, whilst that deposited on the slides taken out of the weakest selution was in globules below, that is, near to the surface of the dense alkaline solu- tions, but in crystals above, where the quantity of gum in the solution was smallest. All these crystals examined from above downwards were seen gradually to lose their crystalline form, having their angles gradually rounded and their sides variously curved; after that they assumed the character of dumb-bells of different forms, and lastly they became globules. Fig. 7 is an accurate representation of the forms of carbonate of lime on one of these slides. The other slides presented various forms of carbonate intermediate between those extremes, but fully confirming the correctness of the conclu- sion that the globular form is due to the gum, and that the various modifications of the crystalline forms, as shown in the figure just referred to, are dependent upon the relative quantities of gum and carbonate of lime entering into their composition. Now, it is worthy of remark that all these various forms exist in calcified tissues. In some, the crystal- line form prevails, especially in the densest shells, and in those parts of the less dense ones which are the hardest. In others, the globular form most abounds, and especially where the shell is in an incipient stage of growth, and before the membrane on which the carbonate is formed is entirely covered by coalesced particles ; and lastly, there are shells, as that of the shrimp and prawn, which present both globules and modified crystals near together. 30 RAINEY, ON CARBONATE OF LIME GLOBULES. The cause of these modifications of form produced by the different proportions of gum in combination with the earthy constituents, seems deducible from the facts already men- tioned, namely, that these elements become intimately mixed together in inconceivably minute quantities, and that the gum in the mixture is rendered insoluble, so that the par- ticles so formed and their elements being thus combined, would be under the joint influence of the forces which each element by itself would have been acted upon, and by which its form would be determined. The particles of pure carbonate of lime, being under a force which disposes them in straight lines, would take the crystalline form ; whilst those of gum or albumen, in which the tendency to attract one another is probably strong, as indicated by their tenacity, would, by their mutual attraction, be brought into the globular form. Hence, in the mixture composed of the carbonate element in great excess, the crystallme form would prevail, whilst in that in which the viscid element preponderated the globular form would predominate; and of course intermediate forms would result from such different proportions of these elements as might between these extremes. Some compounds formed in gum ‘do not become globular, as, for stance, oxalate of lime. It remains beautifully crystalline, and increases by the addition of fresh invisible particles to the surface of the crystals, just as the globules do by the addition of particles of carbonate and gum to their surface. This probably arises from the oxalate not combining with the viscid substance and solidifying it in the manner that the carbonate does. If the particles of carbonate become deposited on a crystal of oxalate of lime, they coat it with a globular, and not with a erystal- line, layer, so that it would appear that these particles in their very earliest state are spherical. Besides, the fact of the par- ticles of carbonate thus combined with gum, when so small as only just to be visible with the highest magnifyimg powers, being also spherical, is in favour of this conclusion. All the globular forms of carbonate of lime are considered by some to be crystalline, and are called globular crystals. In some of these forms there is a shght appearance of a crystalline structure ; in others, where either the gum is small in quantity or where the form of carbonate is mixed with some other crystalline compound, or is a carbonate of lime of a more highly crystalline character, this appearance is more strongly marked; whilst there are those carbonate globules com- bined with so large a proportion of gum as to present no appearance whatever of crystallization, which, notwith- standing, exhibit a distinct cross under polarized ight. Now, RAINEY, ON CARBONATE OF LIME GLOBULES. 31 how far these ought to be looked upon as crystals, I shall not attempt to decide ; I may observe, however, that the physical force producing globular shapes is, without doubt, the very opposite of those which produce crystalline ones, and that, even in those cases in which globules are made up of a spherical conglomeration of minute crystals, it may only be where there has been an arrest of that force (attraction) which, though sufficient to bring these crystals into a globular form, would, if its action had extended to their ultimate atoms, also have arranged them in globules. I have now to introduce the account of some very interesting experiments on the reparation of shell-tissue, made by Mr. C. Stewart, of St. Bartholomew’s Hospital, confirmatory of observations of the manner in which this class of structures is formed, published by mesome yearsago. Mr. Stewart’s mode of experimenting is entirely his own. The following is a verbatim copy of his letter to me; “Dear Srr,—Having repeatedl¥ found that snails, which had suffered from an injury to their shells, had repaired them by the formation of new shelly matter, I thought that they would afford a good opportunity for examining the process by which the shell naturally grows. I accordingly removed a portion of the shell of an Helix aspersa, without injuring the animal. I then found, that in a few hours an extremely delicate and perfectly structureless membrane covered the surface of the mantle, and was attached to the edges of the fracture. “On examination at the end of two days, the membrane was seen to be covered externally with crystals of phosphate of lime, and also with some compound globules of all sizes, undergoing coalescence into larger ones, as well as very minute particles of lime, of various and more or less regular forms, exactly like those of the carbonate of lime produced artificially. These, no doubt, are formed on the outer side of the membrane, in consequence of its extreme delicacy, allowing the fluid secreted by the mantle, in which the salts of lime are in solu- tion, to percolate through it. “‘On the third or fourth day, the new shell (which is colour- less) is rertdered sufficiently strong, by the addition of fresh particles of lime, to allow of the animal being withdrawn from the shell without breaking it. The process of repair now progresses very slowly, it taking months, or even years, to form a perfect and coloured lip, if the injury be to that part. The colouring of the shell I believe to be owing to the pig- ment contained in the cells of the mantle being discharged, in 32 -RAINEY, ON CARBONATE OF LIME GLOBULES. consequence of their having arrived at maturity, and blending with the calcareous element, the colouring of the margin of the mantle being similar to that of the shell. Probably, this process is slightly modified in some instances by an especial gland providing the pigment incidentally to other functions it may have to perform. Instances of this might, perhaps, be found in those animals in which the shell, having arrived at maturity, the lip is uniformly coloured. “From these facts I am led to believe, and, I trust, not without sufficient reason, that the shells of these animals are formed by the coalescence of minute particles of lime on the inner surface of a previously formed animal layer (epidermis), being attracted to it before they have time to form globules by their attraction to each other, it beg the immer, mstead of the outer, surface of this membrane, m consequence of its greater thickness preventing the fluid passing through it. ‘This idea is, I think, strengthened by the fact that globules of lime, in considerable quantities and of all sizes, are found in the mucus, on the surface, and also imbedded in the free edge of the mantle of Paludina vivipara, and probably in those of other mollusca, if carefully examined. “ Yours truly, “C, Stewart. “Sr. BaRTHOLOMEW’S HosPITaL; ** Nov. 20, 1860.” Besides the crystals above noticed, there are others which I hope to describe in a future number of this Journal, my present occupations taking up so much time as to render it impossible now to prolong this communication; I hope also to extend the subject to the structure and development of striped muscular fibre. 33 Remarks on the GuossipHonips, a Family of DiscopHorous Annutata. By the Rev. W. Hovcuron, M.A., F.L.S. I am induced to offer a few remarks on the above-named family, in the hopes of drawing the attention of microscopists to the structure and development of a small group of animals which appear to have been almost neglected by British naturalists, and although I have nothing to add to what M. Grube has published in his valuable memoir on the develop- ment of these animals—for he appears to have almost exhaust- ed the subject, while the researches of De Filippi, Miiller, &c., have acquainted us with much that relates to their struc- ture and habits—yet, perhaps, as the members which com- pose this family are but little known, these few remarks will not be deemed altogether superfluous. With the exception of some observations of the late Dr. Rawlins Johnson and a few incidental remarks on some of the species of this family in thé pages of the ‘ Annals and Magazine of Natural History,’ all that we know of the Glossiphonide is derived from the works of Grube, De Filippi, O. F. Miller, F. Miller, and Moquin-Tandon. I can hardly speak in too high praise of Grube’s memoir (‘Untersuchungen uber die Entwickelung der Clepsinen,’? Konigsburg, 1844). Having taken up the subject of the development of these Annelids before I had seen the memoir above named, I am able, from independent observation, to confirm almost every point which that naturalist has advanced. The late Dr. Rawlins Johnson, of Bristol, was the first to establish on satisfactory grounds the genus Glossiphonia and to separate it from that of Hirudo, under which genus it had been, since the time of Linnzeus, generally comprised ; this was in 1816, but, strangely enough, in the following year this writer altered the very appropriate name of Glossiphonia into that of Glossipora, without any improvement in the term proposed ; it is, however, but fair that one of these names should be allowed to stand in preference to the ambiguous one of Clepsine, proposed by Savigny in 1827, although this latter term, in violation of the acknowledged laws of zoological nomenclature, has been generally adopted. The Glossiphonidz are all inhabitants of fresh water, although Mr. Gosse, in his ‘Manual of Marine Zoology,’ has erroneously admitted one species, G. rachana, W. Thompson, into the catalogue of marine worms. The genus contains the following British species: —G. Siocu- lata, G. complanata, G. hyalina, G. verrucata, G. tessulata, 34 HOUGHTON, ON THE GLOSSIPHONIDA. G. marginata, and G. rachana.* G. complanata, hyalina, bioculata, appear to be common everywhere ; tessulata and marginata, which latter species I have lately added to our English Fauna (‘ Annals and Magazine of Natural History,’ vol. v, No. 28, third series), are rarely found. G. tessulata, which is the largest British species known, approaches in its form and consistency to the genera Hirudo, Hemopis, &e. All the members of this family are interesting objects for microscopical study, owing to the extreme transparency of young individuals and the facility with which specimens may be procured. Some of the species, as G. complanata, G. mar- ginata, and G. tessulata, deposit their ova upon the under surface of submerged stones, pieces of wood, &c., sitting upon them until the embryos are hatched; they may thus literally be said to incubate, which they do with an assiduity not inferior to some of the higher orders of animal life I know not who was the first observer to record this singular habit, but nothing of the kind occurs in any other animal so low in the scale of creation; one is’ reminded, indeed, as Grube has observed, of the somewhat analogous case of Coccus, the wingless female of which sits over her ova, but im this case what is life to the new progeny is death to the parent, whose dead body forms a shield-like protection for her young ; but the Glossiphon, though she shows a thin and emaciated appearance after the “‘lying-in,” in time recovers her strength and usual figure. The Glossiphon is a leech-like animal, with a dilated and depressed body; the upper surface is more or less convex, and im some species beset with rows of small, conical, semi- transparent papille ; the under surface is either flat or con- cave; the anterior extremity, which in a few of the species may be said to form a distinct head, is always less obtuse than the posterior ; the mouth, which is situated nearly at the apex of the anterior extremity, is transversely elliptical, two-lipped, and furnished with a strong, muscular, protractile proboscis, on which peculiarity Dr. R. Johnson formed the name of the genus which so appropriately characterises it ; the number of eyes varies in different species, there bemg either one, two, three, or four pairs, generally of a black or deep- claret colour, disposed in two longitudinal series, but slightly * The names of five other species are given in Johnston’s unpublished ‘Catalogue of British Annelida,’ viz., G. flava, G. granifera, G. circulans, G. lineata, and G. vitrina ; the first, which is described by Dalzell, is evi- dently G. marginata, the last appears to be a variety of G. ‘essulata, a most variable species; the claims of the three remaining species rest on very insufficient evidence. HOUGHTON, ON THE GLOSSIPHONIDA. 35 converging towards the anterior extremity ; in some indivi- duals, and frequently in the species G. hyalina and G. com- planata, the anterior pair are wanting, and the order of arrangement is confused. The posterior acetabulum is large and round; the genital openings, of which the male is the upper, occur somewhere between the twenty-fifth and twenty- eighth ring of the body; the digestive system consists of a stomach, having from five to seven pairs of gastric czca ; the intestine has uniformly four ceca. All the British members of this family are strictly oviparous ; one is surprised to read in Diesing’s ‘Systema Helminthum’ (vol.i, 446), “ut plurimum vivipara.” They are incapable of swimming, and move from place to place like the caterpillars called geometric; this is particularly the case in the species G. tessulata and G. mar- gimata, which are very active in their movements. Most of the species roll their bodies up like Onisci if taken out of the water and handled. They inhabit brooks and ponds; and though all the species above enumerated are, as stated by Diesing, “ aqguarum dulcium incole,” they are frequently found in water which is anything but sweet. None of the British species can be truly said to be parasitic, though any of them may be occasionally found upon the bodies of aquatic animals, on the juices of which they feed. I purpose now to make a few observations on— Ist. The structure of the Glossiphons. 2dly. Their mode of increase, and the development of the embryos. Ist. The normal form of the body, when at rest is pear- shaped, the posterior extremity being rounded and obtuse, the body narrowing somewhat suddenly towards the anterior extremity, but different species vary slightly inter se; the mouth, which is always subterminal and bilabiate, and with- out teeth, leads to the proboscis by a delicate, transparent, membranous cesophagus, with which it is continuous, and by which it is included; this membrane is drawn back over the proboscis, when it is extended, in a manner similar to the unfolding of a glove from the finger ; the form of this exsert- ile tube is cylindrical, minutely lipped or segmented at the apex, and commonly bulbous at the base; it is of a sub- cartilaginous consistency, and supplied with powerful mus- cles, by means of which it is worked ; under the microscope, the reticulated, muscular structure is observable, more espe- cially on the bulbous portion of the proboscis. It is by means of this tube that the animal pumps out the juices of its victims, its labiated apex seeming to act the part of a mouth. There are some slight modifications of form in the 36 HOUGHTON, ON THE GLOSSIPHONIDA. different species, hut the principle of mechanical action is the same in all. G. dioculata, the smallest British species, if put into the palm of the hand, has the habit of thrusting out its proboscis to the length of, perhaps, a third of its own body. I have not noticed this habit in any other species. Connected and continuous with the bulbous base of the proboscis is another, transparent, hollow membrane (the continuation of the cesophagus), which, when the proboscis is not exserted, twists and rests upon itself. At the base of this membrane is the commencement of the stomach, the walls of which are attached to the surface of the body of the animal. The stomach is furnished with five or seven pair of gastric ceca, which are either simple or forked at their extremities; there are also, in some species, very small czca, in advance of the large sacs, which, perhaps, have a kindred function. The last pair of czeca, which is always the largest, is directed downwards towards the posterior extremity, while the rest are nearly at right angles to the mesial axis of the body. De Filippi (‘ Lettera al Sign. Rusconi, sopra VAnatomia e lo Sviluppo delle Clepsine, Pavia, 1839) asserts that he has observed between the digestive canal and the blood-vessels a special communication, by means of which animal juices sucked by the Glossiphon pass almost immediately into the blood-vessels, and that thus, by trans- fusion, as it were, the snail-leech acquires a supply of blood. T have never noticed anything of this kind in the numerous examples I have submitted to patient investigation. The intestine in these animals is furnished uniformly with four pair of ceca, the two anterior pair of which are directed upwards; the anus, which is more readily recognised when the animal is out of the water, is round, and situated just above the juncture of the acetabulum and trunk of the body. In young specimens, and more especially in those of the beautiful little species G. hyalina, the digestive ceca are frequently found to be of a brilliant-red or vermilion colour. Whence is this red colour derived? Moquin Taudon (‘ Monographie de la Famille des Hirudinées,’ 1846) has figured a young G. sexoculata (complanata) with these blood- red ceca; he says the specimen had sucked the blood of an Hemopis. But if this colour be derived solely from blood which the animal has swallowed, how can we account for the fact that it is always, as far as I remember, in the young individuals that the red colour is observed? Full-grown specimens do not exhibit this appearance. I have reared individuals from ova which had been deposited in vessels in which it was impossible for the young ones to have obtained HOUGHTON, ON THE GLOSSIPHONIDA. 37 red blood, but it was a common thing to remark that speci- mens of about three lines long, and seven or eight weeks old, had their digestive system thus beautifully coloured. The subject is worthy of further investigation. The circulation in the Glossiphonide may be most readily watched in the young of any of the species, and in adult individuals of G. bioculata and G. hyalina, but from the transparency of the circulating fluid, and from the com- plexity of the vascular system, with its numerous network of vessels which communicate with the dorsal and lateral ones, it is extremely difficult to make out with satisfaction the true and complete course of the vital fluid. This much, however, I have been able to notice. There is a large and tortuous dorsal vessel, a ventral vessel, two lateral vessels, with innumerable other small ones, which form almost a network of communication between the grand central and lateral canals. The dorsal vessel is furnished, at intervals, with valve-like processes, which are arranged alternately on either side of it; it is contractile and heart-like in its functions. This group thus differs in a very important particular from the true leeches which form the genera Hirudo, Hemopis, Aulostoma, Trochetia, and Nephelis, in all of which the side vessels, arid not the dorsal, are contractile, and act the part of a heart. I have carefully studied the mechanical action of these valve-like processes alluded to above, and believe that they are designed to propel a large portion of the vital fluid to the sides ; this they do by partly closing a section of the dorsal vessel, and thus stopping a certain quan- tity of the blood from flowing up it; this section of the dorsal vessel contracts and forces a portion of the blood into the numerous branching channels which communicate with the dorsal and lateral vessels ; indeed, the dorsal vessel may be considered to consist of several hearts, each one of which, so far as its functions are concerned, being formed by the space included by the valves, which, simultaneously with the contraction, swing on their narrow bases, by which they are attached each to the opposite side of the dorsal vessel, and thus partially close it, not entirely, however, for even when the valves are closed corpuscles may be seen to pass through the narrow portal from one of the dorsal cham- bers to another; in this manner a large portion of the blood ‘finds its way through the imtercommunicating chan- nels to the grand lateral vessels, for the purpose, as will be seen by and by, of becoming oxygenated. F. Miller (‘ De Hiru- dinibus circa Berolinum observatis’) supposes these valves are merely intended to prevent: the vital fluid from flowing 38 HOUGHTON, ON THE GLOSSIPHONIDZ. down the main dorsal vessel, instead of up it. I feel confident, however, that they have such a function as I have endeavoured to explain. Respiration in the Glossiphonide is, no doubt, in some measure carried on by the entire skin, as in the true red- blooded leeches, the vital fluid being oxygenated by fresh currents of water, which the animal is careful to create by attaching itself by the two extremities, and waving in an undulatory manner the intermediate portion of its body. There is, however, another and a very important method by means of which the respiration is performed. All the members of this group have the margins of the body much dilated and very thin. Careful focussing of the micro- scope will enable the observer to recognise the presence of minute channels down each side, which lead from the two main lateral vessels to the extreme verge of the margin; into these channels the blood flows, describing a kind of a circuit, and returning again to the lateral vessels; the extreme tenuity of the margins must thus allow the blood to be freely and rapidly renewed in those vessels which per- meate it by the contact of the water which surrounds the vessels, and which is thus brought into close proximity with them. The nervous system in these animals is readily recognis- able by dissection ; it lies on the ventral surface, and consists of a nervous cord, or, as it 1s usual to say, of two nervous filaments united together, having a large, ganglionic, cesopha- geal ring, with about twenty ganglia situated at irregular in- tervals one from the other, the last ganglion being the largest. The generative organs are represented in Plate ITI, fig. 11. Tn the spring of the year a long, white band may be discerned through the integuments of the abdomen, reaching some way down towards the posterior extremity; these are the testes, which descend as lengthened filaments and then turn backagain, the ascending and descending lines being entwined together. The spermatozoa are arranged in curious, curved, wedge- shaped masses, and, at the proper season, an immense quan- tity of these may be seen. The female organ is just under- neath the male. The ovaries are two sac-like, membranous lobes, within which, at one period of their development, are to be seen several round vitelli, which are attached on either side of a long, tortuous cord ; these are, of course, detached from the funiculus before exclusion. Notwithstanding most attentive observation, I have never witnessed anything like a generative act in any of the numerous individuals which I have had under inspection. JF. Miiller, however, has proved HOUGHTON, ON THE GLOSSIPHONIDA. 39 that this act does take place in the case of G. tessulata, but further observations on this pomt are needed before we can decide whether all these animals are self or mutually im- pregnating, or how far the presence of two individuals is necessary for the purpose of generation. If specimens of these worms be procured early in March, and kept im vessels of water, ample facility will be afforded of noticing the manner of depositing the ova, the period of incubation, and the gradual development of the young from the vitellus to the perfect individual ; and the extreme trans- parency of very young individuals renders a study of their structure easy and delightful. G. hyalina and G. bioculata do not sit upon their ova, but carry them about with them on the abdominal surface. The ova and young of G. dioculata are very effectually protected by_means of the folding inwards of the sides of the parent, which are thus made almost to meet and to form a sort of pouch; this fact will, I believe, explain the error of some who have asserted that the Glossiphons are, in some cases, viviparous. The young are hatched, 7. e. the partially developed embryo leaves its pellucid, gelatinous envelope in about ten days after the ovum is deposited; the number of vitelli in each envelope is variable, not only in the different species, but in individuals of the same species and in the individual itself. In G. complanata and G. marginata three to fifteen vitelli may be contained by the delicate covering. G. tessulata is the most prolific of all the species ; I have counted a hundred and twenty young ones attached to the parent. The young, for some little time after they are perfectly formed, continue tied to their “ mother’s apron-strings,”’ which they generally leave when they are about six weeks old. The Glossiphons, like all other animals, and _ especially such as are aquatic, have their external and internal parasites ; upon the curious, horn-like plate of membrane in the neck of G. bioculata it is a very common thing to find a species of Hpistylis firmly attached to it. I have never observed this parasite either on any other Glossiphon or on any other part of G. dioculata but on the cervical plate. If it has never been described, I propose to call it Hpistylis Glossi- phonie. ‘ I am quite unable to form the most remote conjecture as to the use of the plate referred to above. It is situated and opens out at the upper part of the neck. This membranous, cup-shaped body is characteristic of G. bioculata. 40 An Account of some Parasitic Ova found attached to the Consunctiv# of the TurTLr’s Eyes. By Epwtn Canton, F.R.C.8., Surgeon to the Charing Cross Hospital, and Lecturer on Surgical Anatomy. (Reprinted from the ‘ Dublin Medical Press.’) In July last, while engaged in the microscopiéal examina- tion of the tissues of the eye of the common Turtle, I dis- covered a large number of parasitic ova attached to all parts of the conjunctiva, with the exception of the modified portion of this membrane which extends across the cornea. The ova were equally numerous in both eyes. I repeated the examina- tion, and, in five consecutive stances, met with these cystic bodies, in the same situation, in the two eyes of each of the turtles. In a sixth specimen, however, the ova were entirely wanting. The turtles were lively at their death, which was of a sud- den and violent character, and took place in the city. I could discover no epizoon on any part of their heads which were sent to me. With such fixedness are. the ova adherent to the conjunc- tiva, that not even roughly scraping off the thick, slimy, secretion which covers this tunic detaches them. I de- tected them once within a few hours after the death of the animal they infest, and, in this instance, found them present in large numbers on the eyes of a turtle weighing upwards of a hundred pounds. As I have already stated, they were seen on all parts of the palpebral and sclerotic, but not on the corneal conjunctiva. So minute are these bodies, that they are undistinguishable to the naked eye. Subjoined is a magnified view of them, in a group, as shown under the microscope, and drawn by the end of the camera lucida. Form.—Elongated, unequally ovate; at each extremity the body is prolonged into an infundibuliform appendage, one of which is about a third of the length of the long dia- meter of the body, gnd terminates in a fine point, abruptly curved so as to constitute a short hook, whereby secure anchorage to the conjunctiva is effected ; the other is larger and longer, nearly equalling in length the whole ovum, and ends also in a fine point ; it is curved at the terminal point, so as to form a coil, which often presents one or two turns ; ~ CANTON, ON PARASITIC OVA. 4] this may be regarded as the suctorial portion. The body is a simple sac, entirely destitute of internal organs. Size.—For the convenience merely of stating the following measurements, I may refer to the different parts of an ovum as head, neck, body, and tail. Some of the ova are rather smaller than others, but the annexed has reference to one of larger and more ordinary dimensions : Inch. mr ea a. ae te w cayy es ONS MEMEO TCC gee woe wt an CHD! +4 HOUSE tes petra nel isc) Ponce tC UIE i (STN Ra Ra a fs PPP SRR 99 9.0 reset of head... | 6s be ils pene OOOLS Mecca little below this ....4 7... ... 0001 meer oriem from, body. ts, aster ds: 0005 ody at its widest part .21 «+. «+... "0028 RTC OT IN ko the ys cye rs hal nay ior OOS Colour.—The colour of all the ova is yellowish; or, per- haps, it may more correctly be said to be a light, ochreish- yellow; this tint pervades uniformly every part. Consistence—The chitinous shell-membrane appears to be tough and resistant ; for when, in examination, an ovum has been irregularly compressed, it is thrown into large and sharply-angled folds,—no fine wrinkling is to be observed. Aggregation—The ova are commonly found to be solitary or in pairs; more rarely are they gregarious ; but when in VOL. I.—NEW SER. D 42 CANTON, ON PARASITIC OVA. groups, there are five, eight, or sometimes ten, collected to- gether. In all the eyes examined, with the exception of those of the sixth turtle, I discovered a second form of ovum, not dif- fering, however, in any material degree, from that already described. The body is elongated, but not so swollen as in the pre- ceding variety, though it is still unequally ovate. The shorter filament, which terminates one extremity, is less regularly infundibuliform ; its thinnest portion is rather sud- denly bent at an acute or right angle to the body, and ends in two hooks, jomed by their convexities. From the oppo- site portion of the body the suctorial filament passes, and is, relatively to the corresponding part in the first-mentioned ova, longer and more thread-like ; slightly funnel-shaped at its commencement, it soon contracts, and, after a more or “less flexuous course, ends by a rather sudden expansion into a flattened disc. These ova are exceedingly few in number, and are generally smaller than those first described; they are, for the most part, found solitary: I presume them to be the same as those previously mentioned, only in an earlier stage of development. Dr. Spencer Cobbold has obligingly examined my speci- mens, and I am indebted to him for the favour of the following communication :—~ After a careful examination, I have ar- rived at the conclusion that the foreign cystic bodies adherent to the conjunctiva are the ova of an ectozoon, the latter being parasitic, either upon the turtle itself, or upon some crustaceous epizoon likewise infesting the turtle. “These ova differ in appearance from any I have hitherto encountered, and are especially interesting m the circum- stance of their presenting filamentary appendages at both ends. The hook-like filament is, probably, distinctive of the species of parasite to which the ova may be referred. “The eggs of various forms of entozoa, and also in the allied ectozoa, display filamentary appendages at both ends of the chitinous shell-capsules; these processes generally re- CANTON, ON PARASITIC OVA. 43 sembling each other, as may be seen, e. g. in Monostoma verrucosum infesting the fox, in Tenia cyathiformis belonging to the swallow, and in Tenia variabilis of the gambet. In some cases, where the filaments are shorter, the eggs more closely resemble those to which you have directed my atten- tion. This is evident in the ova of a curious trematode— Octobothrium lanceolatum—attached to the gills of the com- mon herring, and likewise in the eggs of the still more eccen- tric-looking parasite—Polystoma appendiculata—found on the branchiz of various marine fishes. “Tn all probability, the entozoon from which the ova you have found proceed is closely allied to those forms of trematode, or fluke-worm parasites, whose eggs display only one thread- like appendage, or ‘holdfast.’ For example, the eggs of different species of Dactylogyrus infesting the gills of the pike exhibit ova of this kind (a good representation of this is given by Guido Wagener in ‘ Sicbold and Kolliker’s Zeit- schrift,’ vol. ix, plate v, fig. 8). The eggs of Diplozoon pa- radoxum are also especially worthy of notice, as, from G. Wagener’s recent Prize Essay (‘ Beitrage zur Entwicklungs- geschichte der Eingeweidewiirmer’), it would appear that the single filament is liable to vary in length; whilst (as Van Beneden, Dujardin, and other observers have shown) the end of the filament is ordinarily coiled upon itself im a man- ner precisely analogous to, that noticeable in the ova from the eye of the turtle. “On the whole, therefore, I think we may safely conclude that the ova under consideration are referable to a parasite more or less allied to the well-known Diplozoon paradoxum of Nordman; and I have little doubt that—if not already known to some Continental helminthologist—we shall, ere long, discover them in the oviducts of some species of Poly- stoma, Tristoma, Octobothrium, Dactylogyrus, or other allied genus of trematode worm.” rd TRANSLATIONS. Note on Tricutna spiratis. By Professor Vircnow- (‘Comptes Rendus,’ July 2, 1860, p. 13.) I wap the honour last autumn of communicating to the Academy some of the first results of my researches respecting the development of T’richine introduced into the animal economy through the digestive passages. Since then the Academy has been made acquainted with the researches of Professor Leuckart, which appeared, in contradiction to mine, to show that Trichocephalus was a stage in the regular development of Trichina. Subsequent observations have proved that Trichina repre- sents a distinct genus of entozoa, and Professor Leuckart has himself recognised the truth of my first observations. It is in rabbits that I have been able to trace the develop- ment of the Trichina. When a rabbit has been made -to eat meal containing Trichine, after three or four weeks it _ %. will be perceived to become emaciated; its strength is sensibly *—" diminished, and it dies about the fifth or sixth week after /=-*, the ingestion of the trichinized food. 'The voluntary muscles ~ of the deceased animal will be found filled with millions of Trichine ; and there can be no doubt that death has ensued from a progressive muscular atrophy, consecutive upon the migrations of the 7richine into the system. In one case I was myself witness of the animal’s death. It was so weak that it could not stand on its feet; lymg upon the side, it exhibited from time to time slight struggles ; at last the respiratory movements ceased, whilst the heart con- tinued to beat regularly ; death took place after a few con- vulsive movements. By this method of feeding I have obtained four generations of entozoa. I first fed a rabbit with living Trichine occupymg a human muscle; it died at the end of a month. I then administered to a second rabbit some of the flesh of the VIRCHOW, ON TRICHINA SPIRALIS. 45 former; it also died at the end of a month. The flesh of this rabbit was used to infect three others at the same time, two of which died three weeks afterwards, and the third at the end of a month. I then fed two others, the one with a good deal and the other with a small quantity of the flesh of these three. The first died at the end of eight days, and in this case nothing was revealed on the autopsy beyond an intestinal catarrh ; the second died six weeks after the com- mencement of the experiment. In all these animals, with the exception of the last but one, all the red muscles, save the heart, contained such a quantity of Trichine, that every portion examined under the micro- scope exhibited several, sometimes as many as a dozen. We have here, then, to do with a mortal affection. Attentive observation of the phenomena presented in these animals, as well as in others, afforded the following results. A few hours after the ingestion of the diseased flesh the Trichine, disengaged from the muscle, are found free in the stomach ; they pass thence into the duodenum, and afterwards advance still further into the small intestine, where they become developed. From the third or fourth day, ova or spermatic cells are found, the sexes in the meanwhile becoming distinctly marked. Shortly afterwards the ova are impregnated, and young, living entozoa are developed within the, bodies of the female Trichine. The young are expelled through the vaginal orifice, which is situated towards the anterior half of the worm, and I have noticed them, under the form of minute Milarie, in the mesenteric glands, and more especially, in considerable number, in the, serous cavities, particularly the peritoneum and pericardium. According to all appearance, they had traversed the walls of the intestine, following, probably, the same course as that.pursued by the Psorospermia, according to the researches of one of my pupils, Dr. Klebs; that is to say, they penetrate into the epithelial cells of the intestine. Further than this I have been unable to discover them either in the blood or circulatory system. Continuing their migrations, they penetrate as far as the interior of the primitive muscular fasciculi, where they may be found, as early even as three weeks after the alimentation, in considerable numbers, and so far developed that the young entozoa have almost attained a size equal to that of the Trichine contained in the flesl which had been administered. In order to be certain that before the experiment the animal had no Trichine in its muscles, I have, on several occasions, before administering the trichinized flesh, examined a portion of muscular tissue excised from the back, in which 46 VIRCHOW, ON TRICHINA SPIRALIS. not a trace of the parasites could be discerned, where after- wards they would be found in such great numbers. The Trichine progressively advance into the interior of the muscular fasciculi, where they are often seen, several in a file one after the other. Behind them the muscular tissue becomes atrophied, and around them an irritation is set up, and from the commencement of the fifth week they begin to become encysted. The sarcolemma is thickened, and the contents of the muscular fibres exhibit indications of a more active cell-growth; the cyst consequently is the product of a sort of traumatic irritation. In the dog, the development of the Trichine in the intes- tine may be very readily followed, but they do not pass into the muscles, either because the intestine or the digestive secretions of the dog present obstacles to the migration or to the ulterior development of these worms. I have to thank Professor Zencker, of Dresden, for the muscles of the woman with which I began this series of researches. In this case death had occurred under circum- stances precisely similar to those which I observed in my rabbits ; the autopsy disclosed no lesion beyond the presence of innumerable Trichine in the muscles, and neither here nor in the muscles of the rabbits were they visible to the naked eye. From these facts, then, it results, that fatal cases of infection by Trichine may take place, in which the cause of death cannot be recognised except by the microscope ; and that, up to the present time, no other cases had been observed except those in which the entozoa had not only become encysted, but in which the greater number of the cysts had already reached a very advanced stage of cretifica- tion ; for it is in this condition only that they become visible to the naked eye. Moreover, since the cysts are not formed before the fourth to the sixth week, nor does the cretification take place, pro- bably, till after the lapse of some months, it may be con- cluded that, up to the present time, cases of this affection have not been recognised in the human subject until it had undergone a sort of cure, the symptoms belonging to the recent evolution of the Trichine having been long for- gotten. If the antecedent conditions in patients who have experienced the symptoms above cited were accurately noted, we should probably soon see the number of cases of trichinization increased. Besides the merit of having proved the existence in man of the Zrichine which I had found in the intestine of the dog, experiments with reference to which I have VIRCHOW, ON TRICHINA SPIRALIS. 47 communicated to the Academy, Professor Zencker has dis- covered the source of the Trichine which had infected his patient, and thus been able to throw great light upon the etiology of this affection. As the patient had been brought to the hospital at Dresden from the country, Professor Zencker instituted inquiries, and found that, four weeks previously, a pig containing Jrichine had been killed im the same dwelling; that the ham and sausages made of the flesh of this animal contained a great number; and lastly, that the butcher who had slaughtered the pig, and had swallowed the Trichine in the recent state, as several other persons also did, had, as well as they, presented rheumatic and typhoid symptoms of greater or less severity; but the patient who was sent to Dresden was the only one who fell a victim to the ingestion of the flesh of this pig. This condition therefore now involves questions of great hygienic interest. 1. The ingestion of pig’s flesh, fresh or badly dressed, con- taining Trichine, is attended with the greatest danger, and may prove the proximate cause of death. 2. The Trichine maintain their living properties in de- composed fiesh ; they resist immersion in water for weeks together; and when encysted, may, without injury to their vitality, be plunged in a sufficiently dilute solution of chromic acid for at least ten days. 3. On the contrary, they perish and are deprived of all noxious influence in ham which has been well smoked, and been kept a sufficient length of time before it is consumed. New Experiments on Heterocenesis, by means of the Air contained in the Closed Cavities of Planis. By MM. N. Joxy and Cu. Mussey. (‘ Comptes Rendus,” Oct. 22, 1860, p. 627.) (Abstract.) Ar the beginning of the year, the authors communicated to the Academy the result of some experiments instituted with the view of satisfying themselves with respect to the origin of the Microphytes and Microzoa, which are always and every- where produced in infusions of organic matters. After new 48 JOLY AND MUSSEY, ON HETEROGENESIS. experiments, continued uninterruptedly for six months, they are prepared with fresh evidence in the cause now at issue between the partisans and the opponents of /eterogenesis. As, in fact, the cardinal point of the question is reduced to the means we may have of obtaining air of extreme purity, that is to say, completely deprived of the germs which are said to float in the atmosphere, they conceived the idea of experimenting with the air or gas contained in the closed cavities of organized bodies. The swimming-bladder of fishes, the fruit of the bladder-nut, the fruit of the piment annuel, the enormous cavity in the culinary Cucurbitacee, &e., afforded, as it may be said, exactly what was desired. They then proceed: to detail the results of an experiment of this kind made with the Pumpkin. They boiled for two hours in distilled water some pieces of sheep’s liver. They then took a tube, blown mto a pear- shaped bulb at one extremity, open and drawn out at the other. This tube was heated for half an hour, until the glass was softened, and at this moment the open end was hermeti- cally closed with the blowpipe. When cold, the pomt is plunged into the boilig decoction and broken off below the surface. A portion of the fluid enters the tube, which is immediately placed on burning charcoal. Ebullition recom- mences, and the tube is again closed whilst the steam is escaping. The continuance of the ebullition, sometimes for more than a quarter of an hour after the removal of the tube from the fire, shows that the vacuum is as perfect as possible. When the apparatus is cooled, the point of the tube is inserted in the flesh of the gourd, and broken off after it has entered some distance. On its reaching the cavity of the fruit, a small quantity of air enters the tube contaming the decoction. In order to take every possible precaution, a thick layer of copal varnish, thickened with vermilion, was placed around the wound made by the entrance of the tube. A criterion apparatus was placed alongside, as aterm of comparison. This experiment, simple as it may appear, nevertheless presents considerable difficulties in the performance. The authors succeeded well twice, but made several other attempts in vain; being baffled sometimes by one cause, sometimes by another. At the end of six days’ attentive watching, they examined the decoction, and perceived in it numerous Bacteria. Many were already dead, and the survivors in a languid condition ; a very natural result, if we consider,—1, that the air contained in the pumpkin abounds in carbonic acid, of which it holds about four per cent.; 2, that only a few bubbles of air entered JOLY AND MUSSEY, ON HETEROGENESIS. 49 the decoction, which otherwise contained very little; 3, that the air was not renewed. The criterion apparatus presented the same animalcules, but they were far more numerous and more lively, which is to be attributed, without doubt, to the more abundant supply and easy renewal of the air in contact with the decoction. In support of these results might be cited those which were obtained on the authors repeating, with the utmost care and with some modifications of their own, the experiments of Schultze, of Schwann, and of Mantegazza. In the experiment performed according to the methods of Schultze and of Schwann, they obtained both Microphytes and Microzoa in the one case, and Microzoa only in the other, although the air employed had been purified by sulphuric acid, potass, or heat, and sometimes by two of these agents. With respect to Mantegazza’s experiment,* which the authors think has been too little regarded in France, it has afforded in their hands results very nearly identical with those stated by that physiologist; that is to say, abundance of Bacterium termo and Bacterium catenula. * Vide ‘Giornale del R. Istituto Lombardo,’ tom. ili, p. 467, “ Richerche sulla Generazione degli Infusoria di P. Mantegazza,” Milano, 1851. REVIEWS. The Honey-Bee, its natural history, habits, anatomy, and microscopical beauty. By James Samvus.son, assisted by J. Braxton Hicks, M.D. London: Van Voorst. Tus author of this little work, and his able assistant, Dr. Hicks, are well known for a former attempt at making known the structure of some of the more frequent forms of the lower animals around us. We spoke very highly of ‘The Earth- worm and the Housefly,’ when they appeared; and we feel called on to give the same meed of praise to ‘ The Honey-bee.’ Although Mr. Samuelson has gone over much ground that was previously well trodden, in his account of the structure and history of the habits of the bee, he has succeeded in making the subject his own, and treating it in a way that demands our praise in a literary point of view. The general structure of the bee is highly interesting, and we do not know of any descriptions of the minuter points of the anatomy of these insects which can claim to be more minute and accurate than those contained in this little volume. As much of the matter contained in this department of the volume has not appeared before in a popular form, we take the liberty of making rather a long extract from the chapter descriptive of the eyes of the bee. The author expresses himself as in- debted for this part of his work to the labours of Dr. Hicks, who is well known to the cultivators of microscopical science for the extent and accuracy of his observations. “Tn order to afford some idea of the general character and operation of one of these compound eyes, we shall compare it to a bundle of telescopes (3500, remember !), so grouped together that the large terminable lenses present an extensive convex surface, whilst, in consequence of the decreasing diameter of the instruments, their narrow ends meet and form a smaller concentric curve. Now, if you can imagine it possible to look through all these telescopes at one glance, obtaining a similar effect to that of the stereo- scope, you will be able to form some conception of what is probably the operation of vision in the Bee. This comparison, however, presents but a SAMUELSON, ON THE HONEY-BED. 51 crude and imperfect idea of the organ in question, and we shall now accu- rately describe one of these ‘ telescopes,’ as we have popularly termed them. *‘Hach of the eyelets or ‘ ocelli’ which, aggregated, constitute: the com- pound eye of a Bee is itself a perfect instrument of vision, consisting of two remarkably formed lenses, namely, an outer ‘ corvea/’ lens and an inner or ‘conical’ lens. The ‘corneal’ lens is a hexahedral or six-sided prism, and it is the assemblage of these prisms that forms what is called the ‘corned of the compound eye. “This ‘cornea’ may easily be peeled off, and if the whole, or a portion, be placed under the microscope, the grouping of the beautiful lenses becomes distinctly visible. “ But, stay! we must not yet part company with the corneal lens of the Bee’s eyelet; for, on closer investigation, we shall perceive that it is not a simple but a compound \ens,—a fact of considerable importance, that has, we believe, been overlooked by physiologists. It is composed of two plano- convex lenses (that is, as you doubtless know, lenses having a plane and a convex surface) of different densities or refracting powers, and the plane sur- faces of these lenses being adherent, it follows that ¢he prismatic corneal lens is a compound double convex lens.* “The effect of this arrangement is, that if there should be any aberration or divergence of the rays of light during their passage through one portion of the lens, it is rectified in its transit through the other. Now it is nothing new to find in the eye of an animal lenses of different densities, but we do not recollect ever having heard of any other instance where one compound lens has been found consisting of two adherent ones of this description.+ How remarkable, then, that we should discover such a phenomenon in so humble an animal as the Bee! Aye, reader; and how remarkable, too, that we should find such a contrivance adopted by man in the construction of what he at present considers the most perfect microscopic lens! “With untiring patience and perseverance his mind was directed to the attainment of this end, namely, to correct the aberration of light, which caused his lenses to colour and distort the objects under investigation, until he found that, by employing compound lenses of varying densities, this evil effect was counteracted; and now we see that the Creator had, probably before man was brought into existence, constructed the eye of the Bee on the same principle. * “There is one thought that cannot fail to present itself to the reflecting mind in connexion with this analogy between the eye of the Bee and the achromatic lens, confirmatory of the great declaration that ‘God made man in His own image,’-—Has not man invented what He no doubt suggested, but not alone through the medium of the external senses? for man knew nothing of the compound lens in the Bee’s eyelet when the idea occurred to him to construct an achromatic lens for his microscope, and yet it is obvious that he hit upon one of the most perfect means of attaining the desired end! **A word more regarding the corneal lenses of the Bee. “It appears to us questionable whether the normal shape of these lenses is hexagonal, or whether this form is not rather a necessity of growth; that is to say, we think they are normally round, but assume the hexagonal shape during the process of development in consequence of their agglomera- tion. If this surmise he correct, it applies equally to the compound eyes of all insects, and our inference in this respeet is drawn— * We believe the credit of this discovery is due to Dr. J. B. Hicks. + 1t is not unlikely that the eyes of other insects are similarly con- structed. 52 SAMUELSON, ON THE HONEY-BEE. -“1. From the exceptional character of hexagonal or any other than cir-° cular lenses in the eyes of all animals, and from the fact of the simple eyes of insects themselves being circular. eB pecty the circumstance that, in the insect races, the conical lenses of the ocelli (to be deseribed presently), which do zo¢ impinge one upon another, are not hexagonal but round. “3. Because in the posterior angle of the compound eye of the worker- bee we often find some of the corneal or external lenses of a smaller size, and not adherent, but having a little intermediate space surrounding each, and these facets are invariably round. “From the fact that in one insect at least; the sheep-tick (Melophagus ovinus), which ranks very low in the scale of development, we find au the external facets of the compound eyes non-adherent and circular.* ‘“So much, then, for the corneal lens of the ocellus of the Bee, a com- pound hexahedral prism with double convex surfaces. Following the course of a ray of light after it has passed through tlus lens, we find that it tra- verses a vacant space before entering the conical lens, this space being sur- rounded by the dark pigment already referred to, and constricted or nar- rowed midway into the form of a round hole, on the same principle as the diaphragm in the eye-piece of a microscope or in the Coddington lens. “This natural diaphragm is so formed, that the amount of light which is permitted to pass is to some extent limited, and any remaining * tendene to aberration in this wonderful instrument is thereby completely corrected. The same layer of dark colouring-matter is continued downwards between the conical lenses, so that these are effectually isolated, and the rays cannot become confused by passing from one lens to the’ other. The conical lens is curiously shaped, but simple in its structure, not being compound, as is the corneal lens, but of the same density throughout. It is also double convex, the base as well as the apex (from which the point is removed) pre- senting rounded surfaces. “At the apex it comes into contact with the bulbous expansion of the - optic nerve, which receives the image of the external object, and this nerve proceeds downward in a line continuous with the axis of the ocellus, until it meets the nerves of the other eyelets. ‘Tliese then unite and form a com- mon trunk that communicates with what we may pope call the insect’s brain (strictly speaking, the ‘cephalic ganglia’). “But you may, perhaps, be puzzled to understand how so many small images, as must necessarily enter the compound eye of the Bee, ean become amalge amated and combine to form a single picture of the external field ; the effect will, however, be perfectly clear to your mind, if you only con- sider the auiion of our own two eyes, which convey to our brain not two, but only one distinct image of the surrounding objects ; and supposing that, instead of two, we had a considerable number of eyes properly dis- posed, the ultimate effect would be just the same. Now, an examination of the external lenses of the compound eye of the Bee shows that their surfaces, especially the inner ones, are not all of equal convexity, and there appears to be, as we might expect, such an arrangement and disposi- tion of the whole mass as to ensure the most perfect co-operation between each lens and the surrounding ones. We also find regularly scattered over the surface of the cornea—in fact, one between almost every Jens and its neighbour—a great number of long hairs, and these also aid, no doubt, mm * A careful examination. of the eye in the pupa, whilst in process of development, confirms the opinion here expressed. SAMUELSON, ON THE HONEY-BEE. 53 the stoppage or diversion of indirect rays that might tend to confuse the common image. “Tn a former work* we expressed the opinion that the object of these numerous facets in the compound eyes of insects is to render the external field clearer when the insect has occasion to enter the dim hollows of flowers and other dark places in search of food, through the formation of a single picture by the union of agreat number of smaller images; and this view would appear to receive striking confirmation from the organs of vision in the Bee, which spends a considerable portion of his time in the corolle of flowers, or in the darkened hive.” After this lengthened extract, which will give our readers a good idea of the style and the matter of the work, we can only say that many other points in the anatomy of the bee are treated in the same way. ‘The functions of the bee are examined in detail, not omitting the curious question of the parthenogenetic origin of the male or drone bees. The ques- tion of the original form of the cell, as towhether it be hexagonal or cylindrical, is discussed ; and the author is inclined to adopt the view of Mr. Darwin that they are originally cylindrical. The drawings illustrating the anatomy of the insect are admi- rably done, and they will be found invaluable to those who wish to mark, with microscope in hand, the beautiful structure of these familiar creatures. This volume is a worthy com- panion of ‘The Earthworm and the Housefly,’ and is, in fact, as far as matter and treatment go, superior to that volume. There are other “ humble creatures” whose history might be profitably told in the same way, and we hope Mr. Samuelson and Dr. Hicks will be encouraged to go on in the interesting path which they have thus far so successfully trodden. * ©The Harthworm and Housefly.’ A History of Infusoria, including the Desmidiacee and Diatomacee, &c. By Anprew Prircnarp, M.R.1. Fourth Edition. Enlarged and revised by J. T. Artines, W. Arcuer, J. Ratrs, W. C. Witiiamson, and the Author. Forty Plates, pp. 968. WHEN a work has reached a fourth edition, it may be con- sidered in most cases to have passed beyond the domain of the reviewer; and Pritchard’s ‘ Infusoria’ has been so long before the world, and, as the number of editions through which it has passed shows, so well appreciated by microscopical observers, that it might now fairly be expected to have escaped any further critical ordeal. But the fact is, that although the old title, and a considerable part of the contents of former editions, are retained, the present may, in all essential respects, be regarded as a new and, to some extent, an original work. As such, we cannot but congratulate the world of microscopists upon its appearance. The names on the title-page are sufficient guarantee for the value of the re- spective portions they have contributed to thecontents; and we have no hesitation, after a careful survey, in saying that we regard Mr. Pritchard’s work, in its present guise, as a valuable contribution to science, and well calculated to afford to those who are interested in the subjects upon which it treats a satis- factory and lucid compendium of nearly all that recent observations have brought to lght. Nothing is more striking in the progress of hiological science than the daily increasing extent to which the subdivision of labour is carried ; whilst, at the same time, for the advance of real knowledge nothing has become more indispensable. The indefatigable and continual labours of collectors and ob- servers have so multiplied the objects of natural history in all branches, that it is now quite impossible for any imdi- vidual, however acute his perceptive faculties, or however retentive his memory, to embrace more than a very limited range of subjects. This is obvious enough even in the case of the higher and specifically less numerous classes of animals and plants ; and in the lower, the multiplicity of forms is so vast, as torender even extreme subdivision imperatively necessary for their accurate study. And the same considerations apply in their fullest force to those lowest forms of living organisms which constitute more peculiarly the subjects of microscopic study. We consequently find, that although Ehrenberg, but a few years back, was able, like a second Linnzeus on a small PRITCHARD, ON INFUSORIA. 55 scale, to embrace the whole of the then known microscopic world, at the present time anything like a sufficient view of it, even in a general sense, requires the concurrence of several observers, each of whom has made a particular depart- ment in it the subject of his special attention. The present work is a favorable instance of what may be effected by this scientific co-operation. The work is divided into two parts; the former comprising a “ General History,” and the second a ‘‘ Systematic History, of the Infusoria,” as they are termed. But this term, it must be understood, is here used in a wider sense than that in which it is now usually accepted. Mr. Pritchard, we presume, for the sake of keeping up a uniformity of title with the former editions of the work, retains the term “ Infusoria” in the wide or Ehrenbergian sense; whilst most recent writers confine it to a particular class or division of the rather vague sub-kingdom Protozoa, corresponding pretty nearly with the “ sub-section” here (p. 266) termed Ciliata. The necessity of adhering so closely to the old title of the work may, in a commercial point of view, have been considered imperative, but in a scientific, it is much to be regretted; for im science—and this applies as strongly to science presented in a popular form as in a more rigid guise—precision in the use of terms, it is perhaps needless to insist, is of the utmost importance. The Infusoria, then, as the term is here employed, are sub- divided into—1, Bacillaria ; 2, Phytozoa; 3, Protozoa; 4, Rota- toria, or Rotifera; and 5, Tardigrada; and the mere sight of these names is sufficient to show the confusion that must arise in the non-scientific mind, when it finds organisms of such extreme diversity embraced under any common term, and especially when it discovers that that term has, within a few years, been employed to distinguish a group of organisms regarded almost as an equivalent to a sub-kingdom of animals. In this sense it has long been discarded by all naturalists, and it is much to be regretted, as it appears to us, that a work so deservedly popular as the present will undoubtedly become should have a tendency, from the want of due explanation, to perpetuate a grievous error. With respect to the mode in which the different sections of the work have been elaborated by the respective editors or authors, as they might properly be termed, we can only repeat that it is in the highest degree satisfactory. The care and judgment with which the most recent observations and views have been collected, condensed, and in many instances commented upon, are deserving of the highest commendation. And as regards the general arrange- 56 WALLICH, ON MARINE ANIMAL LIFE, ment and execution of the book, our verdict would be equally satisfactory, although some space, perhaps, might have been saved by the omission from the “second part” of many par- ticulars concerning different groups which either are or might have been embraced in the first part, or General History. The additional illustrations, fillimg twenty-one new plates, appear to have been well selected, and equally well executed. Without any special reference to the present work, which, it must be confessed, is sufficiently bulky already, we would remark upon the strange circumstance, that in most works devoted to microscopic objects, scarcely any notice is taken of one of the most numerous, varied, and beautiful class of microscopic creatures—viz., the Polyzoa. Not only are the beauty and variety of form presented in these animals as great as in any others of those which more commonly come under the observation of the amateur microscopist, but im a scientific, and more particularly in a geological point of view, their study is fully as important and interesting as is that of the Diatomacee and Foraminifera. We hope therefore, in time, to see these brought more conspicuously under popular notice in works expressly devoted to the entertaimment and imstruc- tion of MICROSCOPISTS. Notes on the presence of Animal Life at vast depths in — the Sea, with Observations on the Nature of the Sea- bed as bearing on Submarine Telegraphs. By G.C. Wauuicu, M.D., &e. Dr. Watiicu has just returned from an arduous under- taking. Ata very short notice, animated by the ardent zeal by which he is distinguished, he started as naturalist on board the Bulldog, commanded by Sir L. M‘Chntock, and employed in the survey of a proposed telegraphic route to North America. The first-fruits of this expedition, m anti- cipation, doubtless, of a further and more detailed account of his observations, have been printed by Dr. Wallich, under the above title; and a very interesting communication it is. It is scarcely too much to say, that Dr. Wallich’s observations, on this voyage, will have the result of considerably modifying the views of naturalists, as to the necessary limits placed by depth in the ocean to the existence of animal life. The WALLICH, ON MARINE ANIMAL LIFE. 57 results of former observations of the soundings obtained in the survey of the route for the Great Atlantic Telegraph showed the strong probability, if not the absolute certainty, that animal life could be maintained at the enormous depth of between four and five miles; in fact, that the bed of the ocean, throughout a vast tract, was composed of a soft bed, formed of the shells of defunct and living Foraminifera, for the most part Globigerina ;—a fact perfectly in accordance with what might have been concluded from our knowledge of the composition of Chalk, and other similar formations of a more recent date; as for instance, that which occurs near Oran, in Algeria. But Dr. Wallich’s late dredgings, if the term can be used, have shown, that not only can the lowly organized Rhizopod exist far “ removed from light of day,’ and under a pressure of many tons on the square inch, but that creatures of the high type of organization presented in the Echinodermata are also capable of existing at a depth of 1260 fathoms, or in water condensed under a pressure of about 4000 lbs. on the square inch and what is more mar- vellous still, that animals of that complex structure can bear to be suddenly brought to the surface, without apparent injury. Besides this, “ on two occasions, living specimens of Serpula, one from 680 fathoms, and in conjunction with a living Spirorbis, other free Annelids and two Amphipod Crustaceans were also taken alive at 445 fathoms.” Here, then, as Dr. Wallich observes, “ there is a fresh start- ing-point, in the natural history of the sea. At a depth of two miles below the surface, where the pressure must amount to at least a ton and a half on the square inch— where it is difficult to believe that the most attenuated ray of life can penetrate—we find a highly organized species of radiate animal living, and evidently flourishing; its red and light pink-coloured tints as clear and brilliant as in its conge- ners inhabiting the shallow waters, where the sun’s rays penetrate freely.” The circumstances recorded leave no doubt that the Ophiocoma in question, of which numbers were brought up, must have resided at the depth mentioned; and this fact might be concluded even from the contents of its stomach, which consisted of Globigerina shells, more or less com- pletely freed of their soft contents. The little brochure contains many other highly interesting observations, and especially some having reference to the value of microscopic soundings in the determination of the course, &c., of oceanic currents—a subject which had at- tracted the attention of the late lamented Professor Bailey, VOL. I —NEW SER. E 58 DAY, ON CHEMISTRY RELATING TO PHYSIOLOGY, &c. and which promises to afford important results in the hands of future observers, who will now have the advantage of being armed with an ingenious contrivance for the bringing up of deep soundings, for which naturalists are, we believe, mainly indebted to the ingenuity of Dr. Wallich. Chemistry in its Relations to Physiology and Medicine. By Grorcr HE. Day, M.D. London: Bailliere. AurnoucH the science of physiology cannot be fully com- prehended, unless studied in connection with the organs which perform the functions of life, there can be now little doubt of the yast importance to be attached to the chemical constitu- tion and changes which the organs of living bodies undergo. In fact, the great development, in recent years, of physiological science has been in the direction of chemical inquiry. It is the object of Dr. Day, in this book, to set forth more par- ticularly the relations of chemistry to physiology ; and he has produced a work of great practical value. We have been previously indebted to him for having translated Simon’s work on ‘ Animal Chemistry’ and Lehmann’s ‘ Physiological Chemistry,’ and no one could be better fitted for giving a view of the whole subject than Dr. Day. But whilst it is easy to separate the chemistry of life from any detailed ac- count of the morphology of the organs of living beings, it is impossible to treat this subject satisfactorily, without describing the histological structure of the organs and secretions. Hence the necessity for the use of the microscope, and the examination by its aid of the various tissues and secretions. Whilst, therefore, writing a book expressly devoted to the chemistry of life, Dr. Day has felt himself compelled to refer constantly to the nature of those living products which can only be detected by the aid of the micro- scope. The work is accompanied by five plates, illustrative of the microscopic structure of the crystals and histological elements found in the blood and secretions. These illustra- tions are got up in the style of those published in Funk’s ‘Physiological Atlas,’ and will be found of great value to the student who is beginning to work at this subject. Dr. Day has divided his work into three great heads or departments: 1, The organic substrata of the body; 2, The chemistry of the animal juices and tissues ; 3, The great zoo- chemical processes. It is in the second part more particularly DAY, ON CHEMISTRY RELATING TO PHysioLocy, &c. 59 that the student of the microscope will find the subjects of his study more specially treated of. The subjects there successively taken up are the digestive fluids, the blood and its allies, the fluids connected with generation and development, the secretions of the mucous membrane and the skin, the urine, pus, and the solid tissues of the body. To those who wish to make the use of the microscope subservient to the study of physiology, we confidently recommend Dr. Day’s volume as one of the most trustworthy guides in our language. 60 NOTES AND CORRESPONDENCE. Atmospheric Micrography.—Under the above heading, there appeared in No. XXII of the ‘ Microscopical Journal’ the translation of a paper by Professor Pouchet, of Rouen, pur- porting to be the description of an instrument termed the aéroscope, but which, at the same time, revived what some might call the exploded theory of spontaneous generation. As it appears to me that this question cannot be said to be finally disposed of, but as the learned professor’s arguments in favour of the theory are somewhat biassed, it may not be inappropriate that the attention of microscopists should be once more directed to the subject. By most advanced naturalists, the theory of spontaneous generation has been discarded as absurd, or, at least, as highly improbable, and mainly, I believe, on two distinct grounds, viz.—Ist, that it is directly opposed to the accepted theory that, for the production of a new individual, in either the animal or vegetable kingdom, there must be a conjugation of the “germ” and “sperm” cells (pre-existent, therefore) ; and 2dly, in consequence of the well-known experiment of Professor Schultze with filtrated and unfiltrated air upon de- composing animal substances.* Neither of these grounds suffices, however, for the final rejection of the theory; for in a great many of the Protozoa conjugation has never been traced, and, so far as they are concerned, the sexual theory is, to some extent, hypothetical ; and secondly, I do not recollect having read or heard that Schultze’s experiment has ever been confirmed by any English or foreign microscopist or chemist of note, although the complete confirmation of this experiment would effectually dispose of the theory. Having thus given fair play to the advocates of the theory, I shall now proceed briefly to examine Dr. Pouchet’s argu- ments in its favour. * See ‘Carpenter on the Microscope,’ p. 485, &c. &e. MEMORANDA. 61 His evidence consists, on the one hand, of the fact stated by him, that his investigation of the atmosphere with his aéroscope has not enabled him to detect the “ ova of infu- soria ;” and, on the other hand, that when “ suitable’ infu- sions are exposed to the air, millions of “ infusoria’”’ are sure to make their appearance in it. (I would draw especial attention to the words in italics.) At the same time, he declares that the “ova” are “ infi- nitely rare,” even in situations where they might be expected to occur. In the first place, it is right that I should remind your readers of the fact (of which I can hardly suppose Dr. Pouchet to be ignorant), that the term “ infusoria,”’ formerly applied by Ehrenberg and others to a great variety of forms belonging to the Protophyta, Protozoa, Annuloida, &c. &c., is now restricted to that group still denominated “ Polygastrica,” by Dr. Pouchet. As before stated, in many of these forms, conjugation of the “germ” and “sperm” cells has never been traced, and I think I am correct in saying no “ ova” have been discovered. It is therefore not surprising that Dr. Pouchet should not have been able to detect the “ova” of Polygastrica (so called) in-the atmosphere, granting even the utmost perfection to his apparatus; and I should be much surprised if I heard that even the highest powers of our microscopes had revealed the dried germs of these organisms in their earliest stage. This brings us to the second phase in Dr. Pouchet’s evi- dence. He says, that whenever a suitable infusion is employed, and placed in contact with not more than a décimétre of air, millions of infusoria are almost sure to make their appearance. He does not state of what his “ suitable infusion” consists, nor what are his infusoria. In No. XVII (October, 1856) of this Journal, you pub- lished an abstract of my paper, read before the British Asso- ciation, in which I described an experiment tried by me with an infusion of chlorophyll. This consisted of the juice of cabbage mixed with a solution of gum, and baked at an in- tense heat over a furnace, so that all traces of life must have been destroyed; the chlorophyll cake thus obtained was dis- solved in distilled water, and this formed the infusion. I found, on exposing this compound to the air, that in a day or two, a few of the forms known as ‘‘ Glaucoma sciniil- lans” made their appearance; and these multiplied with incredible rapidity. The conclusion at which I arrived from this experiment was, that the dried zoospores, or germs, floated about in the atmosphere; and I had at least as good 62 MEMORANDA. reason to believe so as Dr. Pouchet has for assuming that when a suitable infusion is exposed to the air, the “ ova” of infusoria, or the infusoria themselves, spring into life byspon- taneous generation. The value of this portion of his evidence would have been better appreciated if he had stated accurately of what substances his suitable infusion consisted, whence the substances were obtained, what species of infusoria made their appearance, and after what lapse of time the first ap- peared. Dr. Pouchet, as a physiologist, would not wittingly seek to uphold an erroneous theory simply because he had formerly espoused it as correct. No doubt he and others will again give it an unprejudiced trial, and it appears to me that there are various ways of arriving at a satisfactory conclusion. Any one, even without a laboratory at his disposal, may verify or controvert the statement of Professor Schultze. The exposure of various dissimilar infusions to the atmo- sphere in the same place, and of stmzlar infusions in different places (care being taken in every case that the germs of life are extinct in the substance exposed), and the examination of the living forms that appear in them, would also aid in solving the problem. If the latter expedient be resorted to, it would be as well to bear in mind that, in the infusion of cabbage juice and distilled water exposed by me in the neighbour- hood of Hull, the form that presented itself (alone, so far as my memory serves) was Glaucoma scintillans. Without reference to the question of “ spontaneous genera- tion,” I feel satisfied that good results would follow from a repetition of these experiments ; for the observer must neces- sarily watch the development of different forms of animal and vegetable existence, and in so doing he would not only obtaim a clearer insight into this organisation, but would, in all pro- bability, be able to add to the small stock of information that we possess on this interesting branch of natural history.— JAMES SAMUELSON. thin Stage for the Microscope. Constructed by Thomas Ross.—p D is a dovetail plate affixed to the main body or box of the instrument. In this works the fitting c, which has a strong bar, EE, at right angles to it (all one casting). Motion is given to the fitting, c, by means of the screws. a, milled head fastened to screw; this screw works in a spring box, which prevents loss of time. On the bar, at right angles to Cc, moves a strong-fitting box, Kk, to which motion is com- municated by the milled head and pinionc. Surmounted on | cman celia ial i 2 ee ee ee MEMORANDA. 63 box, Kk, is a plate, 11, supported by two strong curved brackets, NN, which give great strength and support to the & @) plate, 11, in which a circular plate is fitted, and to which the top stage-plate, L, is also fixed. By means of the circular plate the upper stage may be rotated. This form of stage is exceedingly convenient, and, applied to the more portable instruments, will enable them to work with the same illuminating apparatus as the larger ones. The entire thickness does not exceed one quarter of an inch, and the support brackets are so constructed as to prevent tremor. Oscillatoriaceze.— When going over some of these organisms, afew days ago, I observed one coiled up like the accompanying diagram, in which it will be observed that both extremities of the filament are pointing in the same direction. The filament thus coiled continued to revolve steadily upon 64 MEMORANDA. the centre of the coil, in the same direction, viz., from left to right, for half an hour, at the expiration of which time I was obliged to leave it; on my return, in about a quarter of an hour, it had vanished, and couldnot of course be recognised among its numerous brethren, when uncoiled. If I do not err in supposing that a motion of this kind in Oscilla- toria has not been recorded, I beg you will be good enough to “ make a note of it” in your columns for this purpose. The filaments of this species are transparent tubes, sparsely studded with small granules, that appear brown, or reddish brown, by transmitted light; their diameter is 1-6000th of an inch; the length varies, but amounted in the longest to 1-50th of an inch. No markings or segments were visible with Ross’s quarter. I did not use any higher power. They were gathered from the bottom of a very muddy pond, nearly dried up, when searching for the “Tank-worm.””—J. Mircue.z, Lieutenant,. Madras Veterans. On preparing the Shells of the Polycystine, from Springfield, Barbadoes.—Through the kindness of one of our members, Admiral Duff, I was put in possession of some of the Barbadoes earth from Springfield estate. The shells are in countless multitudes, but imbedded in a light porous substance resemb- ling discoloured chalk. As the shells are known to be sili- ceous, some of the earth was boiled in hydrochloric acid, some in nitric, and some in sulphuric, but no effect was produced. Some was boiled in caustic soda, but the shells dissolved as freely as the matrix. As it is needless to describe numerous failures, I shall proceed at once to the process which succeeded. There was procured— 1. A large glass vessel such as gold-fish are put in; 3 or 4 quarts of ordinary pipe water were put into this. 2. A new tin saucepan, holding about a pint. 3. Two thin precipitating glasses, holding about 10 ounces each. Take about 3 ounces of Barbadoes earth (lumps are best), and break them with a piercer into tolerably small fragments. The earth should be quite dry. Put 3 or 4 ounces of common washing soda into the tin, and half fill the vessel with common water. Set on a clear fire until it boils strongly ; then throw MEMORANDA. 65 in the earth, and let it boil for half an hour or more ; take off the fire and pour about nine tenths of what is ia the saucepan into the large glass vessel holding the cold water. The undissolved lumps which remain in the tin may now be gently crushed with a soft bristle brush, soda and water added as before, and boiled again; pour off as before, and repeat the pro- cess until | ‘nothing of value remain in the tin. Then take an ivory spatula, and stir round and round the contents of the large glass vessel; let it stand for about three minutes, and then pour off gently nine tenths of the contents, a considerable quantity of a sandy-looking substance will be found at the bottom. These are the shells partially freed from the matrix, but still very unclean. Wash out your tin, cover the large glass vessel, and the shells will keep for the next leisure evening. _ Second process.— Put common washing soda, as before, and water into your tin; transfer all your shells into the tin, and boil as before for an hour or more. Transfer all into the large glass vessel containing water, as before, and after standing one minute pour off the: muddy contents ; add a large quantity of cold water, stand for a minute, and pour off, The shells may now be transferred to one of the precipitating- glasses. Each washing brings“over more and more of a kind of flock, which seems to be the skins of the sarcode bodies of those minute creatures. We are now ready for the third process Drain off the water from the sheils which are in your precipitating-glass until not more than half an ounce of water remains above them; add about half a teaspoonful of bi- carbonate of soda, which will dissolve pertectly with a little warmth; then pour’ in gently about an ounce of strong sulphuric acid. The violent effervescence acts as a purge on the shells, blowing out the softened contents, and liberating a large quantity of sarcode flock. The acid also (which is in great excess) dissolves the iron colouring-matter, making the shells beautifully transparent. All that ‘remains now to do is repeated washing, during which process the shcils can be sorted. Thus, fill the precipitating- glass having the shells in it with water, let stand for three quarters of a minute, and pour the water into the second precipitating-glass; let the second glass stand for two minutes, and throw away what still remains suspended ; repeat this, and all the smailer shells will find their way into the second glass, and all the larger ones will remain in the first. If the large shells are not perfectly clear, repeat the boii in soda, the acid, and the washing. 66 MEMORANDA. It is true, this method destroys a few of your larger globes ; but you can afford to lose them, as they are too large for the microscope. You can examine the shells from time to time bya drop-tube, letting a single drop fall on a glass slide placed horizontally on the stage. An oblique light shows them best.—THomas Furtone, 10, Sydney Place, Bath. Further Notes on Finders.—At the conclusion of a letter on “ Finders’ (inserted in your Journal for last July), I en- deavoured to impress upon opticians the desirableness of directing more attention to the subject of the Binocular Microscope than they have hitherto done; and it appeared to me a singular coincidence, that the very number contain- ing my suggestion should also contain what looked like a precise answer to it. I allude, of course, to the intensely interesting essay by Mr. Wenham, at page 154 of the ‘Transactions.’ On reading that paper, I felt quite satisfied that the ultimatum, or something very near it, had at length been attained; and immediately commenced a correspondence with Mr. Wenham upon the subject. Nothing could possibly exceed the kindness with which that gentleman took up the matter; even offering to send me his own instrument for examination. But this I declined, as it was clear to me that the mode he had adopted must answer. I, according, re- quested him to supervise the adaptation of one of his prisms to a double tube added to my miscroscope. And now that this has been done, and I have had time for a fair and deliberate examination and trial of it, I should consider myself very deficient in duty to my brother micro- scopists, if I delayed another moment to recommend it to them, as by far the greatest advance’ that has been made upon the instrument since the invention of achromatics. It is, indeed, a very magnificent improvement. The comfort (or, I may truly say, the duxwry) of using both eyes equally, when both are equally good, is very delightful; but that is not the only nor, indeed, the chief point of superiority. It is the entire relief from all that unpleasant optical fatigue produced by the old practice of using one eye at atime. With the binocular arrangement the observer may go on hour after hour with perfect impunity, feelimg no worse than if he had merely been reading a book through a binocular hand-glass or a common pair of spectacles. But after long use of the one-eyed tube, it is not so. It produces more or less feeling of pain, confusion, megrims, giddiness, &c., and, in the course of years, is pretty sure to effect some MEMORANDA. 67 degree of permanent injury to the chiefly used eye, as I can testify from experience. It would have been a great boon to me if I could have had the Wenham Binocular thirty years ago; and, therefore, I consider it, as I have said, a duty to recommend it to those who are commencing their micro- scopic career. Now, with regard to its “ performance” (as the opticians say), I almost fear to write all I think, lest my own words (in my letter alluded to, page 201) should be retaliated upon me, and I should be accused of giving a “ flaming account !” I would, therefore, rather express my own opinion in the words of one of the firm of Smith, Beck, and Beck, who adapted the prism, and made the brass-work, &c. He says, in a letter which was privately shown to me, “ I am de- lighted with it. For injections it is glorious! I do not wish to see any thing better.” And, in a letter to me, since sending the instrument, he writes, “I am getting to like it more and more.” ‘The latter remark is wonderfully borne out in practice; for, as a prisoner who has long hobbled in shackles is, when relieved of them, some time before he comes to the full enjoyment of the natural use of his limbs, sO a microscopist who has for years been im the habit of poking and straining through his ha/f-microscope with one eye, while he winks and blinks, and squeezes up the other, or (as I have seen multitudes do) holds down its lid with his fingers, is really some time before he comes to the full enjoyment of using both eyes in a natural manner. This, however, is, when the eyes are good, soon surmounted ; and then commences what may truly be called “ the real binocular delight !” But here an objector may put in, “ Fine talking, sir! but I have heard that, although these new-fangled double- barrelled affairs may do for low powers (inches and two inches, &c.), m order to exhibit ‘pretty things’ as a raree- show for young people, &c., yet they will not do for high powers, and are quite insufficient for ‘ test-objects’ of every kind,” &e. I reply, never was there a greater mistake. The new in- strument certainly has a clearer field with a low power, and with the one-inch objective and lowest eye-pieces I can dis- tinctly read the Lord’s Prayer, which was written for me with Mr. Peters’s machine (‘ Microscopical Journal,’ No. XII, p. 55) within a “circle of the one fiftieth of an inch. With the half-mech it is as legible as pica prt. With the quarter-inch IT can beautifully exhibit what were, not very long since, considered “ high tests ;”? such as the delicate markings on 68 MEMORANDA. the scale of the Podura, and the lines and cross-bars on the fan-shaped scale of the Morpho Menelaus. This is as far as most persons care to go. Nevertheless, I do not deny, that beyond this there does exist a very limited class of what I call “excruciating objects” for which “ the Binocular” is not so well adapted; and for such profoundly erudite researches the determined observer may keep an old single barrel, which can be adapted, in place of the double one, in less than half a minute. It should be contrived to pack into the same case, and should be called “ the excru- ciating tube.’’ By its means, together with a Powell’s one sixteenth or a Wenham’s one twenty-fifth, he may possibly be enabled to solve such infinitesimally argute problems as whether the scale of Pontia brassica has, or has not, diagonal as well as longi- tudinal lines; and whether the dots on Pleurosigma angu- latum are of a round shape, as represented in ‘ Microscopical Journal,’ vol. iv, Pl. XII, or hexagonal, as revealed in Dr. Carpenter’s ‘ Revelations,* p. 307;—researches which, to use the quaint words of Dr. Goring, are “ about as profitable to ourselves and our fellow-creatures as if we were engaged in the sublime and important occupation of determining whether the small star of « Bootes is of a greenish blue or bluish green, or whether some nebula is very gradually, or very suddenly, much brighter in the middle.”+—Henry U. Janson, Pennsylvania Park, Exeter. * Tt is to be regretted that it should have been stated in that work that there is a difficulty in adapting the Wenham binocular to “the varying distances of the eyes of different individuals.’’ The truth is, the said adap- tation is one of the best things about it, and consists merely in drawing out or pushing in the two eye-tubes. f ‘ Microscopic Illustrations,’ p. 211. 69 PROCEEDINGS OF SOCIETIES. Microscoricat Socirtry, October 10th, 1860. Dr. Lanxester in the Chair. C. T. Simpson, Esq., and Dr. Betts were balloted for and duly elected members of the Society. The following papers were read :—‘ On the Self-Division of Micrasterias denticulata,” by Mr. Lobb (‘ Trans.,’ p. 1). “On a portable Field or Clinical Microscope,” by Dr. Beale (‘Trans.,’ p. 3). : “ Description of the Objects in the Slides of Diatomacez,” presented by the Boston (U. 8.) Natural History Society. November 14th, 1860. Dr. LANKESTER in the Chair. L. C. Baily, Esq. ; Thos. Wain, Esq.; P. J. Mitchell, Esq.; John Burton, Esq.; and M. Bywater, Esq., were balloted for and duly elected members of the Society. The following papers were read:—“ Ona New Form of Dis- secting Microscope,” by Mr. Smith (‘Trans.,’ p. 10). “ On New Undescribed Species of Diatomacee,”’ by Mr. Norman (‘Trans.,’ p. 5). December 12th, 1860. Dr. LANnKEsTER in the Chair. Geo. Western, Esq.; Jas. H. Steward, Esq.; Alexander Fitz- gerald, Esq.; Peter Jones, Esq.; P. J. Firmin, Esq. ; Jas. Samuel- son, Esq.; and W. L. Freestone, Esq., were balloted for and duly elected members of the Society. The following papers were read :—“ On a New Form of Bino- cular Microscope,” by Mr. Wenham (‘Trans.,’ p. 16). “On the Corpuscles of the Blood,’ by Dr. Addison (‘ Trans.,’ p. 20). 70 PROCEEDINGS OF SOCIETIES. Presentations to the Microscopical Society. October 10th. Observations on the Genus Unio. By Dr. Lea Description of Hight New Species of Unionide. By Dr. Lea Hirst Report of a Geological Reconnoissance of the Northern Counties of Arkansas during 1857, 1858. By David Dale Owen List of Diatomacee found in the neighbourhood of Hull. By George Norman : Annuaire de P Academie Royale de Belgique Bulletins ditto ditto Transactions of the Academy of Science Gf St Louis, for 1857 Ditto ditto ditto for 1858, Nos. Lg, 3 Journal of the Proceedings of the Linnean Society. Supplement to Vol. IV—Zoology Recreative Science, Nos. 11, 13, 14 3 Annals and Magazine of Natural History, Nos. 30—34. Proceedings of “the Literary and Philosophical ae of Liverpool, No. 14 The Canadian Journal of Industry, Science, ‘and Art . Transactions of the Tyneside Naturalists’ Field Club. Vol. IV, part 3 : Proceedings of the Academy of Natural Sciences of Philadelphia 5 Journal of the Geological Society, 1 No. 62 Photographic Journal, Nos. 98 to 101 British Dental Jourual, Nos. 48, 49, 51 A Box containing slides of American Diatomacer, fr om the Boston Natural History Society November 14th. The British Diatomacee. By the Rev. W. Te Vols. I, 11,1858, 1856 ; > Ralt’s Br itish Desmidie, 1848 Pritchard’s History of Infusorial Animalcules, Se The whole of the Quarterly Journals of Microscopic Science up to the present time The Select Works of Antony van Leeuwenhoek, Vols. I, IJ, 1800 to 1807 Swammerdam ee Tnsestoram Vols. I, ae Ts 1737 Hooke’s Micrographia, 1667 : Adam’s Essays ¢ on the ‘Microscope, L787 ihe Esperienze interno alla generazione degl’ insetti fatte a Francisci Redi de ‘Animalcules ‘ On the Foraminifera, T. R. Jones and W. R. Parker . Quarterly Journal of the Geological Society, Vol. XVI, parts 3, 4 . Presented by The Author. Ditto. Ditto. Ditto. The Society. Ditto. Ditto. Ditto. Ditto. The Editor. Purchased. The Society. Ditto. Ditto. Ditto. Ditto. The Editor. Ditto. The Society. Hackney Micr. Soc., per F.C.8. Roper, Ditto. Dr. Millar. - Ditto. Ditto. Ditto. Ditto. The Authors. The Society. ° PROCEEDINGS OF SOCIETIES. The Annals and Magazine of Natural History, No. 35 The Canadian Journal of Science and Art, No. 29 The Photographic Journal, No. 102 Recreative “Science, No. 16 : 5 Six Microscopic Slides Two Microscopic Photographs December 12th. Researches on the Foraminifera. By Dr. Carpenter, from ‘ Phil. Transactions, June 17th, 1858 : Researches on Tomopleris onisciformis. By Dr. Car- penter, from ‘ Transactions of Linnean Society,’ 1859 and 1860 Right Slides illustrating the Development of the Comatula Six Slides of Bryozoa from Arran Journal of Recreative Science, No. 17 Photographic Journal, No. 103 Journal of the Proceedings of the Linnean Society, Vol. V, No. 18 cf Annals and Magazine of Natural History, No. 36 Notes on the Presence of Animal Life at vast De pths in the Sea, with observations on the nature of the Sea-bed, as bearing on submarine telegraphy. By Dr. G. C. Wallich” Observations on the Neuration of the Hind Wings of Hymenopterous Insects, and on the Hooks which j join the Fore and Hind Wings together in flight. By Miss Staveley British Journal of Dental Science, six numbers One Slide of Insect é 71 Purchased. The Hditor. Ditto. Ditto. J. F. Norman, Esq. G. Jackson, Esq, The Author. Ditto. Dr. Carpenter. Ditto. The Editor. Ditto. Ditto. Purchased. The Author. Ditto. Hditor. .S. C.* Whitbread, Esq. , W. G. Srarson, Curator. The Royau Society or Eninspureu and the Nettx MeEpAt. Av the opening meeting, on 5th curt., for session 1859-60, of the Royal Society of Edinbur oh, the Neill medal and prize was presented, through Professor Balfour, to W. Lauder Lindsay, Mee. ELS... for his ‘ Memoir on the Sper mogones and Pyenides of filamentous, fruticulose, and foliaceous Lichens,’ read to the Society during the last session. In addition to awarding this prize, the Society is expending a considerable sum in publishing the memoir in question in the forthcoming part of its ‘ Transac- tions’ (vol. xxii), and in engraving the relative illustrations, exe- cuted by the author, which consist of twelve plates of between 400 and 500 drawings. =) xc) PROCEEDINGS OF SOCIETIES, Hui Micro-PuHinosorHicaL Socipry. Tux first meeting of the sessional course of this Society took place on Friday evening last (21st September, 1860), at their rooms in the Royal Institution, on which occasion Mr. P. Bruce delivered a lectire on the “Use and Construction of the Mi- croscope,” in the course of which he congratulated the Society on its progress, and on the resolution of the previous meeting to form a microscopic library and museum. Mr. Bruce alluded to the fact of the introduction by him of the first achromatic microscope into Huil, and to his discovery (hitherto attributed in all microscopic w orks to Mr. Sollitt and Mr. Harrison) of the delicate markings on certain Diatomacez,which have since become the almost universal test for a good instrument; if, indeed, they have not contributed greatly to the production of the present high quality of the achromatic object-glass. An animated discus- sion took place on the various subjects connected with the lecture, which occupied the meeting till the usual hour of separation.— Hull Packet. + Istincton Lirerary AND ScIEenTIFIC INSTITUTION. A MICROSCOPICAL soirée was held at this institution, November 1st, 1860. About fifty microscopes were exhibited by Mr. Thomas Ross, Messrs. Powell and Lealand, Messrs. Smith and Beck, and other makers, and several members of the institution. Among the objects exhibited were the rotatory circulation of the sap of the Valisneria spiralis, exhibited by Mr. Lobb; the circulation of the sap in the hairs of the petal of the Tradescantia and of the blood in a small water-newt, by Messrs. Powell and Lealand; the ciliary action of a portion of the gill of a bivalve molluse, by Messrs. Smith and Beck; some curious microscopic photographs of a thousand-pound note, ee Lord’s Prayer, the Creed, and several views of cathedrals, , by Mr. Dancer, of Manchester ; and also some beautiful a by polarized light, by some of the members of the institution. Mr. Thomas Ross exhibited some new microscopic objectives, which were remark- able for their large aperture and accurate defining power. Mr. Hislop delivered a lecture on the construction and uses of the Microscope, illustrated by diagrams of Ross’s large Mi- croscope, and of the earliest Achromatic Microscope, which was manufactured by Mr. Tulley, of Islington, one of which is now in the possession of Dr. Bowerbank. This institution has, in connection with it, a class for the study of the microscope, and the following papers are announced to be read during the ensuing session :—‘ On Entomostraca and the Eyes of Insects,” a Mr. T. W. Burr; ‘©On Marine and Fresh-water Polyzoa,” | by Mr. W. Hislop ; “On Fresh-water Alge,’ by Mr. Mestayer; “On the Vegetable Cell,” by Mr. R. Moreland, jun.; “On the Organization -of Insects,” by Mr. Reiner; “On Foraminifera,” by Mr. Slade; “On Polarizing Crystals,” by Mr. Thomson. PROCEEDINGS OF SOCIETIES. 73 Mancuester Literary AND PHILOSOPHICAL SOCIETY. MicroscoricaL SECTION. April 16th, 1860.—The Srormtary read a paper, by Mr. Hepworth, “ On Preparing and Mounting Insects.”’ Mr. Hepworth first destroys life by sulphuric ether, then washes the insects thoroughly in two or three waters in a wide- necked bottle; he afterwards immerses them in caustic potash or Brandish’s solution, and allows them to remain from one day to several weeks or months, according to the opacity of the insect ; with a camel-hair pencil in each hand, he then in a saucer of clean water presses out the contents of the abdomen and other soft parts dissolved by the potash, holding the head and thorax with one brush, and gently pressing the other with a rolling motion from the head to the extremities, to expel the softened matter: a stroking motion would be liable to separate the head from the body. The Author suggests a small pith or cork roller for this purpose. The potash must afterwards be completely washed away, or crystals may form. The insects must then be dried, the more delicate specimens being spread out or floated on to glass slides, covered with thin glass and tied down with thread. When dry they must be immersed in rectified spirits of turpentine, placed under the exhausted receiver of an air-pump. When sufficiently saturated they will be ready for mounting in Canada balsam, but they may be retained for months in the turpentine without injury. Before mounting, as much turpentine must be drained and cleaned off the slide as possible, but the thin glass must not be removed, or air would be re-admitted. Balsam thinned with chloroform is then to be dropped on the slide so as to touch the cover, and it will be drawn under by capillary attraction. After pressing down the cover, the slide may be left to dry and to be finished off. If quicker drying be required, the slide may be warmed over a spirit, lamp, but not made too hot, as boiling disarranges the object. Vapours of turpentine or chloroform may cause a few bubbles, which will subside when condensed by cooling. Various specimens, beautifully mounted by this process by Mr. Hepworth, were exhibited. Mr. Mosley read an account of a Microscopical Examination of Flour, illustrative of the commercial advantages which may be occasionally derived from a knowledge of the use of the mi- croscope. Mr. Dancer exhibited Diatomacea and Foraminifera, obtained from deep soundings in the Atlantic and from the Red Sea. _ Mr. Lynde exhibited pupa cases of Insects, from the Gold Coast of Africa. Mr. Hepworth sent for inspection an ingenious diatom box, constructed for a friend going to travel on the Continent. VOL. I.—NEW SER. hinds 74 PROCEEDINGS OF SOCIETIES. AwnvuaL Merrine, May 21st, 1860.—The following gentlemen were elected Officers of the Section for the ensuing session :— President, Professor W. C. W1iit1amson, F.R.S. E: W. Bryyzy, F.BS., F.G8., Vie Pest] W. J. Ripzovrt, JosEPH SIDEBOTHAM. _ Treasurer, J. G. Lynpz, M. Inst. C.E., F.G.S. Secretary, GEorcE Mos ey. Mr. Lynde presented two slides of pupa cases of insects, called Gold Shells, from the Gold Coast of Africa. He also exhibited the circulation of the blood in the tail of the stickleback. Mr. Latham presented to the Section, and also to each member present, a portion of sand, from Aden, in the Red Sea, containing Foraminifera, Spicula, &c. Mr. Dancer exhibited a number of slides of various new and interesting objects. June 20th, 1860.—The Secretary read a few extracts from a private letter from Mr. Frembly, of Gibraltar, in which he refers to the rotifera found in that neighbourhood: they differ very little from the British species described by Carpenter, Henfrey, &c. He found with them, free vorticella with spiral stalk or tail, whilst in England the free vorticella is generally found without tail. Its utility in the case of those living with such neighbours is manifest, for the vorticella would now and again become in- volved in the eddy made by the cilia of the rotifera, but invariably before coming in contact did they succeed in escaping by the muscular power of the tail, which by suddenly coiling enabled them to throw themselves out of the influence of the current. Mr. Frembly had found one of the Alge of the chlorosperm order, which was new to him, and of which he had not found any description. He intends to send specimens for examination. _ A letter was read from Mr. Hepworth, of Crofts Bank, accom- panying specimens of Sarcina, injected kidney, spores of Equise- tum, Euglena, Batrachospermum moniliformis of two kinds, some diatoms, &c. Mr. Samuel Hardman, of Davyhulme, presented a few well- mounted specimens of the larva of the wire-worm, willow moth, Cimex, and Curculio. _ Mr. Mosley exhibited the living (so-called) skeleton larva and pupa of the Corethra piumicornis (Pritchard), pupa of Ephemera, marine Gammarus from Gibraltar, and aquatic Gammarus from near Northenden, almost identical with each other; the shell or scales of the marine animal being most transparent. ; Mr. Brothers exhibited the tongue of a cricket, circulation in the chara, &e. _ Mr. Dancer sent for exhibition a specimen of Topaz, with PROCEEDINGS OF SOCIETIES. 75 natural cavities containing fluid and gases, which on boiling present curious phenomena; also a box of objects, two micro- scopes, &e. September 17th, 1860.—A specimen of envelopes was exhibited by the Secretary, such as were proposed to be sent to captains of vessels, in which to preserve the soundings they obtain in different parts of the world, for this section. The envelopes were much approved of, and were thought likely to be productive of future interest to the section, and to microscopists in general. Mr. Latham referred to Mr. Hepworth’s method of mounting insects in Canada balsam, and described his own experience of the same. Mr, Latham spoke in very favorable terms of the facility with which slides can be washed off and finished. He found that the balsam should be as thick as possible, almost even to dryness ; then dissolved in chloroform, to a consistence only thin enough to flow easily under the thin glass; the object having previously been mounted by Mr. Hepworth’s process, under thin glass tied on with thread, exhausted of air, and saturated with turpentine. After heating over a spirit-lamp the balsam sets hard almost as soon as cool, when the slide, after cleaning with alcohol, is ready for the cabinet. Mr. Latham exhibited several slides thus mounted, with specimens of the gizzard of a cricket, the saw-fly, entire trachea system of the silkworm, ichneumon-fly, spiracle of the silkworm, goldfish scale, leaf of wheat showing spiral vessels. Mr. Lynde exhibited a fine Plumatella living on the shell of a large Lymnea or water-snail. Mr. Mosley exhibited specimens of Hydra and other aquatic objects. October 15th, 1860.—A. circular was read, addressed to cap- tains of vessels, with a request that they will preserve the pro- duce of the soundings they make when abroad, in the envelopes sent therewith.—A letter was read from Mr. Hayman, of Liver- pool, tothe effect that circulars and envelopes have been supplied to the captains of eight steamers belonging to Messrs. John Bibby and Sons, in the Mediterranean trade ; three of Messrs. M‘Iver’s steamers, plying between Liverpool and New York ; to the steamer Armenian, for Madeira, Sierra Leone, Calabar, &c.; to the Marco Polo, and two other vessels to Melbourne; as well as to vessels which have gone to Woosung in China, Bombay, Alexandria, &e., &e. The Chairman made some observations in praise of the plan, which he had no doubt would be productive of advantage, and add to the interest of the meetings of the section. It was suggested by Mr. Brothers that a special subject, pre- viously fixed upon, should be discussed at each meeting; the suggestion was at once adopted. The subject for discussion at the next meeting will be, “ Upon the Best Method of Preparing and Mounting Diatoms, &c., obtained from Soundings and other 76 PROCEEDINGS OF SOCIETIES. Sources.” It is requested that the members of the seetion will meanwhile obtain and communicate all the information they can, on the subject. Mr. Lynde exhibited a specimen of a small insect allied to the Podura, which he found leaping about on the surface of the water in his aquarium. Mr. Lynde had never seen a description of such an insect, nor was it known to any of the members of the section present. Mr. Brothers exhibited the Hydra viridis, &e. A few specimens and parts of flowers obtained at the Botanical Gardens were exhibited by the secretary. In the tank of the Victoria Regia little minute animal life could be discovered during a short visit. A specimen of Cetochilus was shown, which was found there, as also a few diatoms not fully examined. November 19th, 1860.—A letter was read from Mr. R. D. Darbishire, relative to the deposits from the raised sea bottom found at Capell Backen, Uddevalla, near Gottenburgh, in Sweden. He observes that “the hill side from a height of about fifty feet, above the level of the sea to that of about two hundred and thirty feet, consists of layers of fossil shells, varying from ten to thirty feet thick, alternating with beds of more or less coarse grayel and clayey sand.” Mr. Darbishire contributed, for the use of the members, a parcel of washings from shells, and a box containing dry sieved soil for microscopical examination. A letter was read from Mr. John Hepworth, of Crofts Bank, describing his method of washing and mounting calcareous and siliceous shells, dry and in balsam. Mr. Hepworth also presented to the Members of the Section, for mounting, a piece of injected kidney. A ht by Mr. J. B. Dancer, F.R.A.S., was read, “ On clean- ing and preparing diatoms obtained from soundings and other sources.” The Srcretrary exbibited a portion of sea-weed from the Gulf Stream, in which were found a few diatoms, remains of entomos- traca, &c., contributed by Mr. A. da S. Lima, of London. ZOOPHYTOLOGY. Descrirrion of New Potyzoa, collected by J. Y. Jounson, Esq., at Manverra, in the years 1859 and 1860. By G. Busk, F.R.S. (Continued from vol. vi, p. 285.) I. CHEILOSTOMATA. Fam. 1. ScrupocELLARIIDA, B. Gen. 1. Serupocellaria. V. Ben. 1. 8. Maderensis, B. Pl. XXXII, fig. 1. Having, upon further search, met with a tolerably good specimen of this species, which is described in the last part of “‘Zoophytology” (vol. vii, p. 280), I now give a figure of it, sufficient to facilitate its recognition. Fam. 2. MEMBRANIPORIDS. Gen. 2. Membranipora. Blain, S. 1. MW. irregularis, D’Orb. Pl. XXXII, fig. 3. Cellulis distantibus subovalibus, inéqualibus irregulariter dispositis ; mar- gine granulato, inermi ; aviculariis 0 (?) Cells distant, mostly oval or suborbicular, very irregular in sizé, and placed irregularly ; margin granular, wholly unarmed; no avicularia. M. irregularis, D’Orbig., (Am. Mérid., pl. viii, fig. 6). (?) WV. simplex, D’Orbigny (ib., figs. 7—9). (?) M. Lacroivii (var.), Aud.; Bk.; Alder. (?) Flustra distans, Hassall; Johnston; W. Thompson. There are two or three species with which the present might be confounded, and, in fact, from which its absolute distinctness is by no means certain. These are : 1. WW. imbellis, Hincks. 2. M. Lweroiwii, Aud. 3. M. simpler, D’Orb. 78 ZOOPHYTOLOGY. From the former, which, with the greatest deference to Mr. Hincks’ opinion, I am disposed to regard simply as an unarmed variety of M. Flemingii, M. wrregularis differs principally in the more oval or rounded shape, and more irregular disposition, and inequality in size of the cells. From worn specimens of M. Lacroixii it would be difficult to distinguish M. irregularis, excepting by the total absence of any marginal spines and of any vestige of avicularia; whilst between M. irregularis and M. simplex, D’Orbigny, I am unable to perceive any important diversity. Gen. 2. Lepralia, Johnst. 1. L. multispinata, n. sp. Pl. XXXII, fig. 5. Cellulis suberectis, immersis, inferne ventricosis, superne coarctatis ; super- jicie granulosa ; orificio arcuato, labio inferiort recto integro ; peristomate producto crasso, anticé excavato ; spinis marginalibus 8—10, Cells suberect, immersed and ventricose below, contracted above ; surface granular ; orifice arched, with an entire, straight lower lip; peristome raised, thick, forming a cup in front of the orifice; 8—10 marginal spines. Hab.—Madeira, on shell, J. Y. J. Fam. 3. CELLEPORID#, B. Gen. 3. Cellepora, O. Fab. 1. C. ampullacea,u. sp. Pl XXXII, fig. 4. Cellulis ovatis ventricosis ; superfice sparse perforata, vel punctatda ; orificio orbiculart : peristomate tenui, integro ; avicularits 0. Cells ovate, ventricose; surface smooth, sparsely punctured, chiefly in the upper part of the cell, or dotted; orifice circular; peristome thin, an- nular ; no avicularia. Hab.—Madeira, on shell, J. Y. J. Fam. 4. EscHarip#, B. Gen. 4. Eschara, Ray. 1. #. tubulata, n. sp. Plate XXXIII, fig. 1. Polyzoario e ramis Vinearibus subcompressis, tenuibus, curvatis composito Cellulis tubulatis, productis, superficie delicatule granulosa ; orificio orbiculari mandibulo semicircularit ascendenti, intus armato; peristomate incrassato simplict. Polyzoary composed of linear, curved, slender, subcompressed branches. Cells tubular, produced above; surface finely granular; orifice orbicular, with an avicularium just within the lower border, the semicircular mandible looking upwards and backwards ; peristome thickened. Hab.—Madeira, J. Y. J. A species of Eschara occurs in the Egean Sea (of which I have specimens collected by E. Forbes), having the polyzoary constituted of slender, subcylindrical branches, and the cells produced in a tubular form above, and which consequently in some respects corresponds with the present species, but on ZOOPHYTOLOGY. 79 closer comparison the two will be found quite distinct. In the Egean form (of which a figure and description, under the name of E. cervicornis, are given in “‘ Zoophytology”’ (‘ Quart. Journ. Micr. Soc.,’ vol. iii, p. 322, Pl. IV, figs. 4, 6). . The cells, are in the first place, more or less ventricose below, whilst the orifice is not quite circular, and presents a small denticle on the lower border, and has no avicularium within it. Gen. 2. PsILEscHaRA, n. g. _ Polyzoario erecto, e ramis linearitus subcompressis composito ; cellulas in uné Juciei tantum gerente; cellulis quincuncialibus, in seriebus longitudinalibus dispositis. Polyzoary erect, branched, branches linear, compressed; cells opening on one side only, quincuncial in longitudinal series. 1. P. Maderensis, n.sp. Pl. XXXII, fig. 2. Cellulis superne liberis subtubulosis, ad basin immersis, margine elevato cir- cumdatis; ad latera punctatis, superficie granulosa, avicularium mandibulo acuto ascendente, infra orificium medio gerentibus. Cells free and subtubular above, immersed below, surrounded with a raised border, and punctured on the sides; surface granular. An avicula- rium immediately below the orifice in the middle and front; mandible acute, _ ascending. Hab.—Madeira, J. Y. J. In a list of some fossil Polyzoa, collected by the Rev. J. E. Woods in South Australia, given by me in ‘Quart Journ., Geol. Soc.’ (vol. xviii, p. 261), I have enumerated two species of Escharidz, which differ from the other members included in that family in having a simple, branched, not reticulated, polyzoary, constituted of a single layer of cells, that is to say, in which the openings of the cells are all on one side of the branches, the opposite surface presenting only the backs of the cells. To these two fossil forms is now to be added a third living one. The Family Escharide will now include— Eschara, Melicerita, Biflustra, Retepora, Psileschara, and Celeschara, only known at present as a fossil form. II. CycLostomata. Fam. I. IpMoneip#. Gen. 1. Hornera, Lamx. 1. H. pectinata,n. sp. Pl. XXXTII, figs. 4, 5, 6. Polyzoarium paroum, basi diffuso afixum, irregulariter ramosum ramus- culis teretibus ; cellularum orificio exserto, denticulato ; superficie anteriori 4 * . . . . . X sparse punctato, polito, irreguluriter sulcato ; posteriort sparse punctata. 80 ZOOPHYTOLOGY. Polyzoariam small, branched, attached by an expanded base, branches irregular terete ; tubes exserted, border of orifice toothed; surface sparsel punctured, porcellanous, irregularly suleate ; posterior sparsely vantaree like the anterior. Hab.—Madeira, J. Y. L. This Hornera appears, from the specimens furnished, to be of small size, probably not exceeding an inch at most in height. The erect, irregularly branched growth arises from a wide, expanded, discoid base, and the branches taper towards the ends. The character of the surface and the pectinate border of the orifice suffice at once to distinguish it from any other species, recent or fossil, with which I am acquainted. (To be continued.) DESCRIPTION OF PLATES XXXII & XXXIII. PLATE XXXII. Fig. 1.—Scrupocellaria Maderensis, p. 65. 9.—Psileschara Maderensis, p. 67. 3— 55 (back). 4.—Cellepora ampullacea, p. 66. 5.—Lepralia multispirata, p. 66. 6— 57, | *oUidiam: PLATE XXXIII. ; 1.—Eschara tubulata, p. 66. 9— ,, (orifice x 50 diam.) 3.—Membranipora irregularis, p. 65. 4.—Hornera pectinata (nat. size). 5.— , * 2b diam. 6.— ,, portion of back. ZOOPAY TOLOGY. Plate XXXII. Avy. = ZOOPHYTOLOGY. Plate AXXIL sn ata sitsinnee ORIGINAL COMMUNICATIONS. On Changes of Form in the Rev Corpruscies of Human Bioop. By Wiii1am Appison, M.D., F.R.S. In the natural history of plants and animals, the relations between different parts of the structure of an individual have, on many occasions, been established by the study of malformations or irregularities. In botany, the relation of stamens and petals to leaves has been made out by irregularity in the structure of the flower ; and in human anatomy, the relations and uses of an organ have been illustrated by some malformation—some departure of it from the normal form. In any effort made to distinguish the relations subsisting between the two principal elements of blood, and between these and outward things, it must be remembered that the corpuscles are in contact with the liquor sanguinis, and that they come into contact with air in the lungs. Also that the liquor sanguinis is replenished by diet—food and drink, and that the corpuscles of the blood swim in it. The offices of the stomach are more closely associated with the liquor sanguinis than with the corpuscles; whereas the office of the lungs has chiefly do with the corpuscles. These several relations (1) between the two parts of the blood, (2) between articles of diet and the liquor sanguinis, and (3) between the corpuscles of blood and the air, are sketched in the following diagram : | ‘Air. Corpuscles, and Diet Liquor sanguinis. Blood. | | | | It follows that the corpuscles may wee their properties VOL. I,—NEW SER. G 82 ADDISON, ON BLOOD-CORPUSCLES. changed or interfered with by substances in solution in the liquor sanguinis, and also by substances in solution in the air; and that the liquor sanguinis may have its properties altered by substances taken into the stomach, also by matter . which may be discharged into it from the corpuscles. Bearing upon the relations subsisting between the liquor sanguinis and the corpuscles of the blood, an interesting example of malformation or irregularity of structure in point has been narrated by Mr. Erichson, and we ground our argu- ment in part upon the results of his experiments. Thomas Furley, aged thirteen years, an intelligent but sickly-looking lad, has been afilicted with extroversion of the bladder from birth. The inner surface of the posterior aspect of the bladder protrudes through an opening in the abdominal wall, and forms a tumour the size of half an orange. At the under surface of this tumour are the orifices of the ureters. “TI eagerly seized this opportunity,” says Mr. Erichson, “of making some observations and experi- ments respecting the length of time that elapses between the introduction of different substances into the stomach and their appearance in the urine. ‘The substances experi- mented with were the yellow ferrocyanuret or prussiate of potass, infusion of galls, of rhubarb, of madder, of uva ursi, and decoction of logwood ; the citrates ‘of soda and potass, tartrate of soda and acetate of potass.” The experiments with prussiate of potass, galls, and uva urst were performed, by receiving the drops of urine, as they fell from the ureter, into a glass containing a solution of per- sulphate of iron; those with rhubarb, by receiving the urine into a dilute solution of potass; and those with the citrates, tartrates, and acetates of potass ‘and soda, by testing the urime with litmus or turmerie paper. Ten experiments were made with prussiate of potass, the quantity taken at a time varying from 20 to 40 grains. The period which elapsed between taking the salt and its appear- ance in the urine depended upon the state of the stomach ; when no food had been taken for some hours, the salt could be detected in the urine in two minutes after it had been swallowed ; whereas when it was taken shortly after a meal, it required from six to forty minutes for its passage from the stomach into the urine. The time required for the vegetable substances to make their appearance in the urine varied from sixteen to thirty-nine minutes. The citrates and tartrates of soda and potass made the urine alkaline in from twenty- eight to forty minutes, and greatly increased its flow.* * *Vondon Medical Gazette,’ vol. i, 1845, p. 363. ADDISON, ON BLOOD-CORPUSCLES. 83 In the year 1832 numerous cases of epidemic cholera were treated with saline liquids, injected into the blood, not only without detriment to the patients, but in many instances the injected fluid evidently conduced to the preservation of life. In the ‘ Provincial Medical Journal’ of October, 1844, eight cases of cholera treated by injection are reported, in one of which (case 4) ten quarts of a saline liquid were thrown into the circulation in fourteen hours, and the patient recovered. _ A very remarkable case is reported in the ‘ Lancet,’ in which five gallons of a saline fluid were injected by a vein in the course of four days. At seven in the morning of the 29th of May an injection of ten pounds of the fluid, with ten grains of sulphate of quinine, was made; and on the 2d of June six drops of a solution of morphia were added to the fluid used for injection.* Now Mr. Erichson does not state that the substances given to Furley in any way impaired his health. The only evidence of their passage through the blood was that they were found in the urine. And, with respect to the cholera cases, there is abundant evidence that the condition of the patients was improved by the liquids forced into the blood. Knowing, then, the great importance of the red corpuscles of the blood in the functions of life, the natural inference is that they were not injured in their essential properties by the proceed- ings in either of the two examples. And it would seem that prussiate of potass is a salt which may pass through the liquor sanguinis without disturbing either the corpuscles of the blood or the cellular elements of any of the fixed organs, except perhaps those of the kidney. Dark or venous blood, inclosed in a moist bladder and exposed to the air, soon assumes the bright arterial tint. The change of colour has reference to the corpuscles, and the experimett proves that these bodies do not lose this, one of their most striking properties, until at least some time after their withdrawal from the body. In the preceding number of this Journal, (January, 1861) we have described and fig ueet certain changes of form or outline which blood-corpuscles spontaneously undergo when just withdrawn from the human body (p. 20, Plate TIN) ; also the changes of form they experience by mingling weak saline, allcaline, and acid fluids with the liquor sanguinis. Moreover, we have shown that corpuscles which have been thus changed may be restored to their normal form and appearance by a counteracting agent. Acids restore them * ‘Lancet,’ 1831-32, vol. ii, p. 748. Also, for another remarkable case, see * Lancet,’ 1831-32, vol. ii, p. 275; 84, ADDISON, ON BLOOD-CORPUSCLES. when they have been altered by an alkali, and vice versd. That is to say, corpuscles which have assumed the rough or alkaline outline regain their natural aspect under the influ- ence of the diluted hydrochloric acid, and retain it for a longer or shorter space before assuming the form charac- teristic of the acid influence. (Plate III, figs. 2 and 3.) We have made a saline solution similar to that used for injection into the blood in cholera cases, and we find it gives the corpuscles a rough outline, as do other saline and alkaline fluids; but the altered corpuscles are very readily changed back again to the normal form, upon the addition to them of an acid. In a solution of prussiate of potass, in the propor- tion of a grain of the salt to one fluid drachm of water, the corpuscles undergo the same changes as they do in weak acid fluids (Plate ILI, fig. 3) ; and they recover their-normal form very readily upon the application of liquor potasse. In this experiment—as I have said of others —the lhquor potassz destroys numerous corpuscles ; but when it is diluted with the required amount of liquor sanguinis, there the changes we refer to take place (ante, p. 28). Again, when sherry wine is mingled with the liquor san- guinis, the corpuscles exhibit actions of a very curious kind. A molecular matter exudes from them, floating off into the liquor sanguinis; and long tails, with a singular movement, are projected from the interior of the corpuscles. In all these phenomena it is the quality, and not specific gravity, of the fluids which governs the effect. Changes of form thus wrought in blood-corpuscles by mingling extraneous matter with the liquor sanguinis is additional evidence that, not- withstanding their withdrawal from the body, they still pos- sess special properties; and so long as the changes thus produced are of the same kind with, and do not exceed those which the corpuscles spontaneously exhibit, and as long as they retain the property of recovering their normal form and appearance by the application of a counteracting agent, so long we may presume they are not greatly injured. When viewing the circulation of blood in the frog’s foot, we may see many corpuscles bent, elongated, and squeezed into all manner of shapes; but they regain their natural form when the restraint or obstacles are overcome, and the animal suffers no detriment from the temporary alteration in the corpus- cular forms. Likewise, it may be argued with respect to the action of sherry wine, that so long as the corpuscles retain the pro- perty of projecting moveable tails, thus long they retain their active qualities. That the action in this case is an ADDISON, ON BLOOD-CORPUSCLES. 85 exhaustive one, and the corpuscles are ultimately destroyed by it, does not vary the argument that the projection of the tails is an exhibition of a species of reaction on the part of the corpuscles, produced by the vinous fluid when mingled with the liquor sanguinis. Now, on repeating our experiments, we have found that quinine, morphia, aud strychnine do not vary the pheno- mena. ‘They do not prevent corpuscles which have sponta- neously changed their form, nor those which have been altered by a saline or alkaline liquid, from resuming their normal form under the influence of an acid. Nor do these vegetable alkaloids interfere with the action of sherry wine, even when they are in the proportion of a grain to a fluid drachm of the wine. Whereas, if only the one eighth of a grain of the bichloride of mercury be added to a fluid drachm of the wine, not only is the projection of tails from the corpuscles prevented, but also those corpuscles which have changed their outline are rendered incapable of restoration to their normal form. Experiment.—Nine grains of refined sugar were dissolved in half a fluid ounce of water, and an experiment was made in the manner described in our former paper (page 20, ante). The corpuscles which floated out into the fluid had a smooth outline. A mixture was now made of four parts sugar solu- .tion and one part laudanum. Upon using this mixture there were numerous corpuscles with a rough or prickly outline, mingled with smooth ones. But liquor potassz rendered the corpuscles with smooth outilnes prickly; and diluted hydro- chloric acid restored the prickly forms to their normal shape, just the same as if no laudanum were present. It would appear, then, that substances which are poisonous to the brain and nervous matter have no particular effect, no marked action, upon the corpuscles of the blood. A parenchymatous organ (the brain, liver, salivary glands, and kidney) is composed of cellular particles to which the special function and susceptibilities of the organ are attributed. And in medical practice it is well known, that one organ may be influenced by a medicine or remedy taken by the stomach, to the exclusion of other organs. The corpuscles of blood are cellular particles of an ana- logous kind; and that they should possess analogous pro- perties—a measure of indifference or even of resistance against some substances in the liquor sanguinis, and a special sus- ceptibility to other substances—is no more than might have been expected if they be bodies with the properties of cells. In every department of nature, cellular bodies, whether 86 ADDISON, ON BLOOD-CORPUSCLES. fixed or moveable, so long as they preserve their vital proper- ties, have special susceptibilities; they are not at the mercy of every inorganic element which may assail them. In every experiment we have made with the corpuscles of human blood, some have been found more altered m outline than others, although swimming side by side in the same eurrent; because, as we apprehend it, amongst a great multitude of these bodies some are more susceptible than others. We would avoid laying too much stress upon micro- scopical observations ; but when their evidence points in the same direction with that of other facts, they are entitled to full consideration. The whole of the evidence concurs in indicating that the most striking distinction between the active elements of a fixed parenchymatous organ and the active elements—the cor- puscles—of the blood is that the former are grouped in fixed positions and irrigated by the liquor sanguinis, whereas the latter are mobile, in circulation, swimming in the liquor sanguinis. And imasmuch as all cellular bodies, whether fixed or moveable, have a vital or physiological property of © resistance in common, so therefore we look for evidence of a resisting power in the corpuscles of blood.* At all events, we know that morphia and landanum may be taken by the stomach so as to act upon the brain, without any known evidence of disorder in the corpuscles of the blood. Our microscopical observations show that neither morphia nor Jaudanum has any interfering effect upon the corpuscles of blood; and the conclusion we draw from our investigation is that— The liquor sanguinis may be altered in various ways—by an unwholesome diet, by medicines and poisons, by sub- stances taken into the stomach, so as to influence the elements of some fixed organ—before interfering with the properties of the corpuscles of the blood. Supposing this conclusion established, how, it may be asked, are we to know when the corpuscles of the blood are interfered with? What are the signs or symptoms of an injurious action upon these bodies as distinguished from the liquor sanguinis? ‘These questions we hope to attempt to answer on a future occasion. * Gulstonian Lectures, 1859, vide ‘ British Medical Journal,’ April, May, &e., 1859. 87 On AMPHIPLEURA PELLUCIDA. By Wo. Henpry, Esq., Surgeon, Hull. Berne favoured with the published results of Messrs. Sul- livant and Wormley’s investigations on the subject of Nobert’s test-plate and the striz of Amphipleura pellucida, and in sup- port of my views heretofore advanced in the ‘Microscopical Journal’ (July, 1860) relative to a coarse striation of many of these diatoms, I now transmit the measure of a series con- tained in several slides in my present possession, as under ; having rejected every aspect of ambiguous character, and exercised due care in the micrometer adjustment. I have selected purposely a comparative coarse striation, in contrast to the high numbers promulgated by Mr. Sollitt, whose 135 striz in ‘001” said to be counted, and whose 175 in 001” reputed to be visible, are beyond my compre- hension and experience; at the same time [I believe myself prepared to compete in the exhibition of the finest visible striation, using for my own part a 4th objective made by Dallmeyer, optician, of London. Slides. Strie. No. la . 42 in = 001" = Amphipleura pellucida. 2 a : 40 +3 33 33 3) 3) b MI 40 33 +3 33 33 +) c $ 40 PP) 2) oD) 33 3a . 42 » 93 3 p 33 b iL 38 33 3) 23 33 4 a O 38 3) 33 33 33 d3 b H Bd 3) 33 3) 33 33 Cc : 49 22 33 3) Hi a . 45 33 ” ” os) 2» b . 45 » ” 5B) a” a ¥ 34 3) +P) 33 33 33 b -. 40 33 3 bP) 5S 5B) c . 40 3 ” ” ” Te, 89 ae ie re a 8 a 2 39 33 43 33 33 9 a c 24 3? 33 33 ”) 5B) b . 48 23 22 22 3 i 41 22 oe) 5B) Ss 1a . 40 rf A Hs e Tl a : 34. 33 33 33 23 In the measurement of the above, as on all other oceasions, - I have found it convenient to tabulate the adjustments of 838 HENDRY, ON AMPHIPLEURA PELLUCIDA. objective to different foci; thus the index being marked 5, 10, 15, 20, the revolution of index occasions circumstances of importance in actual practice. Lyepiece Mi- crom., lines each. Index at 1O covered, closed value 17,500 A; 15 u alittle open ,, 17,250 H. 20 i; more open > LAO as 5 FE midway » 16,500 He 10 uncovered, tending to close ,, 16,000 es 15 ne nearly closed 9» 10,00 4 20 pos closed > 103500 It is hence evident that, with index at 10, the micrometer value may be either 17,500ths or 16,000ths of an inch, and so also of any other term of indices; and hence the necessity, in every case of measurement, that the objective should be removed from the body of the instrument, and carefully ex- amined as to the relations of the index to being wholly or partly covered or uncovered, when differences will be thus obtained materially affecting the value of observations, espe- cially in dealing with fine striation. In slide 9 the lines are not fully developed, or rather dis- played, but exhibit tops and bottoms, 7d est, marginal mark- ings so regular as to leave not a shadow of doubt of their being of the true nature of striz; in no one instance have I ever been able to resolve a coarse striation of Amp. pellucida into dots, like angulatum, &c. I suppose such transverse striz to partake of the character of canaliculi. Slide 11 exhibits a singular development of lines, the dark colour of which, together with the intermediate spaces of light, surpass any diatom I have hitherto seen; and thus leaving not a shade of doubt as to truthful interpretation by the most sceptical regarding the existence of veritable stria- tion. I believe the severity of test to depend not so much on the number of lines in ‘001’, as on degree of development. For example, compare Nobert’s test-plate, 14th and 15th bands, with the Fasciola; and both these, again, with the lines upon Nitzschia angularis ; all of which range from about 52 to 56 in 001”, but differ widely in facility of resolution. Neither do the highest powers invariably exhibit the highest markings equally distinct with powers somewhat inferior; penetration being required in some cases even at a sacrifice of amplification, Observe Nitzschia sigmoidea, for example, with 3th and 4th objectives. So also with Amphipleura pellucida ; and although HENDRY, ON AMPHIPLEURA PELLUCIDA. a I have never used the ;1,th or 31,th inch objectives, or any ac- cessory apparatus, I deem such of no utility for the object of the present research. In surveying a slide for the more sballow or difficult mark- ings, almost every shell lying in a proper position should be carefully examined with an ith or 1;th inch objective, and B eye-piece ; and when indications are observed, then all at- tention, both to direction and precise focus, must be paid; which will not unfrequently open out a striation when not expected, and which is far from élusory ; for with such latter appearances I do not, for my own part, profess to deal, leaving others to answer for themselves, in reply to Messrs. Sullivant and Wormley. I believe there is yet much to overcome in the preparation (boiling, &c.) and mounting of slides. The observer should not trust too much to the apparent beauty of his slide, nor yet suppose that because of the great brilliancy of a coarser diatom, the finer should be necessarily resolved, if re- solvable at all; such a result does not always follow in practice, for the vapours of asphalt, siliceous precipitation, altered refraction, and other causes, yet unknown, may possibly interfere to foil every effort in observation. I am fully satisfied as to the ready resolution of the true striz of Amphipleura pellucida, and in the several slides above referred to can bring out fifty other shells when re- quired. I am equally satisfied that Amphipleura pellucida presents, in opposition to Messrs. Sullivant and Wormley’s views, @ wide numerical value in striation, in common with some other diatoms, as Nitzschia sigmoidea, for example; and were I to abandon these views, I should be at once ready to account the indications of the microscope for the most part fallacious ; believing, however, that these views, honestly set forth, will be ultimately confirmed and adopted. 90 Conrrisutions to the knowledge of the DEVELOPMENT of the Gonrp1a of Licuens, in relation to the UNtceLLuLar ALG#, &e. By J. Braxton Hrcxs, M.D. Lonp., F.L.S., &e. Fasciculus III. CoLLEMA AND Nostoc, &e. &e. Berore entering upon the subject I have proposed for con- sideration in the present contribution, it will be needful to remark that, in 1854, H.Itzigsohn,in the ‘Botanische Zeitung’ (“ Wie verhalt sich Collema zu Nostoc und zu Nostechineen)”? page 521, and J. Sachs, in the same journal, in 1855, 5th January (“Zur Entwicklungsgeschichte des Collema, &c.”), insisted upon the origin of Nostoe from Collema; and they have pointed out one method by which Nostoc springs from that lichen; namely, from a small ball of the jelly-like mucus, enclosing a few of the beaded cells, which becomes extruded from the parent thallus. When one such ball becomes free, it may take one of two modes of development: Ist, it may produce the continuous colourless threads, and thus pass into Collema (fig. 7) ; or 2nd, without any tendency to the formation of these fibres, the ball will increase in size and transparency, become laua dense, while the green beaded filaments increase by subdivision, and the heterocysts common to the Nostochaceze are found at intervals. This latter is Nostoe, and this is one method by which it may arise. Tn the same condition the development may continue for an indefinite period. The first stages are shown at Pl. V, figs. 5 and 6. But there are other modes by which Nostoe may spring from Collema; I am not aware of their having been noticed before, and they form the subject of these remarks. H. Itzigsohn has gone further than any botanist in considering it highly probable that all the Nostochaceze are derived from lichen-gonidia. Be this as it may, there are many points in his observations which are worthy of more careful con- sideration and following out than they have hitherto received in this country ; the more so, as some of his imstances had already been agreed upon by other excellent observers. How- ever, 1 shall revert to this subject presently. The Collemas, like the other lichens, expel certain gonidia from their surface, which can be recognised even within the thallus as larger and lighter green than the others. When they arrive on the exterior, they appear to undergo segmenta- HICKS, ON GONIDIA OF LICHENS, 91 tion as the so-called Chlorococcus; but generally they are small and delicate in appearance (fig. 1a). For how long a period this process may proceed J am not in a position to show, except that I have not met with any considerable mass of Chlorococcus from this source. No doubt in most instances they begin to assume a change which is analogous to Cladonia-Gleocapsa, for we find the results of segmenta- tion become included in acommon mucous envelope, such as Gleocapsa possesses. But there are these differences at first; that while in Cladonia-Gleocapsa the mucous layer is colour- less and delicate, that in Collema is more dense and solid, and coloured more or less of a bluish-green hue. Also, while in the former growth the results of segmentation are nearly always symmetrical, in Collema they are generally irregular, the outline of the protoplasm being indistinct at the commence- ment of these changes. This is shown at figs. 1 6, 2a, 8a. After these early stages the growth proceeds on various plans. In one method the whole mass, both cell-contents and the mucous layer, are of a dark purple colour; each cell undergoing binary division is surrounded by its own mucous layer, the whole being included in a common one (fig. 2 8). After a while the purple coating becomes colourless and fused into one; while the cell-contents become green, and the divisions separated (fig. 3). As segmentation proceeds, the re- sulting cells assume a linear tendency, till at last a number of moniliform filaments are formed, having here and there the vesicular cells (heteracysts) found in the Nostochaceee (fig. 4). Thus Collema passes into Nostoc. A second manner is repre- sented at fig. 8. At a, the early changes above alluded to are shown ; the protoplasm and the mucous coating becoming of a bluish-green hue; but after the segmentary process has proceeded a little, the latter becomes more transparent, colour- _less, and highly refractive (fig. 8). Sooner or later there is a disposition shown in the subdivisions of the cells to arrange themselves linearly, whereby a small Nostoc-mass is pro- duced ; the vesicular cells appearing about the same time (fig. 8, ¢, d). Thus again Collema passes to Nostoc. But the connection between the two is more clearly shown in the fact, that the gonidia of Nostoc pass through precisely the same changes; so that a description of them would be super- fluous, being a repetition of the facts just stated. Many variations occur during the formation of the above into the mature Nostoc. For instance, when the development has arrived at the stage indicated at fig. 8 c, and the vesicular cells are just forming, the mass becomes converted, in part or entirely, into the 92 HICKS, ON GONIDIA OF LICHENS. forms indicated at 9 J, each of which consists of a vesicular cell, having an oval mass of bluish-green mucus extending on one side, containing a single or double row of four or five cells, the green contents and mucus not being distinctly separated from each*other. These may develop themselves in the linear direction, as at 9 a, and ultimately pass into Nostoc through the forms indicated at 9 c. Whether they may continue growing in the linear direction I have no direct evidence to prove, but consider it highly probable. They may also pass directly from the forms at 9 6, to those shown 9c. The variations, however, are numerous, some consisting of two or three portions united by the vesicular cells. These do not originate from the simpler form at 9 4, but consist of a larger portion of a beaded thread which includes two or more of the vesicular cells. Whether the forms at 948 can arise directly from the Nostoc- or Collema-gonidia without passing into the early condition of a Nostoc, or, in other terms, whether the vesicular cell can arise at so early a period of the change as at 8 a, I have not been able to satisfy myself by direct eyi- dence ; still I have every reason to think it highly probable. When these forms are compared with the change which sometimes takes place in the beaded filaments of the Nostoc shown at fig. 10, the similarity of the plan upon which each passes into Nostoc will be sufficiently evident to show how strong a connection exists between Collema and Nostoc. Whether the state of the Nostoc filaments, as shown at fig. 10, should be called a“ sporangium ” seems questionable ; because, at least in this particular instance, it can scarcely be said to produce spores, that is, free spores. At 8 e, isa form in which the cells undergo binary divisions, and appear similar to the cells of the beaded filaments under a similar condition (fig. 11 a). Besides those instances, the gonidia may undergo this Gleocapsoid change within the parent thallus, as I have noticed in the thallus of Cladonia (see Fasciculus II) ; this is by no means a very unusual condition, and is recog- nised easily by the dark-green balls visible upon compressing the frond. At fig. 13 is shown a section of a thallus in this state. After a while the thallus by extrusion, or more com- monly by solution, sets them free, when they assume in some Collemas a Gleocapsa state, the protoplasm being of a very bright green colour, and the mucous sheath colourless and of increased thickness (fig. 13 a). In many the subdivisions assume a quarternary form (fig. 13 c), although they may go on to produce large masses HICKS, ON GONIDIA OF LICHENS. 93 (fig. 134). The quarternary forms have a resemblance to the “‘tetraspores ” of the alge, and may possibly be homologous with them. It would be worth while extending this observa- tion to Lichina. Having thus shown various lines of development through which the Collema- and Nostoc-gonidia pass into Nostoc, I shall now bring forward instances in which it will be seen that Nostoc, by producing the colourless fibres and the so- called epidermic layer, tends to revert to its parent Collema. In old masses of Nostoc, especially where they have been removed to a dry situation, it will not be difficult, by careful search, to find within its substance portions, here and there, in which fibres are developed possessing every character of those in Collema. I have represented this condition at fig. 11, which was taken from a large mass of Nostoc. The pre- cise origin of the fibres I did not make out—whether from the vesicular cells or not; but they were unmistakeable in their appearance. Again, in Nostoc derived from those Col- ~ lemas which have a so-called epidermis, I have found them, by keeping in dry situations, to have a tendency to produce a similar layer—evidently from changes in the vesicular cells in the mode represented at fig. 12. The various vesicular cells in a neighbourhood become enlarged, lobed, or branching, and jointed; when these portions come into contact, and so pro- duce the appearance of a reticulated epidermis of the Collema. If, in addition to this, we refer to the remarks I made at first, that the Nostoc balls which were extruded from the thallus of Collema (figs. 5, 6) had so strong a disposition to throw out these fibres, that very soon they passed into Col- lema (fig. 7), the connection is thence apparent; for retard the fibre-growth at the same time that the gonidial growth proceeds, we then shall have a mass of Nostoc. Thus a connection is established in both directions between Nostoc and Collema. But, as I have before alluded to, the power of producing Nostoc i is not-eonfined to Collema. One instance I have met with, in which the gonidia of a gymnocarpous lichen, whose apothecia, with theca and spores, are figured at fig. 15, a, 6, developed themselves into Nostoc balls while still beneath the apothecia, and within the thallus, which was crustaceous. Fig. 14 represents a section of an immature apothecium, the gonidia beneath being unchanged. Fig. 16 shows a por- tion “of the thallus, in which one gonidium is undergoing the Gleocapsoid change, as at figs. 14 and8a. The further changes which the gonidia pass through, in order to arrive 94: HICKS, ON GONIDIA OF LICHENS. at Nostoc are indicated in figs. 17, 18, 19. Comparing these with the changes in Collema-gonidia, the similarity is evi- dent. At fig. 15 a is shown a perfect apothecia, where all the gonidia are now fully developed Nostoc balls. From the evidence just brought forward, in addition to that advanced by Itzigsohn and Sachs above spoken of, I con- ceive we can no longer consider Nostoc as an alga; but that we must, in company with Gleocapsa, Palinoglea, &e., confide them to the care of lichenologists, and thus add a new field for their observations, and a new phase in the life-history of those curious organisms. Hitherto the origin of Nostoc has only been traced up to Collema, and to the gymnocarpous lichen above mentioned ; but as researches have only been recently made in this direc- tion, it is by no means improbable that other instances may be added to their number. There is one point to which I wish to draw the attention of observers, namely, to watch the changes which the Col- lema- and Nostoc-gonidia may undergo; for, from what I have shown above, it surely cannot be considered an impos- sibility that they may assume a great variety of conditions, and thus give rise to many of the Nostochaceze. Indeed, it has been stated by Itzigsohn* as his opinion that all the Nostochacez are, in all probability, derived from the gonidia of lichens. Whether this be the case, partially or wholly, or not, from what has been shown at figs. 8, 9, 10, 11, such a condition is possible; for if the beaded threads of Nostoc can become modified into such forms as are represented at 9 a, the mucous coating becoming broken up at the same time, setting them free, it certainly cannot be considered beyond the range of physiological probability for them to develop themselves into one of the linear Nostochacez; for let us suppose, instead of a short portion of a Nostoc thread be- coming changed, as at figs. 10 and 11, that a long portion was so affected, or that the short portion so affected con- tinued to segment linearly, and reproduce the altered state— a process which obtains in other vegetations—then we should have forms allied to, if not identical with, the Nostochacez. Supposing such a condition proceeded intermittently, how could it be recognised from such forms as Trichormus, Spherozyga, Spermosira, Dolichospermum, &c.? 1 am not, from direct observation, prepared to assert that such is the origin of these growths; but the following fact seems to bé strongly confirmative of Itzigsohn’s opinion, * «Botan. Zeitung,’ 1854, p. 521. HICKS, ON GONIDIA OF LICHENS. 95 At fig. 20 I have figured a Nostoc ball, in the interior of which is a long, bluish-green, articulated thread (a), which has its origin in a vesicular cell (heterocyst) 5; as do many of the ordinary beaded threads of Nostoc. The whole was unmis- takeably within the mass, and dipped towards the centre, and evidently could not have been derived from without. Besides, it is worthy of notice, that Nostoc balis are always remarkably free from extraneous matter; a condition to be explained by their mode of increase. Hence we may con- clude that this growth had its origin from the Nostoc- gonidia. There is another fact which may perhaps help us, namely, that in contact with some Nostoc balls are to be found many forms of these linear Nostochacex ; they are so _Intimately united, and so mixed up with them, as must to any observer be suggestive of an intimate connection. Such forms I have represented at figs. 21 and 22; and if we admit the articulated thread at fig. 20 to have had a Nostoc origin, then there is no difficulty in accepting a similar source for those at figs. 21 and 22—a form allied to Schizosiphon. In the same position I have seen Scytonema. For these observations I do not wish to claim more import- ance than they deserve; still they bear strongly upon the opinion advanced by the author above named. In the papers of Itzigsohn* on the diamorphosis of Chroococcus and Gleocapsa, and on the relation of Nostoc and the Nostochacez to Collema, there are many remarks which, although they may not be immediately assented to by English observers, yet are worthy, to say the least, of careful con- sideration ; and as he is in part supported by Kiitzing, and by some observations of V. Flotow on the Ephebe pubescens, many points which he has advanced should scarcely be passed aside, without good negative evidence, with such remarks as these, “ We do not place much reliance on the statements of ltzigsohn.”+ To enter into the whole question of the rela- tions of Lyngbya, Ulothrix, &c.,is not within the inten- tion of the present contributions; but, the possibility being granted upon ordinary physiological grounds, we should be prepared to put aside our former notions upon any well- proved fact appearing. Besides, there is nothing difficult in supposing that some forms of Palmella cruenta, for instance, represent the unicellar condition of some of the Oscillatoriz, which have broken up into single cells; and then that these latter * «Bot. Zeitung,’ 1854, pp. 520 and 642. t ‘Micrograph. Diction.,’ 2d edit., p. 496. 96 HICKS, ON GONIDIA OF LICHENS. are, in their turn, capable of undergoing segmentation, and thus multiply in that phase. Such changes are in accordance with well-known conditions in other vegetables. Of course, whilst admitting the probability of these points, we should be very careful that the connection is fairly traced out, and assume nothing as intermediate stages without ocular proof, or such cir cumstantial evidence as cannot be escaped from. Thus the life-history of one, carefully traced, will be worth a hundred new forms without any history. It is to be observed, that the fact of these structures under con- sideration having been included among the alge by algeolo- gists is not to be considered any proof of their really being so; for, their life-history not having been followed out by the observers of species, they can only be considered as pro- visionally so placed ; as indeed must all organisms, vegetable or animal, whose various states, both vegetative and sexual, have not been carefully watched throughout. That many of the above points are now clear and have had their exceeding ambiguity in some measure explained, will, I think, now scarcely be denied. Doubtless a large field is open in this direction, if care and patience be bestowed upon it. As I have before remarked, we must not look upon Gleo- capsa, &c., as arising only from lichens. From facts which have come under my notice during the observations now brought forward, other origins also are to be given these growths, that is to say, forms undistinguishable from them ; and hence it follows that the study of their life-history is the only means of assigning them theirtrue position. At present all the so-called unicellular algze, and some Confervoidez, are on a most unsatisfactory basis; nor can any arrangement possibly take place till more extended researches are carried out in the directions above indicated. 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J.—NEW SER, 98 On OPHRYODENDRON ABIETINUM. By T. Srrernitn Wricut, M.D. A vERY curious protozoon appeared about five years ago in a limited locality, near Granton, on the southern shores of the Frith of Forth, from whence it spreads upwards towards Cramond, and now infests the Sertulariz (S. pumila) which abound for miles along the coast. J described it in September, 1858, in a letter to Dr. Arlidge, one of the editors of Pritchard’s ‘ Infusoria,’ who has introduced it into the last edition of that work, under the title of Corethria sertularie (Wright). I have also given a rough sketch of. it in the ‘Edin. Phil. Journal’ for July, 1859. Professor Claparéde, however, has informed me, that he and Lach- mann had previously deposited an account of it with the Academy of Sciences-of Paris. It will be found referred to as Ophryodendron abietinum, in their recently published studies,* and it is to be more fully described in the con- cluding number of that excellent work. Both Claparéde and Lachmann and myself have inde- pendently placed this creature among the Acinetinians, but not without considerable doubt, as it differs so widely in shape and habits from all others of that family. Dr. Arlidge writes to me, that “there is something so bizarre about the organism that I cannot interpret it.” The body of the animal consists of an oblong mass attached to the polypidom of the Sertularia (Plate VI, fig. 1). From one end of the mass arises a closely wrinkled appendage or proboscis, surmounted by a tuft of short tentacles. Such is the general appearance of the animal; but a second appendage is frequently present, which appears to be a gemma, as it is sometimes found separated from the animal, and at- tached to the Sertularia. When I described this protozoon in 1859, I had not seen any motion in the proboscis; but, during the last summer, when I kept anumber of Ophryodendra in large vessels of sea- water, | was surprised to find the organ in constant motion, sometimes almost withdrawn into the body, and again, at other times, extended to an astonishing length, until it became a clear glassy wand, thirty times as long as the body, and clothed at its upper end by about forty scattered tentacles, which ae about.in most violent motion. The animal * «Wtudes sur les Infusoires et les Rhizopodes,’ Ss Edouard Claparéde et Johannes Lachman, s WYVILLE THOMSON, ON ASTERACANTHION VIOLACEUS. 99 seemed to be constantly searching the water arourid it for prey, and occasionally to press the tentacles firmly to the bdédy of the proboscis, as if to imbed some matter in the substance of the latter. I was unable to detect any opening at the summit of the organ. As Ophryodendron now exists in great abundance in the neighbourhood of several eminent microscopic observers, we must hope that its anatomy and mode of reproduction will be worked out during the ensuing summer, and that it may be discovered in other localities. Claparéde and Lachmann de- scribe it as found on Campanularias; but I have never seen it on any of that class of zoophytes, even when they have been growing intermixed with Sertularia. Ihave only found it on one species of Sertularia, S. pumila. On the Empryontocy of AsTeRACANTHION vioLAcEus (L.) By Professor Wyvirte Tuomson, LL.D., F.R.S.E., M.R.LA., F.G.S., &e. Sars, in his wonderfully suggestive ‘ Beskrivelser,’ &c., published in Bergen in 1835, threw the first ray of light upon the structure of the singular provisional appendages which have been since found to accompany the embryonic condition of most, if not all, of the Echinoderms. We are indebted to the same naturalist for several subsequent com- munications on the same subject; the most important a detailed description* of the early stages in the development of Hichinaster sanguinolentus (Miller), and a shorter notice of the same process in Asteracanihion Miilleri (Sars). These observations are so well known, that I need only refer to them briefly. Sars found that in these two species the mode of repro- duction conformed pretty closely to the usual invertebrate type. Complete segmentation of the yelk took place, and the greater part of the mulberry mass was then moulded into the embryo Star-fish. The process presented, however, this peculiarity. A club-shaped appendage, with three or four‘short radiating processes, each terminated by a sucker, was developed from one part of the surface of the embryonic mass, and remained ched to the embryo during the earlier stages of its * * Fauna littoralis Norvegie,’ Part i, Christiania, 1846, 100) wyVILLE THOMSON, ON ASTERACANTHION VIOLACEUS. growth, withering and disappearing when the permanent external form and internal structure of the embryo became well defined. , The appendage was attached to the dorsal surface of the embryo in Echinaster sanguinolentus, and apparently towards the oral aspect in Asteracanthion Miilleri. Sars’ impression was that the cicatrix indicating the pomt of separation was the madreporiform tubercle. Sars observed an opaque tubercle in the centre between the four terminal suckers of the pedun- cular appendage, but could detect no mouth-opening in this position. Desor (‘ Proc. Boston Soc. of Nat. Hist.,’ February, 1848) describes a mode of development slightly different, but on precisely the same type, in an American Star-fish. In this case the peduncle is simple, and depends excentrically from the oral surface of the embryo. Desor regards the peduncle as a vitelline sac, and believes it to be directly connected with the digestive system, into whose general cavity its con- tents are gradually absorbed. Agassiz (‘ Lectures on Comparative Embryology,’ Boston, 1849) confirms Desor’s observations, but gives no definite opinion on the relations of the accessory appendage. Busch (‘ Beobachtungen tiber Anatomie und Entwickelung elniger wirbellosen Seethiere,’ Berlin, 1851) describes the development of Echinaster sepositus. The embryo of this species closely resembles that of Ech. sanguinolentus, de- scribed by Sars. Busch, however, figures the peduncle as disappearing at the oral surface, and he describes a mouth in the centre of the peduncle, between the four suckers. It is unfortunate that Johannes Miiller, the great authority on echinoderm development, had no opportunity of observ- ing any of this group of embryos alive, all his observations having been made on swimming larve taken with the towing- net in the open sea; he examined, however, carefully, specimens sent to him in spirits, could detect no mouth- orifice to the peduncle, and concluded that the hollow suckers had no immediate connexion with the stomach, which was developed as a distinct sac at some distance from their point of attachment. According to Busch, the plan of development in Asfera- canthion glacialis (l.) is somewhat different, associating itself apparently with the very interesting type described by Koren and Danielssen (‘ Fauna httoralis Norvegie,’ part u, Bergen, 1856) in Pteraster militaris (M. and T.), to which I shall have to refer hereafter. . Several writers, and particularly Dr. Carpenter, in his WYVILLE THOMSON, ON ASTERACANTHION VIOLACEUs. 101 valuable compilations on Comparative Physiology, have suggested a correspondence between the provisional append- ages of the Echinoderms and the temporary vascular appa- ratus of the vertebrate embryo. This view I believe to be correct, and capable of more accurate definition, as will be seen in the sequel. A series of careful observations which I have had an opportunity of making during the last few months upon a common littoral species of Asteracanthion, agree in almost every particular with the observations of Sars, which, in this as in all the other investigations of that most distin- guished naturalist, are singularly clear and faithful. I was fortunate, however, in selecting for study a species in which the provisional absorbent and respiratory vessels are much more fully developed than in Echinaster sanguino- lentus. The whole organism seems to be paler and more trans- parent, and the relations and development of the fnternal organs are accordingly more easily traced. My results are, to a certain extent, at variance with those of some later writers, and particularly with those of Dr. W. Busch. I must state, however, that the plasticity of the tissue of which these temporary embryonic appendages in the Echino- derms are formed seems to be almost infinite. So capri- cious are the variations in a structure essentially the same in all, that it is impossible to anticipate its form in any parti- cular case from the analogy of even the most closely allied species. Early in December of the present winter I procured several specimens of