History of infusoria, including the desmidiaceae and diatomaceae, British and foreign / by Andrew Pritchard.

Andrew Pritchard

Date:: 1861

Credit: History of infusoria, including the desmidiaceae and diatomaceae, British and foreign / by Andrew Pritchard. Source: Wellcome Collection.

Provider: This material has been provided by Royal College of Physicians, London. The original may be consulted at Royal College of Physicians, London.

168/1074 (page 148)

$unclistinguisliable from Pohjtoma Uvella in eveiy matei-ial point—the absence of colotu-, and its habitat in decomposing infusion alone offenng themselves as distinctive of the latter. Nay, what is more, he discove:-s the intimate resemblance of CUamydomonas to the resting-stage of a Vohox which he discovered in decomposing infusions, and named V. hyahna. I'rom these considerations he concludes that Glilamydomonas and Pohjtoma must be ranked Avith Volvox in the vegetable kingdom. But CUamydomonas is made to appear a metamoi-phic condition ot yet other organisms. For instance, Itzigsohn states that, after the joints of the filaments of Oscillaria tenuis are separated, they produce motile gonidia which present in all respects the aspect of Chlamydomonads, but which, after passing through many intermediate forms, grow into perfect Eughnce (J M 8 1854, p. 189). Likemse Hartig, in his account of the transtorma- ions 'of the Phytozoa of Antheridia (/. M. S. 1855, p. 54), makes one phase to resemble Chlaiydomonas destruens of Ehrenberg. Lastly, Cohn confesses (On Protococcus, B. S. p. 555).that the motile or smarming form of P.o ocom^ is scarcely distinguishable from Glilamydomonas, except that the latter has not been observed by him in the ' still' condition. But this presumed point of divergence itself vanishes since Braun's obsei-vations have made us ac- quainted mth the quiescent phase of that organism (p. 14/ ). _ The relation of Glilamydomonas to Stepluvnosplimra, and, in general, its alliance with the Volvocina as a plant, have been reviewed m the preceding another unicelMar, isolated organism of the femiiy Volvocina, has arrested much attention and been descnbed at arte by Plotow, Braim, Cohn, Perty, and others under the additional names of P,oLocc.«, 'H^maLoccus, and Hyscjinu... Ehrenberg - similarly named; but modern researches show that Gyges is in pait its equivalent, although but one phase of its existence. , , •_.„ Ehrenberg's account of Gyges is very meagre. He chaiactemcs it a.s wanting both filaments, eye, and tail, and as '^'^-^^f^.X^t^^'^^^ lorica Can urceolus). He could chscern no traces of a nutiitive system, anr , except a ve y shgM movement rendered evident by colouring the fliud, coSd detectlo indication of animality. On the other hand, Mr. Shu tle- Wh examined G. sanguine.., and stated it to have a hvely motion (Mn.6. ^'t™hm5n!i7 notes on the Fo?voc,Wc. in general, a vegetable nature is ^sS^ed to the Glilamydooocc^. ; and its relation to other Volvoane. is thus laid do-5\Ti by Cohn (A.N.H. 1852, x. p. 66b):— Sll^ydocolus is aViniceUular Alga in the strictest sense o the woid never eom/osed of more than one ceU at any period of g™^!^';-'^^ ^^^^^^^^ division forms the commencement of a new mdividual, whilst the lemnindei Tt\T vlhocinece \i e. excepting Glilamydomomts-] present themselves as fJZ. oflZ^ ^ a dkite numbei of equivalent cells ai-e combined, in some measure, into an individual of a higher order _ » j^^^e The researches of Alex. Braun, like my own, he continues nave ,.vnvpd most distinctly that Ghlamydococms can only be placed with pio- ^ Z^.ZoL he S. It is distinguished, indeed, from the movmg germ- SC-S fe^^^ ti e greater part of the species of .Uga3, are P-Pag«ted' f Lrowhit more complex structiu-e and by the cu-cumstance that the ^^ . Tstrfor Tvery ?ong time, and, finaUy, by the power of the mo^^ng motion lasts toi a ^^^^ « • ^ entering into the state of rest germma- eeUs to propagate a ^ ^^J^^^^'^ ^^'^^^^^^^^^ But these objections$