508 



SYSTEMATIC HISTORY OF THE INFUSOEIA. 



long as broad. Amongst Confervae. 

 Almost 1-1000". 



C. (?) glauca. — Oval, twice as long 

 as broad; anteriorly truncated with a 

 double flageUiform proboscis ; body tur- 

 gid, and of a bluish-green colour. 

 Found with Chlamydomonas Pulvisculus. 

 1-864". 



C. (?) fusca. — Oval, turgid, and of a 

 browm colour. Amongst Confervse. 

 1-1500". 



C. lenticularis. — Orbicular, resembling 

 a lens ; colour green \ lorica thick, 

 1-1729". 



The following are described and named by Dujardin : — 



C. Globulus. — Globular, green, often 

 with folds (stripes), the diaphanous en- 

 velope nearly filled. 1-2600" to 1-2250". 

 This species, in Perty's opinion, is a 

 spoinile of a plant, or a 'sporozoid.' 



C. incequalis. — Ovoid, green, of less 

 thickness than breadth, with a longitu- 

 dinal depression, and one or two unequal 

 notches in the coloured portion, which 

 is always smaller than the envelope. 

 1-2600". In stagnant sea- water, impart- 

 ing to it a green colour. 



C. (Lagenella) injiata. — Ovoid, en- 

 larged posteriorly, contracted anteriorly ; 

 envelope transparent, thicker about the 

 anterior neck-like portion, filled with a 

 green substance, having a central red 

 speck ; motion zigzag. 1-1180". In a 

 vessel of marsh-water with Lemna. 



C. (Lagenella) euchlora (xvni. 31). — 

 Ehrenberg has described under this name 

 an Infusorium of the same size, differing 

 from the last by its more elongated form, 

 and especially by the green contents more 

 completely occuppng the anterior neck- 

 like portion, w^hereas in ours but a nar- 

 row sti-eak is visible. 



C. (TETRAB^a^A) socialis. — Regularly 

 ovoid, green, with a central red point, 

 enveloped by a thick diaphanous lorica ; 



commencing self- division frequently 

 seen ; occurs in regular groups of four 

 individuals, simply agglutinated, and 

 having their filaments directed all to 

 the same side. 1-1700" to 1-1300". 

 In a w^ater-butt in the King's garden, 

 Paris. "I should have taken," s^iys 

 Dujardin, "the specimens of Tetrahcetm, 

 socialis at first for Gonia, if a trace of a 

 common enclosing envelope had been 

 found ; yet I cannot doubt that they have 

 the closest analogy wdth the true Goniu, 

 and wdth w^hat Ehrenberg has called 

 Syncrypta in his family Volvocina. One 

 may suppose that the commencing self- 

 fission observed in some individuals 

 would give rise to such groups upon the 

 desti-uction of the lorica (integimient) in 

 these different genera. This mode of 

 propagation occurs undoubtedly in most 

 of those having a soft gelatinous integu- 

 ment ; but in animals like Trachelomonas^ 

 whose lorica is hard and brittle, we can- 

 not miderstand how multiplication does 

 take place." 



In the addenda to his treatise, Dujar- 

 din has this remark : " I am convinced 

 that my Crypto^nonas (Tetrahcenci) be- 

 longs rightly to Gonium.^'' 



The generic characters of Cryptomoiias, as understood by Perty, have been 

 detailed ; the following are the species he describes : — 



C. polymorpha. — Is so very variable in 

 form that no single description can be 

 applied to it. It ranges between 1-840" 

 to 1-300" in length, and may be green 

 or colourless, browoi or golden yellow, 

 and contain at one time red specks, at 

 another not. The smallest are usually 

 yellow or of a verdigris-green : many 

 small ones are hyaline ; the largest sea- 

 green and brown. These changes of 

 colour are doubtless due to the choro- 

 phyll developed wdthin these minute 

 organisms, and to the modifications this 

 matter undergoes in different stages and 

 conditions of life — a subject w^ell exa- 



mined and illusti'ated in Braun's work 

 on Rej uvenescence in Nature. In figure, 

 individual specimens are oval or globu- 

 lar, compressed, and emarginate. Small 

 ones move rapidl}', frequently in circles ; 

 larger examples more slowly, and at 

 times backw^ards. The species is com- 

 mon among Confervas the whole year, 

 and under the ice in winter. Perty 

 assumes it to represent the following 

 species of Cryptomonas named by Ehren- 

 berg, viz. C. curvata, C. ovata, C. o'osa, 

 C. cylindrica, C. glauca, and C. fusca, 

 and also Chilomonas Paramecium. 



