212 THE PHENOMENON OF 



drawn out to nothing, rather than regularly burst open ; 

 it at length vanishes in some indistinguishable way, the 

 daughter- cells meanwhile acquiring a tolerably thick, 

 closely applied cell-membrane of their own. The division 

 is repeated many times in this way, and as the cells all 

 remain in intimate contact, first small families, but by 

 degrees large conglomerates of cells, are produced. The 

 size of the single cells in these groups varies from -[ioth to 

 Jgth milhm. ; their shape is not truly globular, but partly 

 bounded by flat surfaces, as results from the alternating 

 divisions according to the three directions of space. In 

 this neighbourhood I have ordinarily found the colour 

 hght brown. If ignorant of the rest of its history, 

 one would be led, by the form and mode of division of the 

 cells, to regard thesecrusts asbelongingto aPleurococcus.'"^ 

 In the same crusts occur isolated large cells, loosened 

 from their connection with the others, perfectly globular 

 in foi'm, and appearing to divide no more, but to have 

 past again into the condition of resting spore-cells. They 

 are distinguished from the rest by their darker contents 



* In this condition CJdamidoeoccus phwialis exliibits sucli a decided 

 vegetable character that the advocates of the widest extension of the 

 animal kingdom, if ignorant of its active condition, could hardly conjecture 

 it to be an animal being. But even the active state of Cfdamidococcus 

 cannot be regarded as possessed of animal life, if Ihe swarmiug of thegonidia 

 of the Algse resulting from ciliary motion — which occurs from the Palmcl- 

 lacea upwards to the Jucoideae, and also has its analogue in the higher 

 Cryptogamia, (Characeae, Mosses, Ferns, and llhizocarpeee) in tiie move- 

 ment of the spermatozoids, likewise produced by delicate cilia, — is to be 

 regarded as a phenomenon of vegetable life, which, in spite of our ignorance 

 of the cause and modus operandi of this motion, does not seem to admit of 

 doubt, from the way in which it presents itself as a normal condition connected 

 with the vegetative life. Although the phenomena of motion are of longer 

 duration in Chlamidococcus than is usual elsewhere in the swarming gonidia 

 of Algae, the kind of movement is essentially the same, namely, an uninter- 

 rupted revolution round the long axis, combined with- an advance towards 

 the side of the ciliated point. In Chlamidococcus the direction is con- 

 stantly to the left, as in the gonidia of (Edogonium, while the gonidia of 

 Vaucheria, as also the oval family-stocks of Puiidorina, revolve constantly to 

 the right. With regard to the duration of the movement, Protococcns 

 ■ciridis, the active gonidia of which continue their swarming even in tlie 

 night, forms an intermediate link between the ordinary behaviour and that 

 of Chamidocorcm and the Volvociiieee. 



