244 Mr. II. J. Carter on fecundation 



can only be determined by following the development of the 

 spore from the commencement. One fact I might add, how- 

 ever, viz. that the robust forms about the size given in fig. 1 

 have the power of withdrawing their cilia and protruding them 

 again ; this happens when they are transferred, from the vessel 

 in which they may be contained, to the slide for examination : 

 many may just at this time be seen to be motionless, with the 

 channels for the cilia empty ; but gradually the cilia are pro- 

 truded through them, and as gradually the Eudorina evinces 

 increasing power of motion, until they are fully protruded, and 

 it swims away. 



Chlamydococcus undergoes the same kind of changes in deve- 

 lopment as Eudorina, from which it only differs in structure in 

 being smaller, and globular instead of ovoid, in the absence of an 

 external envelope, and in the cilia of the daughter-cells being 

 included within the parent-cell ; hence it also differs in being 

 motionless, though the compartments of the daughter-cells are 

 sufficiently large for them to turn round and move their cilia 

 freely therein, which they are continually doing (figs. 9, 15). 

 The primary cell of Chlamydococcus, like that of Eudorina, di- 

 vides up into two, four, eight, or sixteen cells, and those of the 

 eight- and sixteen-divisions again into groups of sixteen or 

 thirty-two each (fig. 14), so as to resemble the third stage of 

 Eudorina. Hence we may perhaps infer that its fecundating 

 process is similar to that of Eudorina ; but this remains to be 

 discovered. Chlamydococcus has also a great tendency to stop 

 at the two- and four-division, from which it may pass into the 

 " still" or Protococcus4ovm, and, floating on the water in a kind 

 of crust, present cells of all kinds of sizes undergoing " still " 

 division. In all its multiplications, partial and entire, however, 

 it generally maintains its primary or spherical form, and does 

 not become ovoid or oblong, like the groups of Eudorina, the only 

 exceptions being in the two- and four-division, where the green 

 cells are sometimes ovate (probably from want of room in the 

 parent capsule, fig. 11), as represented by Ehrenberg in C. Pul- 

 visculus*, — to which I should refer it, had he not also given an 

 ovate form to the type-cell of this speciesf; nor can I refer it 

 to C. pluvialis, for in all the changes I have yet seen it un- 

 dergo, the red colour has not increased beyond the minute eye- 

 spot, while this also disappears, and the cilia too, when this spe- 

 cies passes into the "still" form (fig. 15). Here it undergoes 

 the same kind of division that it does in the active state ; but the 

 parent-cell, instead of becoming distended by imbibition, remains 

 closely attached to the daughter-cells, so as to give the group a 



* Tab. 3. fig. 10. 

 I, t There ia an ovate species, common in Bombay; but this has four cilia. 



