4 Mr. H. J. Carter on Fecundation in the tivo Volvoces, 



and that she produces a cell which never becomes a grand- 

 daughter Volvox itself, but produces another cell, which in the 

 end may give rise to a new family or third generation through 

 the process of fecundation. Whether each spore produces one 

 or many Vulvoces, is a question which can only be decided by 

 watching its development. 



Sometimes, on the other hand, instead of either of the forms 

 just mentioned, one, two, three, or even all the eight daughters 

 may present an enlargement of a far greater number of the peri- 

 pheral cells, viz. upwards of one hundred, indiscriminately scat- 

 tered over the whole of their internal peripheries respectively. 

 Mr. Busk states over two-thirds only (/. c. p. 33), and analogy is 

 in his favour ; but I could not detect this (fig. 8). These cells 

 undergo deduplicative subdivision ivithin the parent, until their 

 contents respectively pass into 128 (?) linear, ciliated segments, 

 which are ultimately arranged vertically upon the same plane, in 

 a circular, tabular group, with their cilia upwards ; and when the 

 latter are sufficiently developed, the group oscillates and rotates 

 by their aid both upon its long and short axis (fig. 10 a, b). 

 These segments are, in fact, the spermatozoids, each of which, 

 when they separate, is observed to be linear, horn-shaped, 

 and colourless anteriorly, where it is attenuated, and greenish 

 posteriorly, provided with a pair of cilia which are attached to 

 the anterior extremity, and some distance behind them with an 

 eye-spot (fig. 8 b) ; their progression is vermicular from their 

 extreme plasticity, and they keep up an incessant flagellating 

 movement with their cilia. As yet, I have never seen any of 

 these free in the daughter bearing the spermatic cells when the 

 former has been outside the parent ; nor have I ever seen them 

 free under any circumstances, except once, in the old Volvox, 

 when the daughter containing the spermatic cells from which 

 they had been developed had been partly eaten up by Rota- 

 toria. 



This is the form of Volvox globator which has been called 

 Sphcerosira Fo/t'oa^by Ehrenberg; and, like the daughters bearing 

 the spore-cells, it becomes liberated from the parent before the 

 spermatic cells attain their ultimate development, that is, before 

 the groups of spermatozoids become separated, not before they 

 are formed. It is worthy of remark, too, that the daughter 

 bearing spermatic cells is never more than half the size of the 

 spore - bearing daughter, at least as far as my observations 

 extend. 



Thus we have the spore-cells and the spermatic cells in dif- 

 ferent daughters ; and as I have never seen them together in the 

 same daughter, nor the daughters respectively bearing them in 

 the same parent Volvox, out of some scores of instances, I can 



