330 PROFESSOK W. C. WILLIAMSON ON tOLtOX GLOBATOR. 



Up to this Stage, each germ is still retained within a large 

 transparent vesicle {Figs. 8 a, 9 a, and 10 a), apparently 

 the relique of the cell-wall of the primary cell. Its tenuity 

 is extreme, and not the slightest trace of structure can be 

 detected in it; but it is invariably present. I apprehend that 

 this is the sole bond of union with the parent Volvox; and 

 that, even though the latter may be torn, unless these special 

 vesicles be also ruptured, the young Volvox will not make 

 its escape — a phenomenon which we may constantly wit- 

 ness. Usually, however, this membrane gives way along 

 with, if not prior to, the laceration of the older individuals, 

 and the ciliae being already in action, the young ones float 

 away, and commence their independent life. 



At this time, the cells constituting the substance of the 

 young Volvox are angular, fitting closely together, and hav- 

 ing the lining membrane and endochrome in close apposi- 

 tion with their walls ; they are in fact in the state with which 

 we commenced our sketch. The cell-contents soon shrink 

 away from the cell-wall, excepting at the points of contact, 

 where the radiating threads still retain the contracting mem- 

 brane in a central position, and all the other changes already 

 described are again gone through. 



In this development of germs by a process of cell 

 division, we have merely an ordinary example of the 

 production of a bud — a process common alike to the ani- 

 mal and vegetable worlds. It presents nothing like the 

 development of an ovum, or a seed — though it is very 

 similar in its results to the production and growth of the 

 embryo, as it is developed from the membrane lining the 

 embryo sac, only wanting the pollen tube and its influences, 

 the sac being represented in the Volvox by the entire sphere. 

 But though the germs produced are not true ova or seeds, 

 may they not be endowed with a potentiality which will 

 enable them to develop something analogous to seeds? 

 It is consistent with what we know of other forms of or- 



