GERM CELLS OF COELENTERATES 397 
(figs 3 to 5), but a little later (figs. 6 and 7) becoming vacuolated 
and alveolar. In the periods represented by figure 8 (which may 
be variable as far as the size of the egg cell is concerned) for the 
first time there appear deutoplasmic bodies in the cytoplasm, and, 
since this coincides with the great activity of the nucleolus, it 
seems that there must be some connection between the two con- 
ditions. 
If it be objected that figure 8 shows the deutoplasm closer to the 
periphery of the egg than to the nucleus and therefore there can 
be no connexion between nuclear emissions and yolk formation, 
let the following also be noted. First it is not assumed nor 
believed that all the material which forms yolk bodies comes from 
the nucleus; on the contrary, I believe a greater amount of it 
comes into the cytoplasm from the food stream in the enteric 
cavity of the gonophore and never enters the nucleus. This would 
probably be more abundant near the periphery of the egg than 
elsewhere. In the next place, the first emissions from the nucleus 
occur quite a while before yolk bodies form (figs. 6, 7). It is 
believed that at least the first emissions are of a ferment nature 
and not until they get into the cytoplasm is it possible for the 
material there to be synthesized into reserve food. It is even 
conceivable that the first nuelear contributions to the cytoplasm 
and the later ones are the same. And it is conceivable and pos- 
sible that the same substances will at first hydrolize the food 
material coming into the cytoplasm, hence there will appear no 
yolk bodies, and later the same substance synthesizes the dissolved 
food and the result of this synthesis is yolk bodies. The reversible 
action of enzymes is too well known to call for any particular 
explanation in regard to the relation of enzymes and yolk forma- 
tion. If this possibility be granted, there is no difficulty in account- 
ing for deutoplasmic formation near the periphery rather than 
near the nucleus; indeed it would take place where the concen- 
tration of the hydrolized substances was greatest and this would 
be near the place the original material entered the egg, namely, 
near the periphery. Furthermore, the presence of yolk near the 
periphery is only at the first; the yolk is formed so quickly when it 
once starts that-it fills the whole of the cytoplasm and is especially 
