ABBEY, ON ORGANIC STRUCTURE. 273 
germinal molecules whose functional powers are in abeyance, 
and which, therefore, are closely aggregated into a deeply 
coloured mass, which seems capable of forming a circum- 
ferential deposit or areola of plasma, whose quantity is 
proportionate to the size and age of this composite molecule. 
Here, then, we have the condensed nucleolus active only at 
its outer surface, and surrounded by the colourless plasma 
resulting from that activity; this, again, having a granular 
envelope, composed of similar plasma, and strewed with what 
are, in fact, fragmentary nucleoli. 
As the outlying molecules become insufficient, demands 
for reinforeement are made upon the nucleolus, and this 
demand is answered in various ways. Frequently, successive 
molecules seem to be detached from the surface of the 
nucleolus, becoming more and more widely separated from 
each other as the produced plasma increases. Sometimes 
the whole mass of the nucleolus is at once called into action, 
and thus arises the phenomenon of a new granular nucleus 
contained within the original and paler one. 
At other times, the nucleolus having divided, the one 
part remains in statu quo; while the other, sphered in its 
share of the plasma, goes off to form a new nucleus, 
nucleolated or otherwise. 
Other varieties of fission might be referred to, but it does 
not seem necessary to do so in this place. 
The vital processes of the unimpregnated animal ovum 
correspond very closely with those exhibited by the nuclear 
matter of the vegetable-cell. 
A good general illustration of my proposition is shown 
by that pretty little organism Volvow globator, which may 
very well be looked upon as a sort of glorified mass of 
nuclear matter. It will be remembered that it consists of 
a hollow hyaline globe, studded at regular intervals with 
little green masses of endochrome. This represents the 
nucleus. Contained within the globe is a variable number 
of solid masses of endochrome, each with a viscid transparent 
envelope. These represent the nucleoli. When the time 
comes for one of these latter to assume independent activity, 
it divides and subdivides within its envelope or areola up to 
a certain point, without undergoing other change. Lach of 
the resulting globules—with the exception of a portion 
which, like some part of the yolk of certain eggs, has escaped 
segmentation—secretes around itself the ‘germinal plasma,’ 
until the globe of the Volvox, with its contained nucleoli, is 
reproduced; the plasma-envelope of the original nucleolus 
now forming the containing sac of the whole organism. 
