356 
CRESSWELL SHEARER. 
is difficult to make out exactly what does take place. What 
one sees in sections is that amongst the oogonial cells are 
some that are very large and yolky and have the appearance 
of being formed by the fusion of several primitive oogonial 
cells. They may have three, or as many as live nuclei, that 
seem to be actively dividing quite independently of one 
another, while the large mass of cytoplasm in which they lie 
shows no cell walls, and is distinctly yolky and granular in 
appearance, and very unlike the cytoplasm of the early oogonial 
cells. There are two possible ways in which these masses can 
be formed : first by the proliferation of the nucleus of the 
oogonial cell without any actual cell division ; or secondly by 
the fusion of several independent cells. I am inclined to 
believe that the first stage in the process is begun by the 
division of the nuclei, and that fusion only takes place secon- 
darily, and that the two processes to a certain degree go hand 
in hand. 
A number of these primitive egg masses are shown in the 
interior of fig. 21. Here one sees a large number of nuclei 
distributed throughout a small mass of yolky cytoplasm. In 
fig. 22 one of these masses is showr* under greater magnifica- 
tion, at a somewhat later stage. Here we get a large number 
of actively dividing nuclei, arranged around the periphery 
of a mass of yolk. Examination shows that these nuclei 
are undergoing division, apparently quite independently of 
one another. It is clear that whether these masses are formed 
by the fusion of cells, or by the growth of a single cell through 
multiple nuclear division, the result would be the same. I 
have, however, been unable to determine exactly which of 
these processes takes place. 
To go back to an earlier oogonial stage, a series of figures 
(figs. 16-19) represent the process of nuclear division at this 
stage. Fig. 16 represents a small oogonial cell, the nucleus 
of which is about to divide. Here it can be seen that the 
male and female portions divide simultaneously and amitotic- 
ally. The female portion is much the larger and contains one 
endochromatic vacuole (rfg.). The male portion has already 
