SPERMATOGENESIS OF ASCARIS 429 
interesting interpretation of the condition of the cytoplasm of the 
spermatocyte as shown in figure 10. Here we find granules and 
yolk vesicles of varying sizes scattered throughout the cytoplasm. 
Small granules may be close to the cell wall, while near the 
nucleus we may find fully formed yolk vesicles. Since the karyo- 
chondria do not arise de novo in the cytoplasni there must be 
a constant movement of the cytoplasm, or these inclusions could 
not become thus scattered. Such protoplasmic movement is 
well known in resting plant cells, and it occurs, of course, in all 
dividing cells; but it must occur also in the resting spermatocyte 
of Ascaris (figs. 6 to 10). 
Development 
The karyochondria, almost as soon as they first appear in the 
cytoplasm, increase in size and become less deeply staining. 
They remain spherical in outline as they grow; no irregular or 
dumb-bell shapes appear amongst them. Though their growth 
seems to be quite definitely limited, ceasing when the diameter 
is about ten times that of the original granule, I have not been 
able to find undoubted cases of division or even fragmentation. 
For some time before the maturation divisions, the cytoplasm is 
about half filled with vesicles evenly distributed through it and 
uniform-in size and staining reaction. A count of the vesicles 
‘in the median plane of such a cell corresponds so closely with one 
made in a cell in the midst of the growth period, when only a 
few of the granules have become fully formed vesicles, that it 
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Plastochondria | 
{ 
Arise in the oxy- 
chromatin: 1.e., 
the linin net- 
work, true nu- 
¢ leo lu sor 
plasmosome or 
plastosome, the 
centrosome and 
centrosphere 
Minute granules 
which make up 
the interalveolar 
reticulum, the 
fibrillae, the rays 
and fibers of the 
division figure. 
After reaching 
the egg cyto- 
plasm they dis- 
solve and help to 
form the fertili- 
zation membrane 
Mitochondria of 
Marcus, Mayer, 
Romieu, ete. 
Microsomes 
Plastidules 
Archoplasm 
Protoplasmic 
puscles. 
Paraplasm or met- 
aplasm (Wilson) 
cor=, 
