398 GEORGE T. HARGITT 
prevalent near the nucleus (figs. 9, 10; fig. 9 is of the same stage as 
fig. 8). 
With regard to the direct connection between the nucleolar 
matter and the yolk bodies, it is true that the nucleolus dissolves 
within the nucleus and there is certainly some commingling of 
nucleolar matter and nuclear sap, probably also a mixture of some 
of this matter with the chromatic network. But the growth of 
the nuclear reticulum and the dissolution of the nucleolus do 
not go on together, the reticulum showing almost no change until 
the nucleolus has disappeared. Again it is found, as figures 13 
to 17 show, that the nucleolar fragments are always surrounded 
by a space; that is, they lie in a vacuole. Further, the smaller 
particles, when abundant, are often arranged in a rather definite 
row close to the nuclear membrane (figs. 14 and 15) as though 
it were here that dissolution was most rapid and the current out- 
ward had carried them here. These facts show that the dissolv- 
ing nucleolar material is not being added directly to the nuclear 
reticulum, but, since the nucleus is increasing in size during this 
period, it is probable that the nuclear sap is increased very much 
in amount by the dissolved substance. Figure 16 shows well that 
the nucleolus is dissolving little by little; in this case the different 
particles showing different staining reactions, since the lightly 
stained nucleolar fragments show small drops of the material 
passing into the vacuole surrounding the fragment. The most 
satisfactory and crucial evidence of the connection between the 
nucleolus and yolk lies in this: during all the time that yolk bodies 
are being formed there is evidently a considerable exchange of 
material between the nucleus and the cytoplasm as shown by the 
currents already mentioned. During this same time (figs. 7 to 
12) there is no change in the nuclear reticulum, which remains 
very fine-meshed, exceedingly finely granular and staining very 
faintly; that is, the reticulum is apparently unchanged and un- 
modified by any of the striking and active modifications that are 
going on. Since the nucleolus is the only portion of the nucleus 
showing signs of activity during this period and since there is 
clearly great activity going on in the cytoplasm in the synthesis 
of food matter, there appears to be no other possibility than to 
