Vol. 6, 1920 ZOOLOGY: D. H. TENNENT 219 
blue, saffranin-gentian violet, thionin, and some of the carmine stains 
were used. 
In the sections of the Arbacia-Moira material a cycle of changes may be 
noted, changes concerned with the appearance and disappearance of baso- 
philic bodies in the cytoplasm. The development of these bodies may be 
followed as they appear in a cloud outside of the nucleus, then in lines 
radiating from the nucleus, then scattered irregularly in the cytoplasm, 
the nucleus during this time being in the resting condition. 
The basophilic bodies appear first in the form of fine granules in the 
immediate vicinity of the nucleus, then as short rods, which may be seen 
either singly or in short chains throughout the cytoplasm. These rods 
are of about the thickness and length of the chromosomes of Arbacia. 
A study of the nucleus in the sections of the eggs of this period reveals 
the fact that the nucleoli have become much paler. In the earlier stages 
they stain uniformly; in the later the surface (rim in the sections) , only 
stains, while the center remains clear. Deeply stained granules may be 
seen aggregated at the inner surface of the nuclear membrane as though 
adsorption were taking place. In some sections a massing of granules 
may be seen at one side of the nucleus, this mass probably being the ex- 
panded chromatin of the male nucleus. There is a distinct impression of 
diffusion from the nucleus, but there is no evidence of the emission of 
chromatin as such. At the end of this stage the nucleus is distinctly acido- 
phile. 
Then a reversal of the process begins. The sections give the impression 
of a movement of some of the contents of the cell toward the nucleus; 
again there is the appearance of a diffuse cloud in the region of the nucleus; 
the number of rods becomes distinctly smaller, until in the late prophases 
the cytoplasm has cleared almost completely. The nucleus becomes in- 
creasingly basophilic as it passes into the prophases of division. The nu- 
cleus increases in size. In the metaphase and in the anaphases of division 
the cytoplasm is free from rods. During this stage there is no visible 
evidence of the passage of materials through the nuclear membrane and 
into the nucleus, but the nuclear content has distinctly increased. 
If we correlate these facts with the conditions shown by Chambers to 
exist in the egg at this time, we find that the diffuse cloud appears while 
the nucleus is lying in the liquid hyaloplasm sphere. This is at the be- 
ginning of the "pause" Wilson (1895), succeeding the fusion of the nuclei 
in fertilization. The sudden appearance of granules and then of rods in- 
dicates a rapid diffusion of enzyme throughout the cell. The rods are 
very numerous at this time and lie without definite orientation in the cyto- 
plasm. M. R. Lewis determined for Chambers that diffusion of cresyl- 
blue takes place quickly — in a few seconds — after injection within a ceU. 
The formation of the granules and rods may be interpreted as the result 
of a reaction of the cytoplasm to the nuclear enzymes. 
