STUDIES ON GERM CELLS 511 
The nurse chamber is now completely formed (fig. 13, n.c.). 
The nurse cells are still free from the bacteria-like rods and their 
nuclei, as pointed out by Blochmann (’86), possess very thick 
membranes (fig. 30, ). Part of one of these nuclei greatly en- 
larged is shown in figure 32. The membrane contains, in a 
homogeneous matrix, a number of vacuoles and a great many 
granules of various sizes which appear in material fixed and 
stained by a number of different methods. Their reactions all 
indicate that they are chromatic in nature and their position 
suggests that they may have migrated into the membrane from 
inside of the nucleus and are on their way into the cytoplasm. 
It could not be definitely determined, however, whether this is 
a true case of chromatin emission or simply a condition due to the 
action of the fixing solutions used. 
A further increase in the amount of cytoplasm within the 
oocyte is evident when Stage H (fig. 15, H; fig. 33) is reached. 
Here an opening (a) is present in the follicle connecting the 
oocyte directly with the nurse chamber. The small plug of 
cytoplasm filling this channel is no doubt homologous with the 
nutritive string present in the ovarioles of insects whose oocytes 
are not accompanied by a group of nurse cells, but are connected 
with the terminal chamber by a protoplasmic thread. In this 
stage the oocyte nucleus (0) is still closely pressed by the secondary 
nuclei (s) surrounding it and the entire group lies within the 
cytoplasmic zone. Such a group is shown enlarged in figure 34, 
in which the oocyte nucleus may be distinguished from the 
secondary nuclei by its irregular shape, central position, and 
clearness. 
The succeeding stages in the growth of the oocyte (fig. 15, J, 
J, K, L; figs. 35-39) are characterized by a decrease in the number 
of bacteria-like rods, by the formation of yolk globules, and by 
the increase in number and the scattering of the secondary nuclei. 
Part of a section through an oocyte of Stage I (fig. 15, [) is shown 
in figure 35 which represents a portion extending from a point 
midway between the two poles out to the middle of the oocyte. 
Just within the follicular epithelium (e) is the suggestion of a 
clear layer (k) which later becomes the ‘Keimhautblastem.’ The 
JOURNAL OF MORPHOLOGY, VOL. 26, NO. 3 
