STUDIES ON GERM CELLS 507 
months. In this way oocytes in all stages of growth were ob- 
tained up to almost the period of deposition. Sections were 
cut and stained as in the queen bee. 
The ovaries of the carpenter ant resemble those of the queen 
bee in general structure and the ovarioles are likewise similar. 
The youngest ovaries obtained had already passed the period 
when the oocytes and nurse cells are differentiated, so there was 
. ho opportunity to study the events that occur during this differ- 
entiation. Four regions may be distinguished in the ovarioles 
as shown in figure 13. There is a terminal filament (t) at the 
anterior end. This is followed by a region which we may call 
the terminal chamber (t.c.) containing oocytes, nurse cells, and 
epithelial cells without any special arrangement. The next part 
of the ovariole is short and contains oocytes which have grown 
considerably but have not yet taken a position in the axis of the 
tubule. This we may call the first zone of growth (g). The rest 
of the ovariole consists of a linear series of oocytes (0) each with 
its accompanying group of nurse cells (n). Each oocyte is larger 
than the one anterior to it and the nurse cells gradually become 
grouped into a definite nurse chamber (n.c.). The bacteria-like 
bodies discovered by Blochmann are present only in the last 
described zone. The first signs of nuclear-like bodies around the 
oocyte nucleus also appear here. For the sake of convenience 
oocytes in the various stages which need to be referred to have 
been drawn in outline and to scale as shown in figures 14 and 15. 
The posterior end of the terminal filament (¢) and anterior 
end of the terminal chamber (t.c.) are shown in outline in figure 
16. The cells of the terminal filament are long and slender and 
extend entirely across it. One is shown enlarged in figure 17. 
Within the terminal chamber are two kinds of cells, oocytes and 
nurse cells. The oocytes, as indicated in figure 18, are the 
youngest to be found in the ovarioles at this time and I have 
regarded them as Stage A (fig. 14). The cell walls of the nurse 
cells are not very distinct. Their nuclei (fig. 19) are much smaller 
than those of the oocytes and contain a single irregular mass of 
chromatin granules. The structure of the oocytes and nurse 
cells is similar throughout the entire terminal chamber. 
