508 ROBERT W. HEGNER 
The terminal chamber is separated from the first zone of growth 
(fig. 20) by what appears to be a distinct membrane (m). The 
condition of all of the oocytes is similar throughout this zone 
(Stage B, fig. 14). The oocytes have grown considerably and 
their nuclei (fig. 21) contain a few clumps of chromatin granules 
lying near the nuclear membrane. Outside of the nucleus (fig. 
21) is a layer of darkly staining substance which resembles 
chromatin in some respects and may represent chromatin which 
has passed through the nuclear membrane into the cytoplasm. 
The nurse cells now have definite cell walls (fig. 22) and are also 
characterized by a layer of darkly staining material lying around 
the nucleus. Among the oocytes and nurse cells are a few 
epithelial cells (fig. 23); these have no definite cell walls, and 
their nuclei are rather irregular in shape and contain a single 
mass of chromatin. 
Whether or not the first zone of growth is definitely separated 
from the remaining part of the ovariole could not be determined 
with certainty, but its limit is conspicuously marked by the abrupt 
appearance of the bacteria-like bodies of Blochmann. This is 
indicated in figure 24, which shows.the posterior portion of the 
first zone of growth and the anterior part of the rest of the ovari- 
ole. In the upper part of this figure is a single oocyte in Stage B 
and a number of nurse cells. These are apparently embedded 
in a loose reticulum of cytoplasm. Further down the ovariole 
the spaces surrounding the nurse cells and epithelial cell nuclei 
are filled with more or less wavy rods which Blochmann con- 
sidered symbiotic bacteria. These rods extend throughout the 
ovariole in all directions, being represented by distinct spherical 
granules where cut across. 
From this point on, the oocytes are arranged in a linear row 
in the central axis of the ovariole (figs. 13 and 25). The cyto- 
plasm of the oocytes increases rapidly in amount, but the nuclei 
enlarge very little. The nurse cells (fig. 25, n) become arranged 
more or less definitely into rows which radiate toward the upper 
end of the oocyte. Those nurse cells closest to the oocyte in- 
crease more rapidly in size than do the others. Compare, for 
example, that lettered a in figure 25 with its companions, and 
