CRESSWKLL SHEARER. 
350 
wards until they reach the odcyte stage. In the oogonial 
region the cells are seen rapidly dividing, while in the oocyte 
region they are seen fusing together to form the large 
female and the small male eggs. The oocytes or ovarian 
eggs fill up the greater part of the ovary, and crowd the 
oogonia laterally and ventrally. The largest oocytes are 
found in the posterior part of the ovary. The peritoneal 
investment of the ovary consists of an extremely delicate 
epithelium which encloses the oogonia and oocytes as in a 
Text-fig. 5. 
A. Rough outline drawing of ovary of young female in which 
fertilisation has been avoided. The sperm are not present 
in oogonial cells, b. Enlarged view of a few of the oogonial 
cells, showing only one chromatic body, the sperm chromatic 
body being absent. 
bag (Text-fig. 3, Im. m.). This investment sends strands to 
the body- wall and the alimentary canal (fig. 42). 
In the larval female leaving the egg-capsule the condition 
of the ovary is very rudimentary. It consists of a small 
triangular mass of tissue, filling the space between stomach 
and gut. It is very difficult at this stage to make out its 
structure. In whole preparations stained with aceto-carmine 
no cell outlines or nuclei can be seen. It seems to consist of 
a perfectly clear homogeneous mass of cytoplasm, uniformly 
finely granular throughout. In the living condition, certain 
