CHROMOSOMES OF TIGER BEETLES 457 
granular thread which becomes continuous with the axial fila- 
ment. It can only be hoped that an interpretation of these 
two bodies and the significance of the migratory movement will 
be revealed by future researches on this and similar forms. 
A third body, which may be the acrosome, makes its appear- 
ance at this time (fig. 71) and later fuses with the other two. 
9. OBSERVATIONS ON THE OOGONIA 
A. Oogonial growth period and prophase 
The resting oogonia present little similarity to the correspond- 
ing cells of the male. There is no trace of a syncytium or even 
a cyst wall, but every cell is surrounded by its own conspicuous 
membrane (figs. 80 to 82). In view of the suggestion that each 
spermatogonial syncytium acts as a unit in the process of cell 
growth, we should expect a greater irregularity in the develop- 
ment of adjacent oogonial cells. This, indeed, is the case, for 
even though certain regions of an ovarian follicle show in gen- 
eral the same stage of development, it seems to be a matter of 
rare chance for adjacent cells to proceed with their development 
with the precise unity found in the corresponding spermatogonial 
cells. 
The oogonial nucleus is much smaller than the spermatogonial 
and usually contains two well-defined chromatin nucleolei. 
The remaining chromatic material is scattered more or less in a 
fibrillar form throughout the nucleus. Upon the approach of 
the prophase condition, this chromatic material collects in 
masses, usually at the periphery of the nucleus. These chromatic 
aggregations gradually condense into the prophase chromosomes. 
The nuclear wall is now practically invisible as in the male 
(fig. 82). : 
B. Oogonial chromosomes 
The oogonial number of chromosomes was practically estab- 
lished when the behavior of the double odd-chromosome in the 
male was determined. In order to further substantiate the 
earlier observations, special effort was made not only to obtain 
