2 
Psyche 
[March 
of a genital pouch above and a brood sac below the junction 
of the oviduct with the genital chamber. These rudiments 
may have no important specific function in this species for, 
it will be recalled, the female is oviparous and utilizes the 
vestibular portion of the genital chamber for oothecal 
formation and placement of the eggs within the ootheca 
cast there. Figure 2 gives diagrammatic dorsal and lateral 
views of this system in D. dytiscoides. The brood sac is 
somewhat enlarged and asymmetrical in shape for eggs 
with young embryos are enclosed. They are placed dia- 
gonally because their slightly narrower micropylar ends, 
occupying less space, are directed toward the left. 
Six ovarioles comprise an ovary which is cone-shaped 
with the base resting on the distal end of a paired oviduct. 
Each ovariole tapers anteriorly to the germarium and ter- 
minal filament in the usual fashion. The former contains 
twenty or thirty oogonia within its lumen and there are 
always seven or eight clearly discernible oocytes within the 
vitellarium or lower portion of the ovariole ; two more than 
shown in the upper ovariole in the figure, for only part of the 
Figure 1. Blatta orientalis. Diagrammatic median section through 
the genital chamber of the female reproductive system. AC.GL, acces- 
sory gland; BR, rudiment of a brood sac; GEN., rudiment of a genital 
pouch; OV, cross-section of proximal end of left oviduct; SP, sperma- 
theca; SP.GL, spermathecal gland; V, vulva; VE, vestibule. (Re- 
drawn and relabelled from Snodgrass, 1933: Smithsonian Miscellane- 
ous Collections, v. 89, no. 8) 
