172 



THE COCKROACH 



open beneath the last tergum, and the uterus between the 8th 

 and 9th sterna. In the adult female Cockroach, however, the 

 8th and 9th somites are telescoped into the 7th, and completely 

 hidden by it. Their terga are reduced to narrow bands. The 

 8th sternum forms a semi-transparent plate which slopes down- 

 wards and backwards, and is pierced by a vertical slit, the 

 outlet of the uterus. The upper edge of this sternum is hinged 



Fig. 97. Hinder end of abdomen of female Cockroach. In the upper figure the 

 halves of the 7th sternum are closed ; in the lower figure they are open. 



upon the projecting basis of the anterior gonapophyses (to be 

 described immediately), and the parts form a kind of spring 

 joint, ordinarily closed, but capable of being opened wide upon 

 occasion. The 9th sternum is a small median crescentic plate, 

 distinct from the 8th ; it supports the spermatheca, whose duct 

 traverses an oval plate which projects from the fore-edge of 

 the sternum. 



By the telescoping of the 8th and 9th somites the sterna 

 take the position shown in fig. 96J?, and a new cavity, the 

 genital pouch, is formed by iiivagination. This receives the 

 extremity of the body of the male during copulation, while it 

 serves as a mould in which the egg-capsule is cast during 

 oviposition. Its chitinous lining resembles that of the outer 



