90 THE COCKROACH [CH. Ill 



backward into a large boat-shaped process, which forms 

 the actual extremity of the body, the corresponding parts 

 of the eighth and ninth segments being telescoped inwards 

 so as to lie dorsal and anterior to that of the seventh, and 

 similarly the ninth to the eighth. The eggs when mature 

 pass out of the opening of the common oviduct by an 

 aperture in the ventral part of the eighth segment into 

 the cavity formed by the seventh; at the same time 

 spermatozoa are poured from the spermathecal opening, 

 which is in the ninth segment and almost directly above 

 the oviducal aperture. Sixteen eggs, one from each of the 

 sixteen ovarian tubules, mature and are fertilised at about 

 the same time, and pass into the genital pouch formed by 

 the seventh segment: the walls of this pouch are lined by 

 the secretion of the " colleterial glands," which hardens in 

 that position and forms as it were a hollow cast of the 

 pouch itself. Into this cast the future egg-capsule the 

 eggs are passed one by one, until the capsule contains 

 sixteen eggs, arranged in two alternating rows of eight 

 each ; the inner end of the capsule is then closed, and the 

 whole is ready for deposition. It is now a dark, mahogany 

 coloured, horny structure of oblong shape, with rounded 

 ends, and a toothed longitudinal ridge along its upper 

 surface; it is about half an inch long, and a quarter of 

 an inch wide and high. Females are often seen carrying 

 the egg-capsule half protruding from the genital pouch, 

 and are presumably seeking a favourable place and 

 opportunity for depositing it. When this is accomplished 

 they take no further interest in their progeny. 



The eggs are upright within the capsule, the future 



