274 



ANIMAL BIOLOGY. 



[Part II. 



form a short uterus, which opens by the genital aperture (e. o.) on 

 the eighth sternum into the genital pouch. 



Above the eighth sternum, with its genital aperture, is the 

 ninth sternum (see Fig. 80, D.), which carries at its anterior end 

 the aperture of the spermatheca, which consists of a rounded 

 sac and coiled caecum, The spermatheca is a sperm-reservoir, 

 and always contains spermatozoa in the fertile female. 



VIII. C.O. 



FIG. 83. COCKROACH : REPRODUCTIVE ORGANS. 



A. Diagram of female organs of generation. c. g. Colleterial glands, e. o. Genital 

 aperture, od. Oviduct, viii. Sternum of eighth abdominal segment. 



B. Mushroom gland of male. d. e. Ejaculatory duct. ts. Testes. 11. 6. Utriciili 

 breviores. u. m. Utriculi majores. v. d. Vas deferens. 



Into the uterus, on its under side, there open the tubular 

 accessory cement (colleterial) glands (c. g.\ asymmetrically 

 developed, the left being the larger. Within these long white 

 csecal tubes crystals of (?) oxalate of lime may be developed. 

 Their function is to form an egg-capsule, within which sixteen 

 ova, arranged in two rows, are normally laid. The capsule 

 hardens and becomes brown by exposure to the air. It presents 

 a longitudinal slit along its dorsal margin, the serrated edges of 

 which bear tooth-like impressions, due to the grasp of the 

 posterior gonapophyses. 



The ova are about one-sixth of an inch in length, oval, with 

 one face convex and the other slightly concave. The chorion 

 which invests them is ornamented by being divided up into 

 polygonal areas. In its convex moiety there are numerous 



