17G 



THE COCKROACH 



consists of a peritoneal layer and an epithelium, which is folded 

 inwards along transverse lines. The cells of the epithelium 

 give rise to spermatocysts,* which enclose sperm cells. By 



r. 



Fig. 99. 1. Male Organs, ventral view. Ts, testis ; VD, vas deferens ; DE, 

 cluctus ejaculatorius ; U, utriculi majores ; u, utriculi breviores. 2. Do., 

 dorsal view, showing termination of vasa deferentia. 3. Conglobate gland, and 

 its duct. X 8. 



division of the nuclei of the sperm cells spermatozoa are 

 formed, which have at first nucleated heads and long tails. 



* The spermatocysts are peculiar to Insects and Amphibia. They arise by 

 division of the spermatospores, or modified epithelial cells, and form hollow cysts, 

 within which sperm cells (or spermatoblasts) are developed by further division. 

 The sperm cells are usually placed radiately around the wall of the spermatocyst. 

 They escape by dehiscence, and are transformed into spermatozoa. 



