176 I'HE COCKROACH. 



F. The Reproductive System. 

 1. In the male. 



a. The testes are a pair of organs lying immediately 



below the fourth and fifth terga of the abdomen. 

 They are imbedded in the fat-body, and are hence 

 difficult to find. 



b. The vasa deferentia are a pair of exceedingly 



narrow tubes leading from the testes to the vesi- 

 culae seminales. 



c. The vesiculse seminales, together known as the 



' mushroom-shaped gland,' are two tufts of white 

 glandular caeca, opening into the slightly dilated 

 anterior end of the ejaculatory duct. 



d. The ejaculatory duct is a short musqular tube 



opening behind to the exterior, just below the 

 anus. 



e. The gonapophyses are a series of strong chitinous 



hooljs and plates, forming a complex copulatory 

 organ. They are asymmetrical, and surround 

 the genital aperture. 



2. In the female. 



a. The ovaries are two sets of elongated tubular organs 

 in the hinder part of the abdomen. Each set 

 consists of eight tubes, united in front and 

 attached by a ligament to the dorsal wall of the 

 thorax. Behind and below they unite to form 

 the oviducts. Each tube has a moniliform ap- 

 pearance, from the bulgings caused by the con- 

 tained ova : in the hinder and lower part of the 

 tube the ova are large and nearly mature ; those 

 in the upper part of the tube are in various 

 earlier stages of development. 



At the time of laying, one ovum escapes from 

 each ovarian tube, and the sixteen are laid side 

 by side in a capsule. 



