BEPEODUCTIVE SYSTEM 167 



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. 



b. The oviducts, formed as above, are a pair of short 



wide tubes which unite, and open to the exterior 

 by a median vertical slit between the eighth and 

 ninth sterna. 



c. The spermatheca consists of two unlike and unequal 



caeca of small size, opening by a median aperture 

 on the ninth sternum. It lies close behind the 

 last nerve ganglia. 



d. The colleterial glands are a pair of much-branched 



tubular glands, whose ducts open separately, but 

 close together, behind the spermatheca, and 

 between the inner gonapophyses. 



e. The gonapophyses are six symmetrically arranged 



and strongly chitinised processes : they are 

 outgrowths of the sternal surface, between the 

 vulva and the anus. They aid in depositing the 

 eggs. 



