Ovaries — Vagina 



/:? 



the egg-tube is less simple than in the cockroach. 

 Special cells take on the work of nourishing the 

 egg-cells, and these are grouped in " nutriment 

 chambers," which alternate in position with the eggs, 

 their contents being finally absorbed by the latter. 

 Or the forward region of the tube may contain a 

 supply of nutriment-cells which are in connection, 

 by means of fine threads, with the eggs in the hinder 

 region (2, 47, 56). 



The number of tubes to each ovary is frequently 

 eight, as in the cockroach, but it varies greatly in 

 different insects. In some Springtails {Campoden), 

 each ovary has but one tube ; in the queen Honey-bee 

 there are nearly a hundred (fig. 51), and in a queen 

 Termite fifteen hundred. In Mayflies the two ovi- 

 ducts open separately direct to the exterior (49), and 

 there is no vagina. 



Vagina. — The walls of the vagina are muscular 

 and are lined with chitin. Into its lower wall open a 

 pair of glands consisting of very fine tubes repeatedly 

 branched ; the left gland is much larger than the 

 right. These are the colleterial glands (fig. 49 C, G); 

 they secrete crystals of oxalate of lime and a fluid 

 which coagulates on exposure. The purse-shaped 

 egg-capsule (fig. 53), or "raft," of the Cockroach 

 is formed from these substances. As mentioned 

 above, the outer opening of the vagina is situated 

 between the seventh and eighth sternites of the 

 hind-body. In the cockroach the eighth and ninth 

 sternites are very small and are withdrawn behind 

 the seventh, which is greatly enlarged and bent up- 

 wards so as to enclose a cavity, the genital pouch, 

 on to whose upper wall (through the eighth sternite) 

 opens the sperm-reservoir (spermatheca), a short, spiral 

 tube swollen at its blind end, wherein are stored 

 sperm-cells received from the male during sexual 



