16 



FOREST ENTOMOLOGY. 



or 



occurring 



egg passes into the latter, the corresponding portion of the ovarian 

 tubule shrinks, and thus the egg next in front is brought nearer to 

 the duct. The two oviducts unite to form an unpaired portion, the 



vagina, which opens ventral to the 



anus, either freely on the surface 



into a cloaca, an invagination 



at the hinder end of 



body. There is usually an 



the 



evagination of the vagina which 

 serves as a receptaculum seminis, 

 and one or a pair of accessory 

 glands, which secrete either a 

 sticky fluid to attach the ova to 

 foreign bodies, or the mucus sur- 

 rounding them {e.g., in insects 

 Sometimes there is also an evag- 



Fig. 19. Diagrams of the heart of an insect. 



which lay their eggs in water). 



ination of the vagina to form the bursa copulatrix, into which the 



Fig. 20. 'Female genital organs of the cockchafer. 



On the right, the ovarioles are lying together in the natural position ; on the left they are 

 separated, and two are cut away, g, vagina ; k, glands which open into the receptacula ; 

 I, oviduct; o, segments of the ovarioles, containing almost ripe ova; o', regions of the 

 same, containing immature ova ; p, bursa copulatrix, ; r, anterior ; r', r", posterior buds 

 of the ovarian tubules ; s, glands ; sg, receptacula ovorum. (Alter Boas.) 



penis of the male is inserted in copulation. Not infrequently 

 there is at the female aperture an ovipositor (Locusts), consisting 

 of complicated knife - like or dagger - shaped laminae, or a sting 



