Female Organs 



1T3 



which fills almost the whole abdomen, and bulges 

 a little into the thorax. Above it lies the empty 

 alimentary canal. Many tracheae ramify on the surface 

 of the ovaries. 



A single ovarian tube consists of three successive 

 chambers of unequal size, connected by narrow passages 



^-- 



Fig. 82. — Ovary, from pupa. To left a number of follicles ; 

 to right a single follicle, o, ovum. 7/, yolk-granules. 



V - 



(fig. 81). The free extremity is a short thread, and from 

 the other end a narrow duct passes towards the axis 

 of the ovary.' Microscopic study 

 of the large chamber in an oviduct 

 not yet mature shows that it con- 

 tains, as in other Diptera, an ovum, 

 several nucleated cells, yolk, and 

 a follicular epithelium. This last 

 secretes the chorion or egg-shell, 

 and afterwards disappears (fig. 83). 

 The two chambers next above each 

 contain a small ovum and a few ^ „ r. ■ , , 



Fig. 83. — Ovarian chamber, 



nutritive cells ; the distal portion ^i^n"^ %• »' o^™- *'. nntri- 



live cells. </, yolk. 



or germarium is very minute, and 



its contents are not visibly differentiated. 



The rest of the female reproductive organs is derived 

 from invaginated epidermis, and lined with chitinous 



