REPRODUCTION IN DROSOPHILA. 



221 



The outer chorion of the egg shows hexagonal sculpturing pro- 

 duced by the hardening of the much flattened follicle cells sur- 

 rounding the oo'cyte during the growth period. This pattern is a 

 little less developed in the transparent region described above 

 (Fig. 7,0). 



The passage of the eggs through the oviduct takes place very 



FIG. 9. Lateral view of the uterus containing an egg ; this figure was out- 

 lined with the camera lucida, the genitalia being in the fresh condition, e, egg 

 with the appendages within the oviduct, d; f, fertilization cavity; m, micro- 

 pyle cone of the egg; o, vaginal orifice; p, parovaria ; s, spermathecse ; u, 

 uterus with ', its vaginal portion ; v, ventral receptacle, containing spermatozoa. 



quickly if we judge from the considerable number of egg-laying 

 females dissected in which no eggs were present in this duct. 

 The actual entrance of an egg into the oviduct was observed only 



