REPRODUCTION IN DROSOPHILA. 



215 



of the anterior portion of the uterus by means of two narrow 

 openings, placed close to each other. They are mushroom-shaped 

 bodies whose terminal cavity is lined by a hard cuticle of brown 

 color (Fig. 6, c'} secreted by the epithelium (e} forming the 

 walls of the organ. They are connected with the uterus by nar- 

 row ducts which on account of circular ridges present in their 



FIG. 6. Diagram of a spermatheca. c, cavity lined with the brown cuticle 

 c' ; d, duct of the spermatheca; e, epithelium. 



cuticle closely resemble tracheae. The circular ridges of the distal 

 portion of each duct bear processes resembling stiff hairs which 

 are directed towards the openings of the ducts (d} into the uterus. 



The ventral seminal receptacle (Figs. 3 and 9, z/) is a long con- 

 voluted tube which opens into the anterior portion of the uterus, 

 immediately dorsad to the anterior pouch (Fig. 5, v'}, between 

 the latter and the oviduct. The lumen of this tube is very narrow 

 in its proximal portion, gradually expanding and becoming nar- 

 row again in the distal or free portion of the organ. In the 

 normal position the tube is tightly coiled and is placed at the ven- 

 tral surface of the uterus, immediately above the anterior pouch. 

 The lumen is lined with a cuticle produced by an epithelium of 

 cubical cells. 



The size of the ventral receptacle varies a good deal according 

 to the species ; in Drosophlla obscura it is shorter and wide, while 

 in D. virilis it attains an enormous length. 



A sagittal section of the anterior portion of the uterus (Fig. 5) 

 shows that the opening of the ventral receptacle (v r ) is placed a 



