THE ANATOMY OF ONOHOLAIMUS VULGARIS, BAST. 135 



is fairly narrow, viz. '102 mm. This portion is the oviduct 

 (PI. 8, fig. 27). Further on it widens ont somewhat, to 

 become the receptaculum^ measuring "255 mm. in diameter. 



The wall of both oviduct and receptaculum consists of an 

 epithelium with an external basement membrane (ibid., bm.). 

 In the oviduct the epithelial cells are rounded, the lamina 



Text-fig. 5. 



OVT 



R.S. 



poorly marked. The outer portions of the epithelial cells 

 show indistinct circular fibrillation, as if they might act as a 

 sphincter. 



On passing to the receptaculum the lumen widens out, and 



Tkxt-fig. 6. 

 Ovr ut 



the epithelia cells become less spherical, although they still 

 project into the lumen. Their protoplasm is reticular. The 

 basement membrane becomes thick and distinct. The contents 

 consist of spermatozoa, which frequently form a single layer 

 on the surface of the epithelium, and of ova in small groups. 

 Fertilisation takes place here. 



The uterus (text-fig. 6, ut.) extends from about the end of 

 the sixth tenth forward to the middle of the body, where it 



