136 F. 11. STEWATJT. 



unites witli its fellow to form the vagina. It is tlie widest 

 and most distended portion of the tract. In a transparent 

 specimen the mass of ova wliich fills it is very prominent. 

 Its course is fairly straight, wiili the exception of an S-shaped 

 bend at one point, where it is constricted. Its wall (PI. 8, 

 fig. 28) is three-layered, consisting of epithelium and basement 

 membrane as in the oviduct and receptaculum, with the ad- 

 dition on the outside of a layer of flattened epithelioid cells. 



The epithelium is more flat than in the oviduct. On the 

 internal surface the protoplasm is differentiated into a more 

 dense, almost cuticular, layer. 



The outer epithelioid layer {ml.) is exceedingly fine, and it 



Text-fig. 7. 



is difficult to demonstrate it except where the nuclei cause a 

 slight bulging. Its function I believe to be muscular. It is 

 continuous with the muscular layer of the vagina. Hamanu 

 describes a similar layer in Lecanocephalus as muscular. 



The uterus is always distended with masses of spermatozoa 

 and segmenting ova. Spermatozoa predominate towards the 

 commencement, ova toward the termination. Toward the com- 

 mencement the spermatozoa produce a remarkable appearance, 

 arranging themselves on the surface of the epithelium in a 

 closely-packed single layer, the nuclei lying at tlie free ends 

 (ibid., s.). It is very easy to mistake them for a tall columnar 

 epithelium. 



The vagina (text-fig. 7) extends from the junction of the 

 two uteri at the level of the middle of the body to the external 



