2/0 



THE ANIMAL PARASITES OF MAN 



There is no Laurer's canal. The ova almost equally attenuated at either extremity ; 

 they have a small terminal spine, and are not provided with a lid. They contain 

 a miracidium, ciliated on all sides, which is characterized by the possession of two 

 large glandular cells, which discharge anteriorly beside the. gastric sac. They live 

 in the vascular system of mammals. (An allied genus [Bilharziella] lives in the 

 blood-vessels of birds.) 



Schistosoma haematobium, Bilharz, 1852. 

 Syn. : Distoma hczmatobium, Bilh. ; Distoma capense, Harley, 1864. 



The Male is whitish, 12 to 14 mm. in length, but is already mature 

 when 4 mm. long. The anterior end is 0*6 mm. or a little over in 

 length. The suckers are near 

 each other, the oral sucker is in- 

 fundibular, and the dorsal lip is 

 longer than the ventral one. The 

 ventral sucker is a little larger, 

 o'2& mm., and is pedunculated. 

 A little behind the ventral sucker 

 the body broadens to a width of 

 i mm., decreasing, however, in 

 thickness ; the lateral edges in-roll 

 ventrally, so that the posterior 

 part of the body appears almost 

 cylindrical, 0*4 to 0*5 mm. in 

 diameter ; the posterior extremity 

 is somewhat more attenuated. 

 The dorsal surface of the pos- 

 terior part of the body is covered 

 with spinous papillae. There are 

 delicate spines on the suckers, and 

 larger ones in vest the entire internal 

 surface of the gynaecophoric canal, 

 as well as a longitudinal zone at 

 the edge of that side of the external 

 surface that is covered by the other 

 side rolling over it. The oeso- 

 phagus is beset with numerous 

 glandular cells (fig. 173), and pre- 

 sents two dilatations; the intestinal 

 bifurcation is close in front of 



FIG. 171. Schistosoma hcematobtum, Bil. : 

 male carrying the female in the canalis gynae- 



cophorus. 1 2/1. (After Looss.) 



the ventral sucker, the two 



branches uniting sooner or later behind the testes into a median 

 trunk, which may again divide at short intervals. The excretory 

 pore is at the posterior end, but placed somewhat dorsally ; the 

 genital pore is at the beginning of the gynaecophoric canal, thus 



