SCHISTOSOMA H^EMATOBIUM 



2 7 I 



FIG. 172. Tiansverse section 

 through a pair of Schistosoma 

 hamatobium in copula. In the male 

 the p6int of reunion of the intestinal 

 forks has been cut across. (After 

 Leuckart.) 



behind the ventral sucker ; into it opens the vas deferens which, 

 posteriorly, broadens into the seminal vesicle and then continues 

 as the vasa efferentia of the four or five testes (fig. 173). 



The Female filiform, about 20 mm. in length, pointed at each end, 

 and measuring 0-25 mm. in diameter in 

 the middle. Their colour varies accord- 

 ing to the condition of the contents of 

 the intestine. (Posteriorly they are dark 

 brown or blackish.) The cuticle is smooth 

 except in the sucker, where there are very 

 delicate spines, and at the posterior end, 

 where there are other larger spines. The 

 oral sucker is a little larger than the 

 pedunculated ventral sucker (0*07 and 

 0*059 mm. respectively). The anterior 

 part of the body, o'2 to 0*3 mm. in length ; 

 the oesophagus is as in the male. The 

 intestinal bifurcation is in front of the 

 ventral sucker, the two branches uniting 

 behind the ovary and the trunk running 

 in a zigzag manner to the posterior border. 

 There are indications of diverticula at the 

 flexures. The ovary is median. In young 

 females it is of an elongated oval shape ; 

 in older females the posterior end becomes 

 club-shaped, whereas the anterior end 

 becomes attenuated ; the oviduct origin- 

 ates at the posterior end, but immedi- 

 ately turns forwards and joins the parallel 

 vitelline duct in front of the ovary (fig. 174), 

 where the shell gland cells open ; the 

 common canal becomes dilated to form 

 the ootype, and then proceeds as the 

 uterus, with only slight convolutions, 

 along the central field to the genital pore, 

 which lies in the middle line immediately 

 behind the ventral sucker. The single 

 vitellarium starts behind the ovary and 

 extends to the posterior end. The acini 

 are situated at the sides of the excretory 



duct, which runs a median course. The eggs are compact spindles, 

 much dilated in the middle ; they have no lid, and are provided with a 

 terminal spine (rudimentary filament) at the posterior end, measuring 

 120 ft to 150 p, in length and 40 /ju to 60 //, in breadth, but vary in size 

 and shape (fig. 175;. 



FIG. 173. Anterior end of the 

 male Schistosoma hcematobium^ Bilh. 

 V.s., ventral sucker ; /., gut cseca ; 

 G.p., genital pore ; T. t testes ; 

 O.s., oral sucker ; Oe., oesophagus 

 with glandular cells; V.s., vesicula 

 seminalis. 40/1. (After Looss.) 



