218 



THE ANIMAL PARASITES OF MAN 



The food of the Trematodes consists of mucus, epithelial cells, the 

 intestinal contents of the hosts, and often also of blood, and this not 

 only in those species living in the vascular system, but also in species 



lr. c.v 



v.d.e. 



FlG. 123. Polystornum integerrimum, a 

 -monogenetic fluke from the urinary bladder 

 of the frog, z., intestine; h., large hooks 

 of the sucking disc ; h.k., smaller booklets ; 

 l.c.v., longitudinal vitelline ducts; o., oral 

 orifice ; Ool., ootype ; ov., ovary ; s.p., suckers 

 of the disc ; tr.c.v., transverse vitelline ducts ; 

 //., uterus with ova; v., entrance to the 

 vagina; v.d.e. , vas deferens; v.d.i., ductus 

 vitello-intestinalis ; the vitellaria and testes 

 are not shown. Magnified. (After Zeller.) 



FlG. 124. Allocreadium iso- 

 porum, Looss. Excretory appa- 

 ratus. Of the other organs, the 

 oral sucker, pharynx, genital 

 pore, ventral sucker, ovary and 

 testes are shown ; the cylin- 

 drical excretory bladder is in 

 the posterior end. 38/1. (After 

 Looss.) 



living as ectoparasites or in the intestine or biliary passages of their 

 hosts. 



The final products of assimilation dissolved in the fluids of the 

 body are distributed throughout the parenchyma and are thence 



