Diseases of the Digestive Organs. 267 



eigMy-eight ■worms of the digestive organs it is useless to 

 attempt any description in a work of the present limits, so 

 that our attention must be mainly confined to their symp- 

 toms and treatment. Eor further information the reader 

 is referred to the author's larger work or to those of 

 Leuekhart, Diesing, Dujardin, BaiUet, Cobbold and othei 

 helminthologists. 



The transformations of tape-worms have been already 

 ref eiTed to under parasites, and those of flukes under dif 



Fig. 24. Fig. 25. 



Fig. 24 — Sclerostomum Equinum. Fig. 25 — Oxyuris Curvula. 



Mature and young forms, nat. size. I Female ; 2 male, nat. size. 



etises of the liver. The thorn-headed toorns lay their eggs 

 within the body of their host, and these being passed with 

 Ihe dung are swallowed by crustaceans in which they en- 

 cyst themselves and develop the characters of the adult 

 worm in miniature, but remain very minute and fail to at- 

 tain their full size till their host is swallowed by another 

 animal. Among domestic animals ducks and j)igs harbor 

 these, probably because of their carnivorous appetite. The 

 round worms mostly Uve in their young and imn lature con- 

 dition, out of the body, in water or moist earth or on veg- 



