DISEASES OP RESPIRATORY ORGANS 145 



eysts are much more common in sheep. The cysts contain only 

 one tapeworm embryo, differing in tliis particular from the cysts of 

 the Taenia echinococeus. They have a double membrane, the em- 

 bryo being suspended in a thin, watery fluid that fills the cyst, which 

 may attain the size of an English walnut. 



Stephanurus dentatum, both in the adult and larval stage, may 

 be found in relation to the peritoneum. The lesions they produce 

 in the peritoneum are the same as those produced by this parasite 

 elsewhere in the body. 



The Ascaris suum may bore through the intestine and be found in 

 the peritoneal cavity. As they pass out of the intestine they carry 

 various bacteria with them and possibly also permit the escape of 

 some intestinal content which is always teeming with bacteria. Thus 

 infectious, usually septic, peritonitis results. 



