CONTKOL OF ANIMAL PAKASli - 



fe i the ripe proglottides from man to calves, ami was thus able to dis- 

 cover how man acquires this tapeworm from eating measly beef. The 

 tiny egg hatches iu the stomach of the cow, burrows through the wall 

 of the intestine, and in from three to six months has grown to a 

 bl idder, or cyst (the cysticercus). the size of a small Wan, and is then 

 found in the muscles. After the cysticercus passes through the human 

 st )niach, the head everts (pops out like turning a glore-finger), bringing 

 the hooks and suckers to the 

 outside; these anchor in the Man 



intestine and begin a new life 

 ojcle. While the beef tape- 

 w rm ( Ttrnia saginata) may 

 e use some irritation, and un- 

 doubtedly steals some digested 

 t\od. it seldom does serious 

 iijury. This is due to the 

 simple fact that its eggs can- 

 nit hatch and pass into cysti- 

 cr-ici in the muscles or other 

 o-gans of man. The cystioer- 

 c is stage is confined closely to 

 cattle, and the adult stage as 

 c osely to man. The eggs of se v- 

 e ! of the other species do, how- 

 e ,er, develop cysticerci in man, j- IO> n5. Life cycle of pig tapeworm ; 

 v hich renders them much more infection from uncooked pork 



d.mgerous and sometimes fatal. 



The pig tapeworm Taenia solhan. This j^arasite is distributed the 

 v orld over, wherever the pig is raised and eaten raw or rare. It is found 

 also in the wild boar, sheep, deer, dog, oat, bear, and monkey. The eggs 

 atid newly hatched. embryos (t^caqptores) are microscopic, the latter 

 only 0.02 millimeter in diameter so small that they are easily carried 

 t > foods on dirty hands, eaten with polluted vegetables, or even swal- 

 1 *wed by flies and carried to foods anywhere. These eggs, if swallowed, 

 i lay find their way to any part of the body muscles, eyes, brain, and 

 t ven heart, and there become cysticerci. These, too, are large (t>-*20 niilli- 

 i leters long by 5-10 millimeters thick), so that even one may prove fatal. 

 1 a expelling this tapeworm great care must be used to avoid causing nau- 

 s ?*, for a single ripe proglottis, forced back into the stomach and releas- 

 i ig its myriad embryos, would leave little chance for a patient's recovery. 



