WORMS IN THE INTESTINAL CANAL HELMINTHIASIS. 625 



Our ideas of the etiology of helminthiasis have been totally changed 

 by the discoveries of recent times ; most causes to which it was for- 

 merly attributed are now recognized to be without effect. It even ap- 

 pears improbable that any decided change of the intestinal mucous 

 membrane, or any peculiarity of the contents of the intestines, is 

 necessary for the development and future life of the worms. The eti- 

 ology of taenia solium is frequently discoverable. Jfilchenmeister found 

 young taenia in the intestines of a decapitated criminal, to whom he 

 had administered cysticerci a few days before death. Of the animals 

 whose flesh we eat, swine are the most apt to have the scolex of taenia 

 solium. It also occurs in the meat of the goat, and, although more 

 rarely, in beef. In Jews and Mohammedans, who eat no pork, taenia 

 are very rarely found ; and, while in Abyssinia almost every one has 

 tape-worm, the Carthusian fathers, who eat only fish, remain exempt 

 from them. Taenia are much more frequent in regions where pork- 

 raising flourishes, while they are rare where swine are scarce. Cysti- 

 cerci cannot withstand boiling, roasting, or smoking, and tape-worm 

 never results from the use of measly meat prepared in these modes. 

 On the other hand, they are most likely to occur in persons who eat or 

 chew raw flesh, or put knives, soiled with cysticerci, in their mouths, 

 as is not unfrequently done by waiters, cooks, and butchers. The 

 latter may greatly aid the spread of tape-worm by cutting the sausage 

 or ham that they sell with a dirty knife, as these articles are often 

 eaten without further cooking. The practice of giving badly-nour- 

 ished children raw shaved meat to eat is not devoid of danger, for cases 

 have occurred where children have undoubtedly acquired tape-worm 

 (taenia mediocanellata) in this way. 



The supposition, that the use of meat, containing trichina spiralis, 

 led to the development of trichocephalus dispar, has been disproved. 

 If, as has been supposed, ascaris and oxyuris are most frequently found 

 in persons who subsisted chiefly on amylaceous food, this might be ex- 

 plained by the observations of Stein, who found entozoae in weevils. 

 It is possible that, by using bad flour, eggs or larvae of ascaris or ox- 

 yuris may reach the intestines. 



SYMPTOMATOLOGY. The symptoms excited by intestinal worm? 

 vary greatly with the peculiarities of the person affected. Frequently 

 there are no signs till worms, or fragments of worms, are passed at 

 stool. This is chiefly true of tape-worms. Many patients with taenia, 

 or bothriocephalus, enjoy the best health, have neither stomach-ache 

 nor any reflex symptoms, and the links that pass away, from time to 

 time, alone call attention to their disease. Frequently it is difficult foi 

 the physician to recognize the dried proglottides that are brought to 

 aim wrapped in paper. In other cases, the patients complain, from 

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