46 ANIMAL PAHASITES. 



the antiperistaltic movements of the intestine. That this passage 

 of the proglottides from the duodenum into the stomach is 

 possible is shown by those cases in which (as is not unfrequently 

 the case in dogs and cats) tape-worms are vomited, and hang out 

 from the moutli ; and perhaps, also, by the occurrence, which does 

 not appear to be rare, of Cysticerci (e. g. in the eye) at a period 

 when the individuals are suffering remarkably from vomiting. 

 Thus, two of Graefe's patients complained, during pregnancy, of 

 the appearance of Cysticercus cellulosce, and women in general 

 appear to suffer particularly from this Cysticercus, and indeed from 

 Taenia solium. If we admit this mode of self-infection of tape- 

 worm patients with Cysticerci, the exclusion of the brood would 

 only take place when the eggs arrive in the stomach of the host, 

 exactly as in other cases. 



The question still remains, whether, when the eggs are set free 

 in the small intestine by the rupture of the proglottis, the 

 embryos can escape from them, so as never to pass through the 

 stomach of an animal. In this case, also, I am firmly convinced, 

 that if an embryo be freed from its egg-shell anywhere in the 

 small intestine, it must migrate forward, although this case will 

 certainly be of very rare occurrence, as Leuckart has only met 

 with a free embryo once in the duodenum and once in the 

 small intestine, but never with uninjured eggs or numerous 

 remains of egg-shells. Leuckart denies the possibility of the 

 exclusion of the brood from eggs thus set free immediately in the 

 small intestine of their host, and, at the same time, thinks that 

 if the intestine possessed the faculty of setting free the brood, 

 there would hardly be a tape-worm patient without Cysticerci. 

 Unfortunately, Leuckart did not succeed in testing this question 

 by experiment, in the way recommended by me. Thus, the 

 establishment of fistulse in the small intestine, and the subsequent 

 introduction of the eggs of Taeniae through these into the intestine, 

 did not succeed for a sufficiently long time, as all the animals 

 experimented on died immediately. As soon as I have sufficient 

 material by me, I shall again test this question experimentally, 

 by tying up a portion of the small intestine in the living rabbit, 

 and introducing eggs and proglottides of Taenia serrata into this 

 portion of intestine. The result will show whether an exclusion 

 of the brood will take place, or whether this is effected only when 

 the brood has passed once through the stomach. Until then, 

 however, I must, in opposition to Leuckart, regard the supposition 



