SUPPOSED OCCURRENCE OF THE T^NIA IN MAN. 593 



days sooner, and was without Tcemce.* Krabbe also thrice obtained 

 a positive result in the experiments carried on by him and Finsen. 2 

 The animals used were all young and had lived under conditions 

 which excluded the possibility of a spontaneous infection, and were 

 seen on dissection to be free from T. marginata and T. ccenurus, which 

 so commonly occur beside the T. echinococcus in the Icelandic dog. In 

 five of the animals used no young Tcenice were to be seen, but this 

 negative result probably finds its explanation in the fact that the hy- 

 datids used for feeding were not always first examined to see if there 

 were heads present, and were further, in some cases, used several 

 days after the death of the host. The tape-worms found exhibited a 

 development and hook-formation corresponding to the period of feed- 

 ing, so that the cogency of the experiments can hardly be doubted 

 although they were made in Iceland in a country where T. echino- 

 coccus is extremely prevalent. 3 



While Kiichenmeister still maintained the specific distinctness of 

 the human Echinococcus, and was forced, therefore, to regard the 

 Tcenia arising from the latter as different from the T. echinococcus, 

 he advanced the hypothesis that the tape- worm of the first occurred 

 not only in " dogs and cats," but specially in man himself, " in the 

 intestine of those individuals who suffer or have suffered from the 

 corresponding species of Echinococcus in any part of their body, and 

 in whom one of these Echinococci has opened into the intestine." 



If this were indeed the case, then the existence of this Tcenia, 

 could hardly have escaped the investigations of the pathological ana- 

 tomists. In the new edition of his work on parasites, Davaine cites 

 no fewer than forty cases of Echinococci which had opened into the 

 intestine. In no case, however, was a T. echinococcus found, nor was 

 it so in any of the forty-five cases cited by the same author in which 

 the Echinococcus-bladdeYs opened into the bronchi, and in which their 

 contents had been coughed up. Kiichenmeister objects to the rele- 

 vancy of the question since the Echinococcus-heads did not reach the 

 stomach, but he forgets that the above conditions could hardly occur 

 without some portions of the Echinococcus being swallowed, and that it 

 is far more likely that the organism should be infected through forms 

 already in the mouth, than with forms that have first to be brought 

 into the mouth from outside. 



Although Kiichenmeister does not regard my objection as valid, 

 and still keeps to his former opinion, in regarding man as well as the 



1 "Ueber die zu Echinococcus hominis gehorige Taenia," Mutter's Archiv f. Anat. 

 u. Physiol., p. 412, 1863. 



2 Loc. cit., pp. 49-52. 



3 [Thomas refers to two feeding experiments with Echinococcus hominis, both of which 

 yielded positive results (op. cit., p. 205). R. L.] 



2P 



