452 Dr. J. D. Thomas. Taenia Echinococcus in [June 18, 



This case is not entirely satisfactory, since no mention is made of 

 any precautions having been taken to prevent infection of the dog in 

 question, from other sources than the experimental feeding, and as 

 dogs in Iceland are very frequently infested with Taenia echinococcus * 

 the experiment cannot be regarded as decisive. Besides, the feeding 

 took place some months previously, and as the sojourn of Taenia echi- 

 nococcus in the intestine of the dog is believed not to exceed about 

 two months, this renders the experiment still less conclusive. 



Experiment No. 4 was by far the most successful one performed by 

 MM. Krabbe and Finsen. On this occasion tivo dogs, which had been 

 kept under close surveillance by M. Finsen since they had ceased 

 suckling, were fed with the Echinococci of man upon two separate 

 occasions at an interval of a month. Three months after the second 

 feeding, they were examined. One gave a negative result ; the other 

 contained a moderately large number of Taenia echinococcus and 

 four examples of Taenia canis lagopodis. f This experiment would 

 be a very satisfactory one, if the presence of Taenia canis lagopodis 

 could be accounted for ; but failing this, some doubt must exist as to 

 whether some accidental infection had taken place or not. 



Experiment No. 6. — Two dogs were fed : one yielded a negative 

 result. In the other there were found four specimens of Taenia 

 echinococcus, in company with four hundred of Taenia canis lago- 

 podis. The remarks made upon Experiment No. 4 apply with greater 

 force to this observation. It will thus be seen that out of nine dogs 

 experimented upon only three yielded any specimens of Taenia 

 echinococcus. In one of these only one mature point was found ; in 

 another only four examples of Taenia echinococcus to one hundred 

 times as many of Taenia canis lagopodis. 



Naunyn's experiments were performed in Berlin in 1863. J 



He administered to two dogs the contents of a hydatid of the liver 

 which contained. Echinococcus heads, and which had been obtained 

 from a woman operated upon by puncture of the cyst. One of the 

 dogs, which was examined twenty-eight days subsequently, contained 

 no intestinal worms; but in the second one Naunyn found, on the 

 thirty-fifth day after the feeding, examples of Taenia echinococcus 

 from one to one and a half lines in length. The chief drawbacks to 



* Krabbe, during a visit to Iceland in 1873, examined 100 dogs procured from 

 various parts of the country, and found Tcenia echinococcus in 28 instances. 



f Krabbe found this parasite in more than one-fifth of all the Icelandic dogs 

 (over 100 of all ages) examined by him. It seems to be a peculiar species, whose 

 genetic history is not yet known. Krabbe and Cobbold regard it as identical with 

 the Tcenia litterata of Batsch. Be that as it may, its frequent presence in Ice- 

 landic dogs seriously vitiates the results of the experimental feedings of M. Krabbe. 



% " l) eber die zu Echinococcus hominis gehorige Taenie," Beichert und du Bois- 

 Eeymond's Archiv fur Anatomie und wissensch. Medicin, 1863. Heft IY, p. 412. 



