DISCOVERY OF THE LARVAL STAGE. 669 



taneously (on one occasion through the nose), and sometimes with the 

 stools, and continued moving for a time after their expulsion. Ac- 

 cording to the communications made to me, they had a length of 5 to 

 8 mm., and a breadth of 1/5 to 2 mm., exhibited the well-known red 

 colour, and, if investigated in a fresh condition, contained the already 

 described clusters of eggs. Schoch-Bolley of Zurich, who in one case 

 succeeded in expelling entire worms by means of Kamala, while in all 

 the other cases only portions were obtained, estimates the length of 

 the worm at nearly a foot. As but two worms were voided in this 

 case, it appears that T. cucumerina does not occur usually in such 

 large numbers in man as in dogs and cats, and that in most cases 

 only a few are found living together. 



So far as I know, no symptoms of disease were observed in any of 

 these cases. If a larger number of worms were present, it might per- 

 haps be otherwise. At least it has been observed that under such 

 circumstances dogs sometimes exhibit cramp and other symptoms of 

 nervous or gastric disease. I have already (p. 143, note) quoted a 

 case of this kind from Goze's famous " Naturgeschichte." A second 

 one is cited in another part of this work from the observations of 

 Wagler, 1 which, however, only differs from the former in the increased 

 gastric disturbances. 



Now, however, we are not only acquainted with the fact that T. 

 cucumerina is by no means very rare in man during childhood, but 

 have also learned the way in which children are infected ; in other 

 words, an unexpected disclosure has been, made regarding the life- 

 history of the worm. 2 



This discovery was made in the summer of 1868 by one of my 

 Russian students, now Professor Melnikoff, while 

 busied in my laboratory with investigations 

 regarding the embryology of the louse. He was 

 examining for the purpose the dog-louse (Tricho- 

 dectes canis), and one day discovered in the 

 body-cavity of this parasite (which, instead of 

 the piercing and sucking mouth of Pediculus, 

 is well known to possess a masticatory apparatus, 

 and to gnaw the epidermis of its host), some 

 small white bodies which he did not know how 

 to interpret. After close investigation, I recog- 

 nised them as the cysticercoid forms of Tcenia p IG . 343. Cysticer- 

 cucumerina. The rostellum and the formation c ? id of Tomia cucume- 



/> , , , , i-iiiT i nna. ( x 60.) 



or the hooks removed all doubt as to the 



correctness of the diagnosis. Strange to say, the Cysticercoid was 



1 Loc. cit., p. 324. 2 Archivf. Naturgcsch., Jahrg., xxxv., Bd. i., p. 62, 1869. 



