AND THE LOWER ANIMALS. 217 



has no trace of reproductive organ. How, then, is it 

 reproduced ? 



This problem has been solved by Kiichenmeister. 

 Led by his former experiments, he fed a dog with the 

 Coexmri, and he soon found in its intestines the 

 Tssnise which till then had been regarded as peculiar 

 to the wolf.* Next, when this worm was fully 

 developed, he fed sheep with those segments whose 

 eggs already exhibited embryos with six hooklets, 

 and in a few days these sheep were attacked with 



# The determination of the species thus obtained presents some 

 difficulties, not yet quite got rid of ; this fact has been dwelt on 

 with some force by Valenciennes, and was first noticed by myself, 

 " Comptes Rendus," 1854. But these are difficulties of detail, and 

 " do not affect the general results that I have been endeavouring to 

 convey an idea of ; the transformations and migrations of cestoids 

 are facts so clearly demonstrated now, that they are universally 

 accepted. Among the works which have contributed to decide the 

 question, I may mention the persevering researches of the two 

 writers to whom I have already alluded, Siebold's various works, 

 and especially two memoirs translated into French in the u Annales 

 des Sciences naturelles," for 1851 and 1852 ; Wagener's important 

 memoir, " Die Entwickelung der Cestoden," published in the 

 " Memoires de I'Acaclemie de Breslau," 1854 ; that of Baillet, 

 entitled " Experiences sur le Cysticercus tenuicollis, et sur le 

 Tenia qui en resulte," 1861 ; and M. Koeberle's work, " Des Cysti- 

 cerques du Tenia chez l'Homme," 1861, &c. 



It must be remembered that the experiments were not confined 

 to the lower animals, but were made even on man himself. Leuckart 

 experimented on his patients (" Die Blasenbandwiirmer und Hire 

 Entwickelung," 1856) ; Kiichenmeister operated on criminals 

 (" Gazette Hebdomadaire de Medecine et de Chirurgie," 1860). Dr. 

 Humbert of Geneva experimented upon himself, and voluntarily 

 produced tapeworms within himself (Bertolus, " Dissertation sur 

 les Metamorphoses des Cestoides," 1856, alluded to by Koeberle). 

 The results of all these experiments were the same as those in the 

 cases of the lower animals. 



