28 ANIMAL PARASITES. 



metamorphosi/ Wratislnvinc, upon the conversion of Cysticercus 

 pisiformis into Taenia seriata ; lie also amplified these confirmatory 

 observations in his ' Zeitschrift' for 1853, Band iv, p. 400. ] 



At the same time Von Siebold had administered the Cysticerci 

 of rabbits to rabbits, and reared in their intestine a developmental 

 form similar to that which I had obtained by the administration 

 of the Cysticerci of rabbits to cats, which I have just mentioned. 

 The forms with band-like, inarticulate appendages, reared, accord- 

 ing to Von Siebold, from the Cysticerci of the rabbit in the 

 intestine of that animal, were made use of by myself to transfer 

 them through an incision into the abdominal cavity of rabbits, in 

 order to test the opinion of Von Siebold and Van Beneden as to 

 the production of the vesicular worms from the ready-formed 

 tape-worm heads. The result was, that I could not confirm the 

 opinion of these two zoologists, as the worms thus transferred 

 into the abdominal cavity retained the form which they possessed 

 at their introduction, or, if any change could be said to take place, 

 instead of an inflation of the abdomen, a diminution of the band- 

 like appendage was rather observed. 



Subsequently, I also obtained a peculiar tape-worm (T. ex 

 Cysticerco tenuicolli) by the administration of Cysticercus tenuicoUis 

 to dogs. This is probably the same which Von Siebold supposed 

 he had reared from Cysticercus cellulosce in the dog ; but I 

 never succeeded in rearing a mature Tcenia from the latter 

 cystic worm in dogs, which, however, as we know by expe- 

 rience, must take place in the human subject, and which, indeed, 

 did take place according to an experiment of Leuckart's. 



In the meantime Von Siebold, who appears to have felt per- 

 sonally injured and affronted because I had attacked his notions 

 upon the nature of the Cysticerci in the ' Prager Viertel- 

 jahrschrift/ and at the same time made an ironical remark about 

 the theory of dropsy and recovery, was led to make personal 

 attacks on me, in the ' Breslauer Zeitung/ and, amongst other 

 things, was induced to remark that if he had not come to my 

 assistance by his determination of the species, the whole theory 

 of the process of metamorphosis would have been thrown by me 

 into a state of confusion which could hardly be corrected, as I 

 was not in a position to determine the particular species of 

 Tcenia and Cysticerci. I of course admitted this, but at the 



1 [See a translation in ' Quarterly Journal of Microscopical Science,' vol. ii, p. 255.] 



