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worms, which, instead of the intestine, had got into 

 the parenchyma of their host, and, under the influence 

 of this unusual dwelling-place, had advanced to the 

 abnormal state of development which we call a cystic 

 worm. 



In 1850, Van Beneden, of Belgium, in his work. 

 " Les Vers Cestoids ou Acotyles," considered these 

 cystic worms to be the larval condition of the Taeniae ; 

 but, in his further conclusions, he made the mistakes, 

 1st, of considering that a tapeworm can pass through 

 all the separate phases of its development in the intes- 

 tine of its host ; and, 2d, in considering that the cau- 

 dal vesicle is formed by dropsical degeneration, and 

 that the head there sinks into it in order to become a 

 Cysticercus (Kiichenmeister). 



In 1851, Kiichenmeister, from some experiments 

 with the C. pisiformis of the rabbit, and the C. fascio- 

 laris of the rat, arrived, among other conclusions, to 

 these two, that, 



1. "The cystic worms are not strayed dropsical 

 tapeworm nurses, but tapeworm larva? furnished with 

 a provisional organ (caudal vesicle), probably acting 

 as a reservoir of nourishment, and incapable of sexual 

 multiplication, for which there is neither room nor 

 sufficient nourishment ; " and that, 



2. " The cystic worms constitute a necessary step 

 in the development of the Taeniee." 



Furthermore he says, 



" At the same time I proved that the Cysticerci 

 administered, when transferred to the intestine of 

 other animals (as for instance the C. pisiformis in the 



