THE CYSTIC ENTOZOA. 481 



echinococci, and which are attached to the internal surface of 

 the membrane, are merely the young acephalocysts either of 

 the secondary or tertiary stages of development. They will 

 be, as already fully described in this paper, of tlie secondary- 

 generation, if found growing from the walls of tlie original 

 containing sac, and tertiary if found growing from the walls 

 of those sacs floating free in the fluid contained witliin the 

 original sac. This animal is an acephalocyst, and not an 

 echinococcus. Bremser, in the atlas of his work. On the 

 Intestinal Worms of Man, calls it an echinococcus, but upon 

 false grounds, for the proper definition of echinococcus, he 

 says, at p. 294 of his work alluded to :* — 'OL lludolplii dis- 

 tingue les hydatides en vivantes et en non vivantes ; il regarde 

 rechinocoque provenant des intestins des bisulques {Erhi- 

 nococcus vetcrinorum) comme luie hydatide vivante, par la 

 raison que Ton trouve dans le liquide qu'elle contient les ec- 

 hinocoques, propremeut dits, c'est-a-dire, des petits corps mi- 

 croscopiqiies, pour\iis de quatre sugoirs et d'une couronne de 

 crochets." Tlie animal described by Mr. "Wilson is also 

 referred to in the same abstract by Dr. Budd, " who examined 

 seven hydatid tumours which had been for many years in the 

 JNIuseum of King's College," when he found appearances 

 exactly similar to those described by Mr. Wilson. It is more 

 than probable that the animals here alluded to by Dr. Budd 

 are similar to that I have called Acephalooystis ai-matus, which, 

 if the case, from the want of suckers, cannot be an Echi- 

 nococcus, being merely a transitory stage of the acephalocyst. 

 For I have examined gi-eat numbers of these animals, pre- 

 served in the ^Museum of the Eoyal College of Surgeons in 

 Edinburgh — a collection particularly rich in preparations of 

 these animals — and in no instance have I been able to make 



* Trait6 Zooloffiqm et Phiisiolotjiqiw sur hs Vn-s Intfstinaux d( r Homme, 

 jiar M. liri'iiistT. Tnwluit <lc rAUcmaiul jKir M. IJruiulUT. Revu et augniente 

 »U' Notes par M. ili- HlainvilU'. 



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