458 CYSTIC STAGE OF T^NIA SAGINATA. 



rate is certain, that the perforation progresses from without inwards, 

 and gradually extends in depth as it increases in breadth. Here 

 and there the hole has two points of origin instead of one, but both 

 are in the anterior half of the joint. The superficial extension is 

 greater anteriorly, so that the posterior wall of the joint is in 

 extremte cases broader than the anterior. This circumstance seems 

 to be in some way associated with the special organization of the 

 sexual apparatus, but this connection can hardly be so simple as 

 Bremser would have it. This is evident enough from the fact that 

 the perforation is sometimes apparent in joints which are still far 

 from maturity. 



The true nature of this abnormality — ^perhaps rather a disease 

 than a malformation — is still unknown. Even Kiichenmeister can 

 hardly be right in regarding it merely as the result of digestion. 

 The appearance of the worm, the smooth character of the sides of 

 the holes, and the duration, of the malady, are. difficult to harmonise 

 with this hypothesis. 



The Bladder -Worm of Taenia saginata and its Development. 



Leuckart, "Die Parasiten des Menschen," Th. i., pp. 296-406 (first edition), 1863. 



Having proved that the human intestine harbours not only Taenia 

 solium, but a second large-jointed species of Tcenia, we are naturally 

 led to ask the question. How does this latter originate ? Kiichen- 

 meister at first (1855) believed that the young of the latter occurred 

 along with the ordinary bladder-worm of the pig, which had mean- 

 while been experimentally proved to belong to the life-cycle of 

 Tcenia solium, Eudolphi. In a communication made to the Academy 

 of Paris in 1860,^ he reports having actually found the young form of 

 T. saginata in the pig. The discovery has not, however, been con- 

 firmed, and the thrice repeated feeding experiments conducted by Dr. 

 Schmidt in Frankfort and by myself have yielded only a negative result. 



But the result of this experiment is not the only argument against 

 Kiichenmeister's supposition. The geographical distribution and 

 occurrence of Tcenia saginata point in another direction. 



Specially instructive in this connection is the fact that the 

 Abyssinians, who are almost, without exception, from their earliest 

 years infested with Taenia saginata, eat no swine's flesh, but, accord- 



' Comptes rendvs, t. 1., p. 367. In the second edition of his work on parasites wo 

 read (p. 199, note) — " Since my preparation, which I held to be the Cysticercus of T. 

 mcdiocanellata, and which was taken from the pig, has been lost, I have no other means 

 of proof. This may be regarded by some as unsatisfactory, but I decline to quarrel 

 over it." 



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