BENEDEN, ON THE TRANSFORMATION OF ENTOZOA. 271 



standing tlieir having proceeded with every requisite pre- 

 caution, these lambs, contrary to the results obtained by 

 other experimenters, never presented any of the symptoms of 

 'staggers/ nor did their brains at the end of four months 

 contain a single vestige of a Cmmrus. 



" Not to mention the perfectly successful experiments per- 

 formed at Munich, at Zittau, and at Toulouse, those which 

 were made about the same time at Louvain, at Giessen, and 

 at Copenhagen, with ova, afforded by one and the same 

 dog fed with Ceenuri, all produced exactly the same results, 

 and pretty nearly after a similar lapse of time. In all three 

 places the lambs were attacked with /staggers' about the 

 fifteenth day, with this difference only, that at Copenhagen 

 only two out of three sheep were affected. 



"What is the reason that the experiments of MM. Pouchet 

 and Verrier have afforded such different results ? This arises, 

 without doubt, from the circumstance that those observers 

 administered to their iambs, not the ova of Tania canurus, 

 but those of T. serrata. If they wish to succeed in the ex- 

 periment, let them administer ova really derived from Tania 

 C(2nurus, and, like others, they Avill find all the symptoms of 

 staggers manifested. 



" But even should they be equally unsuccessful a second or 

 even a third time, is it wise to conclude from this negative 

 result, as they have done, that the Ccenurus is developed spon- 

 taneously in the sheep's brain ? Clearly not. What would be 

 said of any one who, having sown for the first time some 

 flower seeds, and not finding them to grow, should assert 

 that his neighbour's flowers sprang up spontaneously in his 

 garden ?" 



M. Van Beneden goes on to relate an interesting experiment 

 just concluded with perfect success by Professor B. Leuckart. 



'^ It is some years since a second species of Tcenia has been 

 known to infest the human subject — Tania medio-canellata. 

 It has already been noticed in several countries. If this Ento- 

 zoon be really distinct from Tcenia solium, by what means is it 

 introduced, what are the characters of its Cysticei'cus scolex, 

 and whence is the latter derived ? 



" Having considered aU the facts relating to the history of 

 this parasite, the skilful and learned professor of Giessen was 

 induced to administer the ova of T. medio-canellata to some 

 calves, and in a short time he found that such numbers of 

 Cysticerci were developed in the muscles of all parts of the 

 body, that they appeared, as it were, to be ' larded' with 

 them. And, besides this, he noted another circumstance which 

 gives the experiment a great value, namely, that this Cysti-. 



