DE. T. S. COBBOLD ON CESTOID ENTOZOA. 177 



negative result. This dog was likewise the subject of a Triehina- 

 experiment in which we were entirely successful. It also har- 

 boured eleven specimens of Asearis marginata, and many examples 

 of Taenia cucumerina ; these, of course, were introduced by natural 

 causes. 



Tcenia solium. — The only two cestodes which I have hitherto 

 not succeeded in rearing are the present and foregoing species. 

 My non-success in the former case I can very readily explain — 

 not so in the latter. Negative results, however, oftentimes prove 

 highly instructive ; and it is, even here, just possible that I may 

 have hit upon the true explanation of my non-success in the case 

 of Tcenia solium. At all events it is but fair to place the facts 

 on record. 



Exp. 1. On the 30th of January, 1865, and on the 23rd of the 

 following February, numerous tapeworm-proglottides were given 

 to a pig, which afterwards displayed no measle-symptoms. It 

 was destroyed on May 16th, 1865, and on examination yielded no 

 cysticerci. Most, if not all of the " joints " first given, I subse- 

 quently ascertained to be those of Tcenia mediocanellata, whilst 

 those of the second feeding were from what I had previously 

 described at the time as a " very small variety of Tcenia solium.''^ 

 I now believe the latter to have represented neither T. solium nor 

 T. mediocanellata, but an altogether distinct and new-form ces- 

 tode. If this conjecture turn out correct, the explanation of this 

 non-success is suflBciently obvious, 



Exp. 2. On the 30th of January, 1865, some of the same 

 experimental material was given by Mr, Simonds and myself 

 to another pig. On the 15th of March following, seventy pro- 

 glottides of a T. solium (which I fear had been placed in spirit 

 before transmission to me) were also administered, and again, on 

 the 13th of April, not less than 200 proglottides of my so-called 

 small variety of T. solium were likewise introduced. In this 

 case the small "joints" were transmitted to me by Dr. Alexander 

 Eleming, of Birmingham, along with other parasites, to which I 

 have elsewhere referred. The pig was killed on the 30th of May, 

 1865, and the result was again negative. The explanation of our 

 non-success is similar to that I have assumed to hold good in the 

 previous case. The March feeding, certainly, might have yielded 

 Gysticercus cellulosee, but I never could ascertain who sent me the 

 parasite, and I had not a little reason for believing that the para- 

 site had been immersed in alcohol. My previous experiences had 

 shown that even a comparatively weak spirit-solution effectual! v 



LINlf. PEOC. — ZOOLOGT, YOL. IX. 14 



