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



In this rabbit I only found one solitary and perfect Cysticercus 

 pisiformis — a somewhat unusual circumstance. Mr. Simonds 

 placed this larva in a small piece of paper, and in the form of a 

 bolus gave it to a little puppy which belonged to the same litter 

 as the former, being readily distinguished by its black ears. We 

 did not destroy this whelp until the 7th of the following February, 

 thus allowing a period of thirteen days to elapse for the develop- 

 ment of the solitary Tcenia serrata which we desired to rear from 

 the cysticercus. Mr. Simonds, as usual, requested me to examine 

 the alimentary canal ; and I had the satisfaction of removing the 

 solitary Tcenia serrata we had thus successfully reared. It was 

 iu.st 6 inches in length, showing the same correspondency as to 

 growth, in respect of time, which my previous and independent 

 experiences with the artificial metliod of rearing this parasite had 

 invariably supplied. The proglottides were still immature, but 

 the cephalic development was in all respects complete. 



Tcenia marginata. — On the 28th of January, 1865, Mr. Simonds 

 removed fourteen specimens of the so-called slender-neclced hy- 

 datid from the omentum and surroimding viscera of a hogget. 

 Pive of these large cysticerci (C tenuicollis) were administered 

 to the mother of the two whelps above referred to. They were 

 swallowed entire, without any additional material. This dog was 

 killed on the 7th of the following February, thus allowing only 

 ten days for the development of the corresponding adult tape- 

 worms. As usually happens in all old dogs, we found in the in- 

 testinal passages many examples of the extremely common cucu- 

 merine tapeworm (T. cucumerina) ; but these of course could have 

 no genetic relation to the tapeworm-larvse, which latter were 

 already known to be the ofl:spring of an entirely diff"erent species 

 of cestode parasite. Our experiment, indeed, was a perfect suc- 

 cess ; for, in addition to the cucumerine tapeworms (of which 

 there were fifteen mature specimens of variable size and growth), 

 I found in the duodenal portion of the intestinal canal five young 

 and sexually immature examples of the Tcenia marginata. These 

 were of uniform size and severally 1 inch in length. Not a 

 shadow of doubt could be entertained as to their relation to the 

 five cysticerci which had been administered. Their specific cha- 

 racteristics, uniform development, degree of growth, and separate 

 location in the canal, pointed unequivocally to the source whence 

 tliey had been derived. Here again, therefore, previous expe- 

 riences received abundant confirmation. 



Tcenia coemiriis. — Exp. 1. On the loth of March, 18G5, Mr. 



