DR. T. S. COBBOLD ON CESTOIB ENTOZOA. 173 



distributed throughout the muscular system, there could not have 

 been less than 12,000 of these degenerated measles in the animal, 

 I have no hesitation in saying that, if there had been 12,000,000 

 of these measles, no butcher would ever have noticed them ; but, 

 fortunately, in this condition their ingestion could do no pos- 

 sible harm. In point of fact, the flesh of the animal has since 

 been entirely eaten ; and healthier beef I never saw. Even in their 

 perfect, non-degenerated state, the beef measles are readily over- 

 looked ; and until recently no person besides Mr. Simonds, Mr. 

 Pritchard, and myself, and those who assisted . us, had even seen 

 them in this country. The experiment now recorded is the first 

 in which the natural process of cure has been traced ; and it is of 

 great practical importance, inasmuch as it proves to demonstra- 

 tion that a period of ten or twelve months is fully sufficient to 

 ensure the natural death (by calcareous degeneration) of the 

 smaller tapeworm-larvse which reside in cattle. This is a positive 

 contribution to our knowledge of the life-economy of these smaller 

 cysticerci, and it serves to fix the period of their larval activity. 

 All the entozoa, in their juvenile stages, whilst occupying the 

 flesh of man and animals are liable to be affected by this law of cal- 

 careous degeneration ; but the actual time required to bring about 

 the death of the parasite varies considerably in diflerent species. 



Tcenia serrata. — Exp. 1. Three examples of the pea-shaped hy- 

 datid {Oysticercus pisiformis) were removed from the abdominal 

 viscera of a recently killed rabbit. Two of them were rather more 

 perfectly developed and larger than the third. The rabbit har- 

 boured no others. These three cestode larvge were administered, 

 on the 25th of January 1865, to a healthy puppy, reared at tlie 

 Veterinary College and nearly twelve weeks old. Five days sub- 

 sequently, namely on the 30th of the same month, the puppy vias 

 destroyed. In the alimentary canal I found three young Ta"nice, 

 and three only. Two of them were severally about 1 inch in 

 length, the third being a trifle shorter and not quite so large. 

 These sexually immature tapeworms presented all the true chai-ac- 

 teristics of T. serrata, and their degree of develoj)ment was in exact 

 accordance with my previous experiences in this relation. Tlie 

 more feeble development of the third tapeworm proved its genetic 

 connexion with that larva which at the time of the worm-adminis- 

 tration was noticed and recorded as being rather incompletely de 

 veloped. The experiment was a perfect success. 



Exp. 2. On the 25th of January, 1865, a second rabbit was 

 destroyed, for the purpose of procuring additional tapeworm-larvse. 



