166 DR. T. S. COBBOLD ON ENTOZOA. 



ments, and I therefore regret that circumstances have prevented my carrying out more 

 fully an intention of verifying some of those particulars which have recently attracted our 

 notice. Tw^o of a few experiments, however, having been completed and attended with 

 partially satisfactory results, I take this opportunity of placing them on record : — 



On the 5th of February, 1856, 1 administered to a Dog three minute Cysticerci, obtained 

 from the fresh livers of two wild Rabbits. These cysts were perfectly round and measured 

 only the twelfth of an inch in diameter, and were evidently not to be referred to the 

 common C. pisiformis. A fortnight after (19tli) six similar cysts were obtained from 

 the liver of another wild Rabbit and given to the same Dog. Ten days subsequently the 

 canine animal was destroyed by chloroform, when, on laying open the small intestines, six 

 specimens of Tcenia cucumerina were detected. Three of these individuals were severally 

 about 12 inches in length, the others measuring only 3 inches. Thus far, therefore, 

 but for the circumstance of three of the nine cysts administered being undeveloped or lost, 

 no doubt whatever could be entertained as to the complete success of this experiment. 

 As it is, we have the interesting result of three nearly completely developed tape- worms, 

 the growth and number of which exactly correspond with the circumstances that ap- 

 parently led to their presence in the viscera of the Dog ; and in addition we have three 

 other individuals, only one-fourth of the bulk of the former, which may legitimately be 

 regarded as the partially developed representatives of three of the six Cysticerci that were 

 subsequently administered. It would appear, in consequence of the C 'pisiformis being 

 frequently present in the liver of the Rabbit, as well as in the mesentery, that our minute 

 Cysticercus has not hitherto been recognized as distinct ; at least, I find no notice of it in 

 foreign works, and shall therefore in future speak of it as C. cucumerinus. In order to im- 

 part additional value to the above experiment, a young tame Rabbit was next procured, 

 and the three larger Tsenias (whose caudal proglottides contained multitudes of imper- 

 fectly formed ova) were given to it, the Living worms being greedily devoured with portions 

 of a cabbage-leaf. Eleven days after, the Rabbit was destroyed, and the liver found to 

 contain numerous minute cysts corresponding to those of C cucumeriwus, the great omen- 

 tum likewise containing four specimens of C. 2)isiforntis. No inference of any value can 

 be deduced from the presence of both kinds of Cysticerci in this case, for they are almost 

 always present in tame Rabbits, young or old, whether they have eaten tape-worms or not. 

 On the same day, 11th March, portions of the liver were given to a young Dog, and on the 

 17th many examples of C. pisiformis from the omentum of another tame Rabbit were 

 given to the same animal. Two or three days before the second worm-feeding, this dog 

 had commenced ejecting its ordinary food, and I have no doubt that by far the greater 

 part of the more recently introduced worm-feedings shared the same fate. This throwing 

 up of the stomachal contents was followed by total abstinence ; and as the dog appeared 

 weak, it was accordingly destroyed on the 20th, thus allowing only three days for the 

 development of any pisiform Cysticerci that might chance to be retained, and but nine 

 days for the smaU liver-cysts. The result was as follows : — Seven tape- worms were pre- 

 sent in the intestine ; of these, four were specimens of Tcenia cucumerina, varying from 3 

 to 10 inches in length, and the remaining three were examples of T. serrata, the segmen- 

 tation of which was scarcely manifested, the longest individual measuring less than an 



