TAPEWORMS. 37 



necessary examinations for the purpose, and was ulti- 

 mately regarded by securing this extremely minute 

 body under circumstances of the utmost difficulty. 

 To arrive at this result it was necessary to examine 

 several quarts of fsecal matter ounce by ounce ; the 

 object sought being itself smaller than the head of 

 a pin, and readily mistakeable for other foreign 

 bodies liable to occur in the discoloured mucus and 

 faeces. In this case, however, I was encouraged to 

 persevere by the recollection of a previous ex- 

 perience, under even much greater difficulties. 

 This occurred to me during my investigations of 

 entozoa in the bodies of animals dying at the 

 Zoological Society's Menagerie, Regent's Park. The 

 instance is, I think, worth recording separately. 

 On January 16, 1858, I observed some partially 

 disintegrated proglottides in the lower part of the 

 intestine of a horned pheasant. These were the 

 remains of a small tapeworm, evidently a solitary 

 specimen (Ttenia infandibuliformis}. Being anxious 

 to secure the head, which was far too small to be 

 rendered visible to the naked eye, I subjected the 

 entire contents of the alimentary canal to micro- 

 scopic examination, drop by drop, and at length, 

 after a tedious investigation, discovered the isolated 

 head, measuring considerably less than the one- 

 hundredth of an inch in diameter. Such an unex- 

 pected success as this has naturally given me great 

 confidence in my searches after the heads of human 



