WORMS. 327 



into two genera, the common 1 and the grape- 

 headed tapeworms. 2 The former is the most 

 common in England, 3 but the latter 4 seems the 

 most gigantic of any. Sir A. Carlisle, who has 

 a most excellent paper upon the former, in the 

 second volume of the Linnean Transactions, 

 says that he has met with them from less 

 than six feet long and consisting only of fifty 

 joints, to thirty feet long with four hundred 

 joints. But these are nothing compared with 

 others of the latter observed by continental 

 writers. Bonnet mentions them as sometimes 

 extending to the length of thirty ells, probably 

 meaning French ells, or one hundred and 

 twenty-five feet, and Boerhaave, one that greatly 

 exceeded that length. 



These animals differ little from each other, but 

 in the common tape- worm, the head which has 

 a circular orifice or mouth at its extremity sur- 

 rounded by a number of rays of a fibrous tex- 

 ture, and probably serving to fix the mouth, has 

 on each side two small suckers which doubtless 

 attach the head more strongly. The mouth, 

 before spoken of, is continued by a short duct 

 into two canals, which pass round every joint 

 of the animal's body conveying its aliment, and 

 sending a transverse canal along its bottom 

 which connects the two lateral ones. Sir An- 

 thony injected upwards of three feet of these 



1 Tania. 2 Botryocephalus. PLATE I. B. Fro. 3. 



3 Tcenia solium. 4 Botryocephalus latus. 



