24 OF THE PRINCIPAL WORMS 



neck of a very long taenia, compared with its body 

 does not seem to pertain to the same animal ,(^3) 

 in tliis manner several naturalists have been deceiv- 

 ed, and subdivided the same worm into, two par- 

 ticular species. The body of the taenia is form- 

 ed by entire articulations, which we call perrect,(23) 

 iu which the papillae are clearly visible and open at 

 their summit, whether they are symmetrical, (34) 

 or irregularly situated in the lateral edges of 

 the taenia. (35) Finally the tail terminates by a 

 piece quite truncated, or cut off and raised on its 

 sides in. form of two hooks, rounded at their sum- 

 mit. Both the hooks or crotchets have the same 

 small holes or apertures, which are observed in 

 the papillae we have mentioned. 



The border or edge of each, which connects th» 

 articulations, is slightly concave towards the tail, 

 and a little convex tov/ard the head. 



In this manner the diameter of the body of the 

 taenia gradually lessens as it approximates either 

 extremity of the worm. 



§, VII. The bigness and external form of the 

 taenia of the same species also vary. A patient in 

 the Clinical Institute of Pavia, voided in several 

 pieces, in the winter of 1797? the taenia represent- 

 ed, PI. I. fig. 1, 3. 



In these pieces we discovered the head, with 

 the fangs or hooks above named, as well as the 

 posterior extremity of its body, which we have con- 

 sidered as the tail. 



These pieces taken together were from fifteen 

 to sixteen metres in length. 



