CESTODES. 



271 



pendent animals/ but the so-called head can, after the loss of its 

 chain of joints, grow again to a new tape-worm within a few weeks. 

 Can we wonder that these observations long ago raised a doubt as to 

 the correctness of the usually accepted theory, and that thoughtful 



Ftg. 131. 



Fio. 132. 



Fig. 131. — Tape-worm form of Tcenia sa;/!- 

 ' nata a. mediocanellata. 



Fig. 132. — Isolated Proglottides of the same. 



investigators more than a century ago suggested tliat the tape-worm 

 was no simple individual, but a compound animal. 



Not to speak of the Arabian physicians, this was the opinion of 

 Vallisnieri^ and Ooulet,'^ and also of Linne, who places the tape- worm 



^ In fact, these discharged joints, especially of Tcenia saginata, have been repeatedly 

 considered both in ancient and modern times &s distinct parasites. Vermes cucurhitini. 

 " " Considerazioni ed esperienze intorno alia generazione dei vernji del corpo umano," 



p. 75 : Padova, 1710. Digitized bv l\^icrQsom^ , 



' " Tractatua de ascandibuB et lumbrlco lato, p. 37, &c. : Lugd. Bat., 1729. 



