324 SYNOPTIC COLLECTION. 



suckers (fig. 5) for the purpose of attachment. From 

 the neck, which is smooth in front and irregularly wrin- 

 kled behind, grow out sections divided by regular joints. 

 This process continues until an immense number have 

 been formed, those nearest the neck always being the 

 youngest and those at the posterior end the oldest. . 



Weinland 1 has pointed out that the articulation of a 

 Cestode is by no means homologous with that of an 

 earthworm or any true segmented animal. 



When we consider how these sections develop into sex- 

 ual organisms or proglottids (fig. 6), how these break 

 away from the chain and live for a while as independent 

 individuals (Van Beneden), we see how very far removed 

 they are from the true segments of the typical worm. 

 They serve the one function of reproduction, containing 

 such an incredible number of eggs that it may be said 

 "in no group of the animal kingdom do we find any 

 fecundity to be compared to this of a cestode worm." 2 



A specimen of Taenia now in the possession of the 

 Boston Society of Natural History measures thirty feet, 

 but this is incomplete, not having the head ; while the 

 complete specimen, No. 800, measures sixteen and a half 

 feet. The tiny, knob-like, and reddish brown head is 

 seen on the right of No. 800, a short distance from the 

 bottom of the jar. The youngest sections are small and 

 narrow, but the oldest are large and sexually mature. 

 Not only is the adult without a mouth and digestive 

 system, the fluid being absorbed through the body 

 wall, but no nervous system has been discovered. 



1 Tape-worms of Man, 1858, p. 9. 



a Van Beneden, Animal Parasites and Messmates, 1876, p. 208. 



