III. CESTODA. 



279 



almost thread-like in front, increasing posteriorly to a broad band, 

 whence the common name. At first the proglottids are small; 

 they increase by individual nourishment to considerable size, and 



FIG. 238. 



FIG. 239. 



FIG. 238. Tcenia saginata. (From Boas, after Leuckart.) Head with series of pro- 

 glottids taken from various regions of the strobila. 



FIG. 239. Nervous system of Monezia. (After Tower.) a, suckers ; e, excretory tubes; 

 p, cerebral ganglia. Nerves black. 



separate from the hinder end of the chain and live separately when 

 a certain measure of development is reached. For example, the 

 young proglottids of the human tapeworm, Tcenia solium, are 0.5 



