in. CESTODA. 



279 



almost thread-like in front, increasii^g posteriorly to a In-oad Land, 

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

 they increase by individual nourishment to considerable size, and 



Fig. 238. 



fio. -a'.). 



Fig. 238.— Tanm saginaia. (From Boas, after Leurl<;ut.) Head "with ^series of pro 



glottids taken from various regions of the strobilii. 

 Fig. 239.— Nervous system of Moni^zia. (After Tower.) a, suekers ; e, excretory tubes; 



g, 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, Tmnia solium, are 0..5 



