152 



Platyhelminths. 



rostellum, but witli veiy powerful suckers. The branches of the uteras are 

 more numerous than in T. solium, which this species usually resembles closely ; 



it attains a length of 7 — 8 

 A B Cm. The development as 



before. The bladder-worm, 

 almost exclusively in the 

 muscles of Cattle, is very 

 much like that of T. solium, 

 but a little smaller. 



(c) T. ccenurus. With 

 Crown of hooks ; in the 

 digestive tract of the dog; 

 1-m. long. The bladder- 

 worm {Ccemurus cerehralis), 

 lives in the brain of Sheep, 

 in which it induces gid- 

 diness. It becomes very 

 large (as large as a Hen's egg or more), and produces, by budding, numerous 

 scolices, so that there is a colony of Cestode-heads in the same vesicle. 



(d) T. echinococcus. A very small Cestode (at most 5 m/m. long), with 3 — 4 

 proglottides ; in the alimentary canal of the Dog. The bladder, the Echinococcus, 

 in the liver and other organs of Cattle, Sheep, Pigs, and Man, often attains a 

 considerable size (that of a child's head or more), and is surrounded by a thick, 

 stratified cuticle. Many small heads, as in T. ccenurus, bud out from the 

 vesicle, but in T. echinococcus are always formed as little invaginations of 

 the wall [see Fig. 113 B), the so-called brood-capsules. The Echinococcus 



Fig. 112. " Head " of Taenia solium (A), of T. medio- 

 canellata (B), and of Bothriocephalus latus (C). — Orig. 



rig. 113. Tamia echinococcus. A Tapeworm enlarged. — After 

 Leuokart. — B diagrammatic section through a cyst:, v wall, c 

 cuticle, y brood-capsule, y' the same in an incipient state. — Orig. 



occmi-ing in Man — ^rare in most places, but common in Mecklenburg, Iceland, 

 and Australia — ^is distinguished by often attaining an enormous size, and by 

 having within the original bladder many smaller daughter vesicles (brood- 

 capsules), which exhibit the same structure as the former. The brood-capsules 

 seem to arise by a modification of heads which have broken free from the waU. of 

 the parent bladder. 



(e) T. cucumerina. '75 m. long. The head provided with a retractile 

 proboscis-like process, with several circles of hooks. Ripe proglottides oval. 



