23(> 



ZOOLOGY 



-SECT. 



(Fig. 184), the uterus, with its contained accumulation of eggs, 



becomes so large as to fill the greater part of 



the interior of the proglottis, the remainder 



ci&; .-.!'> of the reproductive apparatus meanwhile 



having become absorbed. 



Development. When the ripe proglottides 

 are detached they pass to t{ie exterior with the 

 faeces of the host. For a time they exhibit 

 movements of contraction. The embryos con- 

 tained within the eggs have meantime assumed 

 the form of rounded bodies, each armed with six 

 chitinoid hooks the six-hooked or hexaeanth em- 

 bryo (Fig. 185, A) enclosed within two mem- 

 branes. If the proglottides or the eggs which 

 have escaped from them, should now be taken 

 into the alimentary canal of the Pig, which forms the ordinary 

 second host of the parasite, the hooked embryos, becoming freed 



P 



FIG. 184." Ripe " pro- 

 glottis of Taenia 

 solium. (After 

 Leuckart.) 



Fii:. 1>C). Development of Tapeworm. A, hexaeanth eml>ry>: />'. 1'roscolex of T^mia 

 .,; ,, f itu,- CE, stages in the formation of the scolex of the same : C, The imagination before 

 the hooks and suckers have become developed; />. after the appearance of the hooks :m<l 

 suckers; E, partly evaginated ; F, fully evaluated srokx of T. solium with caudal vesicle; 

 (i. scolux <>f T. rrata with remains of the vesicle ; //, young tapeworn of T. *< n-ata. (After 

 Leuckart.) 



from their coverings, bore their way with the aid of their hooks 

 through the wall of the alimentary canal, and reach the voluntary 



