1 74 METAMOBPHOSES OF MAN 



stalk, and they grow to a far greater size. The 

 vesicle which results from the development of one of 

 these, is five or six times as large as those above 

 described, and is traversed from end to end by the 

 living tube which enters into all the ramifications of 

 the polypidom. In the covered species it is upon this 

 axis that the reproductive polyps are produced, which 

 ensure the perpetuation of the species. 



Bach of the new productions presents within it, 

 even on its first appearance, one or two well-marked 

 ova; these grow pari passu with the original, and 

 become converted into as many ciliated larvas. As 

 soon as they have reached a certain development, the 

 polyps burst the capsular membrane and appear ex- 

 ternally. They then resemble medusas, minus the 

 digestive apparatus, which they do not require, as 

 they remain in communication with the vital portions 

 of the polypidom, and thus derive nutriment from 

 the materials drawn in by their long-tentacled 

 brethren; besides, their lives are extremely short. 

 The larvae soon found new colonies at a distance ; 

 and now that their functions have been performed, 

 the polyp mothers fade away, and are gradually 

 resorbed. 



Although there appears little analogy between the 

 phenomena presented in the development of Oam- 

 panularia and Aurelia, yet there are very close rela- 

 tionships between them. 



In both cases a ciliated larva or scolex is produced 

 by the ovum. It happens, however, in Campanularia, 

 that the first polyp is the result, not of a process of 

 metamorphosis, but of one of budding, which produces 

 a being very different from that which preceded it. 



