200 METAMORPHOSES OF MAN 



materials necessary for its growth, from the parent ; it 

 abstracts its nourishment, but it tends more and more 

 to become an isolated being. Whether the operation 

 takes place externally as in Polyps, or internally 

 as in Salpse, the phenomenon is essentially the same. 

 In the Echinoderms, on the contrary, the bud in 

 the course of growth, surrounds the existing organs 

 and appropriates them. Viewed as a whole, the 

 process of gemmation is one of geneagenesis ; but 

 the stomach in Sea-urchins and Ophiuridae, and the 

 entire digestive apparatus, and some other organs in 

 Holothuriaa, are submitted to a simple metamorphosis 

 only. 



The development of Bchinoderms forms a sort of 

 connecting link between these two classes of phe- 

 nomena, and prevents one of those leaps to which 

 Nature ever seems to be so averse.* 



* M. Edouard Claparede has come to a similar conclusion on 

 this subject, although we have investigated the matter from very 

 different points of view. 



