14 METAMORPHOSES OF MAN 



which alter extensively the general form and mode of 

 life of the individual. 



Finally, I shall designate by the term geneagenesis * 

 the changes which relate to generations themselves. 

 It is upon this latter order of phenomena that I shall 

 dwell more especially, as being the least known, f 



* From ysvea and ykvetng, literally the reproduction of genera- 

 tions. Other expressions have been coined to designate the phe- 

 nomena referred to here. Further on we shall examine this ques- 

 tion in detail and make the facts known. 



t M. Ed. Claparide published (" Bibliotheque universelle de 

 Geneve," 1854) a work on one of the principal phenomena of genea- 

 genesis (" La Metagenese, ou Generation alternante "), but it is im- 

 possible to approach this subject without touching upon other 

 modes of development ; and, in consequence we have sometimes 

 treated of the same questions. Now I have remarked that this 

 naturalist admits also three modes of development among the 

 lower animals ; viz., " 1st. Development by metamorphoses, of 

 which we see examples in Batrachia, Insecta, Crustacea, Arachnida, 

 Mollusca, and a portion of the Annelida. 2nd. Development by 

 metagenesis, either alternate generation, or through two degrees ; of 

 which we find examples among the Aphides, the Salpae, the Hel- 

 minthes, the Medusa?, and the Infusoria properly so called. 3rd. 

 Mixed development, in which metagenesis and metamorphosis 

 coexist, one beside the other, or rather blended together. This is 

 the case in the Echinoderms." This extract shows that there are 

 certain harmonies and also great differences between our opinions. 



