132 DARWINISM STATED BY DAEWIN HIMSELF. 



by a few stages ; but tbe transformations are in reality 

 numerous and gradual, thougb concealed. A certain 

 ephemerous insect {Ghloeon), during its deYelopment, 

 molts, as shown by Sir J. Lubbock, above twenty times, 

 and each time undergoes a certain amount of change ; 

 and in this case we see the act of metamorphosis per- 

 formed in a primary and gradual manner. Many insects, 

 and especially certain crustaceans, show us what wonder- 

 ful changes of structure can be effected during deyelop- 

 ment. Such changes, however, reach their climax in the 

 so-called alternate generations of some of the lower ani- 

 mals. It is, for instance, an astonishing fact that a deli- 

 cate branching coralline, studded with polypi and attached 

 to a submarine rock, should produce, first by budding 

 and then by transverse division, a host of huge floating 

 jelly-fishes ; and that these should produce eggs, from 

 which are hatched swimming animalcules, which attach 

 themselves to rocks, and become developed into branch- 

 ing corallines ; and so on in an endless cycle. The belief 

 in the essential identity of the process of alternate gen- 

 eration and of ordinary metamorphosis has been greatly 

 strengthened by Wagner's discovery of the larva or mag- 

 got of a fly, namely, the Cecidomyia, producing asexually 

 other larvae, and these others, which finally are developed 

 into mature males and females, propagating their kind in 

 the ordinary manner by eggs. 



P e SB? ■'■* ^^^ ^^^^ already stated that various parts 

 in the same individual, which are exactly alike 

 during an early embryonic period, become widely different 

 and serve for widely different purposes in the adult state. 

 ~^o, again, it has been shown that generally the embryo^ 

 of the most distinct species belonging to the same class are 

 closely similar, but become, when fully developed, widely 



