MY ISLANDS. 17 



the eggs or larvae of American beetles, while several 

 others were driven ashore from the Canaries or Maderia ; 

 and in one instance even a small insect, belonging to a 

 type now confined to Madagascar, found its way safely 

 by sea to this remote spot, where, being a female with 

 eggs, it succeeded in establishing a flourishing colony. 

 I believe, however, that at the time of its arrival it still 

 existed on the African continent, but becoming extinct 

 there under stress of competition with higher forms, it 

 now survives only in these two widely separated insular 

 areas. 



It was an endless amusement to me during those long 

 centuries, while I devoted myself entirely to the task of 

 watching my fauna and flora develop itself, to look out 

 from day to day for any chance arrival by wind or 

 waves, and to follow the course of its subsequent vicissi- 

 tudes and evolution. In a great many cases, especially 

 at first, the new-comer found no niche ready for it in the 

 established order of things on the islands, and was fain 

 at last, after a hard struggle, to retire for ever from the 

 unequal contest. But often enough, too, he made a 

 gallant fight for it, and, adapting himself rapidly to his 

 new environment, changed his form and habits with 

 surprising facility. For natural selection, I found, is a 

 hard schoolmaster. If you happen to fit your place in 

 the world, you live and thrive, but if you don't happen 

 to fit it, to the wall with you without quarter. Thus 

 sometimes I would see a small canary beetle quickly 

 take to new food and new modes of life on my islands 

 under my very eyes, so that in a century or so I judged 

 him myself worthy of the distinction of a separate 



o 



