264 Plant Life and Evolution 



forces have been at work longer in some of them 

 than in others, and it can be clearly seen that this 

 longer time has been efficient in producing a more 

 varied and specialized flora in the older islands. 



Thus the island of Kauai, the oldest of the group, 

 has many more peculiar species than the very much 

 larger but more recent island Hawaii, which is still 

 in process of formation. The flora of these islands 

 is derived mainly from the Polynesian region to the 

 south, but there are also evidences of some American 

 immigrants. Most of these, however, have become 

 so changed, that of the certainly indigenous species 

 of vascular plants, it has been claimed that over 

 eighty per cent are endemic, i.e., are peculiar to the 

 islands, a proportion probably unequaled in any 

 other region of the world, except perhaps in the very 

 isolated area of Western Australia. 



The Flora of Krakatau. The reestablishment of 

 the vegetation upon the island of Krakatau is an 

 instructive demonstration of the origin of island 

 floras. In 1883, this volcanic island lying in the 

 Straits of Sunda, between Java and Sumatra, was 

 the scene of the most violent volcanic disturbance 

 that has ever been recorded. The greater part of 

 the island was blown into space by the great ex- 

 plosion, and what was left, as well as some of the 

 neighboring islands, was covered deep with hot cin- 

 ders, which completely destroyed all vegetation and 

 left the island a barren desert. 



A visit was made to the island three years later, 



