CHAP. XV THE SANDWICH ISLANDS 321 



the peculiar CerambycidsG could have been introduced by 

 the same means. The absence of so many important and 

 cosmopolitan groups whose size or constitution render them 

 incapable of being thus transmitted over the sea, as well 

 as of many which seem equally well adapted as those 

 which are found in the islands, indicate how rare have been 

 the conditions for successful immigration ; and this is still 

 further emphasised by the extreme specialisation of the 

 fauna, indicating that there has been no repeated 

 immigration of the same species which would tend, as in 

 the case of Bermuda, to preserve the originally intro- 

 duced forms unchanged by the effects of repeated inter- 

 crossing. 



Vegetation of the Sandwich Islands. — The flora of these 

 islands is in many respects so peculiar and remarkable, 

 and so well supplements the information derived from its 

 interesting but scanty fauna, that a brief account of its 

 more striking features will not be out of place ; and we 

 fortunately have a pretty full knowledge of it, owing to 

 the researches of the German botanist Dr. W. Hilde- 

 brand.^ 



Considering their extreme isolation, their uniform 

 volcanic soil, and the large proportion of the chief island 

 which consists of barren lava-fields, the flor of the 

 Sandwich Islands is extremely rich, consisting, so far as at 

 present known, of 844 species of flowering plants and 155 

 ferns. This is considerably richer than the Azores (439 

 Phanerogams and 39 ferns), which though less extensive 

 are perhaps better known, or than the Galapagos (332 

 Phanerogams), which are more strictly comparable, being 

 equally volcanic, while their somewhat smaller area may 

 perhaps be compensated by their proximity to the 

 American continent. Even New Zealand with more than 

 twenty times the area of the Sandwich group, whose soil 

 and climate are much more varied and whose botany has 

 been well explored, has less than twice as many flowering 

 plants (1430 species), and Mr. W. B. Hemsley thinks that 

 this number is probably too high. 



^ Flora of the Hawaiian Islands, by W. Hildebrand, M.D., annotated 

 and publislied after the author's death by W. F. Hildebrand, 1888. 



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