34 DERIVATION OF THE FLORA OF HAWAII 



CONCLUSION 



It is evident, however they may have reached the islands, that the 

 majority of both the animals and plants of Hawaii have been derived 

 from the regions of the Southern Pacific, and have relatively little in com- 

 mon with the shores of the North Pacific, the nearest mainland. 



While the. ancestors of some of the species may have been introduced 

 through the agency of wind or ocean currents, or by migrating birds, 

 there are many more species, both plants and animals, whose transport 

 over the great expanse of ocean lying between Hawaii and the nearest 

 source of origin seems beyond the possibility of any known agency. The 

 presence of these species can best be explained by the assumption of some 

 former more or less direct land connection between Hawaii and the Indo- 

 Malayan region. 



There is evidence of a great extension in comparatively recent time 

 of the areas now occupied by the Marshall and Caroline Islands lying to 

 the southwest of the Hawaiian Archipelago, between them and the Malay 

 Archipelago; and this may point to a much more extensive land area at 

 some earlier period. While much of the ocean between Hawaii and the 

 South Pacific is 10,000 to 15,000 feet in depth, it is much shallower than 

 that between Hawaii and North America. While a subsidence of such 

 extent might seem improbable, the great time that has elapsed since the 

 Tertiary would make this quite possible, even if it took place very slowly. 



It is quite conceivable that very extensive subsidence occurred in the 

 Pacific during Tertiary times, coincident with the enormous elevation of 

 the land in western America, during which the great cordillera of North 

 and South America was thrown up. 



The evidence furnished by the existing fauna and flora is very 

 strongly in favor of the view that the Hawaiian Archipelago represents 

 the remains of the northern extension of some large land mass, connected 

 quite closely with the lands of the Southern Pacific. Polynesia, as a 

 whole, may be regarded as the fragments of one or more such submerged 

 continental masses, upon which, as they subsided, have been superim- 

 posed the volcanic islands which now exist. 



