228 



A NATURALIST IN THE PACIFIC 



CHAP. 



therefore, went over the ground again, and found, as shown in the 

 table below, that the percentages of peculiar species amongst the 

 total available for my use were not very far apart, 58 per cent, for 

 the upper region and 43 per cent, for the lower region. 



From the above it would appear that although the process of 

 species-production in the Hawaiian islands has seemingly been 

 rather more active above than below 4,000 feet, if we were to 

 compare the entire vascular cryptogamic flora of Fiji with that of 

 the corresponding lower levels of the Hawaiian group we should 

 obtain much the same contrast in the proportion of peculiar species 

 that we obtained when comparing all the ferns and lycopods of 

 both groups. In other words, if we were to restrict our com- 

 parison with Fiji, and I may add Tahiti, to that lower portion of 

 Hawaii that corresponds in elevation, we should not get results 

 very different from those to be obtained by including the Hawaiian 

 upland regions as well. 



We are, I think, on these grounds justified in assuming that the 

 relatively great development of new species of ferns and lycopods 

 in Hawaii as contrasted with Fiji is not to be connected with the 

 greater elevation of those islands. The only thing that we have 

 been able to associate with the greater altitude of the Hawaiian 

 Islands, and the consequent greater range of climatic conditions, 

 when contrasting the Fijian and Hawaiian vascular cryptogams, is 

 the 'occurrence of a number of peculiar mountain species and of 

 wide-ranging temperate species that are found in the uplands of 

 Hawaii, but not in the less elevated islands of Fiji. 



On the whole, therefore, it is to be inferred that the greater 

 display of formative power among the ferns and lycopods of the 

 Hawaiian Islands is in great part to be associated with the isolation 

 of this group as compared with those of Fiji and Tahiti. The 

 indications supplied by the vascular cryptogams resemble in kind 

 those we shall obtain from the study of the flowering plants, but 

 there is this important distinction. In formative power, as shown 



