xix THE PHYSICAL CONDITIONS 217 



the average annual fall would be less than 80 or 90 inches, except 

 perhaps in the Undu Promontory, whilst on the lava-bound coast 

 of the west or lee side of Hawaii, it may be reduced to 20 inches 

 and less. There is no doubt that this was to some extent the case 

 in pre-European times, since Fiji must have possessed for ages, on 

 the northern sides of the larger islands, its arid " talasinga " or 

 " sun-burnt " plains ; and in the island of Hawaii there must have 

 always been vast, scantily vegetated lava fields at the sea-border. 

 It is probable, however, that it is in the older islands of the 

 Hawaiian group, those where the volcanic forces have been long 

 extinct, that the rainfall has been chiefly affected by deforestation. 

 Speaking generally, in pre-European times the climatic conditions 

 of the lower levels of the group, that is below 4,000 feet, which are 

 alone comparable with Fiji, were less contrasted with the climatic 

 conditions of the Fijian islands than they are at present. By reason 

 of their great elevation, the Hawaiian islands present a mountain 

 climate not found in Fiji, and scantily represented in Tahiti. It is, 

 therefore, in the flora of the Hawaiian uplands that we should 

 expect to find the great distinguishing feature between that group 

 and Fiji. 



Summary of the Chapter. 



(1) Whilst the winds and the currents have been working 

 tranquilly through the ages, bringing always the same vascular 

 cryptogams and shore-plants to the Pacific islands, the bird has 

 ever been a disturbing factor in the inland flora, and changes often 

 of a revolutionary character have taken place from time to time 

 within the forest-zone. 



(2) In the discussion of the inland plants of these islands, the 

 Fijian, Tahitian and Hawaiian areas are taken as centres of develop- 

 ment and dispersal, and as including the groups around. 



(3) On account of the contrast in physical conditions presented 

 by these archipelagoes, differences with which some of the most 

 distinctive features of the floras are to be connected, a com- 

 parison of the islands from this standpoint is first necessary. 



(4) Since the largest islands of the Fijian and Hawaiian areas 

 are from five to ten times the size of Tahiti, the largest island of 

 the Tahitian region, we would expect to find in the two first-named 

 groups a much more varied flora. 



(5) There are three huge mountain-masses in the Hawaiian 

 group which rise to between 10,000 and 14,000 feet, and there is in 



