5i8 A NATURALIST IN THE PACIFIC chap. 



characteristic of Hawaii, are also to be found in the Tahitian 

 region, but they are absent from the Fijian area. Chiefly American 

 in their affinities, their dispersion over the Pacific took place during 

 the Tertiary submergence of the archipelagoes of the Western 

 Pacific, in which are included the groups of the Fijian area (Fiji, 

 Samoa, Tonga). These early forms of Compositae and Lobeliacese 

 are often arborescent in habit ; and it is observed that Tree- 

 Lobelias also occur high up the slopes of lofty mountains in 

 tropical regions, as in Equatorial Africa, under conditions similar 

 to those prevailing on the slopes of the Hawaiian mountains, 

 where the Tree-Lobelias, termed by Dr. Hillebrand " the pride of 

 our flora," abound. 



The other Hawaiian endemic genera, marking the first chapter 

 in the history of the flowering plants, arrange themselves in two 

 groups, one chiefly American in general affinities, and containing 

 highly differentiated Caryophyllaceae, Labiatae, &c. ; the other 

 largely Malayan, and indicating the close of the first era of the 

 flowering plants, when the main source of the plants was shifted 

 from America to the Old World. The Fijian endemic genera, 

 which are few in number, miscellaneous in appearance, and dis- 

 connected in character, are regarded as having probably acquired 

 their endemic reputation through their failure at their sources in 

 the regions to the west. 



The second era of the flowering plants is indicated by the non- 

 endemic genera. Here we are concerned on the one hand with a 

 mountainous flora mainly Hawaiian, in which genera from the 

 New Zealand and Antarctic floras take a conspicuous part, and 

 on the other with a low-level flora chiefly derived from Indo- 

 Malaya, and including the plants of the lower slopes of Hawaii 

 below 4,000 and 5,000 feet, and the floras in mass of Fiji and 

 Tahiti. 



On account of their lower altitude, the extensive mountain 

 flora of Hawaii is but scantily developed in Tahiti, and is repre- 

 sented by a mere remnant in Fiji and Samoa. Two-thirds of the 

 Hawaiian non-endemic mountain genera contain only species 

 restricted to the group, and, although amongst these disconnected 

 genera, Acaena, Gunnera, Coprosma, Lagenophora, &c, of the 

 New Zealand and Antarctic floras take a prominent part, a large 

 proportion of the genera like Ranunculus, Rubus, Artemisia, 

 Vaccinium, and Plantago represent generally the flora of the 

 north temperate zone on the summits of tropical mountains. 

 The Tahitian mountain flora, scanty as it is when judged by 



