CHAPTER XXI 



the eras of the flowering plants 



The Age of Composite. 



The islands of the tropical Pacific as the homes of new genera and new species. 

 — The significance of a large endemic element. — Synopsis of the eras. — The 

 era of endemic genera. — The endemic genera of Compositce. — Their 

 affinities and mode of dispersal. — The mystery of the suspension of the 

 dispersing agencies. — Mr. Bentham's views. — The remnant of an ancient 

 Composite flora in the tropical Pacific. — The dispersion of the Compositae 

 antedates the emergence of the island-groups of the Fijian region at the 

 close of the Tertiary period. — Summary. 



The Endemism of the Pacific Island Floras. 



As far as the production of new species is concerned, the 

 Hawaiian group presents the same contrast with the Fijian and 

 Tahitian groups in respect of the flowering plants that it does as 

 regards the ferns and lycopods. The proportion of endemic species, 

 after excluding all introduced plants, is in Hawaii 80 per cent, in 

 Fiji about 50 per cent., and in Tahiti 35 per cent, (see Table A). 

 The same contrast is also displayed in the number of peculiar 

 genera. In Hawaii there are, according to Dr. Hillebrand, 37 or 

 38, and in Fiji Dr. Seemann discovered 16; whilst, as we learn 

 from Drake del Castillo, there are only 3 or 4 in the Tahitian 

 Islands. (As will be pointed out later on, these numbers for Fiji 

 and Hawaii have to be reduced, but the general inference to be 

 drawn from them is not materially affected ; see Table B.) 



But if we look at the accompanying table (Table B) we notice 

 that the flora of Hawaii is sharply contrasted with those of Fiji 

 and Tahiti not only in the large proportion of endemic genera, but 

 also in the large number of non-endemic genera with peculiar 



