xxv SAPINDUS AND PHYLLANTHUS 325 



de novo the dispersion of man in the Pacific from the standpoint of 

 plant-dispersal (see Chapter XXVIII). 



SAPINDUS AND PHYLLANTHUS. 



Brief reference can alone be made to these two genera. Fore- 

 most comes Sapindus, which is represented by two endemic species, 

 one in Hawaii and one in Fiji, and by another species, found in 

 Tahiti, the Marquesas, and Easter Island, which is identified by 

 some botanists with the well-known American " soap-tree," S. 

 saponaria. There are several difficulties connected with the 

 presence of this genus of the Old and New World in the Pacific. 

 Not the least of them is connected with the transport of the large 

 seeds of this genus, an inch in size, to the isolated Hawaiian Group, 

 where it is represented by a solitary endemic species in the island 

 of Oahu. The fleshy mesocarp of the fruits might attract birds ; 

 but it is not easy to perceive how birds could carry such large seeds 

 over some 1,500 or 2,000 miles of ocean. Yet the same difficulty 

 exists with a few other genera, such as Osmanthus and Sideroxylon, 

 that are only represented in Hawaii by endemic species, genera 

 which require the agency of birds to explain their occurrence 

 unless we wish to postulate a continental connection for this group. 

 (See under those genera in Chapter XXVII.) 



The large Euphorbiaceous genus Phyllanthus, spread uni- 

 versally over the tropics and containing some 500 known species, 

 clearly indicates by its distribution in the Pacific islands that 

 genera with dry fruits, such as are typical of the order, are as 

 widely distributed and just as much at home in these islands as 

 the genera with fleshy fruits, such as Psychotria and Cyrtandra. 

 The small trees and shrubs of Phyllanthus are common in dry, 

 open, partially wooded districts near the sea-border. The genus 

 attains its greatest development in this ocean in New Caledonia 

 and Fiji ; and since the number of species diminishes the further we 

 penetrate the Pacific, it can be scarcely doubted that the genus has 

 entered this ocean from the west. In Fiji there are at least 20 

 species, of which probably half are not recorded from elsewhere. 

 In Samoa there are seemingly but few peculiar species. In 

 Hawaii there is only one indigenous species, and that is endemic. 

 The genus, however, has developed a lesser centre of distribution 

 in East Polynesia, there being about a dozen species known from 

 Tahiti and the Marquesas, of which half are peculiar to one 

 or other of those groups. From experiments made by me in Fiji 



