XVI LITTORAL AND INLAND PLANTS' RELATIONSHIP 163 



inland Tahitian form of that tree, and is to all appearance a 

 derivative of it. It is chiefly distinguished by its thinner, more 

 hairy leaves, which taper at each end and are not subcordate at the 

 base as is often the case with the leaves of G. speciosa. The 

 coverings of the fruit are less fibrous and the putamen is not 

 so deeply notched or grooved. The difference also extends to 

 the buoyancy of the fruits in accordance with the principle laid 

 down in Chapter IL Whilst those of G. speciosa float for many 

 months and are of common occurrence amongst the stranded drift 

 of tropical beaches, as for instance in the Keeling Islands, in the 

 Solomon Group, and in Fiji, those of the inland species float only 

 for a few weeks, their softer coverings decaying more rapidly 

 in sea-water. 



We seem therefore to have had two principles at work in Fiji 

 in determining the origin of the inland species of Guettarda. 

 Whilst in one case the inland species is so sharply distinguished 

 from the coast species as to require the independent agency of 

 frugivorous birds to explain its presence, in the other the inland 

 form, as in the instance also of the Tahitian variety, is so much 

 akin to it that the probability of derivation from it is very great. 



Section VI. 



In this section are contained genera possessing littoral species 

 restricted to the Western Pacific islands, and dispersed by birds, 

 but having little or no capacity for dispersal by the currents. 

 They are regarded as derived from the inland species of the genus 

 in the western part of the Pacific, and as distributed from thence 

 over the islands in that part of the ocean. We are here only 

 concerned with Fiji, Tonga, and Samoa and the neighbouring 

 islands. The genera Eugenia, Drymispermum, and Acacia are 

 here comprised. 



The genus Eugenia, though essentially inland in its station, is 

 apt to lend species to the beach-flora in different parts of the 

 tropics. Such species, being dispersed by frugivorous birds and 

 other animals, and possessing but slight capacity for distribution 

 by the currents, are usually restricted in their areas. Thus, 

 Schimper (p. 118) names two or three species, including E. 

 javanica, as amongst the Indo-Malayan strand-flora. Ridley 

 notices that E. grandis is a common sea-shore tree in the Malay 

 peninsula ; and the author observed two littoral trees of the genus 



M 2 



