XXVII THE ABSENTEES FROM TAHITI 389 



where the stone or seed is an inch in size and over, are absent from 

 Tahiti. Thus the genera Canarium, Dracontomelon, Myristica, 

 Sterculia, and others, of which the three first-named are known to 

 be dispersed by fruit-pigeons, have not advanced into the Pacific 

 eastward of the Fijian region. We miss in the Tahitian islands the 

 large-fruited palms of Fiji, such as the Veitchias with fruits two to 

 two and a half inches (5 to 6 cm.) long, and we find in their place 

 a Ptychosperma, evidently very rare, and the widely spread 

 Pritchardia pacifica, that may have been introduced by man, both 

 with drupes not far exceeding half an inch (r2 cm.) in size. The 

 islands of the Tahitian region also lack the Coniferse ; and genera 

 like Dammara, Dacrydium, and Podocarpus that give such a 

 character to the Fijian forests are not to be found. In this region 

 we do not find many of the large-seeded Leguminous genera, such 

 as Cynometra, Storckiella, and Afzelia, that occur in Fiji, the only 

 large-seeded genera that it possesses being such as are brought by 

 the currents, namely, Mucuna, Strongylodon, Caesalpinia. The 

 difficulties presented by the occurrence of the inland species of 

 Canavalia and Mezoneuron in Hawaii do not offer themselves in 

 Tahiti (see Chapter XV). Tahiti also lacks, as often before 

 observed, the mangroves and most of the plants of the mangrove- 

 formation. 



As above remarked, the Fijian trees with large " stones " and 

 heavy seeds an inch in size are not to be reckoned amongst the 

 indigenous Tahitian plants, " size " being an important determining 

 factor in the exclusion. The occurrence of Elseocarpus in Rarotonga 

 presents no real difficulty, as I have explained in Chapter XXVI. 

 An apparent exception is presented by the existence in Tahiti of 

 Calophyllum spectabile, where the stones are about an inch across ; 

 but since its fruits can float in sea-water for nearly a month, and on 

 account of the value placed on its timber by the Polynesians, we 

 cannot altogether exclude the agencies of man and the currents. 

 One seeming exception is also offered by the presence of Serianthes 

 myriadenia, a tree which in Fiji grows both in the forests and on 

 the banks of the tidal estuaries. Its seeds, which are six to seven- 

 tenths of an inch (15 to 18 mm.) in length, have no buoyancy, and 

 the pods float only two or three weeks. The case of Lepinia 

 tahitensis is alluded to elsewhere, but it may be added that these 

 and other difficulties await further investigation. 



A great many Fijian plants are not found in the Tahitian 

 region, such as Micromelum, those of the order Meliaceae, the 

 Melastomaceous genus Medinilla, Myrmecodia, Ophiorrhiza, &c., 



