326 ORIGIN OF LIFE IN AMEEICA 



than they are at present. Even Mr. Guppy, however, some- 

 times relents and partly withdraws from his precepts when 

 confronted by really difficult cases of distribution. Thus he 

 acknowledges that the conifer Dammara vitiensis, which grows 

 on the Fiji islands, is unfitted for accidental dispersal by any 

 of the known modes of conveyance. The genus Dammara is 

 confined to New Zealand, eastern Australia, New Caledonia, 

 the New Hebrides and Fiji islands. From this region it ex- 

 tends westward to Java and Borneo, the centre of distribution 

 being in the western Pacific. The absence of the genus from the 

 neighbouring Samoan and Tongan groups is, as Mr. Guppy * 

 remarks, very significant, and it is evident that the ordinary 

 agencies of dispersal by birds, winds or currents have here 

 failed to extend Dammara over a few hundred miles of sea. 

 For once Mr. Guppy concedes, therefore, that the present 

 relations of land and sea do change sometimes, and that, 

 " nolens volens," we must admit that Dammara may well be 

 cited in support of any continental hypothesis affecting the 

 western Pacific. Later on, in fact, he expresses the opinion 

 that the Fiji islands mark the site of a Mesozoic continental 

 area in this region. 



There is thus a certain amount of distributional evidence 

 in favour of the theory of the existence of a large land sur- 

 face in the western Pacific. Whether the remainder of that 

 ocean was ever completely occupied by land is a more difficult 

 question to answer. But even on the distant Marquesas, 

 islands granites and gneisses occur, as I mentioned before. 

 In the tuffs of the Kermadec islands numerous boulders of 

 hornblende granite have been found. New Caledonia consists 

 of an ancient series of mica schists and slates with a general 

 north-easterly strike. There are also shales containing fossils 

 identical with those of the New Zealand Trias, followed by beds 

 of coal of Jurassic age. Gneisses, crystalline'limestones and 

 serpentines, like those of New Caledonia, are reported from the 

 New Hebrides. Crystalline schists, granular limestone, 

 granite, diorite and gabbro have been discovered on the Fiji 

 islands. The occurrence on the Tonga group of fragments 

 of garnet, tourmaline and uralitic gabbro suggests the close 



* Guppy, H. B., "A Naturalist in the Pacific," n., pp. 297—306. 



