BOTANICAL STUDIES IN FIJI — SMITH 315 



of insular regions that have been isolated for a long period. It is 

 probable that both the total number of species and the percentage of 

 endemism will rise sharply with future exploration and study. 



Any consideration of phytogeographical relationships is premature 

 until the floras of the regions under study are thoroughly known, and 

 in the Pacific such complete floristic knowledge is probably a century 

 or two in the future. In the meanwhile, however, botanists can cast 

 considerable light upon the problems of earth movement. A statisti- 

 cal analysis of the Fijian phanerogam flora,^ however incomplete, 

 shows that an overwhelming proportion of Fijian plants has its affini- 

 ties with the plants of Malaysia, and especially those of New Guinea, 

 the Solomon Islands, and the New Hebrides. Only about 5 percent of 

 Fijian species appear to be closely related to groups that are typically 

 New Caledonian or Australian, and only about 3 percent can be con- 

 sidered as belonging to strictly Pacific elements. A very few species 

 have relationships toward New Zealand and what is thought of as an 

 Antarctic element in the Pacific. 



The result of this study, however incomplete and provisional it may 

 be, is to support the hypothesis of land movement in the western 

 Pacific most favored by geologists, namely that Fiji lies near the edge 

 of a once-extended ]\Ielanesian continent that embraced New Guinea 

 and Australia, and that its separation from other parts of the con- 

 tinent did not take place until the Tertiary Era. At this time, accord- 

 ing to paleobotanical studies, the existing families and genera of flow- 

 ering plants were already largely differentiated and often widely dis- 

 tributed. Our studies indicate that the last land connections to be 

 sundered, as the old continent broke up into its present remnants, 

 were those along the Fiji-New Hebrides-Solomon Islands chain. 

 Land connections leadmg from Fiji toward New Caledonia and Aus- 

 tralia must have been broken much earlier, if they ever were well 

 established during the Tertiary. 



In the southwestern Pacific we have, as it were, a laboratory for 

 the study of plant speciation by isolation, and examination of the 

 existing modern floras can be of great significance not only to phyto- 

 geographers but also to geneticists. Experimental biologists would 

 do well to supplement the valuable findings of their laboratory re- 

 search by turning to the far vaster laboratory of the earth's surface, 

 where the evolutionary history of millions of years lies written, to be 

 read in the light of cooperative research by students of all biological 

 disciplines. 



'Smith, A. C, The vegetation and flora of Fiji, Sci. Month., vol. 73, No. 1, 

 pp. 3-15, 1951. 



