The land-bridge theory in botany with particular reference to tropical plants

This essay was primarily made as a background study for a lecture on ‘Transpacific Floristic Affinities, particularly in the Tropical Zone’ in a symposium on ‘Pacific Basin Biogeography: Tropical Relationships’ at the 10th Pacific Science Congress, Honolulu, August 1961 ¹). The occasion was a welcome challenge to crystallize my knowledge and views on the fascinating subject of the Indo-Pacific plant geography which has occupied my thoughts for several decades. Besides, as a corollary of plant-geographical studies on the Malaysian flora, my interest in it was distinctly restimulated by the compilation of maps of Pacific plants for the work ‘Pacific Plant Areas’.