It has appeared, and it is in itself remarkable, that the conclusions drawn by Van Steenis (1936b) from an analysis of the microtherm genera in the Lesser Sunda Islands (see p. 201) are confirmed by the present very much larger survey of the flora. According to Malaysian standards the Lesser Sunda Islands flora is a relatively poor one, of predominantly Asiatic affinity, most closely allied to that of Java, rich in species and genera with wide areas, poor in autochthonous elements (endemics and subendemics), and without any important supplementary Eastern elements which might be expected on the basis of its geographical situation close to the Australian continent. Within the Lesser Sunda Islands the percentage of Westerndistributed elements decreases from Bali eastward to Timor, whereas the number of Eastern elements decreases in the reverse direction. The figure indicating the ratio of the percentages Western to Eastern elements per island decreases markedly from Bali to Lombok but then gradually eastward, which gives a faint indication of a demarcation between Bali and Lombok. There is no significant difference in botanical composition between volcanic and non-volcanic islands. It has appeared that by taking either the genus or the species as the unit for the considerations, the general picture emerging from the analysis is similar in both cases.