No. 31. — 1885.] CEYLON FLORA. 



145 



2,642, which must be much below the actual number. Thus 

 then, when it is remembered that Ceylon is situated in that 

 part of the Oriental area — the Indian — which is poorest in 

 species, its total of native plants— including Ferns, &c., nearly 

 3,000 species — shows decided richness, and is probably 

 greater than that of any part of Peninsular India of the 

 same area. 



5. In one of his admirable Presidential addresses to the 

 Linnean Society of London, the late Mr. Bentham, remark- 

 ing on the fact that no Flora of a tropical country of large 

 extent had yet been completed, added, with regard to 

 Thwaites's enumeration of the plants of Ceylon— then (in 

 1869) lately published, and the only completed Flora of any 

 tropical region — that the chief interest of this isolated dis- 

 trict " would lie in the comparison of its very rich vegetation 

 " with that of other portions of the Tropical Asiatic flora, 

 " which," he added, " has not yet been made." In the follow- 

 ing remarks I purpose to make some progress towards such a 

 comparison, though 1 have not at present the opportunity 

 or the leisure to do so in detail, or as fully as the subject 

 requires. Let us then endeavour to ascertain the elements 

 of which our flora consists. 



The most interesting portion of the vegetation of any 

 country, and especially of islands, is that composed of the 

 plants peculiar to it and not found elsewhere, or as it is called 

 endemic. The proportion of such species is found to vary 

 remarkably in different places, and on this to a chief extent 

 the individuality and interest of any flora depends. In the 

 British Isles, among over 1,400 native species there is pro- 

 bably not one which is peculiar or endemic, though four or 

 five strongly marked local varieties are considered speci- 

 fically distinct by some British botanists. As a contrast, in 

 New Zealand more than 72 per cent, of the species found 

 there are found nowhere else. Between such extremes there 

 is every gradation. It has long been observed that oceanic 

 islands — that is small islands (usually volcanic) widely 

 isolated from continents in the deep ocean — possess a large 

 proportion of endemic species. Thus in Mauritius (inclu- 

 ding Seychelles and Rodriguez) 29 per cent, are peculiar, and 

 22 per cent, more do not extend beyond the other Mas care ne 



