34 RELATION BETWEEN CLIMATE AND VEGETATION. 



parallels thaii* those of any other, and this, indeed, was to be 

 expected from the fact that the ocean forms a ready medium for 

 their transmission from one country to another by means of tides, 

 Avinds, and currents, while at tlie same time their seeds, unlike 

 tliose of most other plants, are not injured by immersion in salt 

 water. Most of the shrubs which inliabit the muddy shores of 

 the sea and of the salt lagoons which are so numerous towards 

 the north of the island, and which are known by the name of 

 Mangroves, belong to that natural order of plants which botanists 

 call Rhizophoreae, a tribe which is strictly intertropical. My 

 researches have already yielded me about half a dozen species, all 

 of which, I find, are common to Ceylon, the shores of the con- 

 tinent of India, and of those of the Eastern islands ; and the 

 same I find to be the case with a few other shrubs belonging to 

 other tribes, such as .iEgiceras fragrans, which extends even to 

 the shores of Australia, Epithinia Malayana, Pemphis acidula, 

 Dilivaria ilicifolia, Lumnitzera racemosa, Thespesia populnea 

 (the Tulip-tree of Ceylon), and Paritium tiliaceum, the last 

 having a far more extensive geographical range tiian any of the 

 others, as I possess specimens in my herbarium from the shores 

 of the West Indies, Brazil, and the Sandwich Islands, besides 

 from various parts of India. The Cocoa-nut tree, which gives 

 so marked a feature to the west coast of Ceylon, and which is 

 now so generally cultivated along the shores of all intertropical 

 countries, is essentially a seaside plant, and has as good claims to 

 be considered indigenous to Ceylon as to any other pait of the 

 world. The same observations that apply to the shrubs of our 

 shores, apply also to the herbaceous vegetation. 



The great flat tract which extends between the sea-shore and 

 the central mountain range is possessed of a very extensive 

 Flora ; but as its general character is stamped by a few^ species 

 which are very numerous in individuals, it is to them chiefly that 

 my remarks will extend. In this tract a very great proportion 

 of the species are identical with those of similar ones on the 

 coasts of Coromandel and Malabar. The generally acid nature 

 of its soil, together with its much drier climate than that of the 

 interior, is well shown in the Northern Province, especially by 

 the more wiry and stunted nature of the trees and bushes, their 

 prickly stems and brandies, and the smaller size of their leaves, 

 together with a much greater proportion of fleshy shrubs, such 

 as Euphorbias, &c. The species whicli preponderate in indi- 

 viduals in the northern province, are different kinds of Acacia, 

 mostly very thorny ; the Wood Apple (Feronia elephantum), 

 Limonia alata, Salvadora persica (the true Mustard-tree of 

 Scripture, a tree which extends northward and westward to the 

 Holy Land, and which I was the first to point out as a nati\e of 



