54 THE JfATURAL HISTORY EEYIEW. 



tropical climate, showing as it does that many of the common weeds 

 of our own country have the power of establishing themselves under 

 climatic conditions so very different from our own. Some of the 

 species are, it is true, confined to the upland districts of Jamaica ; 

 but even here the mean annual temperature is high compared with 

 any part of Northern Europe, and the extreme temperatures very 

 feebly contrasted. 



Turning to the elements of the indigenous British West Indian 

 Flora (exclusive of Cryptogams), these may be roughly classed into 

 the Endemic and non-Endemic, the former being quite one-third of 

 the whole ; about 1030 out of 3050 being hitherto found only in the 

 West Indian Islands (British and others). No doubt a certain number 

 of them will yet be discovered on the main land of America ; but, on 

 the other hand, probably a more than counterbalancing number of 

 Endemic species remain to be discovered in the Islands. Whether 

 this proportion represents the Endemic character of the w^hole West 

 Indian Elora or no, it is impossible to say. Cuba and Haiti will no 

 doubt add enormously to the number of peculiar plants ; but on the 

 other hand, such islands as Curacoa and Tobago must contain a 

 large proportion of continental species not found in any of the other 

 Islands. Meanwhile, we are glad to learn, that Dr. Grisebach pro- 

 mises us a work on the distribution of the whole Elora of the West 

 Indies, as far as is known, which will, no doubt, throw great light 

 on the precise relation between the Floras of the several Islands and 

 between these and the neighbouring parts of the Continent. 



Let us now briefly consider this Flora, and compare it with that 

 of other tropical countries. Of the above 2000 indigenous species 

 (or thereabouts), which are common to the West Indies and other 

 countries, 1750 are American exclusively, and about 250 are also 

 natives of the Old World. The latter is a surprisingly small number, 

 considering the great similarity that pervades the vegetation of 

 most tropical littoral climates, and observing how readily so many 

 Asiatic and African trees and shrubs have become naturalized in the 

 islands after being introduced by man. 



When again these 250 extra- American plants are divided into 

 African and Asiatic, another curious fact appears, viz., that notwith- 

 standing the proximity of the West Indies to Africa, and the constant 

 traffic between these countries for upw^ards of three centuries, there 

 are actually fewer plants common to the West Indies and Africa 



