INTRODUCTORY ESSAY. o7 



-Cabul to the Irawadi, which is approximately near that from 

 the Bay of Biscay to the Caspian Sea. The extreme breadth 

 of India along a diagonal line is from Cabul to Malacca, and 

 that is also about the extreme diagonal breadth of Europe from 

 Spain to the northern termination of the Ural mountains at 

 the Arctic Sea. We wish to press these comparisons espe- 

 cially upon the attention of local botanists, and of those more 

 familiar with species of plants than with geography, for the 

 following reason, — that on several occasions, having identified 

 a plant of the lower Himalaya with one that inhabits an ele- 

 vation of 8000 feet in Ceylon, we have been met with expres- 

 sions of surprise and incredulity, by naturalists who do not 

 for a moment hesitate to unite many species of Scotland 

 with those of a sufficient altitude on the Sierra Nevada in 

 South Spain; who habitually quote the Alps and Pyrenees 

 as containing many species in common with Iceland and Nor- 

 way, and even Arctic America ; and who, whilst acknowledging 

 that many of the elements of the Floras of the Pyrenees, Alps, 

 Carpathians, Ural, Norway, Iceland, and Arctic America are 

 identical, are prepared to deny a similar extension of species 

 over the mountains of Ceylon, the Madras peninsula, Khasia, 

 Himalaya, and Java. 



If, on the one hand, we experience opposition to our iden- 

 tifications of species inhabiting localities iu India sundered 

 by considerable areas of land and sea, so, on the other, we 

 find equal or greater difficulty in persuading a large class of 

 our fellow-botanists of the specific identity of Indian plants 

 with those of other better known but more distant countries ; 

 and we have hence felt anxious on this account also, so to ex- 

 tend the limits of our Flora, that we might meet such bota- 

 nists on their own ground as it were, and trace these species 

 continuously from those parts of the world with which they 

 are familiar to those we know best. It is, however, impossible 

 altogether to overcome a proneness of the human mind to 

 regard everything from an unknown country, or that is seen 

 surrounded with foreign associations, as itself unknown, and 



