INTRODUCTORY ESSAY. 41 



Applying this view to the Indian Flora, we may illustrate 

 it by assuming, as an example, that the majority of the many 

 plants common to the Himalaya and Java migrated over con- 

 tinuous intervening land, which has been broken up by geo- 

 logical causes, chiefly by subsidence ; just as the partial sub- 

 sidence of Java itself would effect a further dismemberment 

 of an area now continuously peopled with plants, and which 

 would result in a cluster of islets, having a vegetation in com- 

 mon. Extending this idea of submergence and emergence of 

 land, one island may at difierent epochs have been continuous 

 with difierent continents, from all of which it may have re- 

 ceived immigrants. We are very far from denying the active 

 agency of the winds and of animals in aiding distribution, 

 and, to a limited extent, of oceanic currents also ; but all the 

 phenomena of geographical distribution, when carefully stu- 

 died, are so uniform in their nature, and so harmonious, as to 

 demand some far higher and more comprehensive agent than 

 the desultory and intermittent motions of the elements or of 

 animals, to produce the present grouping of plants. 



There is a very curious theoretical point bearing iipon the 

 distribution of species, first enunciated, we believe, by a most 

 accomplished observer, Dean Herbert, and which, we think, 

 has never been sufiiciently appreciated or followed out ; it is, 

 that species in general do not grow where they like best, but 

 where they can best find room. Plants, in a state of nature, 

 are always warring vrith one another, contending for the 

 monopoly of the soil, — the stronger ejecting the weaker, — 

 the more vigorous overgrowing and killing the more delicate. 

 Every modification of climate, every disturbance of the soil, 

 every interference with the existiag vegetation of an area, fa- 

 vours some species at the expense of others. The life of a 

 plant is as much one of strife as that of an animal, with this 



cannot too strongly recommend this able and original essay to the study of our 

 readers, as the most important contribution to the philosophy of distribution 

 that has ever appeared. We consider the principles embodied to be soimd, of 

 universal appUoation, and as necessary to be understood by the student of nature 

 as are the laws of climate and the distribution of heat and cold. 



