INTRODUCTORY ESSAY. 93 



full growth of individuals on the one hand, and that exclude 

 gregarious species on the other. In the more humid jungles 

 of the luxuriantly clothed parts of India, a very few species 

 are to be found in close contiguity, but many in a moderately 

 large area. In the drier and hilly districts of Central India 

 we have found it difficult, especially in winter, to collect 150 

 species in a walk of several miles, and this where there was no 

 apparent want of trees, shrubs, or herbs. On the other hand, 

 during the rains we have, in the Panjab, collected eighty 

 species, chiefly of tropical annuals, in an area of a hundred 

 yards square; these, . however, were brought together by local 

 circumstances, and the total Flora of the country for ten 

 miles around the same spot probably comprised less than 800 

 species. At 4-5000 feet elevation in the Khasia we have col- 

 lected upwards of fifty species of Graminea alone, in an eight 

 miles' walk, and twenty to thirty Orchidea; but these are quite 

 exceptional cases. 



There is almost a total absence of absolutely local plants in 

 India, at least so far as our experience serves us ; but in say- 

 ing this, we are only giving the result of general impressions, 

 and of comparing the contents of our collections with those 

 of other travellers, and with the statements of trustworthy bo- 

 tanists in Australia and South America. 



Before dismissing this branch of our subject, we may men- 

 tion that the general physiognomy of the greater part of the 

 Indian Flora probably approximates more to that of Tropical 

 Africa than to any other part of the globe, accompanying in 

 both cases immense alluvial plains, bounded by deserts at cer- 

 tain points, and traversed by mountain-chains of moderate 

 elevation. The more loosely timbered drier regions probably 

 assimilate very much to the districts of Senegal, Upper Egypt, 

 and Abyssinia ; the west shores of the Madras peninsula, and 

 the whole Malayan peninsula to the tropical African coasts ; 

 and the deserts of Sind to those of North Africa. 



Besides the absence of great forests, there is in India no 

 representative of the Catingas of Brazil, the Pampas of South 



