166 



FLORA INDICA. 



which 



the western part of the delta. There mangroves, Sonneratia, 

 JEgiceras, and Heritiera, mingled with gigantic grasses and 

 Typha, abound. Nipa fruticans fringes the watercourses, and 

 vast tracts are covered with Phoenix paludosa, an elegant little 

 palm six or eight feet in height. 



The vegetation of Bengal has been well explored. The foun- 

 dation of its flora was laid by Roxburgh, who was appointed 

 in the year 1793 to the superintendence of the Calcutta Bo- 

 tanic Gardens, which, by his labours and those of his distin- 

 guished successors Hamilton and Wallich, became very rich 

 in tropical plants. A complete enumeration of the plants 

 of Bengal is found in Roxburgh's ' Flora Indica/ Griffith's 

 € Itinerary Notes ' and Voigt's ' Hortus Suburbanus ' also con- 

 tain notices of many indigenous species. 



II. The Himalaya. 



To the north of the great plain of Hindostan is situated a 

 mountain-tract of great extent, strictly defined on its plain- 

 ward face, and increasing in elevation as we advance towards 

 the interior. As a whole, this tract is extremely rugged, lofty 

 mountain-chains being separated by deep valleys. Amid the 

 numerous and intricate ramifications of these chains there 

 is considerable difficulty in acquiring a definite idea of the 

 composition of the mass. Superficial observation gives the 

 impression that numerous ranges rise one behind another, 

 the more distant of which are loftier than those in front ; but 

 a nearer approach shows the fallacy of this impression, and 

 proves that the arrangement is much less simple. 



A prodigiously elevated but scarcely known chain traverses 

 Asia from east to west in about 36° N. lat. South of this 

 chain flow two rivers, the Indus and the Brahmaputra, which, 

 rising nearly together, run in directly opposite directions; 

 one nearly west, the other nearly east. Throughout the 

 greater part of their course they preserve these directions, 



