160 FLOKA INDICA. 



Vuidhia on the south, the Ganges and its tributaries flow 

 through a broad plain, uninteiTupted by any inequality of 

 surface. The Jumna above and the Ganges below the junc- 

 tion of the two rivers, flow near the southern margin of the 

 plain, occasionally washing the rocky extremities of the hills, 

 which advance from the soiithward, and always at no great 

 distance from them, so that the greater part of the plain lies 

 to the north, between these rivers and the Himalaya. As far 

 as the commencement of the delta of the Ganges, its surface 

 is characterized by great uniformity of physical character ; it 

 may therefore conveniently be regarded as one botanical pro- 

 vince, including the districts of Delhi and Agra on the left 

 bank of the Jumna, which adjoin the Rajput states, the Doab 

 between the Jumna and Ganges, and Rohilkhand, Oude, and 

 Benares, with the district of Tirhut, -on the left bank of the 

 Ganges. 



Though the Gangetie plain is not separated from the Pan- 

 jab by any perceptible ridge, the line of separation between 

 the two, which lies very little to the left of the Jumna, 

 between Karnal or Jagadri, and Thanesir, is the most ele- 

 vated part of the plain which lies at the base of the Himalaya. 

 Ambala, on a branch of the Gogra, and Saharanpui', on the 

 left bank of the Jumna, are each about 1000 feet above the 

 level of the sea, and the high lands on the right bank of the 

 Jumna are probably not more than fifty feet higher. Thence 

 the plain slopes very gradually to the sea, with an average 

 fall of about a foot a mile. Agra is 670 feet, Cawnpore 500 

 feet, Allahabad 305 feet, and Benares 265 feet above the level 

 of the sea. 



The mean temperature of the upper Gangetie plain varies 

 from 78° at its lower extremity, to 72^° at Saharanpur, the 

 diminution being mainly caused by the increased cold of the 

 winter months, as the heat of summer is in all parts very 

 great. The rains set in everywhere soon after the sun has 

 attained its most northern limit. The rain-fall is greatest 

 near the Himalaya, and diminishes gradually as we recede 



