404 Professor J. W. Gregory — 



quotes Colonel Godwin Austen as adopting the same explanation 

 for the gneiss boulders along the bed of the Jhelum above TJri. 



The evidence of the low-level boulders in North- Western India 

 is apparently not conclusive of any form of glacier action. They 

 were interpreted as implying, at the most, only ice rafts carried 

 by floods ; and Middlemiss has shown that this hypothesis is 

 unnecessary. 



An analogous claim has been advanced for Eastern Bengal by 

 Mr. La Touche (1910, pp. 198-9). He explains the sheets of 

 alluvium, 100 feet above present river-level, which form the 

 Madhupur Jungle north of Dacca, as deposited by rivers choked with 

 silt during the melting of the ice at the end of Glacial times. He 

 claimed that they are as truly relics of the Glacial period as 

 moraines. This evidence is, however, inferential and does not 

 give any definite indication as to the level reached by the ice 

 which fed the silt-charged rivers. 



Biological evidence. — A climatic change in India during recent 

 geological times, which would have enabled ice to exist in Northern 

 India at lower levels than its existing limits, is indicated by various 

 outliers of the Himalayan fauna and flora on the hills of Southern 

 and Central India. Instances of Himalayan plants on Mount 

 Parasnath in Chota-Nagpur, and in South India have been well known 

 since the time of Hooker. The example that probably gives the 

 most precise evidence is the Sikkim Lizard, Lygosoma sikkimense 

 (Blyth), now found living on Parasnath to the south of the Ganges 

 plain. Dr. Annandale (1912, pp. 46-8) has summarized and 

 explained its evidence. This lizard is not known to descend lower 

 than the level of 3,000 feet, and owing to its life-history it would 

 appear impossible for it to have spread under existing climatic 

 conditions, from the Himalaya to Parasnath across the low dry 

 plains of the Ganges, for the lizard lays its eggs in wet moss on 

 tree trunks during the rains. Tet a colony is now isolated on 

 Parasnath, 200 miles from its main habitat. Dr. Annandale 

 considers this occurrence as evidence that during the Glacial period 

 the humidity in the Ganges plains was much greater than at present. 



6. The Age of the Sikkim Gorges. 

 The occurrence of the glaciated surface at Chakung affords 

 a useful measure of the age of the lower parts of the Sikkim gorges. 

 The general structure of this part of Sikkim is a peneplane sloping 

 southward to the valley, which runs east and west, and is traversed 

 by the lower Rangit and the Rumman Rivers. The peneplane 

 (Fig. 3) was at the level of about 7,000 feet at Pemionchi, and 

 sloped down to about 5,000 feet along the Rangit-Rumman line, 

 where it was joined by the slope northward down from Darjeeling. 

 The Sikkim peneplane has been dissected by old broad valleys, on 

 the floors of which are a series of narrow, steep-sided gorges. As 

 Professor Garwood (1903, p. 295) has shown, the valley system and 

 larger valleys are of great antiquity, while the gorges are relatively 

 young. The gorges are being rapidly deepened by the corrosion 

 of their beds by the torrential rivers; the valleys are being 



