SUB-AERIAL FORMATIONS AND SOILS. 251 



The great regur-spreads on the watershed between the Krishna aud 

 Tungabhadra in the Raichur Doab and the great 

 " black plain '^ in the north-eastern part of Dhar- 

 war district, all resting on gneissic rocks of all kinds, are far more 

 extensive and homogeneous than those on the trap north of the Krishna. 

 It is clear, therefore, that regur may, under suitable circumstances, be 

 formed by organic alteration of the primary products of weathering of 

 almost any rock, if they are sufficiently argillaceous in quality. 



Cases in which the regur-spreads are conterminous with the trap 

 rocks may possibly occur, for they do so largely in Central India near 

 Nagpur and Chanda,"^ but a very large number of cases could be 

 adduced where one and the same regur-spread stretches, without break 

 or change, across two or even three groups of rocks of totally different 

 geological age, the trap being one in every case, and yet in these instances 

 the regur is not alluvial, i. e., has not been subjected to more movement 

 than results from pluvial action. 



Very numerous cases were observed of the trap weathering into red, 

 or reddish, or yellowish-browa soils. As the country rises towards the 



* See Memoirs, Gr. S. of I., Vol. VI, p. 235, v, here tlie subject of tlie formation and 

 occurrence of regur is very tersely and clearly handled by Mr, W. T. Blanford. 



The idea that the regurs of Southern India are generally poorer than those of 

 the Deccan trap area and Central India, appears to me to be ill founded, if, in the 

 latter case, I may judge by the appearance of the crops and trees seen from the railway be- 

 tween Jabalpur and Nasik, a route that I have traversed several times during and after 

 the rains. The jowari crops, for instance, grown in the great black plain of Dharwar 

 district, and in the great regur- covered valley of the Khundair in Karnul and Kadapah 

 districts, especially the latter, are far superior to anything seen in the Deccan, or, as far as 

 my observation extended, between Nasik and Jabalpur. The paucity of trees in the Ceded 

 Districts and other Canarese districts is in great measure due to prejudice on the part of the 

 natives, who believe that if they allowed trees to grow plentifully, they would lose all their 

 crops by the huge flocks of mynas and other birds which would then increase prodigiously 

 in number. It should also be borne in mind that several of the largest regur-covered 

 districts iu the south are situated in districts where the rain-faH is far less than one-half of 

 that received in Central India. The fertility of the regur when iri'igated is imrtiensely 

 increased. 



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