Chap. VI.] superficial deposits and soils. 137 



look like areas which have been tenanted by animal life solely^ or to the 



greatest extent. 



Regur is principally devoted to the cultivation of cotton and other 



dry crops, but experience shows that the most luxu- 

 Agricultural value. 



riant crops are not raised on the very pure or black 



variety, but rather on a soil of medium quality, in which kunkur 

 particles are distinctly visible, and which is of a blackish-brown or black- 

 ish-grey colour. This fact is recognized by M. D^Archiac in his Ilistoire 

 des progres cle la Geologie (Vol. 3, page 329), in which it is stated that 

 cotton-soil is fitter for cotton cultivation in proportion to the quantity 

 of lime which it contains.* 



IV. The least important of the four classes of soils we have de- 

 fined is that of the mixed soils which occupy a small 

 Mixed soils. 



area, comparatively speaking, in the country we 



treat of. We include in this class the various transitions between red, 

 black, sandy, and white soils and vegetable mould. 



These transitions are generally met with at the borders of great 

 spreads of the several pure soils which commonly appear to graduate into 

 each other, a process greatly assisted by the turning up of the soils iu 

 agricultural processes. 



In many cases the transition is very gradual and insensible, and 

 it is often very difficult to decide what to consider as an impure variety 

 of a pure soil, or what to class at once as a mixed soil. 



In -connection with the regur, two classes of mixed varieties may 

 be established. 



* This may possibly be, to some extent, comiectccl witli the fact before adverted to, of the 

 blackest and purest regur occurring at the higher levels, and being therefore not so well 

 situated for retaining the requisite amount of moisture. "WTiere brought under in i"-ation 

 the black soil always appeared to me to be highly productive. ^R, C P, 



s ( 359 ) 



