I’ART 4.] 
Medlimlt: The lick Soils of Upper India. 
275 
whole phenomenon of reh was superficial, due to the inefficient circulation of the 
ntmospheric waters under extreme climatal conditions. 
5. The foregoing brief remarks must suffice as a historical summary of the 
reh question. We may now, perhaps, assume that the rational explanation of 
the situation is accepted, or must become so ; and proceed to form an estimate of 
its conditions. Jily remarks here also must be condensed, referring only to 
the leading features; a fuller discussion of some particulars was given in my 
reports to the Aligai'h Committee of 1878. 
G. The only points to which I need take exception in the views set forth in 
the preceding paper, are those from which it might bo inferred that the state of 
things so much to be deplored—no loss, in fact, than the steadily-advancing con¬ 
version of the choicest lands of India into a howling wilderness, such as now 
obtains over the once luxuriant Mesopotamia—that this is inevitable from natural 
causes. I have pointed out these weak points to Mr. Center, and he has permitted 
mo to explain them, rather than undertake to do it himself :—’It is correctly stated 
that under certain conditions of surface configuration, of ground structure, and 
of climate, the local accumulation of .saline deposits must take place ; the instances 
given arc the great land-locked basins of central North America and Asia. 
The first condition may be ignored, as it is immaterial whether the surplus 
waters are concentrated in a local basin or added to the briny deep. 
7. The second condition is important. In several passages of paras. 14, 21, 
and 24 of Mr. Center’s paper, the strata forming the pilains are described as 
horizontal, so that the conditions of drainage approach those of a basin, the 
underground drainage being usually imperceptible. These features of the bhangar 
land are contrasted (para. 24) with those of the khadai* land, where “ the river 
occupies the line of natural drainage of the counti 7 , and its deposits are parallel 
to the line of slope,” underground drainage taking place freely ; and this, although 
the khadar valley is truly described as cut out by recent erosion from the old 
alluvial plain. The small apparent contradiction hero is easily explained: the 
ground surface in the khadar i.s almost always of very recent sandy deposits, 
the surface of actual erosion being confined to the present river channel; but 
there is a real and greater misconception which it is needful to insist upon. 
It is not questioned that the plains themselves are river depo.sits; their 
too, lies appreciably parallel to that of the actual liver beds throughout^ 
so it is not intelligible how the lie, or the compo.sition of the strata, can bo sup¬ 
posed so different from those of the actual rivers. In the process of land 
formation by rivers, of which the plains of India afford such a striking example, 
there does occur partially the production of local basins. From the diluvial zone, 
where the torrents are discharged from the mountains, to the more exclusively 
alluvial region of the delta, a partial sorting process takes place in the river 
deposits. The coarser materials, which in the former position are boulders 
and gravel, and in the latter fine sand, become thrown down wherever the velo¬ 
city is checked and along the margin of overflow, thus forming the banks between 
w'hich the river flows, wdiethor in a single channel or through several distribu¬ 
taries, often at a higher level than adjoining ground separiding the ehannohs. 
Those intra-fluvial areas become for the time swamps or temporary lakes in 
