﻿682 MR. H. BUEY ON THE DENUDATION OF [Nov. I9IO, 



subsequent river, in some degree comparable to theFarnham River, 

 which produced the similar gravel of Alice Holt. Whether that 

 subsequent river was already connected with the Aran, or whether 

 it joined one of the original consequent streams which the Aran 

 has since captured, I am unable to say ; but in either case it is to 

 be regarded as an early portion of the Eother, which has steadily 

 suuk down the hill-slope in its pursuit of the retreating Chalk 

 escarpment. How soon it originated, there is nothing to show ; but, 

 from the amount of gravel which has slipped down into Harting 

 Combe (see 16, fig. 3, p. 353), it seems certain that the river once 

 extended farther north, and therefore presumably higher than the 

 present summit of Rogate Common. 



To the north of the Rother Valley is a large Y-shaped area of 

 Weald Clay hemmed in on the north, south, and west by two lines 

 of Lower Greensand hills ; and several tributaries of the Rother, of 

 which the Lod is the largest, rise either in the northern ridge, or 

 in the low-lying clay at its foot, and traverse the southern ridge in 

 comparatively narrow gorges. That this structure is, in a general 

 way, due to an anticline (or anticlines ?) which has brought up the 

 clay into the beds of the transverse rivers, is obvious enough ; but 

 I do not think that the details have been satisfactorily worked out. 

 Topley (26, p. 225) regards this as part of the central line of 

 elevation, continued westwards from Horsham ; but the behaviour of 

 the rivers, both here and in the Horsham district, appears to me to 

 place the central watershed farther north (see fig. 6, p. 670). It is 

 possible that we have to deal with a series of wave-like uplifts, 

 arranged in echelon, and that each wave is traversed, at or near its 

 highest point, by a consequent river ; but I confess that I have no 

 proof of this suggestion to offer. That the folds of this region are 

 numerous was long ago shown by Martin (12), but they are very hard 

 to follow, and little has been done since his day to elucidate them. 



Passing now to the main consequent trunk of the Arun, and 

 following it northwards, we find the next important tributary 

 entering from the west near Wisborough Green, after having drained 

 the eastern slopes of Blackdown : it runs in Weald Clay parallel 

 to the line of Lower Greensand hills round Petworth, and in doing 

 so passes across the north of the V-shaped area of clay already 

 mentioned ; the reason why it does not extend into this area is 

 apparently because the anticline which gave rise to the latter dies 

 away towards it eastern end (see 26, pi. ii). For the rest, this 

 tributary appears to be an ordinary subsequent stream, and as such 

 calls for no further observation. 



Following the consequent river still farther northwards, we come 

 to a point at which the stream splits into two branches, an eastern 

 and a western, about 2 miles south-east of Loxwood (fig. 8, p. 684). 

 Taking the western stream first, we find that it drains the whole 

 eastern slope of Hindhead, as far south as Haslemere, and the 



