136 
COLE : ORIGIN AND FORMATION OF WOLD DALES. 
Appendix C. 
" Mud banks left by the retiring tide imitate in miniature a country 
with hill and dale." — Darwin. 
" The repeated drainage action of the falling tide finds its analogue 
on the land in the drainage action of the falling rain." — Jukes and 
Geikie. 
" So close is the similarity of a system t of drainage established in 
this way to what is found in a large river basin, that those who have 
thought most upon the subject believe that one may be taken to explain 
the other." — Huxley. 
It seems presumptuous to differ from so high authorities as to the 
conclusion drawn ; yet, if I have stated the case fairly in the three 
quotations above given, I confess that I have grave doubts on the sub- 
ject, so far as regards the chalk area, where there are neither running 
streams on the surface of the valleys nor any subterranean, as far as can 
be ascertained, in the same lines. 
Speaking of the Wold dales, Professor Phillips writes : " Where 
several of these valleys meet they produce a very pleasing combination 
of salient and retiring slopes, which resemble, on a grand scale, the 
petty concavities and projections in the actual channel of a river. No 
doubt these valleys were excavated by water, but not by the water of 
rains, or springs, or rivulets." 
It may be interesting to compare with the sketch, Plan A, two 
tracings of Norway fjords (B and C), and one of the river Nidd (D), 
in the Vale of York. 
The two former present several points of similarity to the Wold 
dales, not only as seen in the map, but in reality. The fjords are 
long (as much as 120 miles), sinuous, branching inlets, occupied now by 
the sea, with steep, precipitous sides, and a level bottom beyond the 
sea level, and terminate rapidly and abruptly at the inner extremity. 
Their sides are far steeper than those of the chalk dales, probably from 
the difference of material ; and they also differ in having waterfalls and 
streams at work on the margins. They must have been largely eroded 
by glaciers, and ice action is visible everywhere. If the theory of the 
excavation of rockbasins by ice, as held by Professor Ramsay, is true, 
it may be that their great depth, as compared with the sea outside, is 
due to this cause. Others hold that they are depressed land valleys 
that the North Sea is rapidly filling up, but that the debris has not 
penetrated beyond the bar at their mouth. Anyhow, from the existence 
of sea beaches and shells at a higher level than the tops of the fjords, it 
is certain that, like the dales, they have been subjected at some time to 
.the direct action of the sea ; and, from other proofs, that, like the dales, 
they have been moulded by the grinding action of glaciers. These two 
