THE ORIGIN OF OUR ENGLISH SCENERY. 
65 
a cartilaginous strap, bearing a long series of teeth, is capable 
of a rasping or scraping motion, and this tool he thinks quite 
capable of producing small cavities in limestone rocks. At the 
same time, it must be observed that we want more positive 
proofs of the boring action of snails. 
There are some other minor features which deserve a passing 
notice. The occurrence of large masses of loose rock may be 
due to the jointage of beds and their being weathered out in 
situ. Other rocks may jut out naturally and be weathered into 
fantastic shapes, and not only pluvial action may influence 
them, but in some cases wind carrying sand has exerted great 
power in furrowing or in polishing rocks. 
Most of the palaeozoic rocks, and the igneous rocks and 
granites, jut out here and there on the hill-sides, and form often 
a rough barren country, when they yield little or no soil. Large 
blocks of stone may also have been brought from a distance by 
a glacier or iceberg and so deposited. 
It may be thought that the effects of the sea have been rather 
neglected in this sketch, but it is by no means wished to de- 
tract from its power. The shape of the British Isles is in a 
great measure, although not entirely, due to its action; the 
irregularities being for the most part produced by the alterna- 
tion of hard and soft rocks, the former constituting the head- 
lands, the latter the bays. The effects of submergence have 
in some cases allowed the sea to encroach and modify valleys 
previously formed by river-action. This action, as we have 
noted, tends to check the denudation by rivers. While, on the 
contrary, a fact pointed out by Professor Geikie, “ as the land 
rises the cliffs are removed from the reach of the breakers, and 
a more sloping beach is produced, on which the sea cannot act 
with the same potency as when it beats against a cliff-line;” 
and this action promotes subaerial denudation. 
The set of the tides and currents will tend to influence the 
configuration of the coast-line and promote the travelling of 
beaches. In some cases the flow of rivers is checked or diverted 
for a distance by this action. This is notable on the south 
coast of England, between Exmouth and Portland. The origin 
of the Chesil Bank forms an interesting study, and, indeed, 
requires special explanation. Its isolation from the mainland, 
according to the researches of Messrs. Bristow and Whitaker, is 
due to the subsequent subaerial denudation of the land which 
intervened, and which area is now occupied by the Fleet. 
Hillocks of blown sand are produced where there is a great 
expanse of sand at low tide, subject to the influence of the pre- 
valent winds blowing inland. 
In summing up the causes of denudation and their effects 
upon scenery, it may be remarked that there has been a great 
VOL. XIV. NO. LIV. F 
