DESERTS AND THEIR INHABITANTS 
Ir popular errors connected with matters scientific are hard 
to kill, still more is this the case when the erroneous 
opinions have been held by scientists themselves. The 
idea that flints and other stones grow is, I have good 
reason to believe, still far from extinct among the non- 
scientific, and it is not improbable that there are persons 
possessing some acquaintance with science who still cherish 
the belief that deserts are uninterrupted plains of smooth 
sand, originally deposited at the bottom of the sea, from 
which they have been raised at a comparatively recent 
epoch. At any rate, there are several books, published 
not very many years ago, in which it is stated in so many 
words that the Sahara represents the bed of an ancient 
sea, which formerly separated Northern Africa from the 
regions to the southward of the tropics. 
As a matter of fact, these opinions with regard to the 
origin and nature of deserts are scarcely, if at all, less 
erroneous than the deeply ingrained popular superstition 
as to the growth of flints and pudding-stones. And a 
little reflection will show that the idea of the loose sands 
of the desert being a marine deposit must necessarily be 
erroneous. Apart from the difficulty of accounting for the 
accumulation of such vast tracts of sand on the marine 
hypothesis, it will be noticed, in the first place, that desert- 
sands are not stratified in the manner characteristic of 
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