307 
on the Dlsirihution of British Aninials. 
thus distinguished from the older deposits of sand and gravel 
which occur in regular alternating beds. The ablest writers in 
Europe now adopt these distinctions, and would no more think 
of confounding them, than to describe, under the same name, 
gypsum and limestone ^ 
With regard to the second proposition, I think that, to a cer- 
tain point. Dr Fleming's opinions and observations are correct. 
I fully coincide wath him in believing, that the beaver and the 
wolf, like the roebuck, probably the bear, and the Irish elk, 
have gradually disappeared, together with the various species of 
birds, whose expulsion or extirpation he so ably describes, be- 
fore the arrows of the hunter, and the snares of the agricultu- 
rist ; but when he proceeds to apply the same explanation to the 
bones of quadrupeds, imbedded often many fathoms deep in 
masses of drifted clay and gravel, in situations at or near which 
no such deposits are at present taking place, or in caves and fis- 
sures which have been wholly closed, and ^vhose interior has 
been often filled with the detritus of rocks introduced by the 
same sudden and transient inundation, to which alone the exist- 
ence of the superficial deposits in question can be referred, I 
feel obliged to object to the application of' the principle of gra- 
dual extirpation to this part of the subject, and appeal to the 
entire body of phenomena detailed in my Reliquim Diiuvianse, in 
support of my opinion. 
But while I thus contend that there is evidence of a sudden 
and general destruction of animals by a transient inundation of 
the Earth’s surface, I, at the same time, proceed most willingly 
with Dr Fleming to apply his method of illustration, to the ani- 
mals inhabiting the earth antecedently to this great aqueous re- 
volution ; to explain the phenomena of the den at Kirkdale by 
the habits of living hysenas, and to argue on the probable his- 
tory of fossil elephants and hippopotami, from the known ha- 
bits of those which at present inhabit the banks of the Ganges 
or the Niger ; and without tliis practice of illustrating the his- 
tory of the fossil dead by the study of their living representa- 
tives, I could never have arrived at the conclusions I have 
founded on the evidence of the den at Kirkdale. 
* Review of Reliquiae Diluvianae in Silliman’s American Journal of Science,, 
vol, viii. No. 2. p. 3^6. 
