194 Outlines of Geology. 



the den. Cnvier seems inclined to suppose, that the era of these 

 animals was of a later date than that of the mammoth, and as there 

 is no appearance of any sudden catastrophe having attended their 

 sepulture, and as they are unaccompanied by the bones of marine 

 animals, he also thinks that they lived and died in the caverns which 

 now contain their remains. " Each cavern, it has been supposed, in 

 the extensive chain of the Hartz and Hungarian mountains, was the 

 den of a single despot, who sallied forth to prey upon the defence- 

 less inhabitants of those woods which in later times, after men had 

 become masters of the world, were called the Hyrcinian Forest." 



Perhaps the most remarkable unknown species of fossil animal, 

 is the elk of Iceland, to Avhich I ought before to have adverted ; 

 it differs from our present elk, and from the rein-deer, in the size 

 and conformation of its horns, the largest horns of living elks not 

 being more than half the size of those found in a fossil state. 

 But Mr. Weaver has rendered it probable that these remains are 

 not antediluvian. 



But if there be a difficulty, and a great one there is, in account- 

 ing in any plausible manner for the accumulations of bones and 

 remains of animals of species now extinct, and in climates and 

 countries apparently foreign to their habits and constitutions, 

 there also are great difficulties in framing a theory to account for 

 the alternations of salt and fresh-water shells, and for those pro- 

 digious accumulations of pebbles and rounded fragments consti- 

 tuting the beds of gravel that are incumbent upon the clay, and of 

 which London and its vicinity presents us with such numerous and 

 often interesting instances. 



I have already adverted to the notion of the alternate inroads 

 and retreats of the sea, combined with the occasional existence of 

 fresh-water lakes, as having been assumed as the most easy me- 

 thod of accounting for the alternations of shells and deposits that 

 have been discovered in the vicinity of Paris, and in the Isle of 

 Wight ; but this hypothesis is open to unbounded objections ; the 

 beds containing the different deposits closely resemble each other ; 

 the marine limestone and the fresh -water limestone, the marine 

 clay and the fresh-water clay, and the marine grit and the fresh- 



