314 PICTURESQUE SKETCHES 



with an incrustation of carbonate of lime, deposited 

 from water that has filtered in from the limestone 

 rock. The floor of the cave is thus hard, and gives 

 no indication of the fossil riches buried beneath it ; 

 and even where no stalagmitic incrustation exists, the 

 true ancient floor is covered with a thick sediment of 

 soft mud and loam. The general level of the dis- 

 tricts in which the caverns occur has, probably, in 

 most of such cases, undergone slow recent elevation 

 without disturbance. 



In one of the most remarkable of these caves 

 (Kirkdale, in Yorkshire), the appearance, when the 

 mud was removed, is described as resembling the 

 floor of a dog-kennel, being strewed all over from 

 one end to the other with hundreds of teeth and 

 bones of various kinds of animals. These fragments 

 were in greatest abundance near the mouth, that part 

 being the most capacious; but the bones of all kinds 

 of animals were strewed quite irregularly. 



The caverns thus filled with various bones were 

 in many cases the ancient dwelling-places of large 

 Carnivora, such as the hyaena, the lion, the tiger, and 

 the bear: to these spots the temporary owners had 

 brought their prey to devour in secret ; here they lived 

 and died, often from generation to generation, and in 

 these spots we find, written in no obscure language, 

 a portion of the early history of our island after it 

 had acquired its present form, while it was clothed 

 with vegetation, and when its plains and forests were 

 peopled by many of the species which still exist there ; 

 but when there also dwelt upon it large carnivorous 

 animals prowling about in the forests by night, and 

 retiring by day to these natural dens. 



