Bones discovered in a cave at Kirkdale , in Yorkshire . 195 
would not long have escaped total decomposition. For the 
same reason the horn of the rhinoceros, being merely a mass 
of compacted hair-like fibres, has never been found fossil in 
gravel beds with the bones of that animal, nor does it occur 
in the cave at Kirkdale. I have been told that sheeps* horns 
laid on land for manure will be consumed in ten or a dozen 
years ; the calcareous matter of bone being nearly allied to 
lime-stone, is the only portion, of animal bodies that occurs in 
a fossil state, unless when preserved, like the Siberian ele- 
phant, of the same extinct species with that of Kirkdale, by 
being frozen in ice, or buried in peat. 
The extreme abundance of the teeth of water rats has also 
been alluded to ; and though the idea of hysenas eating rats may 
appear ridiculous, it is consistent with the omnivorous appetite 
of modern hysenas ; nor is the disproportion in size of the ani- 
mal to that of its prey, greater than that of wolves and foxes, 
which are supposed by Captain Parry to feed chiefly on 
mice during the long winters of Melville Island. Our largest 
dogs eat rats and mice ; jackalls occasionally prey on mice, 
and dogs and foxes will eat frogs. It is probable, there- 
fore, that neither the size nor aquatic habit of the water 
rat would secure it from the hyaenas. They might occasion- 
ally also have eaten mice, weasels, rabbits, foxes, wolves, 
and birds ; and in masticating the bodies of these small ani- 
mals with their coarse conical teeth, many bones and frag- 
ments of bone would be pressed outwards through their lips, 
and fall neglected to the ground. 
The occurrence of birds’ bones may be explained by the 
probability of the hyaenas finding them dead, and taking them 
home, as usual, to eat in their den : and the fact, that four 
