1822.} Bones discovered in a Cave at Kirkdale, in Yorkshire. 145 
nately scattered and equally broken with the bones of other 
animals in the cave of Kirkdale, were reduced to this state by 
the agency of the surviving individuals of their own species. 
A large proportion of the hyzenas’ teeth bear marks of extreme 
old age, some being abraded to the very sockets, and the majo- 
rity having lost the upper portion of their coronary part, and 
having fangs extremely large: these probably died in the den 
from mere old age: and if we compare the lacerated condition 
of the bones that accompany them, with the state of the teeth 
thus worn down to the very stumps, notwithstanding their pro- - 
digious strength, we find in the latter the obvious instruments: 
by which the former were thus comminuted. A great number 
of other teeth appear to have belonged to young hyenas, for the 
fangs are not developed, and the points and edges of the crown: 
are not the least worn down. I havea fragment of the jaw of an: 
hyena which died so young, that the second set of its teeth had 
uot been protruded, but were in the act of forming within the 
jaw. Others are in various stages of advancement towards 
maturity ; and the proportion of these is too great for us to 
attribute them to animals that may have died in early life from 
accident or disease. It seems more probable, and the idea is. 
confirmed by the above statement of Mr. Brown, and by the 
fact of the hyznas’ bones in the den being gnawed and broken: 
to pieces equally with the rest, that they were occasionally 
killed and devoured by the stronger individuals of their own 
species. 
But besides the evidence their teeth afford to show that the 
animals died at various periods of life, they present other 
appearances (and so likewise do the bones), of having passed 
through different stages and gradations of: decay, arising from 
the different length of time they had Jain exposed in the bottom 
of the den, before the muddy sediment entered, which, since its 
introduction, has preserved them from further decomposition. 
This observation applies equally to all the animals. I have por- 
tions of bone and teeth that are so much decomposed as to be 
ready to fall to pieces by the slightest touch; these had proba- 
bly lain a long time unprotected in the bottom of the den; 
others still older may have entirely perished ; but the majority 
both of teeth and fragments of bone are in a state of the highest 
preservation ; and many thousands have been collected and car- 
ried away since the cave was discovered. In all cases the 
degree of decay is equal in the teeth and jaw bones, or frag- 
ments of jaws, to which they are attached. 
(To be continued.) 
New Series, vou. 1v. L 
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