378 ON THE CO-EXISTENCE OF MAN 
Miocene limestone of Sansan or in the Miocene deposits of the Upper 
Garonne. Thus it is evident that, if the amount of organic matter 
generally diminishes in proportion as the age increases, there are,. 
nevertheless, exceptions to that general rule. 
“ Ag to external appearance, that depends also on the cireum- 
stances of the locality. Itis not long since a large number of bones 
of the Hyena spelea were sent to me, which had been obtained from 
an ancient alluvial deposit in the centre of France. They were in no- 
degree changed in weight or colour, and in external appearance they 
were quite as fresh, if not more so, than the fragment given to you 
by M. Delesse. I have some of them now in my possession ; and 
they are still so much impregnated with animal matter, that I was. 
able with the utmost ease to saw and cut them with a flint knife. 
On the other hand, I have now before me a statuette made of stag’s. 
horn, obtained from a grave at the external base of a barrow, cer- 
tainly not older than the 12th century, the substance of which is so- 
much altered that it might be said to be fossilized, in a certain sense 
of the term, as much as the greater part of those found in caverns 
or diluvium. Hence we perceive that the greater or less amount of 
alteration in bones is not a character from which we can absolutely 
determine their paleontological antiquity. 
« With regard to the mode by which the fossil bones of M. Delesse 
have been sawn, I must confess that at first sight I thought, as M. 
Desnoyers did, that the operation must have been performed with a 
metailic plate ; but upon a more attentive examination of recent bones, 
I became convinced that the peculiar appearance presented by the 
section of one of the bones in the possession of M. Delesse must have 
been produced by the employment of a sharp tool of flint, rather than 
by a metallic plate, which has always given me a section with a very 
different surface. I send you the extremity of a tooth of Hyena 
spelea, which has been sawn by a flint. If you examine with a 
magnifying glass the plane of the section, you will find the same 
system of strie as are observed in the bones collected by M. Delesse, 
sawn with the same kind of tool. You may further satisfy your- 
self that in this fragment nearly all the organic matter remains, 
although the tooth comes from an ancient deposit.” 
In my letter to M. Lartet I had said that when his communica- 
tion was read, Dr. Falconer observed that, a considerable time ago,. 
M. Marcel de Serres had given an account of a fossil Stag’s horn that: 
