258 Marcel de Serres on the Old World 
The beds of organic remains forming every day, differ from 
those of geological times only by their smaller extent, and also 
in the nature and species of the beings which they inclose 
—(See Note 21). 
There is at the same time a phenomenon which seems to 
have undergone no variation from the most remote times ; 
the constancy in the flow of mineral and thermal waters ap- 
pears to have been always the same. 
We have examined the principal differences between the 
ancient world and that which witnessed our arrival on the 
earth. Perhaps it might have been desirable to enter into 
longer illustrations of the collective phenomena submitted 
to your consideration ; but we have not time to do this in a 
manner worthy of the subject. We shall account ourselves 
fortunate if we have caused you to feel an interest in the 
facts disclosed to you, and which are already so remote from 
us; for, as the priests of Sais said to Solon, We are but of 
yesterday on our aged earth. But the sciences count time 
and space as nothing; generations succeed each other and 
pass away, and with them the majestic edifice of human 
knowledge becomes enlarged. Have we not, then, reason to 
hope that the general laws of the principal phenomena of the 
globe, now better known, will soon give us the key to those 
which yet remain mysterious to us ? 
Nore 1. The various modifications which the earth has under- 
gone in geological times, and which have shaped the surface into the 
form we now witness, if considered in relation to us, are fearful re- 
volutions. But, when viewed relatively to the earth itself, the eleva- 
tion of the greatest chains of mountains is a phenomena, of small im- 
portance ; for the inequalities they have produced on it are more 
insignificant in regard to dimensions than those which cover the sur- 
face of an orange. These, however, were necessary, since the globe 
had to receive vegetables and animals, and required the means of 
producing running water. The destruction of a great number of 
organised bodies has been the consequence of the modifications to 
which the outline of the earth’s surface has been subjected, and of 
the gradual sinking of the temperature. This diminution of tem- 
perature has produced new climates. Existing species are no longer 
threatened by the instability of the ancient climates, nor by differ- 
ence in the composition of the atmosphere, which, like that of the 
