306 
emigrant animals ; others, like the horse, have survived 
to this day in our land, these are the existing animals. 
The extinct animals abounded in the earlier quaternary 
age. Several were large and powerful mammalia, carry- 
ing terrible weapons of their own, and the human form 
looked weak and puny by their side. There were, among 
others, the great cave bear (Ursus speleus), the great cave 
lion (Felis sfel@a), the amphibious hippopotamus (Az. 
amphibius), the rhinoceros with the expanded nostrils 
(RA. tichorhinus), the ancient elephant (Z/ephas anti- 
guus), finally and above all the giant, and we may say the 
king of this fauna, the mammoth (Zlephas primigenius). 
It would be superfluous to enumerate the other extinct 
species which lived at the same epoch. The reindeer 
and several animals, now emigrants like itself, were also 
to be found in this fauna, but they were still rare ; and a 
good number of existing species had already made their 
appearance. 
It is with good cause that the first period of the quater- 
nary epoch, that which corresponds with the low level of 
the valleys has been called the mammoth age. 
Every condition favourable to the prosperity of this 
species was then combined. But changes supervened 
which, in the long run, were to lead to its decay. The 
temperature had become less rigorous, and a great number 
of herbivora, till then stunted in their development by the 
inclemency of the atmosphere, had been able to improve 
and increase. 
Already the mammoth sawarrayed against him the power 
of man, who, under this somewhat modified climate, could 
join in bands sufficiently formidable to declare war against 
him. Finally,and above all, this same climate, which suited 
his enemies and his rivals, had become hurtful to his own 
organisation, which required a colder temperature. The 
mammoth, therefore, so common in the earlier quaternary 
period, began to decline. We are inclined to think his 
existence was prolonged to the end of the palzeontological 
age ; but long ere that he had ceased to reign. 
II. There was thus, in the middle of the quaternary 
epoch, an intermediate age, corresponding to the middle 
level of the valleys : an age in which several species con- 
temporary with the mamisch were already extinct, in 
which others, represented only by solitary specimens, were 
on the point of disappearing, while those species were 
on the other hand flourishing, which were better adapted 
to the changing atmospheric conditions. Among these 
latter, the reindeer (Cervus tarandus) already occupied 
an important place, but it was in the succeeding period 
that it flourished. : 
III, This intermediate age gave way by degrees to the 
third and last stage of the quaternary epoch. When the 
layers of the upper level began to be formed, the species 
which we call extinct had almost entirely disappeared. 
A few rare mammoths still survived. Still more rare were 
the gigantic Irish deer (Megaceros hibernicus) and the 
great lion of the caverns. The rest of the fauna had but 
slightly changed, but the reindeer had multiplied to a 
wonderful extent. It formed at that time the chief 
nourishment of man, The third period of the quaternary 
epoch is therefore deservedly styled the Reindeer age. 
The difference in the fauna of those days from that of 
our own time did not alone consist in the presence of .the 
reindeer ; many other hardy species, to whom a cold 
climate was necessary and a temperate one injurious, were 
still existing in our as yet frigid zone. When the state of 
the atmosphere more nearly approached that of the 
present day, there was a disappearance of the individuals 
which represented these species in our hills and plains ; 
but the species themselves did not on that account perish. 
In the colder regions whither they had wandered they 
_* The urus is now extinct, but it is not more than three or four centuries 
Since it existed in Germany and Great Britain. The aurochs is only to b: 
found now in a forest of Lithuania, under the protection of a special law of 
the Russian Empire, A troop of them has been also seen in the Caucasus 
NATURE 
[Z2d. 20, 1873 
found a more congenial air, and they have thus been 
enabled to perpetuate themselves to the present time. 
IV. The disappearance of the reindeer and of the other 
emigrant species marked the end of the quaternary epoch 
ani of the palzeontological age. Then began the modern 
epoch. Our climate was probably still a little colder than 
itis in our own days, but it was alréady temperate, and the 
slight changes which it has since undergone have not 
affected the conditions of life to such a degree as to en- 
danger the existence of species. If the urus (Bos primi- 
genius) and the aurochs (Bison Europeus) have disap- 
peared from our land, we must attribute these results 
more to the destructive action of man than to that of 
climate,* and to man is also attributed the introduction 
of several new species, for the most part domestic animals. 
With these few exceptions, we may say that from the end 
of the quaternary epoch our fauna has not changed, and 
that the recent soil only contains existing species. 
The dates which we seek to establish are therefore 
determined at the same time by stratification and paleon- 
tology. They also rest on data of another order, and 
these constitute a real science, namely prehistoric arche- 
ology. ' 
The point which is certain and which has been irre- 
vocably proved by Boucher de Perthes, is that. the 
most ancient beds of the quaternary epoch contain vestiges 
of human industry. The knowledge of metals only dates, 
one may say, from yesterday; before possessing these 
powerful auxiliaries, man was not unarmed. In the 
manufacture of his weapons and tools he had employed 
several hard substances, the bones, the teeth of large 
animals, the horns of the Ruminantia, but above all, stone, 
and more particularly flint; hence the name Svone age, 
given in the history of man to all the period which pre- 
ceded the use of metals. 
This stone age still continues among some savage 
nations, and it only came to an end among the civilised 
people of antiquity at an epoch very little anterior to the 
historic age. Hence it embraces nearly the whole dura- 
tion of human existence. Now the mode of fabricating 
weapons, their shape, their nature, must necessarily have 
varied during this immense period, according to the 
changes in the wants, the mode of life, and the social 
state of man who employed them; and if we now con- 
sider that hard stones will Jast an indefinite time in the 
ground, we shall understand that the tokens of this primi- - 
Fic. 2. Fic. r. 
The type o! »aint Acheul; Hatchet carv:d on both sides. Fig. 1.—Front 
view. Fig. 2.—Edge view. . 
tive industry constitute indelible medals and chronological 
documents of the highest importance. 
The dates established by prehistoric archeology agree 
pretty well, and sometimes coincide in a remarkable 
manner with those of palzontology and stratification, 
