348 KANSAS CITY REVIEW OF SCIENCE. 
of all, offered by Europe. The Pleistocene, or Quaternary, period in Europe is 
characterised by the arrival of numerous living species, which are divisible into 
four natural groups, according to their present habitats. To the first belong 
those now living in the temperate zone in the northern hemisphere, such as the 
mole, musk-shrew, beaver, lynx, wild-cat, wolf, fox, martin, ermine, stoat, otter, 
brown and grizzly bear, horse, bison, urus, saiga antelope, stag, roe, fallow-deer, 
and wild boar. They emigrated from Asia, and some pushed their way as far 
south as northern Africa. The second consists of arctic animals, such as the 
arctic hare and lemming, musk-sheep, reindeer, and wolverine. These animals 
also came from Asia, and found their way as far to the south as the Alps and 
Pyrenees, and as far to the west as Ireland. The third group is composed of 
those animals now enjoying the cold climate of high altitudes in Europe, such as 
the chamois, ibex, and Alpine marmot. The fourth is represented by animals 
now only found in warm countries, such as the lion, panther, African lynx, spot- 
ted and striped hyena, hippopotamus, and African elephant and porcupine. The 
remains of these animals lie scattered over southern Europe, and as far to the 
north as Yorkshire, and to the west as Ireland. With these, certain extinct 
species appear, hitherto unknown, such as the straight-tusked elephant, mammoth, 
pigmy elephant, woolly and small-nosed rhinoceros, the Irish elk, pigmy hippo- 
potamus, and the cave-bear. 
Owing to these climatal changes every inch of ground, in middle and west- 
ern Europe, would successively form a frontier between the northern and south- 
ern animals, and their remains would be mingled together as we find them to be. 
During the extreme cold, the arctic animals would arrive at their southern limit. 
Closely following on this lowering of the temperature to its minimum, geographi- 
cal changes of great magnitude took place in the north of Europe. The area to 
the north of the line passing from the lower valley of the Severn eastward into 
Russia was depressed beneath the waves of a berg-laden sea, and again lifted up 
so that the British Isles, then an archipelago, again formed part of the main land. 
As the land emerged from the water, the Pleistocene forests crept over it, and 
the animals found their way over the southern and midland counties. 
Such as this was the scene on which man first appears in Europe. Rude 
splinters of stone, and roughly chipped pebbles of flint and chert, at their very 
best trimmed to an almond shape, and mostly intended for use in the hand, occur 
abundantly in the river deposits of England and France, in association with the 
remains of the above animals. They are the implements of savages living by the 
chase, and probably also by fishing and fowling. Not only have the implements 
been discovered, but the very spots on the river-bank where the hunter sat and 
made them have been identified, as at Crayford and other places in the valley of 
the Thames. Could we have penetrated to the banks of the Thames, or of the 
Seine in those times, guided by a thin column of smoke rising over the trees till 
we reached the camp ot the river-drift hunter, we might have seen the men 
selecting blocks of flint and chipping their implements out of them, the women 
