ISLAND LIFE. 
[part I. 
lift 
istic of temperate latitudes (. Elephas antiquus and Rhinoceros 
h&mitcechus). But when it occurs in gravels or in water-borne 
cave-deposits it is sometimes associated with the mammoth, the 
woolly rhinoceros and the reindeer, animals which, as certainly, 
imply a cold or even arctic climate. This difference is intelligible 
if we consider that the hyaena which carried the hones of all 
these animals into the caves, is itself indicative of a mild 
climate, and that there is nothing to cause the remains of 
animals of successive epochs to be intermingled in such caves. 
In the gravels however it is very different. During the warm 
periods the rivers would be inhabited by hippopotami, and the 
adjacent plains by elephants and horses, and their remains 
would be occasionally imbedded in deposits formed during 
floods. But when the cold period came on and these had 
passed southward, the same river banks would be grazed by 
mammoths and reindeer whose remains would sometimes inter- 
mingle with those of the animals which preceded them. It is 
to be noted, also, that in many of these river-deposits there 
are proofs of violent floods causing much re-arrangement of 
materials, so that the remains of the two periods would be thus 
still further intermingled. 1 
The fact of the hippopotamus having lived at 54° N. Lat. in 
England, quite close to the time of the glacial epoch, is absolutely 
inconsistent with a mere gradual amelioration of climate from 
that time till the present day. The immense quantity of vege- 
table food which this creature requires, implies a mild and 
uniform climate with hardly any severe winter ; and no theory 
that has yet been suggested renders this possible except that of 
alternate cold and warm periods during the glacial epoch itself. 
In order that the hippopotamus could have reached Yorkshire 
and retired again as the climate changed, we may suppose it to 
have been a permanent inhabitant of the lower Bhone, between 
which river and the Rhine there is an easy communication by 
means of the Doubs and the 111, some of whose tributaries 
approach within a mile or two of each other about fifteen miles 
south-west of Mulhausen. Thence the passage would be easy 
1 A. Tylor, on “Quaternary G-ravels.” Quarterly Journal of Geological 
Society of London, 1869, pp. 83 -95 (woodcuts). 
