Elgee: Glacial Survivals. 275 
purposes of this argument we shall be on the safe side if we 
regard the temperature of Britian during the Ice Age as being 
a low one, and resembling that of the Arctic Regions at 
the present day. 
The question of Glacial Survivals is not new. In this 
connection Dr. R. F. Scharff stands pre-eminent, and in 
his various works has laid much stress on this survival as 
explaining many curious facts of distribution. But it does 
not appear to have been very precisely specified where or how 
organisms battled through the Ice Age; in many instances 
only sheltered nooks and corners are hinted at in a vague way. 
In the first place it is incontestable that terrestrial species 
could of survive the Ice Age on land covered either by ice 
hundreds or thousands of feet thick, or by the waters of extra- 
morainic lakes. The only possible places where they could 
survive were the regions which we know from geological 
evidence to have been unglaciated. 
At first these might not be thought very extensive, but 
when it is borne in mind, as Mr. Kendall reminds me, that 
‘the whole country south of the Thames, much of the Pennine 
Range south of the Aire Valley, the large area of North East 
Yorkshire, and several patches elsewhere’ were unglaciated, 
it will be seen that the regions on which animals and plants 
may have existed are neither small nor unimportant. 
Only on these areas could any species survive the Glacial 
Period. Those that did manage to exist thereon must surely 
have been principally Arctic forms, and the possibility of 
temperate and southern species managing to live on them 
seems small. It must not be forgotten, however, that the 
approach of the Ice Age would be gradual, and that many 
temperate and even southern forms might, in the course of 
generations, become adapted to the slowly increasing rigours 
of an Arctic climate, at the same time competing against the 
on-coming northern fauna and flora. This consideration goes 
some way towards explaining the strange mixture of animals 
of southern and northern habitats so frequently observed in 
British Pleistocene deposits. 
However this may be, glacial survival can only be postulated 
where there were unglaciated areas on which species could exist. 
The exact location of animals and plants in relation to 
glacial deposits is therefore of vital importance as differences 
in the fauna and flora of two adjacent areas, one covered with 
drift and the other driftless, apart from differences of soil, etc., 
1907 August I, 
