ADAPTATIONS TO HIGH ALTITUDES 59 



ground is very low. The plant's problem is to do 

 with little water, and it is interesting to notice, as we 

 have done, some of the many solutions. The leaf- 

 surface may be reduced to a minimum; the leaf-sur- 

 face may be leathery, waxy, woolly; the leaf may be 

 succulent but with a thick or varnished skin. And if 

 it be asked why water is so essential, the answer is 

 that water is needed as part of the raw material of the 

 sugar and other carbon compounds, which the green 

 leaf builds up in the sunlight, and that living matter 

 cannot live without water. All the processes of life 

 take place in a liquid medium; living matter itself is 

 fluid. 



Before we leave the heights we must at least state 

 a question which inevitably rises in the mind, Where 

 have our British animals, such as Red Deer and 

 Mountain Hare, come from ? But this is a very diffi- 

 cult question, which cannot be answered with any- 

 thing like certainty. In Dr. R. F. ScharfFs " History 

 of the European Fauna" the view is upheld that our 

 fauna mainly consists of three contingents or divi- 

 sions a northern, a southern, and an eastern, and 

 that these correspond to migrations which can be 

 proved to have arrived in this country at different 

 periods in past times. 



Dr. Scharff outlines the possibilities : " In early 

 Tertiary times, when the climate all over Western 

 Europe was moist and semi-tropical, a migration pro- 

 ceeded northward from the south-western corner of 

 Europe. This was strengthened by Oriental migrants 

 which had moved westward along the Mediterranean 

 basin. Owing to geographical changes supervening, 

 the alpine fauna was then enabled to colonise the 



