ARCTIC BRITAIN 



when these hardy little Arctic plants colonized the shingles 

 and rooted themselves amongst the rocks. 



They covered not only the seashore, but they probably 

 made a settlement wherever rock or land of any kind was 

 exposed. These original settlers have had three bands of 

 descendants. One band has remained ever since on the sea- 

 shore of Great Britain; another set gradually travelled 

 northwards. As the ice melted away, leaving the land bare, 

 first in Denmark, then in Norway, and finally in Greenland, 

 this second set followed it, until now we find them far to the 

 northward, populating the Arctic regions of to-day just as they 

 did those of Britain in the Great Ice Age. 



The third set of descendants would at first cover all the 

 land and rocks of the lower hills and valleys near the sea ; 

 then as the ice and snow melted and exposed the higher 

 mountain sides, they would climb the hills and eventually 

 reach the exposed summits where they are now living. There 

 they find themselves in an impossible, savage sort of climate, 

 in which they alone are able to exist. Violent storms, 

 drenching mist, scorching sunshine (when the rocks become 

 so hot that it is almost impossible to touch them), rain- 

 storms and months of snow and hard frost, cannot kill Scurvy- 

 grass, Seathrift, or Plantain, but there are few other plants 

 which can stand such conditions. Lower down on the flanks 

 of the hills and in the valleys, they have long since been dis- 

 possessed of the rich and fertile lands by plants which can 

 grow more rapidly and luxuriantly. 



The little Alpine Creeping and Least Willows, for instance, 

 some of which get up to 3980 feet in Breadalbane, are mere 

 dwarfs only a few inches high, and totally different from 

 their allies in the fertile lowlands, which are trees eighty to 

 ninety feet high. 



105 



