166 EVOLUTION 



at Johannesburg in August 1909, many 

 hundreds of trees were destroyed by the weight 

 of snow on the branches. It was interesting, 

 after the storm, to notice that the elimination 

 was in a marked degree discriminate. The 

 trees that suffered most were the imported 

 Australian trees, such as the Blue Gums and 

 Black Wattles, quickly growing, with soft 

 wood, and with abundant foliage that caught 

 the snow. On the other hand, the deodars 

 from the Himalaya mountains, constitution- 

 ally adapted to let the snow slide from their 

 pendulous branches and acicular leaves, had 

 hardly a twig broken. 



IMPLICATIONS OF THE CONCEPT OF NATURAL 

 SELECTION. As a naturalist of very rich 

 experience Darwin realized the complexity 

 of the evolution problem more than most 

 naturalists have done, and a careful study of 

 his sentences makes it quite clear that when 

 he used phrases like " struggle for existence " 

 and " natural selection," which have acquired 

 by familiarity a somewhat hard and mechani- 

 cal sound in our ears, he had a singularly rich 

 concrete content in his mind. 



" Nothing is easier," he said, " than to admit 

 in words the truth of the universal struggle for 

 life, or more difficult at least I have found it 

 so than constantly to bear this conclusion in 



