TREES IN NATURE 55 



man, he was not thinking of the anatomy and 

 physiology of man, but of his thoughts and his 

 emotions. The trees do not take us on to 

 such high ground ; but they have varying ap- 

 pearance, strength, beauty, and many other 

 qualities such as were sketched out in our first 

 chapter ; and it is with such things as these 

 that we are now to be concerned. 



Are they prosaic? To begin with, there is 

 the ever-present mystery of all the wonderful 

 variety. We must take along with us through 

 this chapter the questionings with which we 

 set out, as to the cause of all the varied forms 

 of life by which we are surrounded. The 

 theory of evolution tells us of variation coming 

 through natural selection, through a struggle 

 for existence and a survival of the fittest. We 

 know how, by artificial selection, many varieties 

 of pigeons have been developed from the blue- 

 rock. We know also how, by a like selection, 

 many varied kinds of animals have been bred. 

 In the vegetable world, it is interesting to note, 

 for example, the various kinds of apples and 

 pears given in John Evelyn's Sylva, and to 

 compare their names with the long lists given 

 in our catalogues to-day. Some that he names 



