28 ECOLOGY AND ITS IMPORTANCE [CHAP, m 



"It must be admitted that there are cases, 

 such as the climatic varieties of certain butter- 

 flies, which raise some difficulties against this 

 explanation (direct influences upon the germ- 

 cells). I myself, some years ago, experimentally 

 investigated one such case, and somehow I can- 

 not explain the facts otherwise than by supposing 

 the passive acquisition of characters produced by 

 the direct influence of climate." l 



We shall see, too, how Mr Reid was impressed 

 with the acquired characters of the Kauri pine. 

 I shall have occasion to quote another early, 

 but like conclusion by Mr Hiern, as to the 

 adaptation of a circular outline to the leaves of 

 water-lilies in 1872. The fact is, that as soon 

 as the relationship between any organ and its 

 surrounding condition occupies the attention, it 

 at once becomes obvious that the result was due 

 to response only. That is all that is required, as 

 the fundamental basis of evolution, the acquired 

 characters being hereditary. 



This is why plant - ecologists have already 

 abandoned natural selection, in the sense 

 Darwin used it; but still recognise the useful- 

 ness of the term as meaning the survival of the 

 better adapted under the circumstances in the 

 struggle for life. 2 



1 (< Essays upon Heredity," etc., Eng. ed., p. 99. 



2 " Introduction to Plant Ecology " (Stanford). 



