ACQUIREMENT VERSUS SELECTION 453 



features as adaptive as possible; but even here we have to 

 admit that the features which best distinguish clematises 

 from anemonies are the ones that are least obviously adaptive. 

 Thus, for example, it would seem to be highly improbable 

 that the life of a plant or the welfare of its offspring could 

 ever depend upon whether it had four or five sepals, and in 

 our endeavor to connect this character with some adaptative 

 feature we had to make a succession of roundabout supposi- 

 tions. Yet most species of clematis are distinguished from 

 anemonies by this very character, while the sharpest distinc- 

 tion between the flowers of these genera is in the sestivation. 

 Here purely mechanical causes seem sufficient to account 

 for clematis having the valvate form while anemony has the 

 imbricate arrangement. A review of our generic, family, 

 and ordinal definitions will show that the main dependence 

 of systematists is upon just such non-adaptive characters 

 as those of floral plan, leaf arrangement, or mode of branch- 

 ing. If from this very large class of non-adaptive characters 

 we subtract all the cases which give evidence of being either 

 vestigial or correlative, we have left a considerable number 

 inadequately accounted for by natural selection. It does not 

 help matters for Darwinians to plead that we are very ig- 

 norant of the functions of all living things, and hence that 

 peculiarities seemingly useless may really be useful; for 

 questioning our ability to distinguish Avhat is useful from 

 what is not tells against our suppositions regarding the uses 

 of parts quite as truly as it does against a belief in their use- 

 lessness. Lamarckism seems weakest when it attempts to 

 account for highly developed adaptations; Darwinism when 

 it deals with non-adaptive characters. 



We are led into further difficulties by Darwin's assumption 

 that the great intensity of the struggle for existence resulting 

 from over-production would suffice to perpetuate even 

 slightly useful peculiarities. If v/e ask ourselves what really 

 happens to the large number of seeds rij^ened by each genera- 

 tion, we cannot fail to see that the struggle which Dar- 

 winians suppose to result from this immense number is much 

 overdrawn. I am writing these lines in a pine grove. The 

 trees are loaded with cones and from them come whirling 



