450 KINSHIP AND ADAPTATION 



had inherited most fully their touglmess would gain a foot- 

 hold where the less favored of their fellows could not survive, 

 and, since the adversities of the new environment would try 

 them more and more as they grew older, only the very tough- 

 est of them could produce seed. Still it might fairly be sup- 

 posed that a few, at least, would do so. Most of these seeds 

 would fall on the drier soil, the seedlings therefore would 

 similarly compete, and the winners be selected from among 

 the very toughest. Such rigorous selection might be expected 

 to insure a progressive toughening in successive generations 

 of drought-defying plants, and a continuation of the process 

 might be expected to result in a gradual invasion of the 

 drier spaces by much toughened descendants of the moisture- 

 loving form. Once accustomed to the drier soil they would 

 have become less fitted for a wet locality and their progenj^ 

 would consequently be excluded from the old home. During 

 the gradual adaptation of the new form to its drier environ- 

 ment, the individuals might acquire more or less adaptative 

 peculiarities and so far as the toughness was not impaired 

 thereby, these new features would be permitted by natural 

 selection and might appear in successive generations just as 

 if they were inherited. From marsh-marigold-like ancestors 

 might thus evolve primitive anemonies through the indirect 

 effect of drier conditions acting along the same lines and 

 producing the same results as Lamarckians maintain Avould 

 come from the direct effect of the same environment. During 

 their evolution these anemonies might become differentiated 

 into sun-loving and shade-loving species ])y the survival of 

 those individuals best fitted to grow in sun or shade respec- 

 tively. Success in the dry open fields would be favored by 

 having the leaves lie next to the ground, so as to avoid as 

 much as possible the withering effect of drying breezes, while 

 in the shade it would be advantageous to have the leaves 

 elevated so as to catch the light. This maj' account for the 

 occurrence of ground rosettes in the anemonies of the open 

 and the prevalence of raised rosettes, borne upon an elevated, 

 lower internode, in anemonies of the wood. These latter 

 might similarly be differentiated through natural selection 

 into shade-enduring anemonies on the one hand, and climb- 



