1893. NATURAL SELECTION AND LAMARCKISM. 343 



Whatever may be said to the contrary, the " widely accepted " view 

 that " Natural Selection will [tend to] increase any advantageous 

 trait " is a sound one; for the verj^ meaning of "advantageous" is 

 that some advantage is conferred, that the welfare of the organism is 

 -aided, and thereby its survival and multiplication. Of course, the 

 •degree of power or influence of Natural Selection will strictly depend 

 upon the degree of advantage, and in proportion as this is slight 

 the corresponding effect will be slight, and may easily be counteracted 

 or masked by the effects of other causes. 



This idea that survival of the fittest can do nothing at all unless 

 it is " frequent," is allied with further misconceptions of the way in 

 which Natural Selection brings about evolutional changes. Mr. 

 Spencer compares each generation with the preceding one and finds 

 that the change is too slight to affect survival. I venture to insist, 

 however, and with all possible emphasis, that the basis of comparison 

 ■of advantage must not be the trivial amount of change occurring in 

 •each successive generation, but the much more notable variations 

 seen in contemporary individuals. If individuals who are the most 

 poorly adapted in any respect are occasionally cut off, while the more 

 perfect are preserved, there may well ensue some amount of evolu- 

 tional change, for the average may thus be altered, although the 

 intermediate or mediocre majority were not appreciably affected by the 

 ■eliminative and selective process. The differences or variations that 

 appear are far greater than Mr. Spencer would allow us to suppose. 

 Thus, some English jaws are two-and-a-half times as heavy as others, 

 while he only concedes a possible variation of about 10 per cent, for 

 Natural Selection to work upon, and makes this allowance, moreover, 

 appear preposterously beyond the degree of variation which would 

 actually be presented to the operation of selective factors. Such 

 fanciful presentments of cases misrepresent the problem before us, 

 and blind us to the actual methods of Nature, whose selective factors 

 naturally act more decisively upon extremes than upon average 

 mediocrity and the minuter degrees of variation. Those who think 

 that Natural Selection acts only upon the almost imperceptible change 

 in each generation, and that this change is too slight to be thus 

 acted upon, ought logically to give up Natural Selection altogether. 

 If the argument were valid, it is hard to see how any of our organs 

 could have been evolved or influenced by Natural Selection. Even 

 the evolution of our most rapidly-evolving organ, the brain, could 

 not be thus brought about, for such evolution has been exceed- 

 ingly slow, and the advance in each generation could be repre- 

 sented as much too insignificant to affect survival, besides being 

 neutralised by the advantages of superiorities in other organs, as a 

 Lamarckian might also urge. 



Another curious limitation imposed on the potency of Natural 

 Selection is its alleged inadequacy to bring about complex evolution. 

 It is acknowledged that it can " keep all faculties up to the mark" 



