'27 H 



EIJMTNATTON AND SELECTION. 



ard, but pro{;;ross in Huroly impossible. Such an objection 

 would, however, imply a forgetfulness of the facts of 

 variation. Variation is constantly takinji; place ; and the 

 variations may be favourable, or unfavourable, or neutral. 

 Under selection, the iavourablo variations will be chosen 

 out ; the unfavourable and the neutral may go. Under 

 elimination, the unfavourable disappear; the favourable and 

 the neutral remain. l?y how much the favourable variations 

 are in excess, by so much, will the race tend to advance. 

 I see no reason why neutral variations should be eliminated, 

 except in so far as, — in the keen struggle for existence, — 

 they become relatively unfavourable.* 



Too much stress is, I thiulc, laid upon utility. Mr. Wallace 

 himself contends " that none of the doiiiiito facts of organic 

 nature, no special organ, no characteristic form or marking, 

 no peculiarity of instinct or of habit, no relations between 

 species or between groups of species, can exist, bat which 

 must now be or once have been useful to the individuals or 

 the races which possess thorn." f And Mr. Eomanes, in his 

 valuable and suggestive paper on Physiological Selection 

 (physiological isolation would better express its scope), 

 brings forward the inutility of speciiic characters as one 

 of the three " cardinal difficulties in the way of natural 

 selection, considered as a theory of the origin of species." 

 " The features," ho says, " which servo to distinguish allied 

 species, are frequently, if not usually, of a kind with which 

 natural selection can have had nothing whatever to do ; for 

 distinctions of specifio value frequently have reference to 

 structures which are without any utilitarian significance." % 



But why should neutral variations, — variations, that is to 



' Cf. " Origin of Species," (Uli ed., p. (')3. 



t " Natural Selection," p. 47. 



\ Journ. Lin. Soc, ZooL, vol. xix., p. 1)38. 



