SEXUAL SELECTION 239 



appreciated Ijy others. As a matter of fact, this xery difficulty as to 

 the first beginnings of variations lias been frequently urged against 

 ])oth hypotheses of selection, and rightly so, inasmuch as this must be 

 above all else the point of attack for further investigations. But it is 

 a mistake to deny the whole processes of selection simply because this 

 point is not yet clear. Later on we shall attempt to gain some insight 

 into the causes of variation, and then we shall return to this question 

 of the beginnings of the selective processes. In the meantime let 

 it suffice to say that Darwin was very well aware that, in addition to 

 the ordinary individual variations, there were also larger deviations 

 which occurred discontinuously in single forms. He believed, how- 

 ever, that such occurrences were very rare, and, on the whole, he was 

 not inclined to ascribe to them any particular importance in the 

 transformation of species. He rather referred the organic trans- 

 formations which have taken place in the course of the earth's 

 history, in the main, to the intensification of the ordinary individual 

 variations, and I believe that he was right in so doing, since adapta- 

 tions from their very nature cannot have been brought about by 

 sudden chance leaps in organization, Ijut can only have become exactly 

 suited to chance conditions of life through a gradual accumulation of 

 minute variations in the direction of utility. Whether, however, 

 purely sexual distinctions may not have had their primary roots in 

 discontinuous variations must be inquired into later. Theoretically, 

 there is nothing against this assumption, when such characters are 

 not adaptations like the lasso antennae of the Copepods, or the turban 

 eyes of the Ephemerids; mere distinctive markings, decorative colora- 

 tion, peculiar outgrowths, and the like, may, if they arose discon- 

 tinuously, very well have formed the basis for further sexual 

 selection, as long as they were not prejudicial to the existence of the 

 species. 



