92 SEX 



theory of sexual selection suggested that a 

 variation in male animals in the direction of, 

 say, better weapons or more beautiful plumage, 

 would be profitable to its fortunate possessors. 

 They would be more successful than others in 

 reproduction and their stock would prevail ; 

 those of their kin who had not the excellence 

 in question would be sooner or later eliminated. 

 If the facts bear it out, the theory is a sound 

 interpretation of the survival of certain 

 characters. But it did not pretend to explain 

 the origin of the variations assumed to have 

 occurred, and it is this question of origins 

 which makes all our evolutionary inquiries 

 difficult alike. 



At this point the Lamarckian interpreta- 

 tion has theoretically the advantage, for if 

 males acquired weapons as a direct organic 

 response to fighting, and decorations as the 

 organic reward of doing their best in the way 

 of showing themselves off without them, or 

 as the result of functional changes in the 

 blood-pressure and in the distribution of the 

 blood-vessels, then the problem of origin is 

 solved. And if these individual acquisitions 

 are entailed on the offspring, then the problem 

 of their becoming racial characters is also 

 solved. But, as we have already hinted, 

 there are great difficulties in the way of this 

 interpretation. 



If we pass to the suggestive view that 

 distinctive sex-characters are all derivable 

 from specific characters by a change of 

 function and by becoming correlated with 

 the reproductive organs, whose internal secre- 

 tions supply the physiological nexus, then 



