Stolzmann's Theory 



are likely to persecute the hens ; we may also 

 grant that many cocks are handicapped in the 

 struggle for existence by the excessive growth 

 of certain of their feathers, but we fail to see 

 how this excessive development has been caused 

 by natural selection in the manner suggested by 

 Stolzmann. Although it may be advantageous 

 to the species for the cocks to be showy, natural 

 selection can perpetuate this only by weeding 

 out the least conspicuous of the cocks. But it 

 is the more gaudy ones, those, according to 

 Stolzmann, whose presence is beneficial to the 

 species, which will be eliminated by natural 

 selection. So that, in this case, that force will 

 act in a manner contrary to the interests of the 

 species, if Stolzmann's idea is a correct one. 



The theory in question would therefore seem 

 to be untenable. Nevertheless there is doubt- 

 less some truth in the notion that too many 

 males spoil the species. Thus, excessive showi- 

 ness and high mortality among the males may 

 be beneficial to the species. But we must not 

 forget that the more beneficial it is, the stronger 

 must be the tendency of natural selection to 

 eliminate the males that possess the desired 

 peculiarity. 



NEO-LAMARCKIAN EXPLANATION 



J. T. Cunningham makes an attempt to ex- 

 plain the phenomena of sexual dimorphism on 



329 



