100 CALIFORNIA ACADEMY OF SCIENCES. 



for and against sexual selection, it will be appropriate 

 to end the discussion with some provisional conclusions 

 concerning it. In the first place, it will be necessary to 

 distinguish between the origination and guidance of 

 sexual colors. Critics of the theory of sexual selection 

 frequently appear to imagine that its acceptance requires 

 the assumption that a female bird has simply to get fixed 

 in her mind in some unaccountable manner a particular 

 style of dress for her lord and master, and then by a 

 patient process of trying on one garment after another, 

 and with perfect, scope to embellish the dress at her 

 pleasure, she will at last get one to suit. The more 

 rational view is, that the female simply passes judgment 

 upon the attire of the male, accepting that which is most 

 pleasing to her sense of sight. 



Grant Allen, in his suggestive little volume on Physi- 

 ological ^Esthetics, treats of the physical basis of color 

 perception, and of the harmony and discord of color. 

 He says :* " We have seen * * * that certain masses 

 of colour are in themselves, apart from any effects of com- 

 bination, pleasurable stimulants of the optic nerve. 

 They may thus be regarded as the analogues of musical 

 tones, which we saw to be similarly gratifying in isola- 

 tion, because they aroused normal amounts of action in 

 fully-nurtured and under-worked nervous structures. 

 But most pleasures of colour are not so simple in their 

 nature as these, nor do those we have already considered 

 rank very high in aesthetic value. Savages are pleased 

 by yards of red or blue cloth, and even cultured eyes are 

 often attracted by a colour of unusual purity and richness , 

 unrelieved by contrast or harmony; but the greater num- 

 ber of artistic effects depend upon combinational con- 

 siderations." He then shows why certain combinations 

 of colors are more pleasing than others. A particular 



*p 161. 



