ADAPTATION FOR THE SPECIES 127 
velops fine colors, ornamental appendages or a capti- 
vating voice. 
An interesting reversal of this process has taken 
place in civilized man. His more savage ancestor 
adorned himself more lavishly than he permitted his 
mate to do. With the advance of civilization man has 
undertaken to defend his own mate most valorously. 
The result is it is safe for her to be beautiful. Under 
these circumstances, however, it is more necessary to 
her welfare that her consort be vigorous rather than 
that he be handome. Hence in the human species 
beauty has become the prerogative of the woman, and 
this is increasingly the case the higher the civilization. 
Whether woman suffrage and self-support will reverse 
this process remains to be seen. There are indications 
that point that way. 
There are many biologists who are at present ex- 
pressing serious doubt as to the validity of sexual se- 
lection. As in the previous cases of protective colora- 
tion, I believe it will be wise for us to retain, even 
though with an interrogation point behind it, the idea 
of sexual selection until such time as those who ob- 
ject to it have furnished us with another theory which 
will more nearly account for the observed facts. 
While entirely conscious of the possibility that there 
is a weak spot in the theory, we will still tentatively 
hold to sexual selection. The fact that beauty in 
