286 SEXUAL SELECriON : MAMMALS. [Pabt IL 



the throat, tlie white marks on tlie fetlocks, and tlie round 

 hhick s{)ot8 on the ears, are all more distmct in the male 

 of the Portax. picta^ than iu the female — when we see that 

 the colors are more vivid, that the narrow white lines on 

 the flank and the broad white bar on tlie shoulder are 



Fio. 69.— Damalis pygarga, male (from the Knowsley Menajrerie). 



more distinct in the male Oreas Derby arms than in the fe- 

 male — when we see a similar difference between the sexes 

 of the curiously ornamented Tragelaphus scriptus (Fig, 

 68) — we may conclude that these colors and various 

 marks have been at least intensified through sexual selec- 

 tion. It is inconceivable tliat such colors and marks can 

 be of any direct or ordinary service to those animals; and 



