300 
SEXUAL selection: mammals. 
Part IL 
singular colours and "marks of many other antelopes,. 
though common to both sexes, have been gained and 
transmitted in a like manner. Both sexes, for instance, 
of the Koodoo (Strepsieeros Kudu, fig. 62) have nar- 
Fig. 6S. Tragelaphus scriptus, male (from the Knowsley Menagerie). 
row white vertical lines on their hinder flanks, and an. 
elegant angular white mark on their foreheads. Both 
sexes in the genus Damalis are very oddly coloured ; in 
D. pygarga the back and neck are purplish-red, shading 
on the flanks into black, and abruptly separated from the; 
