MY SOMALI BOOK 231 



take into consideration the great length of time during 

 which evolution has been going on, and that he assumes, 

 without sufficient justification, that the protective 

 colouration of the zebra was brought into being by 

 conditions precisely similar to those obtaining at the 

 present day. 



I have endeavoured to show that in respect of the 

 nature of the country in which it ordinarily dwells 

 the zebra's habits may have changed. A moment's 

 consideration will show that the lion's habits have 

 also changed ; partially perhaps in the same direction 

 as the zebra's, which might account for the dis- 

 appearance of the spots it once possessed ; but more 

 certainly in another direction. For it hardly needs 

 demonstration that the lion was not always a nocturnal 

 animal. For one thing, the eye of the lion is not 

 inferior to that of animals of diurnal habit and, light 

 being necessary to its perfection as an organ of vision, 

 could never have attained its present perfection if 

 its owner had always avoided the light of day. And it 

 must be remembered that at the present time the lion 

 does, on rare occasions, hunt by day. 



When this was his habitual practice it must have 

 been an advantage to his prey to be inconspicuous. 

 It is not difficult to imagine the processes of evolution 

 that took place ; the zebra and the lion, to begin with, 

 both becoming less easy to see. It is not easy to be 

 sure of the order in which changes occurred, but we 

 may perhaps assume that to counteract the difficulty 

 of seeing their enemy with his increasing stealthiness, 

 the zebra took to the plains while the kudu, instead, 

 developed increased powers of scent. 



