xiv AFRICAN NATURE NOTES 



The whole subject is one fraught with difficulty and 

 deserving of far more careful study than has ever 

 yet been given it. That the general pattern of 

 coloration, so to speak, of birds and mammals of 

 the snowy North as compared to the South, of a 

 dry desert as compared to a wet forest region, is 

 due to the effect of the environment I have no 

 question ; and Mr. Selous' observations and argu- 

 ments show that the protective theory has been 

 ridiculously overworked in trying to account for 

 coloration like that ot the zebra and giraffe, for 

 instance ; but there is much that as yet it is difficult 

 to explain. 



The most conspicuous colors of nature, lor 

 instance, are, under ordinary circumstances, black 

 and white. Yet we continually find black, and 

 sometimes white, animals thriving as well as their 

 more dull -colored compeers under conditions that 

 certainly seem as if they ought to favor the latter. 

 The white goat of the Rocky Mountains may be 

 helped by its coloration in winter, but in summer 

 its white coat advertises its presence to every man 

 or beast within range of vision, and this at the very 

 time when the little white kids are most in need of 

 protection. Eagles are formidable foes of these 

 little kids, and undoubtedly their white color is a 

 disadvantage to them in the struggle for existence, 

 when they are compared with the dull -colored 

 lambs of the mountain sheep of the same general 

 habitat. The sheep tend to become mainly or 

 entirely white at the northern portion of their range 

 thereby becoming exceedingly conspicuous in 

 summer but change to grays and browns from 

 the semi -Arctic regions southward. The goats, 

 however, remain white everywhere. 



Again, birds and mammals of the far North tend 

 to be white, but one of the typical tar northern birds 

 is the jet black raven. It is hard to believe that the 



