1 8 MOSTLY MAMMALS 



types of apparently protective coloration are for their special 

 purpose as good as (or better than) a uniform colora- 

 tion, or under what circumstances, if any, the latter is 

 superior to the former. For, curiously enough, both the 

 forest and the plain type of coloration appear to have 

 been transformed, in some instances, into a uniformly 

 coloured coat. As regards the plain type, the now extinct 

 quagga shows the partial loss of the stripes, which have 

 completely disappeared from the wild asses of Northern 

 Africa. Very remarkable is the circumstance that from a 

 fully striped animal like the so-called Grant's zebra of 

 Abyssinia there is a complete graduation to the typical 

 Burchell's zebra of the Transvaal, in which the stripes have 

 disappeared from the legs, and the dark stripes are inter- 

 calated with paler " shadow stripes." One step from this 

 animal and we reach the quagga, which, be it noted, in- 

 habited the same country as the uniformly coloured Cape 

 eland. Evidently in the Cape district both the forest and 

 the plain types of striping were unsuitable and tended to 

 disappear. In the North African wild asses the disappear- 

 ance of the striping is complete. Before we can attempt 

 to explain this it is necessary to know whether a Grant's 

 zebra and a wild ass are equally inconspicuous in their 

 own particular habitats, and whether any difference in this 

 respect would be noticeable if the one were transported to 

 the habitat of the other. 



An instance of the replacement of the forest type of 

 striping by a uniform coat (otherwise than in the case of 

 a desert-dwelling species) is afforded among the bushbucks 

 by the males of the nyala, which have long, shaggy brown 

 coats with but very indistinct traces of striping. Is this 

 dark coat a better protection than the brilliantly striped 

 one of the female, or is it assumed because the males 



