Mimicry Among Animals 



horse is supposed to have been a sandy or clay- 

 colour. 



The desert birds are still more remarkably 

 protected by their assimilative hues. The 

 chats, the larks, the quails, the goatsuckers and 

 the- grouse, which abound in the North Af 

 and Asiatic deserts, are all tinted and m 

 so as to resemble with wonderful accuracy the 

 average colour and aspect of the soil in thi 

 trict they inhabit. The Rev. H. Tristram, in his 

 account of the ornithology of North Africa in the 

 first volume of the "Ibis," says: "In the 

 desert, where neither trees, brushwood, nor even 

 undulation of the surface afford the slightest 

 protection to its foes, a modification of ( 

 which shall be assimilated to that of the sum (tend- 

 ing country is absolutely necessary. ! 

 without exception the upper plumage of every 

 whether lark, chat, sylvain, or sand-grouse, and 

 also the fur of all the smaller mammals, and the 

 skin of all the snakes and lizards, is of one unifi >rm 

 isabelline or sand colour. " After the testimony 

 of so able an observer it is unnecessary to adduce 

 further examples of the protective colours < »f 

 desert animals. 



Almost equally striking are the cas< 

 animals possessing the white colour thai 

 ceals them upon snowfields and icebergs. The 

 polar bear is the only bear that, is whi 

 lives constantly among snow and ice. The 

 arctic fox, the ermine and the alpine hare change 

 to white in winter only, because in summer 

 75 



