42 AFRICAN NATURE NOTES CHAP. 



white, 1 is one long night, in the gloom of which 

 the wolves and the foxes and the ermines (stoats) 

 search for and find their prey by scent alone, just 

 as foxes, stoats, and weasels do in this country. 

 As long as a hare gives out any scent at all, a fox 

 will be able to follow and find it. The fact that the 

 hare has turned white in the snow-covered ground 

 in which it is living will not help it as long as it 

 throws out the scent of its species, nor can it be 

 shown that the foxes of the sub- Arctic regions, which 

 never turn white in winter, have any greater diffi- 

 culty in approaching and killing the white hares 

 on which they live than the white Arctic foxes 

 experience in catching the Polar hares. 



There is one other point regarding the protec- 

 tion afforded by colour to large mammals against 

 carnivorous foes which I think has not been 

 sufficiently considered by naturalists, and that is, 

 that no matter how well the colour of an animal 

 may harmonise with its surroundings as long as it 

 remains perfectly still, as soon as it moves " it jumps 

 to the eyes," as the French say, no matter what 

 its colour may be. What is called protective colora- 

 tion to be effective must be motionless. Movement, 

 even very slight movement, at once destroys its 

 efficacy. But no herbivorous animals can remain 

 constantly motionless. They lie down and rest 

 certainly during the heat of the day, which is, 

 however, just the time when all carnivorous animals 

 are sleeping. At night and in the early mornings 

 and late evenings they move about feeding, and it 

 is at such times that carnivorous animals hunt for 

 their prey. In the dark these latter are undoubtedly 



1 I do not admit that the raven is a truly Arctic bird. Nanscn, in Farthest 

 .\\ } rth, although lie kept careful rerords of all the birds seen during the three 

 years his expedition lasted, never mentions having seen a raven, which I 

 believe has only penetrated into the Arctic Regions, as an excursionist, in com- 

 paratively recent times, following the whaling ships, and living on the carcases 

 of ihe whales and seals killed. 



