32 Chameleons in Fur [FIFTH WEEK 



one side always runs away while the other pursues. Thus 

 it is in the wars of nature, only here the timid ones are 

 always ready to flee, while the strong are equally prepared 

 to pursue. It is only by constant vigilance that the little 

 mice can save themselves from disappearing down the 

 throats of their enemies, as under cover of darkness they 

 snatch nervous mouthfuls of grain in the fields, and 

 hence their gray colour and their large, watchful eyes; 

 but on the other hand, the baby owls in their hollow tree 

 would starve if the parents were never able to swoop down 

 in the darkness and surprise a mouse now and then, - 

 hence the gray plumage and great eyes of the parent owls. 

 The most convincing proof of the reality of protective 

 coloration is in the change of plumage or fur of some of 

 the wild creatures to suit the season. In the far north, 

 the grouse or ptarmigan, as they are called, do not keep 

 feathers of the same colour the year round, as does our 

 ruffed grouse; but change their dress no fewer than three 

 times. When rocks and moss are buried deep beneath 

 the snow, and a keen-eyed hawk appears, the white- 

 feathered ptarmigan crouches and becomes an inanimate 

 mound. Later in the year, with the increasing warmth, 

 patches of gray and brown earth appear, and simulta- 

 neously, as if its feathers were really snowflakes, splashes 

 of brown replace the pure white of the bird's plumage, 

 and equally baffle the eye. Seeing one of these birds by 

 itself, we could readily tell, from the colour of its plumage, 

 the time of year and general aspect of the country from 

 which it came. Its plumage is like a mirror which reflects 

 the snow, the moss, or the lichens in turn. It is, indeed, a 



