34 BUFFED GROUSE 



ings, being ground-color to match the ground, as 

 the Hummingbird is green to match the green 

 leaves on the trees he frequents, and as the desert 

 birds are sand-color and the arctic ones white to 

 match the snow. But Mr. Abbott H. Thayer, 

 the artist, has shown that there is something more 

 than mere color likeness in protective coloration, 

 a marvelous gradation of tint to counteract the 

 effects of light and shade. As he states the law : 

 " Animals are painted by nature, darkest on 

 those parts which tend to be most lighted by the 

 sky's light, and vice versa" 1 that is, darker above 

 and lighter below. He demonstrates this most 

 conclusively by means of pictures of birds as they 

 are in nature, in contrast to those in which he has 

 painted the under parts uniform with the dark up- 

 per parts, or, as he says, " extended the protective 

 coloration all over them." As we look at the pic- 

 tures, the natural birds are almost invisible, seem 

 scarcely to exist; while the painted ones stand 

 out boldly, unmasked, before us (Plate III.). 



The Grouse is one of the best examples of this 

 wonderful law of adaptation, of the gradation of 

 tints ; and it is also a wonderful example of pure 

 color correspondence to surroundings, and the 

 use of color pattern to disguise form. When the 

 brooding bird sits on her buffy eggs at the foot 

 of a tree, the white that is mixed with the dark 

 brown of her back matches the effect of sunlight 



1 The Auk, vol. xiii. No. ii. p. 125. 



