20 SYLVAN SECliETS. 



It would seem that this power of self-modi- 

 fication serves the bird in the same Avay that 

 the inventive and constructive faculties serve 

 man. The instance of the soundless flight of 

 night-birds of prey is a striking one. A 

 hawk in swooping down upon a quail at mid- 

 day makes a loud roaring with its wings, 

 while an owl falling by night upon its quarry 

 is as silent as " snow on wool." The stillness 

 of night has operated for countless ages to 

 create a natural desire in owls for the power 

 to strike their prey in utter silence, and the 

 desire, transmitted by heredity, has finally 

 so modified the bird's wings and plumage as 

 to respond perfectly to the persistent thought. 



Birds of the polar areas of snow and ice 

 are white, those of the tropics are vari-colored 

 and brilliant-hued. The condition in each 

 instance has been reached through a natural 

 desire to hide by blending with the prevailing 

 tone of Nature. Thus the quail and the par- 

 tridge, the meadow-lark and the flicker, the 

 snipes, the woodcock, the prairie grouse and, 

 in fact, nearly all the ground-feeding birds, 

 resemble one another in general color or plu- 

 mage-tone, simply because their environment 

 has induced parallelism of natural desire — 

 the desire to blend with the prevailing brown 

 tinge of their feeding-places as the most 

 effective protection against the sharp eyes of 

 their enemies. Some of the game-birds have 

 even acquired the power to withhold their 

 scent from foxes and wolves, and from the 

 sportsman's dog as well. There is a good 

 reason why this desire to perfectly disappear, 

 so to speak, in the color of the environment, 

 has been more persistent and successful in 

 the case of game-birds than in that of any 

 other. On account of the sweetness of its 



