GRAY WINGS 



231 



Musclinq 

 and feather- 

 ing ofiisea 

 birds. 



illustration of nature's fashioning things to an 

 end and for a purpose. The body is usually 

 very small — little more than a rack of bones 

 and a wedge of sinews. An oily quality of the 

 flesh, derived from a fish diet, and an outer 

 layer of fat provide heat and enable the bird 

 to live in the coldest climates. In addition 

 there is a thick but light plumage that not only 

 wards off cold and wet but adds to the buoyancy 

 of the bird in the air as in the water. The 

 muscling, in proportion to size, is prodigious. 

 The wing muscles, for instance, are developed 

 to the last degree of elasticity, pliability and 

 flexibility. It seems as though nothing could 

 weary them. And the task imposed upon them 

 is more than herculean. The bird spends 

 whole days, and even whole weeks, upon the 

 wing, darting, soaring, wheeling, diving. The 

 enormous wings with their motor of muscles 



Their 



enormous 



endurance. 



behind them always seem sufficient unto every 

 emergency or requirement. They not only up- 

 hold the body for days at a time but they ride 

 the breeze or gale, they tack, sail free, or dead 

 ahead, as the bird wills; and with apparently 

 as little effort as thistle down drifting with the 

 wind. 



Many of these ocean birds are gray-winged 

 and gray-backed, though not all of them. The 



