T^ 



SENSATION IN FEATHERS. 37 



&c., that seek their prey solely during the lonely hours of 

 darkness. 



Nevertheless, a certain degree of this delicacy of perception 

 is absolutely requisite even for them to secure their safety 

 whilst performing rapid flights through the thickets and forests 

 that they most generally inhabit or take shelter in. This, then, 

 being the case, is it not reasonable to infer that the feathers 

 should at all times be in the highest state of perfection ? This, 

 however, would not be attained, if they were not shed or re- 

 newed from time to time, as they necessarily must become 

 soiled, dried, broken, and ultimately totally unfit for this nice 

 service by the constant exposure they are subjected to, as well 

 as the many accidents they must encounter. 



To remedy these evils, or rather to make provision for such 

 casualties. Nature, ever provident in all her works, very wisely 

 ordains that the feathered race shall moult, or, in other words, 

 shed their plumage entire once or twice a year. The simple 

 shedding of the feathers is not the only precaution that a bene- 

 ficent Providence has established for the preservation of these, 

 the most extensive and beautiful portion of his creations. For 

 we may here also notice the remarkable changes that take 

 place in the tints of the plumage, more especially in those Birds 

 that remain in the northern latitudes during the long and bleak 

 winters. Many of them, from the most sombre hues of spring 

 and summer, become pied, or even pure white; thus cunningly 

 adapting themselves to the pervading color of the objects by 

 which they are surrounded, they are the better able to concerJ 

 themselves from the attacks of their many prowling enemit. 

 that are now driven to great extremes for food. The proteo 

 tion afforded Birds as well as many of the smaller quadruped.^ 

 in this alteration of the color of their plumage and pelage fron» 

 the aggressions of their more powerful foes is not the oiily 

 benefit that results from this wise providence; as the chilling 

 effects of constant exposure to the excessive cold of those 

 hibernal regions are somewhat abated by the transition to 

 white, from the well-established fact that a surface purely white 

 reflects heat far more copiously than a dark one; and consequently 

 it is not difficult for us to infer that, in like manner, it prevents 

 any undue waste of the animal heat by radiation. 



