68 THE FEATHERS. 



appetite ; their eyes become dull, and they betray symptoms 

 of weariness and weakness. In some birds this growth of 

 feathers is always going on, and they may be said to be in 

 a perpetual moult ; while in others again, and those chiefly 

 water birds, the process of moulting or changing plumage 

 occurs only twice in the year, in autumn and in spring ; 

 and here again we shall find that Creative Wisdom is at 

 work in acting for the best. 



That there is a great difference in the summer and winter 

 plumage of many birds is known to almost everybody ; but 

 it requires a closer examination to see that much of this 

 difference consists in a great increase of warmth, to meet 

 the severity of the latter season, which is thus produced. 

 In the autumnal moult, when the summer feathers fall off, 

 the new feathers which take their place will be found to be 

 fringed. This fringe is generally of the same texture, though 

 almost always of a warmer and more downy character, and 

 often of a different colour, which will account for the variety 

 of tints often observed in birds at these different seasons of 

 the year. As the spring advances these little fringes break 

 off, and leave the edge of the feather sharp and defined, but 

 of course shorter ; in this very simple manner is the bird 

 divested of a quantity of winter clothing, when the weather 

 is warmer, and a superfluity of apparel no longer required. 

 In the case of two species of Partridges, called the Wood 

 and Rock Partridge of North America, which, in winter, 

 burrow underneath the snow, a still warmer covering is 

 provided, the growth of feathers being actually doubled; 

 so that they have nearly twice as warm a coat, when they 

 most require it, as they had during ^summer, when it was 

 unnecessary. 



Generally speaking, the colour of the plumage in different 

 species is the same ; there are, however, some constant ex- 

 ceptions, as, for instance, in the Ruffs and Reeves, in which 

 no two birds are ever found exactly alike. The Ptarmigans, 

 again, vary considerably ; the Cross -beak also has the same 

 peculiarity, and it is almost needless to point out the constant 

 variety observable in our common barn-door fowls; but, 



