ARRANGEMENT OF FEATHERS. 403 



desire. We must therefore defer to another occa- 

 sion the duty of discussing the change, and many 

 other particulars connected with the plumage of 

 birds, contenting ourselves with the simple state- 

 ment, that there is a great difference between the 

 plumage of birds in the young and in the adult 

 state, as already noticed, and also in summer and 

 winter. The latter fact is known to almost every 

 person, and the alteration it makes in the appear- 

 ance of birds is very remarkable in certain cases. 

 Popularly the change of plumage in the latter case 

 is known as the " moult." 



Before passing, however, to the next part of the 

 bird's anatomy, it may be instructive to notice 

 the beautiful manner in which the feathers are 

 arranged on the body of the bird. Generally 

 speaking, the feathers are placed one over two, 

 somewhat like the way in which slates are ar- 

 ranged on our house-tops. The middle of one 

 feather is thus placed so as exactly to cover the 

 opening left between the edges of the two beneath. 

 In the upper part of -the body of the bird the 

 feathers are so beautifully arranged in this man- 

 ner, and are at the same time so smooth and close, 

 that they form a covering as waterproof as one of 



