10 OUR DOMESTIC BIRDS 



the movements of the bird. The feathers on adjacent parts 

 give the smooth areas sufficient protection. 



Decorative feather forms. The natural decorative forms of 

 plumage are found mostly in male birds and consist of extraor- 

 dinary developments of the plumage of the neck and back, 

 where the male birds of some species always have feathers 

 differing in form from the feathers on the same parts of the 

 female. When a feather appendage not common to a species is 

 developed on some varieties, as the crest and beard on fowls 

 and the ruff on pigeons, both sexes have it. The most inter- 

 esting feather decorations will 

 be described particularly in the 

 chapters on the species on which 

 they occur. 



Color in feathers. While colors 

 in the plumage are distributed 

 very differently in different 

 species of birds, often mak- 

 ing combinations peculiar to a 

 FIG. i. Brown Leghorn chick species, there is in all the same 



wonderful formation of patterns, 



that depends for its effect in a section upon some overlap- 

 ping feathers being marked alike and others having a different 

 marking ; and for the effect in a single feather, upon adjacent 

 barbs being now alike, now different, in the distribution of the 

 pigment in them. The best common example of a pattern cover- 

 ing a series of feathers is found on the wing of a Mallard Duck 

 or of a Rouen Duck. Interesting examples of the formation of 

 patterns on a single feather may be found in the plumage of 

 barred, laced, and penciled fowls, and also in the lacings on 

 the body feathers of the females of the varieties of ducks men- 

 tioned. Perhaps the most interesting illustrations of this kind, 

 however, are to be seen on the plain feathers of the guinea and 

 the gorgeous tail of the peacock. 



