82 THE AMERICAN BREEDS OF POULTRY 



the incubator manufacturers has been to build a box that would keep 

 out cold as effectively as does the plumage of a hen setting on eggs. 

 They have built double walls and padded them in between. 



The average man who builds a poultry house that his hens may 

 have a decent place in which to live, is usually tempted to build the 

 house tight that the hens may be warm. He fails to learn the lesson 

 from the bird which he sees sitting on the twig of a tree, singing and 

 happy, as he looks out of the house on Christmas morning across 

 two feet of snow. That little bird has been out all night and the 

 wind has blown and it has been cold, but it did not freeze or die, 

 for is it not there on the twig, chirp and happy, singing its Christmas 

 carol? 



Fowls, like birds, breathe all the way through their lungs into 

 four pairs of air sacs (which are the bellows-like portion of their 

 respiratory system) affording the very best possible opportunity for 

 the oxygen of fresh air to combine with the blood and be carried 

 to all parts of the body. One thousand pounds of chickens breathe 

 from 2 to 2^4 times as much air as the same weight of cattle, horses 

 or men, according to F. H. King. Birds have a higher temperature. 

 Therefore, do not shut the poultry up in a close hen house; consider 

 the nature of the bird and its coat of plumage. This overcoat is of 

 nature's best make, effective as an insulator of body temperature, a 

 wonderfully woven fabric of beautiful color. Let us learn more 

 about it. 



The secondary feather. Did you ever examine a feather on the 

 under side? There is a little secondary feather at the base, called 

 the after-shaft. The great feathers of the wing and tail are an excep- 

 tion. This after-shaft of the body plumage serves as "the under- 

 clothes." Dr. P. T. Woods has suggested that when hens are housed 

 in open front poultry houses the after-shaft assumes larger propor- 

 tions than where the birds are cooped in tight quarters. 



The downy part of the feather helps to keep the bird warm, the 

 soft fluff holding more air than were the feather material closely 

 knit into a smooth surface all the way down to the skin. The smooth 

 surface, however, is better to shed rain and makes the better outer 

 protection; it also permits birds in flight to pass through the air 

 with the least resistance. 



It is on the surface that the important color pattern is usually 

 exhibited. In a penciled or laced feather, the design is entirely on 

 the web or smooth surface of the feather. A Barred Rock, however, 

 is an exception, for a good one is barred the entire length of the 

 feather. 



Structure of the feather. Let us examine the feather from the 

 back of a hen. The feather proper may be divided into three parts: 

 the quill or shaft; the web or smooth part which forms the surface 

 of the plumage; and the fluff or downy part at the base. 



The shaft or quill is the axis from which the rest of the feather 



