CHARACTERS AND HABITS OF BIRDS 9 



brush. Such a feather is called a stub feather, or simply a stub. 

 The best place to find these is on the outside of the shank of a 

 fowl with scantily feathered legs. 



The first form of the complete feather is best observed either 

 on the head of a fowl or at the hock joint. The feathers in these 

 places are very small, yet complete. The round quill is length- 

 ened into a shaft. Extending from each side of this shaft is a 

 single row of filaments, called barbs, the edges of which, inter- 

 locked with little hooks, form the web of the feather. On other 

 parts of the body of the bird the feathers are larger, but the 

 general structure is always the same. The size and special 

 structure of the feather are always adjusted to suit the part on 

 which it grows or the service which it has to perform. 



As the first function of the feathers is to keep the bird dry 

 and warm, the body feathers are all soft as compared with the 

 large stiff feathers of the wings and tail ; yet as we look at the 

 feathers on different parts of the body of a bird we notice dif- 

 ferences in their structure, and also notice that the structure of a 

 feather is not always the same throughout its length. On the ex- 

 posed parts of the feathers of the neck, back, wings, and breast 

 the web is perfect and the feathers overlap so closely that they 

 present a smooth surface. Under the surface, especially next 

 the skin, the barbs are not smoothly joined, but are fluffy. Thus 

 the same feathers which present a hard, smooth surface to the 

 weather provide a soft, warm garment next the skin. Under 

 the wings and on the underside of the body the feathers are 

 quite fluffy throughout their whole length. 



Arrangement of the feathers. As you look at a living bird 

 the feathers appear to grow on all parts of the body. When the 

 feathers are removed from the bird you see that while the skin 

 is nearly all rough, with the little elevations where the feathers 

 were removed, there are quite large areas where the skin is per- 

 fectly smooth, showing that no feathers grew there. These 

 places are bare because feathers on them would interfere with 



