16 THE STORY OF BIRD-LIFE. 



materials, which we call feathers — such is a 

 bird. 



All of us know that a bird is clothed with 

 feathers, but probably few know anything of the 

 peculiar manner in which these are distributed 

 over the body, or have ever taken the trouble 

 to find this out; we content ourselves — if we 

 ever trouble to think about it at all — with 

 reasoning from analogy and the deductions 

 drawn therefrom. The hairs of the silky coat 

 of a well-groomed horse, or of a dog or cat, 

 we remark, are set as close as close can be, one 

 to another all over the body as are the hairs 

 in our head. Surely therefore, we assume, the 

 feathers would be similarly distributed. 



Now, this is exactly what does not happen. 

 One of the earliest to point this out was a German 

 ornithologist named Nitzsch. Just upon sixty 

 years ago he published a wonderful book on 

 this very subject, in which he showed that 

 although the whole of the bird's body save its 

 beak and "legs" are concealed from view by 

 the feathers, yet these need by no means occupy 

 a very large area of the bird's skin. On the 

 contrary, he found that they are always more 

 or less restricted to certain definite areas, which 

 he called *' feather-forests" separated by tracts 

 of skin, often perfectly naked. On this dis- 

 covery he based a series of most important and 

 far-reaching observations, which eventually, after 

 his death, were published, and now form the 

 foundation of what might almost be called the 

 " science " of Pterylography. Perhaps we ought 

 to regard his work as something more than a 



