XII 

 THE SKIN AND ITS APPENDAGES 



The skin of birds is very thin and contains no 

 glands except the uropygial or oil gland which 

 lies over the last vertebra. This is two-lobed 

 and about the size of a pea in the fowl. The 

 oily secretion used by the bird to dress the 

 feathers is produced by numerous tubules 

 which pour their secretion into a common 

 cavity, from which it gains the surface by an 

 opening at the summit of a nipple-like pro- 

 jection of the skin. 



A thin, dry, and scurfy epidermis covers 

 those parts of the skin on which feathers grow, 

 while the naked part of the leg is clothed with 

 scales. The toes carry claws, and a horny 

 sheath covers the beak. 



The skin is very sensitive in virtue of 

 the numerous nerve-endings associated with it 

 generally and more especially with the roots 



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