HISTORY OF 



once the purposes of warmth, speed, and security. 

 They mostly tend backward, and are laid over 

 one another in an exact and regular order, armed 

 with warm and soft down next the body, and 

 more strongly fortified and curiously closed ex- 

 ternally, to fence off the injuries of the weather. 

 But, lest the feathers should spoil by their violent 

 attrition against the air, or imbibe the moisture 

 of the atmosphere, the animal is furnished with a 

 gland behind, containing a proper quantity of 

 oil, which can be pressed out by the bird's bill, 

 and laid smoothly over every feather that wants 

 to be dressed for the occasion. This gland is 

 situated on the rump, and furnished with an 

 opening or excretory duct ; about which grows 

 a small tuft of feathers, somewhat like a painter's 

 pencil. When, therefore, the feathers are shat- 

 tered or rumpled, the bird, turning its head back- 

 wards, with the bill catches hold of the gland, 

 and, pressing it, forces out the oily substance, 

 with which it anoints the disjoined parts of the 

 feathers ; and, drawing them out with great assi- 

 duity, recomposes and places them in due order, 

 by which they unite more closely together. Such 

 poultry, however, as live for the most part under 

 cover, are not furnished with so large a stock of 

 this fluid as those birds that reside in the open air. 

 The feathers of a hen, for instance, are pervious 

 to every shower ; on the contrary, swans, geese, 

 ducks, and all such as nature has directed to live 

 upon the water, have their feathers dressed with 

 oil from the very first day of their leaving the 

 shell. Thus their stock of fluid is equal to the 



