CLEANLINESS. 109 



splash, without betraying the smallest irritation. 

 On the contrary, he seems to take pleasure in his 

 little fellow-prisoner, allowing her to peck (which 

 she does very gently) about his whiskers, and to 

 clean from his claws the minute fragments of chest- 

 nuts which happen to adhere to them."* 



Ducks and other water-birds are, if possible, more 

 assiduous in trimming their feathers than landbirds, 

 one reason for which appears to be, that their plume- 

 lets being of very close texture, any slight derange- 

 ment in them is readily felt from the air getting ac- 

 cess to the skin through the breach thus occasioned. 

 The closeness of feather in aquatic birds serves to 

 present an impenetrable texture to the water in 

 which they swim, as well as a smooth surface which 

 diminishes the effect of friction in their progress. 



The greater number of authors, in addition to this, 

 tell us that birds, and more particularly aquatic birds, 

 dress their feathers with a peculiar oil furnished for 

 this purpose by a gland on the rump ; but this is an 

 opinion which we shall presently see admits of con- 

 siderable doubt. It may be well, however, to state 

 the particulars of the common notion. " Upon the 

 rump," says Willoughby, " grow two glandules, de- 

 signed for the preparation and secretion of a certain 

 unctuous humour, and furnished with a hole or ex- 

 cretory vessel. About this hole grows a tuft of small 

 feathers or hairs, somewhat like to a painter's pencil. 

 When, therefore, the parts of the feathers are shat- 

 tered, ruffled, or any way discomposed, the bird, turn- 

 ing her head backward to her rump, with her bill 

 catches hold of the fore-named tuft, and pressing the 

 glandules, forces out the oily pap, and therewithal 

 anointing the disjoined parts of the feathers, and 

 drawing them out with her bill, recomposes and pla- 

 ces them in due order, and causes them to stick 

 faster together, "f 



The recent authors who adopt this opinion would 



* Wilson's Amer. Omith., i., 15. f Ray's Willoughbj, p. 3, 



K 



