210 THE BIRDS OF SHERWOOD FOREST. 



These birds are more thoroughly aquatic than any others, 

 seeking their food entirely under water; and, if the 

 received theory is true, they would require much oil to 

 keep their plumage waterproof, notwithstanding the 

 scale-like character of some of the feathers ; and yet, 

 strange to say, they do not possess the vestige of an oil 

 gland, and- they, consequently, have no means of " oiling 

 their plumage.'"' 



I had some correspondence with Mr. Zurhorst, the 

 eminent poultry breeder of Dublin, on this subject, who 

 considers from his observations on his domestic ducks, 

 that they do, or at least appear to, apply the oil which they 

 obtain from the gland, to their feathers. He says, " At 

 all events the feathers around the glands are raised on 

 end, the bill is buried in them, accompanied by a jerk- 

 ing motion expressive of pressure or squeezing being 

 used on some special part or parts ; this is followed by 

 repeated applications of the bill to the different parts of 

 the plumage not at random, but going carefully over 

 the surface, inch by inch. My Aylesbury ducks, after 

 long confinement, when fattening for exhibition pur- 

 poses, when turned out on the pond for the first time, 

 are evidently loose-feathered ; the plumage becomes 

 speedily saturated, and, if the birds are at once confined 

 again, takes very long to dry ; whereas if, after being 

 allowed time to dry and dress their feathers, they are 

 turned in again, they come out apparently as sleek and 

 impervious to wet as ever they were. I would incline 

 to think that if the oil were supplied by an involuntary 

 operation through the body itself, there would be no 

 deficiency in the supply during confinement. With 

 reference to gallinaceous birds, the dusting process 

 strikes me more as a cleansing process than specially 



