208 THE BIRDS OF SHERWOOD FOREST. 



been repeated by every author, from Montagu to the 

 present time.* 



The gallinaceous birds have generally only one gland, 

 which, as they do not seek their food upon the water, 

 would, according to the common theory, furnish sufficient 

 oil for their wants. But surely a dressing of oil, how- 

 ever slight, would be a bad preparation for the practice 

 of dusting, in which these birds love to indulge. Instead 

 of tending to their cleanliness and comfort, it would have 

 a contrary effect, dirtying and clogging their feathers. 

 And vet we know it is not so ; for, after the dust is ex- 

 pelled by a few vigorous shakes, their plumage is as 

 clean as ever. 



The practice of dusting, which seems merely to be 

 employed as a simple mechanical means of dislodging 

 the parasites with which all birds are infested, I have 

 seen practised three or four times in succession ; and if 

 the feathers had been oiled, this repeated application of 

 dust would but increase their filthiness. 



While thus rejecting the common notion, I would not 

 venture to assert that I am certain of the true use of 



* " Nature, ever provident in all her ways, has taken care to supply 

 every bird, more or less, with an external secretion of an unctuous 

 nature, situated in a glandular bag upon the rump, which they in- 

 stinctively make use of for oiling and dressing their feathers as 

 occasion requires. In water-fowl this bag is most conspicuous, 

 and it is remarkable that birds most frequently use it after washing, 

 previously to their feathers becoming perfectly dry." Montagu's 

 Ornithological Dictionary, p. 136. " And finally, the gland 

 which all birds have at the rump, and from which they express an 

 oily matter to preserve their feathers moist, is most considerable in 

 those that live upon the water, and contributes to make their plu- 

 mage impermeable." The Sea and its Living Wonders, by Dr. 

 G. Hartwig, p. 123. Longmans, 1860. 



