OIL GLANDS OF BIRDS. 63 



there is the following account of the lubricating of 

 feathers : 



" The glands containing the oil used for the purpose of 

 lubricating the surface of the plumage were, in the specimen 

 here represented (speaking of the eagle), [" sea-eagle of 

 America, or bird of Washington "], extremely large. The 

 contents had the appearance of hog's fat which had been 

 melted and become rancid. This bird makes more copious 

 use of that substance than the white-headed eagle, or any of 

 the Falco genus, except the fish-hawk ; the whole plumage 

 looking, upon close examination, as if it had received a gene- 

 ral coating of a thin clear solution of gum arable, and present- 

 ing less of the downy gloss exhibited on the upper part of the 

 bald-headed eagle's plumage." 



Here we have had an abundant flow of oil. If 

 the surface got so much, the under parts of the 

 plumage must have got still more; notwithstanding 

 which, we are told that the glands were extremely 

 large : they ought to have been empty after such a 

 discharge. .Again, if the whole plumage looked " as 

 if it had received a general coating of a thin clear 

 solution of gum arabic," by what process was that 

 general coating applied to the head of the eagle, and 

 to part of the neck, which, we know, cannot possibly 

 be touched by the bill ? If it had not been applied 

 to the head and part of the neck, then the bird would 

 have afforded a singular appearance : just as far as 

 the beak could reach, there would have been a dis- 

 tinct coat of what the writer of the article took for 

 oil from the gland ; beyond the reach of the beak 

 (that is, on the head, and down part of the neck) 

 there would have been no coating at all. 



If that which appeared like a general coating of a 

 thin solution of gum arabic had really been oil from 



