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 arabie, 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 arable," 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 
