OIL GLANDS OF BIRDS. 
61 
curing a liquor from the gland, by means of its beak, 
in order to apply it to the feathers. But, at best, 
this can be only mere conjecture on the part of the 
observer, because the feathers on the rump com- 
pletely preclude the possibility of his having a dis- 
tinct view of wTiat the bird is doing. 
Will any naturalist declare that he has actually 
seen a bird procure liquor, or oil, or whatever else 
you choose to call it, from the gland with its bill, 
and then apply that liquor or oil to the plumage ? 
The gland has somewhat the appearance of a nipple 
upon its upper extremity ; an oily liquor may be ob- 
tained from this nipple by applying our fingers to it; 
but I marvel how it can be procured by the sharp- 
edged bill of a bird. When the nature of the gland 
and the form of the bill are duly considered, it is 
rational to conclude that the application of the hard 
bill to the soft gland would be very painful to the 
bird. Let us here suppose that the bird has suc- 
ceeded in getting some of the liquor into its bill : 
how is the liquor to be applied to the feathers ? It 
cannot be rubbed upon them, because it is within 
the bill ; and if the bird should apply its bill to the 
feathers, they would merely come in contact with 
the edges of the bill, while the liquor would have 
sunk into the cavity of the lower mandible. Grant- 
ing that the liquor were removed to the feathers by 
means of the tongue, then the under part of the 
feathers would receive more than the upper part. 
Here let us keep in mind what a large body of fea- 
thers there is to be lubricated, and how small the 
supply of liquor for the purpose of lubrication. 
