CLEANLINESS. 115 
Wilson remarked that in specimens which he pro- 
cured of the night-heron (Nycticorax Europeus, Str- 
PHENS), the middle claws, serrated on the inside with 
from thirty-five to forty teeth, contained “ particles 
of the down of the bird, showing evidently from 
this circumstance that they act the part of a comb, 
to rid the bird of vermin in those parts which it can- 
not reach with its bill.”* With respect to the night- 
jars, Wilson gives a similar statement. His night- 
hawk, for instance, he says, has its “ middle claw 
pectinated on its inner edge, to serve as a comb to 
clear the bird of vermin.”+ Again he says, “ the 
inner edge of the middle claw of the whip-poor-will, 
another of the nightjars, is pectinated; and from 
the circumstance of its being frequently found with 
small portions of down adhering to the teeth, is 
probably employed as a comb to rid the plumage of 
its head of vermin, this being the principal and al- 
most only part so infested in all birds.”{ He farther 
proves this in the case of the Carolina nightjar, or 
chuck-will’s-widow, by actual observation of the 
fact; speaking of which species he says, “ reposing 
much during the heats of the day, they are much 
infested with vermin, particularly about the head, 
and are provided with a comb on the inner edge of 
the middle claw, with which they are often employed 
in ridding themselves of these pests when in a state 
of captivity.”’§ 
The main instrument, however, by which birds 
trim their feathers is the bill; and if any fluid is used, 
it must be produced from the salivary, and not from 
the rump-glands. By attending minutely to the op- 
eration, indeed, the tongue may be perceived to be 
as actively employed as the other parts of the bill, 
and is certainly the organ which apprizes the bird of 
any rumpling or clotting of the plumelets; and when 
such derangement is perceived, a pause is instantly 
* Wilson, Amer. Ornith., vi., 110, 2d ed. 
} Ibid., v., 70. i tbidy ¥., 77; § Ibid., vi., 97. 
