2992 YEARBOOK OF THE DEPARTMENT OF AGRICULTURE. 
slender, flexible filaments of the hyoid bone, each incased in a muscular 
sheath (fig. 34, a). These filaments, instead of ending at the back of 
the mouth, curve up over the back of the skull, across the top of the 
head, and down on the forehead, and in some species enter the opening 
of the right nostril, and extend forward to the end of the beak (fig. 35). 
In the last case the tongue is practically twice the length of the head. 
By means of its surrounding muscular sheath, the tongue can be pro- 
truded from the bird’s mouth a considerable portion of its length, and 
can thus be inserted into the burrows of wood-boring larve. In order 
to secure grubs or other insects, it is usually furnished with a sharp 
point and is barbed on the sides (fig. 34, 3). 
It is evident that a bird possessing such an 
apparatus must be capable of doing work 
which less advantageously endowed species 
can not accomplish. Hence, while most 
birds content themselves with eating such 
insects as they find upon the surface, wood- 
peckers seek those larve or grubs which are 
beneath the bark, or even in the very heart 
of the tree. To render more effective the 
mechanism here described, these birds are 
gifted with a remarkably acute sense of 
hearing by which to locate their prey within 
the wood. That they do so with great accu- 
racy, is disclosed by examination of their 
work, which shows that they cut small holes 
directly to the burrows of the grubs. 
Downy woopPrEcKER.—Of the various 
species of woodpeckers in the Eastern 
FIG. 34.—Tongues of woodpeckers; States, the two most important are the so- 
a, hyoid of flicker (¢Hlaptes aura- Called downy and hairy woodpeckers. These 
See ae sien birds are especially given to foraging in 
orchards, more particularly in winter; for, 
unlike most species,they do not migrate, but remain on their range the 
year round, 
A study of the contents of the stomachs of many specimens of the 
downy woodpecker (Dryobates pubescens) shows that nearly one-fourth 
of the yearly food consists of ants. A celebrated French writer upon 
popular natural history has spoken of the ant as ‘the little black 
milkmaid, who pastures her green cows in the meadow of a rose leaf.” 
This is a graphic, if somewhat fanciful, picture of the relations of ants 
and plant lice (Aphid); but unfortunately the black milkmaid does 
not limit her pastures to the rose-leaf meadows. There are compara- 
tively few plants which do not suffer to some extent by the ravages 
of plaat lice, and fruit trees and ornamental shrubs seem to be more 
