178 
FEET OF BIRDS. 
But in either he must have been deceived as to its making a nest in 
out-building-s. 
FEET OF BIRDS. — The larg-e crooked talons of birds of prey, and 
their hooked beaks, are well formed for securing and tearing their vic- 
tims. The formation of the feet of the woodpeckers, the toes being placed 
two forward and two backward, is well calculated for climbing; and the 
cuneiform shape of the extremity of their bills is suited to the purpose 
of cutting holes in decayed trees ; their tongue is also wonderfully 
contrived to search out insects beyond the reach of their bill, by its 
great length, which is double that of the tongue at least. The wry- 
neck has this singularity, as well as the like formation of the toes ; 
which last is also found in the cuckoo : but neither of these birds is 
seen to climb up the bodies of trees, nor have either the stiff sharp- 
pointed feathers in the tail, as in the woodpecker, so admirably adapted 
to support them when in the act of hewing. * This agrees with the 
observations of an ingenious living naturalist, the Rev. Revett Shep- 
herd. “ The cuckoo,” says he, ‘‘ is furnished with two toes before 
and two behind, and yet is never known actually to climb, a convincing 
proof that such conformation does not necessarily bring with it the 
power of climbing, more especially when we consider that the nut- 
hatch (^Sitta Europcea) and the creeper, (^Certliia famiUaris^ have 
their toes placed in the usual manner, and yet run up and down 
trees with as much facility as the woodpeckers. The use of the pedes 
scansorii, as they evidently in this case conduce not to climbing, I 
judge to be this ; it is well known that this bird will oftentimes sit by 
the half hour together on the bough of a tree, vociferating its loud 
and pleasing note ; in doing this, it sits remarkably forward, and ap- 
pears in constant agitation, continually moving its body up and down 
with great elegance ; now, as it sits so forward, while using this exer- 
tion, it would be liable to lose its balance and quit its hold, had it only 
one toe behind ; whereas, by the contri vance of two, it is enabled 
strongly to adhere to the branch.** 
The legs and feet of aquatic birds are wonderfully formed for ac- 
celerating their motion in that element, which is their greatest security. 
The bone of the leg is sharp, and vastly compressed sideways ; the toes, 
when the foot is brought forward, close in behind each other in such a 
manner as to expose a very small surface in front, so that, in the action 
of swimming, very little velocity is lost in bringing the legs forward ; 
this is very conspicuous in the diver. Some aquatic birds are web- 
* Linn. Trans, xii., 518. 
