ADAPTATION OF STRUCTURE TO HABITS. 
281 
movement of their pinions suffices to enable them 
again to take wing. Between the Swift and its noc¬ 
turnal representative, the Goatsucker, a difference is 
to be remarked similar to that existing between the 
Falcon and the Owl. The Goatsuckers possess a plumage 
soft and light, like that of the Owls ; their wings, though 
pointed, are not nearly so much so as those of the Swift; 
the pinion-feathers are softer, and the tail-feathers com¬ 
paratively both longer and broader than with the above. 
The eye of the Goatsucker is especially adapted to the 
uncertain light of night and evening ; the jaws and gullet 
are much larger than those of the Swift; the opening 
of the mouth extends far behind the eye, and is, further, 
garnished with stiff bristles, which in a certain degree 
augment its power of seizing its prey. The weak and 
clumsy feet only permit of a shambling walk; the nail of 
the middle toe is serrated on the inside, thus affording 
greater facility for grasping the bark of boughs, upon 
which this bird loves to rest longitudinally. In this way 
we see that the Goatsucker is fully enabled to move, 
noiselessly and with certainty, in pursuit of its prey. In 
addition to this, the colour of its plumage bears the 
closest possible resemblance to the bark of trees, and 
thus serves to hide it from the view of an enemy in open 
day. 
Our examination becomes the more interesting the 
further we extend our circle of observation. Let us now 
pass in review the “ tools” with which the Woodpecker 
is furnished,—the carpenter of the forest, as we may call 
it. Its body is thinly and smoothly feathered; the wings 
are rather short, though in other respects they are not 
peculiar; the tail, feet, beak, and tongue are, on the 
contrary, singularly developed: these, indeed, constitute 
