Ixxiv 
INTRODUCTION. 
customed as we are to measure the actions and ability of other animals by 
our own powers, a standard generally unjust, we forget to allow suffici- 
ently for difference of organization ; though birds, relatively to us, may 
seem imbecile animals, yet, as to themselves, in aerial excursions, they are 
possessed of astonishing strength. 
Manv of the short-wino;ed race that return to us in the summer 
season, join in the chorus of the warblers in our woods ; and such of 
them, to whieh nature has denied the voice of harmony, render essential 
service to us by the destruction of our minute foes. They contribute, 
by their exertions, to preserve the nicely-poised balance between increase 
and destruction, and to clear the atmosphere from the contagion, which 
would arise from the deaths of myriads of insects, dispersing from their 
decomposition the active miasma of putrefaction. 
that he had observed multitudes of small birds at a great distance from land ; and that he had taken 
Larks between Majorca and Sardinia, from immense flocks, which he conjectured came from 
France or Italy, and w’ere on their flight to Africa. And I have received accounts from nume- 
rous mariners, which corroborate the fact, that many of the smaller species, even of those which 
are not termed migrants, are at times discovered at sea, far from land. From the result of many expe- 
riments, I am led to suppose, that birds in general fly more rapidly than we are inclined to admit. 
The speed of the swiftest racer will bear no comparison with that of the Swallow ; a short period 
of extraordinary exertion will diminish and exhaust the strength of the quadruped ; while the 
bird for hours can glide through the air with the rapidity of lightning, unimpeded by the causes 
which would produce, in its competitor, total debility, and a want of power to continue in action. 
Swifts are known, in the summer season, to remain on the wing, without resting, the greater part 
of the day ; a Swift, that had been sitting a brood, was taken, and given its liberty at the distance- 
of nearly two hundred and twenty yards from its nest, which it regained in less than seven, 
seconds. 
