MIGRATION AND FLIGHT. 
107 
smooths them down,) are chiefly natives of a few 
islands in the Indian Ocean ; and when sailing 
between these islands, flocks of them are often seen 
crossing, and always flying against the wind: but 
as, in that climate, sudden squalls often occur from 
an opposite quarter, the birds, when caught by them, 
are observed immediately to dart upwards till they 
ascend beyond the reach of the gale, and are then 
seen to pursue their course as before. 
One other very remarkable fact connected with 
these long journeys, undertaken by birds over seas 
and lands, is, that they are gifted with some secret 
power, enabling them, not only to find their way to 
and from the distant countries they visit, but ac- 
tually guiding them to the very same places from 
whence they came, and the very same spots for 
building their nests. This has been proved by 
marking the claws of Swallows, which were in the 
habit of building in sheds or outhouses, where they 
could be easily retaken on their return in the spring, 
and examined. An instance came under our own 
observation, of a pair of Swallows returning to build 
for three years in a small closet in a school-house, 
entering by a broken pane in the casement, and 
forming their nest in a corner above the window ; 
and as they were never disturbed, the female would 
remain sitting, and the male fly in and out in our 
presence. But though several broods were hatched, 
the old birds allowed no intruders, and not a single 
young bird was ever seen to return to the place of 
its birth after it had once quitted the nest. 
Another instance of confidence placed in man by 
these little birds, when unmolested, occurred at a 
