96 THE ARCHITECTURE OF BIRDS. 
shall begin with one about which there can be the 
least dispute. We are furnished with an instance 
well adapted for this purpose in the American chim- 
ney-swallow (Cypselus pelasgius, LATHAM). 
Wilson has given the following very. interesting 
history of their mode of nestling. ‘“ They arrive,” 
he says, “in Pennsylvania late in April or early in 
May, dispersing themselves over the whole country, 
wherever there are vacant chimneys in summer suf- — 
ficiently high and convenient for their accommoda- 
tion. Inno other situation with us are they observed 
at present to build. This circumstance naturally 
suggests the query, Where did these birds construct 
their nests before the arrival of Europeans in this 
country, when there were no such places for their 
accommodation? I would answer, probably in the 
same situations in which they still continue to build 
in the remote regions of our western forests, where 
European improvements of this kind are scarcely 
to be found; namely, in the hollow of a tree, which 
in some cases has the nearest resemblance to their 
present choice of any other. One of the first set- 
tlers in the State of Kentucky informed me that he 
cut down a large hollow beech-tree which contained 
forty or fifty nests of the chimney-swallow, most 
of which, by the fall of the tree or by the weather, 
were lying at the bottom of the hollow, but sufficient 
fragments remained adhering to the sides of the tree 
to enable him tonumberthem. They appeared, he 
said, of some years’ standing. The present site 
which they have chosen must, however, hold out 
many more advantages than the former, since we 
see that in the whole thickly-settled parts of the 
United States these birds have uniformly adopted 
this new convenience, not a single pair being ob- 
served to prefer the woods. 
“Security from birds of prey and other animals, 
from storms that frequently overthrow the timber, 
and the numerous ready conveniences which these 
new situations afford, are doubtless some of the ad- 
