CHIMNEY SWALLOW. 
427 
which hy the fall of the tree, or by the weather, were lying at 
the bottom of the hollow, but sufficient fragnaents remained ad- 
hering to the sides of the tree to enable him to number them. 
They appeared, he said, to be of many 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 observed 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 advantages. The 
choice they have made certainly bespeaks something more than 
mere unreasoning instinct, and does honour to their discern- 
ment. 
The nest of this bird is of singular construction, being form- 
ed of very small twigs, fastened together with a strong adhesive 
glue or gum, which is secreted by two glands, one on each side 
of the hind head, and mixes with the saliva. With this glue, 
which becomes hard as the twigs themselves, the whole nest is 
thickly besmeared. The nest itself is small and shallow, and 
attached by one side or edge to the wall, and is totally destitute 
of the soft lining with which the others are so plentifully sup- 
plied. The eggs are generally four, and white. They gene- 
rally have two broods in the season. The young are fed at inter- 
vals during the greater part of the night, a fact which I have 
had frequent opportunities of remarking both here and in the 
Mississippi territory. The noise which the old ones make in 
passing up and down the funnel has some resemblance to dis- 
tant thunder. When heavy and long continued rains occur, 
the nest, losing its hold, is precipitated to the bottom. This dis- 
aster frequently happens. The eggs are destroyed; but the 
young, though blind, (which they are for a considerable time) 
sometimes scramble up along the vent, to which they cling like 
squirrels, the muscularity of their feet and the sharpness of 
their claws at this tender age being remarkable. In this situa- 
