AMERICAN CHIMNEY SWALLOW. 97 
vantages. The choice they have made certainly 
bespeaks something more than mere unreasoning 
instinct, and does honour to their discernment.” 
To the following passage we request particular 
attention. 
 “'The nest of this bird is of singular construction, 
being formed of very small twigs fastened together 
with a strong adhesive glue or gum, which is secre- 
- ted 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 generally have two birds in the season. The 
young are fed at intervals during the greater part of 
the night, a fact which.I have had frequent opportu- 
nities of remarking, both here and in the Mississip- 
pi territory. The noise which the old ones make 
in passing up and down the funnel has some resem- 
blance to distant thunder. When heavy and long- 
continued rains occur, the nest, losing its hold, is 
precipitated tothe bottom. This disaster 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 situation they 
continue to be fed for perhaps a week or more. 
Nay, it is not. uncommon for them voluntarily to 
leave the nest long before they are able to fly, and 
to fix themselves on the wall, where they are fed 
until able to hunt for themselves.”* 
Since Wilson seems to be certain that the gluti- 
nous substance employed by the American chimney- 
* Wilson, fy ee v., 50. 
