18 BIRDS THROUGH AN OPERA-GLASS. 
breath and wave their brooms in the air at their 
escape from the dangers below. Though never 
venturing near us the swifts come to live inside 
our houses. Like the robin they are citizens, but 
what a contrast ! 
Their feet are weak from disuse, and it is be- 
lieved that they never light anywhere except in a 
chimney or in a hollow tree, where they sometimes 
go at night and in bad weather. They gather the 
twigs they glue together for their nests while on 
the wing, and their ingenuity in doing it shows 
how averse they are to lighting. Audubon says: 
“The chimney swallows are seen in great numbers 
whirling around the tops of some decayed or dead 
tree, as if in pursuit of their insect prey. Their 
movements at this time are exceedingly rapid; 
they throw their body suddenly against the twig, 
grapple it with their feet, and by an instantaneous 
jerk snap it off short, and proceed with it to the 
place intended for the nest.” 
WV: 
CATBIRD. 
Hiaeu trees have an unsocial aspect, and so, as — 
Lowell says, “The catbird croons in the lilac- 
bush,” in the alders, in a prickly ash copse, a bar- 
berry-bush, or by the side of the garden. In 
Northampton one of his favorite haunts is an old 
