were as near alike as two peas, but that in their songs there were
often marks of originality. Caged or domesticated birds develop
notes and traits of their own, and among the more familiar orchard
and garden birds one may notice the same tendency. I observe a
great variety of songs, and even qualities of voice, among the
orioles and among the song sparrows. On this trip my ear was
especially attracted to some striking and original sparrow songs.
At one point I was half afraid I had let pass an opportunity to
identify a new warbler, but finally concluded it was a song
sparrow. On another occasion I used to hear day after day a sparrow
that appeared to have some organic defect in its voice: part of its
song was scarcely above a whisper, as if the bird was suffering
from a very bad cold. I have heard a bobolink and a hermit thrush
with similar defects of voice. I have heard a robin with a part of
the whistle of the quail in his song. It was out of time and out of
tune, but the robin seemed insensible of the incongruity, and sang
as loudly and as joyously as any of his mates. A catbird will
sometimes show a special genius for mimicry, and I have known one
to suggest very plainly some notes of the bobolink.

There are numerous long covered bridges spanning the Delaware, and
under some of these I saw the cliff swallow at home, the nests
being fastened to the under sides of the timbers,--as it were,
suspended from the ceiling instead of being planted upon the
shelving or perpendicular side, as is usual with them. To have laid
the foundation, indeed, to have sprung the vault downward and
finished it successfully, must have required special engineering
skill. I had never before seen or heard of these nests being so
placed. But birds are quick to adjust their needs to the exigencies
of any case. Not long before, I had seen in a deserted house, on