modulated, "Hear me, Saint Theresa!" This strain, as I have observed
many times since, is, at certain hours, repeated constantly for ten
minutes at a time, and it is one of those melodious sounds that seem to
belong exclusively to solitude.

The Green Warbler (_Sylvia virens_) is a small bird, and though his
notes may be familiar to all who have been accustomed to strolling in
the woods, the species is not numerous in Massachusetts, the greater
number retiring farther north in the breeding-season. Nuttall remarks in
reference to this bird, "His simple, rather drawling, and somewhat
plaintive song, uttered at short intervals, resembled the syllables '_te
de teritsca_, sometimes _te derisca_, pronounced pretty loud and slow,
and the tones proceeded from high to low. In the intervals, he was
perpetually busied in catching small cynips, and other kinds of
flies,--keeping up a smart snapping of his bill, almost similar to the
noise made by knocking pebbles together." There is a plaintive
expression in this musical supplication, that is apparent to all who
hear it, no less than if the bird were truly offering prayers to some
tutelary deity. It is difficult, in many cases, to determine why a
certain combination of sounds should affect one with an emotion of
sadness, while another, under the same circumstances, produces a feeling
of joy. This is a part of the philosophy of music which has not been
explained.

While treating of the Sylvias, I must not omit to notice one of the most
important of the tribe, and one with which almost everybody is
acquainted,--the Maryland Yellow-Throat (_Sylvia trichas_). This species
is quite common and familiar. He is most frequently seen in a
willow-grove that borders a stream, or in the shrubbery of moist and low
grounds. The angler is greeted by his notes on the rushy borders of a
pond, and the botanist listens to them when hunting for those
rose-plants that hide themselves under dripping rocks in some wooded
ravine. The song of the Yellow-Throat resembles that of the Warbling
Vireo, delivered with somewhat more precision, as if he were saying, _I
see you_, _I see you_, _I see you_. His notes are simply lively and
agreeable; there is nothing plaintive about them. The bird, however, is
very attractive in his appearance, being of a bright olive-color above,
with a yellow throat and breast, and a black band extending from the
nostrils over the eye. This black band and the yellow throat are the