Thus, to select examples which every one can observe, when a canary
bird is warbling in its cage and becomes deafening, or when a lark
rises straight up in the air and _incantat suum tirile tirile_--sings
its _tirile tirile_--as Linnaeus picturesquely expresses it; when a
tomtit, leaping from branch to branch of a willow or among the reeds,
repeats its florid warblings; when a raven croaks; when a blackbird
whistles--what significance can we attach to their songs and their
cries? Certainty is impossible, and we can only form more or less
plausible hypotheses concerning the interpretation of them.

The parrot furnishes us one more aid in this matter than other birds,
and this helps us, to a certain extent, in overcoming the difficulty
of interpretation. It has an articulate voice, and when we have taught
it a few words, the meaning which it gives them may be better divined
by us according to the tone and the rapidity or slowness of its
utterance. This permits us to discover the feelings that move it, for
we can better judge from an articulate sound than from one that is
merely musical.

Much has been written on the language of animals. It is neither my
desire nor my intention to repeat here all that may have been said on
this subject. It would take too long and would be of no use. I have
often witnessed facts that may be of interest to those who are
occupied with the mental manifestations of animals. I will simply
relate them; and of such as are already known, I will merely mention
them anew, admitting in advance a priority for others which I do not
demand for myself.

There can be no doubt that animals communicate their impressions by an
inarticulate voice. Common sense and the most superficial observations
are opposed to the negative of this proposition. But when a canary
bird warbles till it stuns us, or a nightingale sings in the shadows
on the fine nights of June, can we follow and discover the
significance of those modulations--now sharply cadenced, now slowly
drawn out, and ending with a trill long and accurate enough to
challenge the most skillful musician?

All the poets of every country have constantly sung of the songs of
Philomela. But their fervent and enthusiastic verses cast little light
on the value of the nightingale's song. It is said that the male sings
for the entertainment of the sitting female, but there is no proof of
the assertion. The note warning of the approach of danger is easier to
r