The Descent of Man

'Todd's Cyclopaedia of Anatomy and Physiology,'
vol. iv. p. 1496.), though they never sing,
and do not naturally modulate their voices to
any great extent. Hunter asserts (38. As stated
by Barrington in 'Philosophical Transactions,'
1773, p. 262.) that with the true songsters the
muscles of the larynx are stronger in the males
than in the females; but with this slight exception
there is no difference in the vocal organs of
the two sexes, although the males of most species
sing so much better and more continuously
than the females.
It is remarkable that only small birds properly
sing. The Australian genus Menura, however,
must be excepted; for the Menura Alberti,
which is about the size of a half-grown turkey,
not only mocks other birds, but "its own whistle
is exceedingly beautiful and varied." The
males congregate and form "corroborying places,"
where they sing, raising and spreading
their tails like peacocks, and drooping their