The Descent of Man

ut from the analogy of other animals, it is probable
that it uses its musical powers more especially
during the season of courtship.
This gibbon is not the only species in the genus
which sings, for my son, Francis Darwin, attentively
listened in the Zoological Gardens to H.
leuciscus whilst singing a cadence of three notes,
in true musical intervals and with a clear
musical tone. It is a more surprising fact that
certain rodents utter musical sounds. Singing
mice have often been mentioned and exhibited,
but imposture has commonly been suspected.
We have, however, at last a clear account by a
well-known observer, the Rev. S. Lockwood
(31. The 'American Naturalist,' 1871, p. 761.), of
the musical powers of an American species, the
Hesperomys cognatus, belonging to a genus
distinct from that of the English mouse. This
little animal was kept in confinement, and the
performance was repeatedly heard. In one of
the two chief songs, "the last bar would fre-