138 WOOD NOTES WILD. 
Genesis oF Brrp Sona. — Contin. 
own addition to the glorious inheritance.” — Torrey, B.: Birds in the 
Bush, p. 47. 
“Let us for a moment try to conceive how this process may have been 
accomplished. We presuppose a certain amount of the power of vocalization 
at different heights or pitches, the results of social needs, etc. We further 
assume, as the correlative of this, the existence of a nascent sensibility to 
differences of pitch, also a feeling of preference for certain kinds of timbre 
over others, The circumstances of wooing, with its eager rivalries, would 
serve to bring out the existing powers of vocalization to their fullest. 
The more striking and attractive the sounds produced by a particular 
male, the more likely would it be to win his mate. Now a voice might 
be more impressive, either through its greater intensity, or through its 
more agreeable timbre, or finally through its greater variety of tone, or 
range of pitch. And thus the fortunate possessors of voices having these 
superior qualities would, other things being equal, outdo their rivals. 
Now this triumph of rich-voiced individuals in the contests of love would 
have important after-results. If from generation to generation the females 
of a particular species continue to choose males with fine voices, there 
would be a gradual improvement of vocal powers generally, according to 
Mr. Darwin’s well-known principle of sexual selection. By this means 
any natural superiorities of voice would tend to be preserved, and the 
average vocal capabilities of each succeeding generation increased. Nor 
is this all. Along with this increased power of producing tones, there 
would go an increased sensibility to the pleasurable effects of tone. And 
this would be brought about in two different ways. In the first place the 
continual performances of the male singers would, by exercising the 
functions of the ear, tend to raise its sensibility. In the second place it is 
plain that superior vocal powers in the male would, as a rule, co-exist with 
superior auditory sensibility ; for the movements of the voice are always 
guided by the effects on the ear. And thus sexual selection would tend 
to improve the musical ear as much as the musical voice. In this way, 
we think, might have been developed among all musical animals, including 
the ancestors of man, the power of producing and of appreciating purity 
of tone, richness of timbre, rhythm, and melody. Little by little, the 
vocal organs would attain the necessary complexity, flexibility, and means 
of adjustment, and little by little the ear would acquire the needed 
nervous elements and their connections.” — Sully, J., in article before 
quoted. (See Index, Sully, J.) 
It is hoped that Mr. Sully will carry out his intention to publish this 
careful, admirable paper in book form. 
