Nov., 1922 MUSICAL ‘‘TASTE”’ IN THE BROWN TOWHEE 195 
tion, and are exposed to essentially like environmental conditions.’’ Is not the 
manner of song modification as much ‘‘identical material’’ of the Brown Towhee 
as is his brown coat or his mincing step as he forages in the grass? Is it not as 
natural that two individuals of a species should behave alike in improving as in 
possessing a song? The facts impressing me as significant because of their ap- 
pearance in both of our towhee songs, are as follows: 
1. The fact of elaboration. 
2. The fact of elaboration through imitation. 
3. The fact of elaboration through adding the imitated syllables at the end. 
4. The fact of the comparative musical quality of the imitated syllables (as 
contrasted with the hard metallic quality of the notes in the “bouncing” 
song). 
Certain ideas, of not too speculative a character, I hope, to be of some value, 
occur to me in connection with each of these four points. 
1. The fact of elaboration.—It would seem that all birds who possess songs 
possess a tendency to elaborate or improve their songs; that is, to render more 
perfect their songs in the number, kind, and arrangement of notes. The finest 
singers among birds (so considered from the human point of view, and so too 
in actuality, I believe) are the producers of comparatively prolonged and com- 
plex musical effects. The evolution of bird song evidently proceeds from sim- 
plicity to complexity. 
The simplest songs are those sung in short set form—running automatically 
i pre-established grooves. Within this definition, the simplest are those con- 
taining only one kind of sound. Finally, these two essentials being’ comphed 
with, the simplest are those in which the one kind of sound involved is derived 
from the eall- or alarm-note of the singer. Charles A. Witchell describes 
(1896, pp. 49-50) the songs of some fifteen birds, and remarks (p. 53), ‘‘In all 
the above-mentioned British species, and in some of their allies, which represent 
many avian races, the males court the females partly by the repetition of notes 
which we observe to be employed in other circumstances as call-notes; and in 
some species these notes are repeated so rapidly that a phrase is constructed. 
But some species have never advanced beyond the mere repetition of their call- 
notes. ”’ He expresses the belief (p. 58) that ‘‘songs were, at first, mere repeti- 
tions of call-notes, or possibly of defiance-cries, which have since been more 
rapidly uttered and varied, with the result that novel strains have been slowly 
developed.”’ Among American birds two species occur to me off-hand as pos- 
sessing songs more or less of this type. One is the Linnet, whose zig-zag, twit- 
tery warble is found on analysis to be composed partly of the eall-note, or chirp, 
of the species. The other is the object of our present study, the Brown Towhee, 
whose normal song is composed wholly of repetitions of its alarm-note. | 
The typical ‘‘bouncing’’ song of the Brown Towhee, though according to 
our definition very simple,-is doubtless even at that an elaboration of something 
still more simple, which in turn we must trace back through imperceptible 
stages to its humble origin, the alarm-note. The alarm-note (in the Brown 
Towhee as in other song-birds) must have existed before the song. Without 
bothering ourselves here about the origin of alarm- and eall-notes (whether to 
be found In spasmodic muscular contractions acting upon the trachea in mo- 
ments of excitement or of effort, or to some necessity of emotional expression for 
purposes of social control [see Wallace Craig, 1908]) we can feel pretty sure 
that the song is the most advanced form of expression in the bird’s vocal his- 
