SONGS. 193 . 
a deeper and more mellow-toned note than a small 
pipe, so the windpipe of the nightingale, which is 
wider than that of the canary, sends forth a deeper 
and more mellow-toned note. Soft-billed birds also 
sing more from the lower part of the throat than 
the hard-billed species. This, together with the 
greater width of the tube in the nightingale and 
other soft-billed warblers, fully accounts for their 
soft, round, mellow notes, compared with the shrill, 
sharp, and clear notes of the canary afd other hard- 
billed song-birds.”* 
Though birds of the same species very closely 
resemble each other in the general tenour of their 
song, individuals differ widely both in the introduc- 
tion of particular passages, the result, probably, of 
accidental acquirements, and in skill of execution 
as well as in intonation, the latter peculiarities obvi- 
ously depending on physical varieties in their vocal 
organs. Wilson says he was so familiar with the 
notes of an individual wood-thrush (Turdus melodus), 
that he could recognise him above his fellows the 
moment he entered the woods.t 
Mr. Knapp has the following excellent and accu- 
rate remarks on the same subject. ‘“ Birds,” he 
says, “ of one species sing, in general, very like each 
other, with different degrees of execution. Some 
counties may produce finer songsters, but without 
great variation in the notes. In the thrush, how- 
ever, it is remarkable that there seems to be no 
regular notes, each individual piping a voluntary of 
his own. Their voices may always be distinguished 
amid the choristers of the copse, yet some one per- 
former will more particularly engage attention by 
a peculiar modulation or tone; and should several 
stations of these birds be visited in the same morn- 
ing, few or none, probably, will be found to pre 
* British Song-birds. 
t+ Amer. Ornith. 
R 
