ON THE NOTES OF BIRDS. 41 
Having shown that the notes of birds are natural, 
or, in other words, that they do not depend upon any 
previous instruction, it follows that they must furnish 
the attentive ornithologist with an excellent method 
of distinguishing species under all the various cir- 
cumstances which are liable to affect their plumage ; 
though it must be observed that the great similarity 
so evident in the songs of birds of the same species 
is more in tone and style than in the individual notes 
of which they are composed *. 
I shall here remark that it is highly probable that 
no bird, in a wild state, ever borrows the notes of 
others, or becomes a mocker. I am well aware that 
several of our native birds, as the Pettychaps and 
Sedge-Warbler, have usually been termed Mocking- 
Birds ; but this is certainly improper; as they con- 
stantly use their own natural notes, and no others, 
they do not at all merit this appellation. The fine 
strain of the first has been thought to bear a striking 
resemblance to those of the Swallow and Blackbird. 
This, however, must be entirely imaginary, as it is 
totally different from them in manner and notes. If 
it be possible to trace any similarity between them, 
it will be found to consist in tone merely. The song 
assured by Dr. Spurzheim, was deduced from carefully conducted 
experiments made by Dr. Gall. 
* Birds of the same species do not always deliver their notes 
exactly in the same order of succession ; neither do they uni- 
. formly use precisely the same notes. 
