SONG OF BIRDS. 
477 
heard to sing sometimes in the middle of winter when the air is mild, 
animated by the genial warmth of the sun, which acts as a stimulus. 
Birds in song are generally found, by dissection, to have the testes 
somewhat dilated. But we shall now proceed to shew, by experiments, 
that birds in their natural state may be forced to continue their song 
much longer than usual. A male redstart made its appearance near my 
house early in the spring, and soon commenced his love-tuned song. 
In two days after, a female arrived, which, for several days, the male was 
continually chasing, emitting soft interrupted notes, accompanied by a 
chattering noise. This sort of courting lasted for several days, soon 
after which the female took possession of a hole in a wall close to my 
house, where it prepared a nest, and deposited six eggs. The male 
kept at a distance from the nest, and sometimes sung ; but not so loud 
or so frequently as at first, and never when he approached nearer his 
mate. When the eggs had been sat on a few days, I endeavoured to 
catch the female on the nest, but she escaped through my hand. 
However, she soon returned, and I caught her. The male did not 
immediately miss his mate ; but on the next day he renewed his vocife- 
rous calls, and his song became incessant for a week, when I discovered 
a second female ; his note immediately changed, and all his actions, as 
before, returned. This experiment has been repeated with the night- 
ingale with the same success ; and a golden-crested wren, who never 
found another mate, continued his song from the month of May till the 
latter end of August. On the contrary, another of the same species, 
who took possession of a fir-tree in my garden, ceased its notes as soon 
as the young were hatched. 
* Although, I confess, there appears considerable force in these argu- 
ments of Montagu, I am disposed to be of opinion, that birds sing most 
frequently from joy and buoyancy of spirits, and not unfrequently in 
triumphant defiance of rivalry or attack. I have a red-breast at present, 
who will sing out whenever I snap my fingers at him ; and the sedge- 
bird sings when a stone is thrown into the bush where he may be. 
Syme’s remarks upon the songs of birds, are worth quoting : The 
notes,” he says, “ of soft-billed birds, are finely-toned, mellow, and 
plaintive ; those of the hard-billed species are sprightly, cheerful, and 
rapid. This difference proceeds from the construction of the larynx ; 
as a large pipe of an organ produces a deeper and more mellow-toned 
note than a small pipe, so the trachea 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 
