72 
ORGANS OF VOICE. 
tuberance on its head, which, when inflated with air, 
stands up like a horn, is, in some way, the cause ; 
hut the Goat-suckers, in all probability, are indebted 
to their peculiar width of mouth and throat for this 
power of voice; for many other birds, in uttering 
loud notes, are observed to puff and swell out their 
throats in a very extraordinary manner. For in- 
stance, our little summer visitant and sweet songster, 
the Blackcap, when warbling forth his finest notes, 
distends its throat in a wonderful degree ; and those 
who have chanced to see a Brown Owl in the act of 
hooting, will have noticed, that they swell up their 
throats to the size of a pigeon's egg. And persons, 
who have fine ears for music, have ascertained, by 
comparing their notes with a pitch-pipe, that their 
variations are according to certain rules ; most of 
them hooting in b flat, though some went almost 
half a note below a. This strain upon the throat 
is sometimes carried to a pitch which endangers the 
bird’s life. The bird-fanciers in London, who are 
in the habit of increasing the singing powers of birds 
to the utmost, by training them by high feeding, 
hot temperature of the rooms in which they are 
kept, and forced moulting, will often match one 
favourite Goldfinch against another. They are 
put in small cages, with wooden backs, and placed 
near to, but so that they cannot see, each other: 
they will then raise their shrill voices, and continue 
their vocal contest till one frequently drops off its 
perch, perfectly exhausted, and dies on the spot. 
This will even happen sometimes to birds in a wild 
state. In the garden of a gentleman in Sussex, a 
thrush had, for some time, perched itself on a par- 
