VOL. LXm.] PHILOSOPHICAL TRANSACTIONS. 443 



did not sing a note of woodlark, though he afterwards hung him again just above 



the woodlark linnet, but adhered entirely to the song of the skylark linnet. 



Birds in a wild state do not commonly sing above 10 weeks in the year; which 



is then also confined to the cocks of a few species: Mr. B. conceives that this 



last circumstance arises from the superior strength of the muscles of the larynx. 



Strength however in these muscles, seems not to be the only requisite; the 



birds must have also great plenty of food, which seems to be proved sufficiently 



by birds in a cage singing the greatest part of the year, when the wild ones do 



not continue in song above 10 weeks. Mr. B. knows well, that the singing of 



the cock bird in the spring is attributed by many to the motive only of pleasing 



its mate during incubation. Those however who suppose this, should recollect, 



that much the greater part of birds do not sing at all : why should their mate 



therefore be deprived of this solace and amusement ? The bird in a cage, which 



perhaps sings 9 or 10 months in a year, cannot do so from this inducement; and, 



on the contrary, it arises chiefly from contending with another bird, or indeed 



against almost any sort of continued noise. Superiority in song gives to birds a 



most amazing ascendency over each other; as is well known to the bird catchers 



by the fascinating power of their call birds, which they contrive should moult 



prematurely for this purpose. 



But, to show decisively that the singing of a bird in the spring does not arise 

 from any attention to its mate, a very experienced catcher of nightingales 

 informed him, that some of these birds have jerked the instant they were caught. 

 He has also brought to him a nightingale which had been but a few hours in a 

 cage, and which burst forth in a roar of song. Yet this bird is so sulky on its 

 first confinement, that he must be crammed for 7 or 8 days, as he will otherwise 

 not feed himself: it is also necessary to tie his wings, to prevent his killing 

 himself against the top or sides of the cage. 



Mr. B. believes there is no instance of any bird's singing which exceeds our 

 blackbird in size; and possibly this may arise from the difficulty of its concealing 

 itself, if it called the attention of its enemies, not only by bulk, but by the pro- 

 portionable loudness of its notes. He rather conceives it is for the same reason 

 that no hen bird sings, because this talent woidd be still more dangerous during 

 incubation; which may possibly also account for ihe inferiority in point of 

 plumage. 



Mr. B. considers how far the singing of birds resembles our known musical 

 intervals, which are never marked more minutely than to half notes; because, 

 though we can form every gradation from half note to half note, by drawing the 

 nger gently over the string of a violin, or covering by degrees the 

 hole of a flute; yet we cannot produce such a minute interval at command, 

 when a quarter note for example is required. Some passages of the song in a 



