THE VOICE-REGISTERS OF BIRDS. 13 
early in October, near Stroud, a Blackbird was singing softly, 
but in a full deep voice; and in the middle of the month a 
Mistle Thrush near Eltham was singing very loud phrases of two 
notes each. 
In the Finches the song generally follows a definite course in 
which several breaks of tone may occur, as in the Greenfinch and 
Linnet. 
In the Yellow Bunting there are two high final notes quite 
distinct from the other part of the song, and never uttered except 
at the end of the song. Are they a survival or an acquisition ? 
I have no evidence that among wild birds the songs of the 
females have most resemblance to the immature warblings of the 
young. The female Starling, which I have often heard, sings in 
much the manner of her mate, but less loudly. In most races 
the infantile cries are abandoned as the birds approach maturity, 
as in the Columbide, whose squeaky notes are not heard from the 
adults. In the common Shellduck is a survival of the peeting, 
whistling cry of the young; while in other common Ducks this 
cry of infancy is lost when the birds attain their full size. 
