132 NATURAL HISTORY OF SELBORNE 
has a variety of hurrying notes, and sings all night. Some part of 
the song of the former, I suspect, is attributed to the latter. We 
have plenty of the soft-billed sort ; which Mr. Pennant had entirely 
left out of his ‘‘ British Zoology,” till I reminded him of his omission. 
See “British Zoology ” last published, p. 16.* 
I have somewhat to advan +e on the different manners in which 
different birds fly and walk; but as this is a subject that I have not 
enough considered, and is of such a nature as not to be contained 
in a small space, I shall say nothing further about it at present.f 
No doubt the reason why the sex of birds in their first plumage 
is so difficult to be distinguished is, as you say, ‘‘ because they are 
REED BUNTING. 
not to pair and discharge their parental functions till the ensuing 
spring.” As colours seem to be the chief external sexual dis- 
tinction in many birds, these colours do not take place till sexual 
attachments begin to obtain. And the case is the same in quadru- 
peds ; among whom, in their younger days, the sexes differ but 
little ; but, as they advance to maturity, horns and shaggy manes, 
beards and brawny necks, &c., &c., strongly discriminate the male 
from the female. We may instance still farther in our own species, 
where a beard and stronger features are usually characteristic of the 
* See Letter XXV. to Mr. Pennant. + See Letter XLII. to Mr. Barrington. 
