132 NA TURAL HISTOR Y OF SEL BORNE 



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 advance 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. 



rot 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 quadtir 

 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. t See Letter XLII. to Mr. Harrington. 



