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it seeds, I could not help wondering : because the reed 
sparrow which I mentioned to you {Passer arundinaceus 
minor J Raii^) is a soft-billed bird, and most probably 
migrates hence before winter ; whereas the bird you kept 
{Fasser torquatus, Raii'^) abides all the year_, and is a thick- 
billed bird. I question whether the latter be much of a 
songster ; but in this matter I want to be better informed.^ 
The former 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 remiiided 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 na- 
ture as not to be contained in a small space, I shall say no- 
thing further about it at present.^ 
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 not to pair and discharge their parental 
functions till the ensuing spring.^' As colours seem to be 
the chief external sexual distinction in many birds, these 
colours do not take place till sexual attachments begin to 
obtain. And the case is the same in quadrupeds ; 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 male sex : but this sexual diversity does 
not take place in earlier life ; for a beautiful youth shall be 
^ The sedge warbler, Salicaria phragmitis. — Ed. 
^ The reed bunting, Emheriza schceniclus. — Ed. 
3 See Letter XXIV. to Pennant, p. 82, note 2.— Ed. 
4 See Letters XXIV. XXV. and XXVI. to Pennant.— Ed. 
^ See Letter XLIl. to Dames Barrington. — Ed. 
