106 
THE NATURAL HISTORY 
[LETT. 
tins year as early as the eleventh of April, amidst frost and snow ; 
but they withdrew again for a time. 
I am not pleased to find that some people seem so little 
satisfied with Scopoli's new publication, " Annus Primus His- 
torico-Naturalis." There is room to expect great things from 
the hands of that man, who is a good naturalist : and one would 
think that an history of the birds of so distant and southern a 
region as Carniola would be new and interesting. I could wish 
to see the work, and hope to get it sent down. Dr. Scopoli is 
physician to the wretches that work in the quicksilver mines 
of that district. 
When you talked of keeping a reed-sparrow, and giving it 
seeds, I could not help wondering ; because the reed-sparrow 
which I mentioned to you (Passer cmmdinaceus minor Eaii)^ is 
a soft-billed bird, and most probably migrates hence before 
winter; whereas the bird you kept (Passer torquatus Eaii)^ 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. Tiie 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 reminded liim of his omission.^ 
I have somewhat to advance on the different manners in 
which different birds fiy and walk ; but as tliis 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.* 
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 commence. The case is the same with 
1 Sedge-warbler, Salicaria phmgmitis, Selby. 
- Reed -bunting, Emheriza schceniclus, Linn. 
See Letter xxvi., to Mr, Pennant, August 30, 1769. 
* See Letter Ixxxiv., to Mr. Barrington, August 7, 1778. 
