SEX OF BIRDS. 131 
but just begin to show themselves, and others are apparently 
thinner than usual ; as the whitethroat, the blackcap, the red- 
start, the flycatcher. I well remember that after the very severe 
sprmg in the year 1739-40 summer birds of passage were very 
scarce. They come probably hither with a south-east wind, or 
when it blows between those points ; but in that unfavourable 
year the winds blowed the whole spring and summer through 
from the opposite quarters. And yet amidst all these disadvan- 
tages two swallows, as I mentioned in my last, appeared this 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 satis- 
fied with Scopoli's new publication f there is room to expect 
great things from the hands of that man, who is a good naturalist : 
and one would think that a history of the birds of so distant and 
southern a region as Carniola would be new and interesting. I 
could wish to see that 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 arundinaceus minor RaiiJ is a 
soft-billed bird ; and most probably migrates hence before win- 
ter ; whereas the bird you kept (passer torquatus RaiiJ abides all 
the year, and is a thick-billed bird. I question whether the lat- 
ter 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 reminded him of his omission. See British Zoology last 
published, p. I6.t 
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. J 
No doubt the reason why the sex of birds in their first plum- 
age is so difficult to be distinguished is, as you say, " because 
* This work he calls his Annus Prirmti Hisborico Naiuralis- 
+ See letter xxv. to Mr. Pennant, 
t See letter xlii to Mr. Barringtoii. 
