206 * NATURAL HISTORY 
Thus is instinct in animals, taken the least out of 
its way, an undistinguishing, limited faculty, and 
blind to every circumstance that does not immedi- 
ately respect self-preservation, or lead at once to 
the support of their species. 
LETTER XIX. 
Selborne, Feb. 14, 1774. 
Dear Sir,—I ReEcEIVED your favour of the 8th 
[of February], and am pleased to find that you read 
my little history of the swallow with your usual 
candour ; nor was I the less pleased to find that 
you made objections where you saw reason. 
As to the quotations, it is difficult to say pre- 
cisely which specics of hirundo Virgil might intend 
in the lines in question, since the ancients did not 
attend to specific differences like modern natural- 
ists ; yet somewhat may be gathered, enough to in- 
cline me to suppose that, in the two passages quoted, 
the poet had his eye on the swallow. 
_ In the first place, the epithet garrula suits the 
swallow well, who is a great songster, and not the 
martin, which is rather a mute bird, and when it 
sings is so inward as scarce to be heard. Besides, 
if tignum in that place signifies a rafter rather than 
a beam, as it seems to me to do, then I think it 
must be the swallow that is alluded to, and not the 
martin, since the former does frequently build with. 
in the roof against the rafters, while the latter al- 
ways, as far as I have been able to observe, builds 
without the roof against eaves and cornices. — 
