158 
NATURAL EISTOBY 
due proportion of eacli sex, it should seem very improbable 
that any one district should produce such numbers of these 
little birds ; and much more when only one-half of the 
species appears: therefore we may conclude that the 
chaffinches {Fringillce ccelehes) , for some good purposes, 
have a peculiar migration of their own in which the sexes 
part. Nor should it seem so wonderful that the intercourse 
of sexes in this species of birds should be interrupted in 
winter; since in many animals, and particularly in bucks 
and does, the sexes herd separately, except at the season 
when commerce is necessary for the continuance of the 
breed. For this matter of the chaffinches see " Fauna 
Suecica,'^ p. 85, and Systema Natur^e,^^ p. 318. I see 
every winter vast ffights of hen chaffinches, but none of 
cocks. ^ 
Your method of accounting for the periodical motions of 
the British singing birds, or birds of flight, is a very 
probable one ; since the matter of food is a great regu- 
lator of the actions and proceedings of the brute creation : 
there is but one that can be set in competition with it, and 
that is love. But I cannot quite acquiesce with you in one 
circumstance, when you advance that, " when they have 
thus feasted, they again separate into small parties of five 
or six, and get the best fare they can within a certain 
district, having no inducement to go in quest of fresh- 
turned earth.'' Now, if you mean that the business of 
congregating is quite at an end from the conclusion of 
wheat- so v/ing to the season of barley and oats, it is not the 
case with us ; for larks and chaffinches, and particularly 
linnets, flock and congregate as much in the very dead of 
winter as when the husbandman is busy with his ploughs 
and harrows. 
Sure there can be no doubt but that woodcocks and 
fieldfares leave us in the spring, in order to cross the seas, 
and to retire to some districts more suitable to the purpose 
of breeding. That the former pair before they retire, and 
that the hens are forward with egg, I myself, when I was a 
See Letter XIII. to Pennant, p. 47, note 1. — Ed. 
