Crossbill 



LETTER VIII. 



To the same. 



SKLBORNE, Dec. ao///, 1770. 

 EAR SIR, The birds that I took for 

 aberdavines were reed- sparrows (Passeres 

 torquatt). 



There are doubtless many home internal 

 migrations within this kingdom that want to 

 be better understood : witness those vast 

 flocks of hen chaffinches that appear with us 

 in the winter without hardly any cocks among them. Now 

 was there a due proportion of each 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 

 Fringillce ccelebes, 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 bird 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 

 Naturae," p. 318. I see every winter vast flights of hen 

 chaffinches, but none of cocks. 



