OF SELBORNE. 229 



flocks of hen chaffinches that appear with 

 us in the Winter without hardly any cocks 

 among them. Now was there a due pro- 

 portion 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 con- 

 clude that the 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 inter- 

 course 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 Sy sterna Naturce, p. 318. I see 

 every Winter vast flights of hen chaffinches, 

 but none of cocks. 



Your method of accounting for the pe- 

 riodical motions of the British singing birds, 

 or birds of flight, is a very probable one : 



