218 



NATURAL 



HISTORY 



LETTER VI. 



TO THE SAME. 



DEAR SIR ; Selborne, May 21, 1770. 



The severity and turbulence of last month 

 so interrupted the regular process of Sum- 

 mer migration, that some of the birds do 

 but just begin to show themselves, and 

 others are apparently thinner than usual ; 

 as the white-throat, the black-cap, the red- 

 start, the fly-catcher. I w^ell remember 

 that after the very severe Spring 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 unfa- 



6 



vourable year the winds blowed the whole 

 Spring and Summer through from the 

 opposite quarters. And yet amidst all 

 these disadvantages two swallows, as I 

 mentioned in my last, appeared this year 

 as early as the eleventh of April amidst 



