MIGRATION. 155 



on September the 22nd, they rendezvoused in a 

 neighbour's walnut tree, where it seemed probable 

 they had taken up their lodgings for the night. At 

 the dawn of the day, which was foggy, they rose 

 all together in infinite numbers, occasioning such a 

 rushing from the strokes of their wings against the 

 hazy air, as might be heard to a considerable dis- 

 tance ; since that, no flock has appeared, only a few 

 stragglers. 



Some swifts staid late, till the 22nd of August ; a 

 rare instance ! for they usually withdraw within the 

 first week*. 



On September the 24th, three or four ringousels 

 appeared in my fields for the first time this season. 

 How punctual are these visitors in their autumnal 

 and spring migrations ! 



LETTER XL VIII. 



[\ 



TO THE HON. DAINES HARRINGTON. 



SELBORNE, February 8, 1772. 

 DEAR SIR, 



WHEN I ride about in winter, and see such pro- 

 digious flocks of various kinds of birds, I cannot help 

 admiring at these congregations, and wishing that it 

 was in my power to account for those appearances, 

 almost peculiar to the season. The two great motives 

 which regulate the proceedings of the brute creation 

 are love and hunger ; the former incites animals to 

 perpetuate their kind, the latter induces them to pre- 

 serve individuals. Whether either of these should 

 seem to be the ruling passion in the matter of con- 



* See Letter XCVII. to the Hon. Daines Barrington. 



