The Natural History of Selborne 97 



four swallows huddled together on the moulding of one of the 

 windows of that college. I have frequently remarked that swallows 

 are seen later at Oxford than elsewhere ; is it owing to the vast 

 massy buildings of that place, to the many waters round it, or to 

 what else ? 



When I used to rise in a morning last autumn, and see the swal- 

 lows and martins clustering on the chimneys and thatch of the 

 neighbouring cottages, I could not help being touched with a secret 

 delight, mixed with some degree of mortification ; with delight, to 

 observe with how much ardour and punctuality those poor little 

 birds obeyed the strong impulse towards migration, or hiding, 1 im- 

 printed on their minds by their great Creator ; and with some 

 degree of mortification, when I reflected that, after all our pains and 

 inquiries, we are yet not quite certain to what regions they do 

 migrate ; and are still farther embarrassed to find that some do not 

 actually migrate at all. 



These reflections made so strong an impression on my imagina- 

 tion, that they became productive of a composition that may perhaps 

 amuse you for a quarter of an hour when next I have the honour of 

 writing to you. 



1 The idea of hiding is, of course, erroneous. ED. 



