482 THEPHILOSOPHY 



fuppofmg they could exift for feveral months without refpiratlon, 

 "What would be the confequence ? The whole would foon be de- 

 voured by otters, feals, and fiflies of various kinds. Nature is al- 

 ways anxious for the prefervation of fpecies. But, if the fwallow 

 tribes were deftined to remain torpid, during the winter months, at 

 the bottom of lakes and feas, fhe would ad in oppofition to her own 

 intentions ; for, in a feafon or two, the whole genus would be an- 

 nihilated. 



Mr White of Selborne has favoured us with the following Infor- 

 mation concerning the migration of fwallows: * If ever I faw,' fays 

 he, ' any thing like adlual migration, it was laft Michaelmas day, 



* 1768. 1 was travelling, and out early in the morning: At firft 



* there was a vaft fog ; but, by the time that I was got feven or 



* eight miles from home towards the coaft, the fun broke out into a 

 ' delicate warm day. We were then on a large heath or common, 



* and I could difcern, as the mift began to break away, great num- 



* bers of fwallows cluftering on the ftinted fhrubs and buflies, as if 

 ' they had roofted there all night. As foon as the air became clear 



* and pleafant, they all were on the wing at once, and, by a placid 



* and eafy flight, proceeded on fouthward towards the fea : After 

 ' this I did not fee any more flocks, only now and then a fl;raggler. 

 ' When I ufed to rife in a morning laft autumn, and fee the fwal- 

 ' lows and martins cluftering on the chimneys and thatch of the 

 ' neighbouring cottages, I could not help being touched with fecret 



* delight, mixed with fome degree of mortification : With delight, 

 ' to obferve with how much ardour and punduality thofe poor lit- 



* tie birds obeyed the ftrong impulfe towards migration, or hiding, 

 ' imprinted on their minds by their great Creator; and with fome 

 ' degree of mortification, when I refleded, that, after all our pains 

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



• do 



