[ 109 3 



the other many fpecies of foft billed birds, which 

 likewife difappear about the fame time ? The 

 following reafon may be affigned : 



" No birds are fo much on the wing as Swal- 

 lows -, none fly with fuch fwiftnefs and rapidity , 

 none are obliged to fuch fudden and various evo- 

 lutions in their flight none are at fuch pains to 

 take their prey -, and we may add, none exert 

 their voice more inceflfantly -, all thefe occafion a 

 vafl: expence of flrength, and of fpirits, and may 

 give fuch a texture to the blood, that other animals 

 cannot experience ; and fo difpofe, or, we may 

 fay, neceffitate, this tribe of birds, or part of 

 them, at leafl:, to a repofe more lafting than that 

 of any others. 



" The third notion is, even at firfl fight, too 

 amazing and unnatural to merit mention^ if it 

 vv^as not that fome of the learned have been cre- 

 dulous enough to deliver, for fa6t, what has the 

 fl:rongefl: appearance of impoffibility ; we mean 

 the relation of Swallows paffing the winter im- 

 merfed under ice, at the bottom of lakes, or 

 lodged beneath the water of the fea at the foot 



of 



