80 SWALLOW. 



If these birds were to remain torpid in the 

 winter, would there not be annual proofs of it in 

 almost every county ? Whereas we have but few 

 accounts of their being taken in that state, and 

 innumerable narrations from mariners and others 

 who have observed them to settle on their ships, 

 whilst out at sea : and would not they appear 

 much earlier in forward years than in backward, 

 and vice versa? The contrary appears to be 

 the case ; Mr. Forster observes, that he has seen 

 them as early as the second of April, when the 

 thermometer was below the freezing point ; and 

 at other times, when there has been a fortnight of 

 mild weather in the same month, not a single 

 Swallow has made its appearance. 



It is the opinion of most modern naturalists 

 that the generality of these birds migrate, but 

 that a few may occasionally remain behind, from 

 being too weak to undertake the journey. The 

 various species do not appear or disappear at the 

 same time. The Sand Martin generally arrives 

 first, about a week after the Chimney Swallow is 

 seen, and in a few days the House Martin makes 

 its appearance. 



It is a singular fact, that Swallows and other 

 migrative birds always return to the same places 

 they left in the autumn, which has been proved 

 by many experiments, particularly by Frisch, who 

 tied threads round their legs, stained with water 

 colours, for the purpose of ascertaining whether 

 they went under water during the winter, and in 

 the ensuing spring, upon taking some of the 

 Swallows that were in the vicinity of his house, 



