182 SWALLOWS : THEIR HIBERNATION. 



the masts of vessels on their journeys of migration. If 

 this theory of the migration of swallows be true, it must 

 be true of those in the northern and southern parts of 

 Asia. On the contrary, they hide themselves in the 

 banks of the Ganges, during the three so-called winter 

 months in that part of the world. Du Tertre mentions 

 that the few swallows seen in the Caribbee Isles are only 

 observed in summer, as in France. We are assured by 

 Dr. Pallas, that not only are there swallows in Eussia 

 and Siberia, but that on the banks of the Wolga, latitude 

 57°, they disappeared about the fourth of August. These 

 birds, according to the theory of migration, ought to have 

 been passing to the more southern parts of Asia. Yet it 

 has not been observed by any Asiatic traveller that they 

 have the same species of swallow, or that they are seen 

 in those parts during our winter. 



As an objection to the theory of the torpidity of swal- 

 lows as their mode of hibernation, it is asked where and 

 when they moult, if not in regions south of Europe, as 

 they do not moult before their disappearance. This is an 

 objection that Mr. Barrington fails to answer. It is im- 

 possible, however, that their moulting can happen when 

 submerged in water or torpid in some concealed resort. 

 The functions of the animal economy would be unable to 

 supply a new plumage while the system is in this state. 

 I would suggest, if the theory of their torpidity were 

 proved, that they may drop their feathers one by one, 

 during all their active season of flight, as human hair is 

 shed. Still, I cannot but think it more probable that 

 swallows leave their northern habitats very early in the 

 season, that they may arrive at their winter-quarters just 

 before the season of moulting; and that the cause of 

 their remaining undiscovered during their residence in 

 the warm regions to which they resort is, that while 

 moulting they live upon the ground in shelters of thicket, 



