WILD LIFE OF ORCHARD AND FIELD 



its nests, and thus enabled the species to spread 

 inland. 



It is one of the earliest birds to arrive in the spring, 

 appearing in Old England during the last week 

 in March, and in New England early in May 

 many passing on to the shores of the Arctic Ocean, 

 where Richardson, at the mouth of the Mackenzie, 

 and Dall, on the Yukon, found them breeding in 

 immense numbers. In these high latitudes its 

 summer is necessarily a brief one, and September 

 finds it back again, picking up congeners for com- 

 pany on the southward journey. 



Where these and other swallows spend the winter 

 was a hotly debated question among ornithologists 

 at the beginning of the nineteenth century; some 

 affirming that they migrate with the sun, while 

 others, believing it impossible that such small and 

 delicate birds could endure the great fatigue and 

 temperatures incident to such a migration, held 

 that they regularly hibernated during the cold 

 weather, sinking into the mud at the bottom of 

 ponds, like frogs, or curling up in deep, warm cran- 

 nies, like bats, and remaining torpid until revived 

 by the warmth of spring. Of this latter opinion 

 was White, of Selborne, who alludes to it again and 

 again; and Sir Thomas Forster wrote a Mono- 



278 



