242 FRIENDS WORTH KNOWING. 



Andean countries. On both continents its wanderings ex- 

 tend to the extreme north, where, in Alaska, it is one of the 

 commonest summer visitors. So this modest little bird, 

 .smallest of his kind, is entitled to our respect as a travel- 

 ler at least ; and, to compare the habits and appearance of 

 the representatives in different portions of the globe of so 

 widely distributed a species, becomes a most interesting 

 study. 



Cotyle ripama, the bank-swallow, sand-martin, sand-swal- 

 low, river-swallow, Fhirondelle de rivage, or back-svala, is 

 generally diffused over the northern hemisphere, though 

 very unequally, avoiding those spots unfavorable to it. 

 In this distribution it seems to have been somewhat influ- 

 enced by man, though owing him no other favors than the 

 incidental help of railroad -cuttings and sand-pits, which 

 have increased the sites suitable for its nests, and thus ena- 

 bled the species to spread inland. 



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

 pearing 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 Kichardson, at the mouth 

 of the Mackenzie, and Ball, on the Yukon, found them 

 breeding in immense numbers. In these high latitudes its 

 summer is necessarily a brief one, and September finds 



