OF NEW ENGLAND. 149 



time as the Cliff Swallows, but I have never observed them in 

 company with those birds. They may be seen in their sum- 

 mer-haunts flying either over the surface of land and water, or 

 at some height in the air, though rarely very far above the 

 ground. They fly much like the other swallows, though per- 

 haps less steadily and with less sailing, but they seldom wan- 

 der far from the banks in which their nests are placed. They 

 are found throughout New England, and much further to the 

 northward, but are much confined to localities, both because 

 of their disposition to colonize, and the necessity of their se- 

 lecting a place where the earth is of a character suitable to 

 their purposes. 



Their choice of a summer-home is undoubtedly influenced 

 very considerably by the nature of the soil, as it is impossible 

 for them to burrow in all kinds of earth. Extremely inter- 

 esting details may be learned through the study of their exca- 

 vations, as these latter vary greatly in size, depth, and the 

 angle at which they run, in accordance with the variation of 

 the soil. The Bank Swallows invariably select a bank, the 

 sand of which will not "cave in," and then burrow to a 

 stratum where the pebbles, which might fall down upon their 

 eggs or young, are not found. Their colonies sometimes in- 

 crease from year to year with rapidity, and, if not disturbed, 

 in the course of a few seasons consist of a large number of 

 excavations. 



How wonderful is that instinct which enables these swallows 

 to find out the best places for their homes, and how wonderful 

 their skill in making these secure ! When a small party boldly 

 advance to a country, hitherto unknown to them, who can de- 

 fine that sense which enables them to discover and select the 

 most fitting bank for their purposes, or even the best part of 

 it? What, indeed, prompts them to part from theif fellows 

 and to become pioneers in new settlements? Instinct can 

 never be fully understood by man, nor its workings. 



Wilson, speaking of the " Sand Martins," says : "We. have 

 sometimes several days of cold rain and severe weather af- 

 ter their arrival in spring, from which they take refuge in 



