THE CHIMNEY SWALLOW. 117 



doubt that great numbers of them in thinly settled districts 

 still breed in hollow trees. The nest is composed of twigs, 

 which are glued together and to the side of the chimney 

 with the saliva of the bird. It is very rarely lined with a 

 few feathers. The strength of these structures is wonderful : 

 and they are so durable that I have known of instances 

 of their remaining in the chimney during three seasons. 

 Usually, the bird displays great sagacity in the choice of a 

 location for a nest, in securing protection from storms and 

 from the attacks of animals ; but occasionally the nest is 

 built in a chimney, open at the top sufficiently wide to 

 permit the rain to trickle down the sides : the result is, that 

 the moisture softens the glue by which the nest is attached 

 to the chimney, and it is, with its living contents, precipi- 

 tated to the bottom. Again, if the nest is built too low in 

 the chimney, the young or eggs furnish agreeable food for 

 rats, which, unfortunately, are sometimes found in dwelling- 

 houses in the country in uncomfortable numbers. The eggs 

 are generally four or five in number, pure-white in color, 

 rathor long in shape. Dimensions of five eggs, in a nest 

 collected in Upton, Me. : .84 by .44 inch, .81 by .46 inch, 

 .80 by .46 inch, .78 by .48 inch, .76 by .51 inch. 



This species is somewhat nocturnal in its habits. From 

 earliest dawn until seven or eight in the morning, it is busy 

 in the pursuit of insects : it then retires to its roosting-places 

 in the chimneys, and is seldom seen until late in the after- 

 noon. From early twilight until late in the night, it is again 

 actively employed ; and, having heard its notes, as it sped 

 through the air, often as late as midnight, I have no doubt 

 that, in pleasant weather, it is busy through the whole 

 night. 



In descending the chimneys where their young are, the 

 birds fly rapidly until they are immediately over them, when, 

 partially closing their wings, they drop suddenly, and with 

 apparent ease, down the flue. 



In ascending, the noise of their wings in the chimney is 



