IIIRUNDINID^E.-HIRUNDO LUNIFRONS. 99 



dry grass, soft leaves, and straw, intermixed Avith occasional feathers, down, and 

 wool. It is thought by some, that, in constructing their nests, the mud of which 

 the foundation is composed is tempered by these birds with their glutinous saliva, 

 and is thus rendered more adhesive. By this means it is supposed to be the more 

 readily and securely attached to its selected site. But if so, it would hardly ap- 

 pear, judging from their usual crumbling nature and the frequency with which, 

 at the lightest touch, they fall to pieces, to be resorted to after the first few layers 

 have been arranged, or certainly sparingly. Mr. Nuttall, in the introduction to his 

 work on the Ornithology of the United States and Canada, speaks of the Cliff 

 Swallow as " concealing its warm and feathered nest in a receptacle of agglutinated 

 mud resembling a narrow-necked purse or retort." A person who had never seen 

 these nests would receive from this an exaggerated idea of the adhesive nature of 

 the external nest, as well as of its internal construction. Feathers are by no means 

 its universal, or even general, lining. While they are often found intermixed 

 with coarser materials, the nest is as often found without as with them. A well- 

 informed and accurate observer, Mr. C. S. Paine, of Randolph, Vermont, writes 

 me in reference to these birds : " They are very common here, and congregate in 

 large communities. A neighbor has a barn with more than a hundred nests under 

 its eaves. They have built there a good many years. A few years ago I spent 

 several weeks in Illinois, on Rock River. I found these Swallows in great abun- 

 dance there. They built their nests on the face of the rocks that line the river. In 

 one place there were at least five hundred nests. The birds would come and go 

 from them like bees from a hive. I frightened them from their nests, and they 

 accumulated in a perfect cloud over my head." 



I have several times seen a settlement disturbed in this manner. It is a very 

 striking sight. The whole colony form into what is well called a cloud, sail over 

 your head in rapid circles, with a combination of sharp outcries and sounds perfectly 

 indescribable. If in the height of the breeding season, and any have young, their 

 agitation is greatly increased, and they Avill even manifest a disposition to attack you 

 as you approach the nests, fly close to your head, with sharp, angry cries, and make 

 a snapping or clicking sound with their bills. 



The eggs of this Swallow exhibit greater variations in markings, size, and shape 

 than are usual with birds of this family, as the variations in the accompanying figures 

 may attest. They may usually be distinguished from those of the Barn Swallow by 

 their coarser spots, the less elongated shape of the egg, and the browner color of the 

 markings. It is, however, frequently very difl&cult to distinguish them. The ground 

 color of the egg is white ; the spots vary in number, size, shade, and distribution, but 

 are usually reddish-brown, and scattered over the whole egg. The folloA\iug are 

 their several measurements : greatest length, | of an inch ; least length, f ; average 

 length, if ; greatest breadth, f of an inch ; least breadth, j\ ; average breadth, ||. 



