194 LIFE-HISTORIES OF BIRDS 



distributed among its particles; and the latter, 

 deprived in a measure, of their means of cohesion, 

 by desiccation, would crumble to pieces. 

 A nest is usually six days in building. Oviposi- 

 tion succeeds its completion. In the duties of 

 incubation which require a period of 1 1 days, the 

 female is occasionally relieved by the male. 

 While she is thus occupied he is very attentive, 

 vigilant, jealous, and affectionate. A stranger is 

 not permitted within his territory without en- 

 countering the most unpleasant reception; the 

 male strength of the whole community is mustered 

 to wreak instant vengeance upon such temerity. 

 Should a human being attempt any familiarities, 

 he is instantly beset by numbers infuriated to the 

 highest degree. 



Two broods are generally reared in a season; 

 one appearing early in June, and the other early 

 in August. At the close of the breeding-season 

 the birds still linger in their accustomed haunts, 

 where they remain until the time of their southern 

 departure. 



The eggs are white and marked with reddish- 

 brown blotches, which are chiefly placed about the 

 larger end. They are less elongated than those 

 of the Barn Swallow, and measure from .86 to .74 

 of an inch in length with an average breadth of .60. 



Cotyle riparia, Boie. 



Unlike the subject of the last article, the Sand 

 Martin is more retired in its habits, but none the 



