82 THE MEANING OF EVOLUTION 



when once she has set her mind on home-making. A 

 bird-lover, some time since, reported how a pair of 

 sparrows had started to build a nest upon his lawn. 

 He, wishing to interfere with the process, took a small 

 rifle and shot the male bird. \\'ithin twenty minutes 

 the female, who had scouted round the neighborhood, 

 returned with another mate and resumed her nest- 

 building process. Again he interjected the tragic note 

 into her life by shooting her second husband, only to 

 find her start out in pursuit of a third, with whom she 

 returned in the course of an hour. He felt that by 

 this time he had interfered with her domestic happi- 

 ness as much as he had any right to do, and suffered 

 her to continue her housekeeping with her third hus- 

 band without further molestation. I imagine it would 

 have puzzled both birds to tell who was the father of 

 the nestlings who appeared two weeks later. 



Not only do sparrows nest early, they nest often. 

 I suggested to one of my students that she locate as 

 early in the season as she could the nest of a pair of 

 English sparrows, which was sufficiently accessible, 

 and that she keep it under observation at intervals of a 

 few days throughout the summer. In the fall she 

 came to me with glowing eyes and gave me her re- 

 port. "It is simply great," she said. "I never went 

 to that nest a single time this summer to find it empty. 

 When I first got there I found four eggs; after a 



