132 WILD LIFE AND THE CA3IERA 



often find in similar nests, pieces of lichen, webs, 

 cocoons, small pieces of broken wood, and such like 

 substances, being fastened to the outside by means 

 of webbing. On the day when the final touch was 

 given, and the nest was in readiness to receive the 

 first eggs, a cowbird came when the vireos were 

 absent and deposited her grey speckled egg in the 

 newly-finished nest ; having done this she departed 

 as silently as she came. 



What were her thoughts as she thus silently 

 deposited her precious burden in this strange cradle ? 

 How was she fulfilling this greatest of nature's laws, 

 the perpetuation of her kind ? Did she reahse that 

 there was some peculiar, and to our limited know- 

 ledge of things, apparently unnatural reason for not 

 being able to take care of her own offspring ? Why 

 was she, of so many thousand species, selected to be 

 denied the cares and joys of inotherhood ? Who 

 can answer ? Did she think at all on the subject as 

 she searched the woods and fields for a suitable 

 home for the young she would never see ? Had she 

 surreptitiously watched these vireos building their 

 nest, knowing that "wdien it was completed she 

 would make use of it ? Who shall say ? Perhaps 

 even it was all a matter of chance, though that 

 is not according to nature's method. Had she 

 suddenly realised that the moment was come when 

 the egg must be deposited, and so chosen the first 

 available nest from which the rightful owners M^ere 

 absent ? None of these simple questions can we 

 answer. Our surmises may be right or they may 

 be wrong. We cannot know. Nature hides well 

 her secrets, and so what are apparently the simplest 



