In North- West Canada. 79 



Another summer yellow bird was known to build a story to 

 her nest, leaving the cowbird's egg in the cellar, and then, 

 finding another cowbird's egg violating her premises, she forth- 

 with built a second story, and finally laid her own eggs on the 

 top flat, leaving the two cowbird's eggs in the two lower stories 

 to addle. The eggs of the cowbird vary considerably both in 

 size, colour and markings, but are so common and well known 

 as not to need a description here. 



