WOODLAND WARBLERS 161 



main until they are hatched. Others are wise enough 

 to know their own eggs, and chief among such sharp- 

 eyed ones is this little Yellow Warbler. 



" Coming home some morning after taking exercise 

 for the good of her health, Mrs. Warbler finds a great 

 white egg spotted with brown, crowded in among 

 her own small pale blue eggs, that have their brown 

 spots mostly arranged like a wreath around the larger 

 end. 



" Being disgusted and very angry to find her house 

 invaded, she and her mate have a talk about the mat- 

 ter. Why they do not simply push the strange egg 

 out, we do not know, but instead of that they often 

 fly off for milkweed fibres and silk to make a new 

 nest right on top of the first one, shutting the hateful 

 egg out of sight underneath. Then they begin house- 

 keeping anew, in a two-storied nest like this one, liv- 

 ing in the upper story, and keeping the Cowbird's 

 egg locked up in the basement, where no warmth from 

 their bodies can reach it ; and so it never hatches. If 

 a second Cowbird's egg is laid, in the new upper story 

 of the nest, the Warblers generally abandon their home 

 in despair, and choose a new nesting place ; but some- 

 times they build a third story over the other two, and 

 thus defeat the evil designs of both their enemies with- 

 out giving up their home. 



" This nest of Rap's is a two-storied one, and when I 

 touched the bottom I could feel that there was an egg 

 in the lower story. By and by, when the birds have 

 flown, we will take the nest apart and you can see for 

 yourselves how ingeniously it is made." 



"To think of all the ways birds have," said Rap; 



