45° 



The Bird 



swooping down one after another upon the nests and 

 each impahng an egg upon its beak and flj'ing off with it. 

 They would never dare such open villainy were the herons 

 undisturbed. 



Fig. 356. — Colony of Great Blue Herons. 



Many of the more isolated cases of exposed white 

 eggs are to be explained. I think, by the fact that the 

 habits of birds often change rapidly, while their structural 



