WILD LIFE OF ORCHARD AND FIELD 



cannot discern the union. The entrance is a cir- 

 cular opening situated in the superior third of the 

 nest, facing southwardly." Mr. Gentry considers 

 this the latest improvement upon a nest which in 

 the beginning was simply a hammock in the fork 

 of a tree, like a vireo's, but which has been made 

 more and more pendulous, until what was at first 

 the whole nest is now only the lining at the bottom 

 of a deep, enclosing bag. 



With the idea of testing Wallace's theory that 

 birds of bright colors, easily detected by birds of 

 prey, are always found to occupy concealing nests, 

 Dr. C. C. Abbott, of Trenton, New Jersey, made ex- 

 tensive notes upon the nests of our subject. In 

 every instance those nests which fully concealed 

 the sitting bird were at a considerable distance 

 from any house in uncultivated parts. In all such 

 localities sparrow-hawks were seen frequently, as 

 compared with the neighborhoods selected for 

 building the shallower open-topped nests, all of 

 which were in willow or elm trees in the yards of 

 farm-houses. The conclusion drawn was that the 

 orioles knew where danger from hawks was to 

 be apprehended, and constructed accordingly the 

 less elaborate nest in the farmer's yard answering 

 every purpose for incubation. Dr. Abbott says, 



258 



