IN THE HEMLOCKS. 71 



bellied intruder would have caused the death of the 

 two rightful occupants of the nest ; so I step in and 

 turn things into their proper channel again. 



It is a singular freak of Nature, this instinct which 

 prompts one bird to lay its eggs in the nests of others, 

 and thus shirk the responsibility of rearing its own 

 young. The cow-buntings always resort to this cun- 

 ning trick ; and when one reflects upon their numbers 

 it is evident that these little tragedies are quite fre- 

 quent. In Europe the parallel case is that of the 

 cuckoo, and occasionally our own cuckoo imposes 

 upon a robin or a thrush in the same manner. The 

 cow-bunting seems to have no conscience about the 

 matter, and, so far as I have observed, invariably 

 selects the nest of a bird smaller than itself. Its egg 

 is usually the first to hatch ; its young overreaches all 

 the rest when food is brought ; it grows with great 

 rapidity, spreads and fills the nest, and the starved 

 and crowded occupants soon perish, when the parent 

 bird removes their dead bodies, giving its whole 

 energy and care to the foster-child. 



The warblers and smaller fly-catchers are generally 

 the sufferers, though I sometimes see the slate- 

 colored snow-bird unconsciously duped in like man- 

 ner ; and the other day, in a tall tree in the woods, I 

 discovered the black-throated green-backed warbler 

 devoting itself to this dusky, overgrown foundling 

 A.n old farmer to whom I pointed out the fact was 

 much surprised that such things should happen in his 

 woods without his knowledge. 



