go THE CITY OF THE BIRDS. 



differently? The nest of birds belonging to the 

 same genus, even, have their peculiar places and 

 mode of construction which can be quite readily 

 distinguished by the practiced observer. The 

 yellow, the chestnut-sided and the black-throated 

 green warblers, for example, so common in the 

 vicinity of Boston, and brothers, we may say, in 

 the extensive genus Dendroica, have special ways 

 of turning out their cups. That even these little 

 woven masses of down, weed and grass-strips, 

 hairs and caterpillars' webs, show in their con- 

 struction specific differences almost as plainly as 

 do the markings and colors on each of these birds, 

 and generally can be as easily identified by the 

 specialist, is something strange and interesting to 

 contemplate. What was it in her life experience 

 that taught the yellow warbler to build a deeper 

 and more substantial nest than that of the chest- 

 nut-sided, and why has the black-throated green 

 taken it into her head to fix her tiny home in the 

 branches of the pine and hemlock trees, so much 

 higher than those of her near relatives } The 

 influences that induced the barn swallow to place 

 its nest on the beams and rafters, that caused the 

 cousin, the cliff swallow, to fasten its mud retort 

 under the outside eaves, or told still another 

 cousin to burrow like the chipmucks in the sand- 

 bank for a nest, are certainly too curious and sub- 

 tle for even the little birds to tell us about them. 



