10 BIRDS' NESTS 



explain the act of building a first nest. If such were 

 really the case, a young bird hatched in a nest of 

 some other species should be able when the time 

 arrives for it to require a nest to set to work and 

 build one on the exact model prevailing with its 

 particular species, and formed of similar materials to 

 those selected by its own kind. This must conse- 

 quently attribute to a bird an inborn inherited faculty 

 for performing a most complex action, and endows 

 that bird with powers that animals on a much higher 

 plane of intelligence are incapable of accomplishing ; 

 for not even man himself can build a shelter re- 

 sembling in its architecture that of his own tribe or 

 race, without some model to copy or the instructions 

 of his more experienced fellows. Then again, instinct 

 or inherited habit being a power transmitted from 

 parent to offspring in one unchanging order of 

 descent, must necessarily be a constant power in 

 the sense of never varying. We must assume it to 

 be a stationary power, as perfect and unerring in 

 the new-born chick as in the adult bird. Birds 

 hatched with this instinctive power to make a nest 

 without imitation, tuition, or experience must be able 

 to exert it successfully under any circumstances ; 

 whilst the ancestral type of nest must resemble in 

 every particular that which is constructed now, or 

 that will be constructed unnumbered centuries hence. 

 But unfortunately for this very attractive supposition, 

 it is not supported by a single particle of fact ; whilst 



