v THE PHILOSOPHY OF BIRDS' NESTS 109 



aid of an unknown and mysterious faculty to do that which 

 is so strictly analogous to the house-building of savage man. 



The observations and experiments of the late Mr. Spalding 

 may seem opposed to this view, as they undoubtedly prove 

 some very remarkable instinctive actions on the part of young 

 chickens hatched in an incubator. These birds appear to 

 recognise the call of a hen ; and one chick walked or ran 

 straight towards her, leaping over or running round small 

 obstacles ; and this only twenty minutes after its eyes had 

 been allowed to see the light and the first time it had ever 

 moved its legs. A young chicken, ten minutes after its eyes 

 had been unveiled for the first time, seized and swallowed 

 a fly at the first stroke. 1 



In subsequent papers Mr. Spalding showed that young 

 swallows could fly well and avoid obstacles on the first 

 attempt ; that young pigs a few minutes old could hear and 

 run to their mother, though out of sight ; and that most young 

 animals give indications of fear at the voice or presence of 

 their natural enemies. 



But in all these cases we have comparatively simple motions 

 or acts induced by feelings of liking or disliking ; and we can 

 see that they may be due to definite nervous and muscular 

 co-ordinations which are essential to the existence of the 

 species. That a chicken should feel pleasure at the sound of a 

 hen's voice and pain or fear at that of a hawk, and should 

 move towards the one and away from the other, is a fact of 

 the same nature as the liking of an infant for milk and its 

 dislike of beer with the motion of the head towards the one 

 and away from the other when offered to it. But when, at a 

 much later period, with all its senses and powers of motion 

 fully developed by use and exercise, and with the results of 

 the experiences of a year's eventful life, the bird proceeds to 

 perform the highly complex operation of building a nest, we 

 have no right to assume without direct proof that it will 

 be guided throughout by instinct alone ; and we have seen 

 that not only is there no evidence to support this theory, but 

 that all the facts we possess are directly opposed to it. 



Since this essay was published, however, some amount of 



1 " On Instinct." Paper read at British Association, sect. D., 1872 ; Nature, 

 vol. vi. p. 485. 



