PERFECTION OF INSTINCT. 161 



Perfection of Instinct. 



An instinct may be said to be perfect when it is perfectly 

 adapted to meet those circumstances in the life of an animal 

 for the meeting of which the instinct exists ; and if it is an 

 instinct this perfection must be exhibited as independent of 

 the animal's individual experience. We may therefore best 

 illustrate the perfection of instinct l)y considering the won- 

 derful accuracy of many among the highly refined and com- 

 plex adjustments which are manifested by the newly-born 

 young of the higher animals. 



The late Mr. Douglas Spalding in his brilliant researches 

 on this subject has not only placed beyond question the 

 falsity of the view " that all the supposed examples of instinct 

 may be nothing more than cases of rapid learning, imitation, 

 or instruction,"* but also proved that a young bird or mammal 

 comes into the world with an amount and a nicety of 

 ancestral knowledge that is highly astonishing. Thus, speak- 

 ing of chickens which he liberated from the egg and hooded 

 before their eyes had been able to perform any act of vision, 

 he says that on removing the hood after a period varying 

 from one to three days, " almost invariably they seemed a 

 little stunned by the light, remained motionless for several 

 minutes, and continued for some time less active than before 

 they were unhooded. Their behaviour, however, was in every 

 case conclusive against the theory that the perceptions of 

 distance and direction by the eye are the result of experience, 

 or of associations formed in the history of each individual life. 

 Often at the end of two minutes they followed with their 

 eyes the movements of crawling insects, turning their heads 

 with all the precision of an old fowl. In from two to fifteen 

 minutes they pecked at some speck or insect, showing not 

 merely an instinctive perception of distance, but an original 

 ability to judge, to measure distance, with something like in- 

 fallible accuracy. They did not attempt to seize things 

 beyond their reach, as babies are said to grasp at the moon ; 

 and they may be said to have invariably hit the objects at 



* Quoted from his article in Macmillan''s Magazine, February, 1873, 

 from which likewise all the subsequent quotations are made. We are now- 

 adays so ready to assimilate scientific truth, that in reading this article — not 

 yet ten years old — it seems difficult to realize that so recently there was such 

 a considerable clinging of competent opinion to the non-evolutionary view of 

 instinct as the quotations in the article show, 



Ii 



