8o Habit and Instinct. 



CHAPTEE IV. 



FURTHER OBSERVATIONS ON YOUNG BIRDS. 



Our consideration of the instinctive activities of walking, 

 running, swimming, diving, and flying serves to bring out 

 the fact that, in such cases, what is inherited is a con- 

 genital co-ordination of motor responses under the 

 appropriate conditions of stimulation. Not only is there 

 inherited a given structure of leg or wing, but a nervous 

 system through which there is an automatic distribution of 

 outgoing currents to the several muscles concerned; so 

 that, without learning or experience, they are called into 

 play with nicely graded intensity, and exhibit complex 

 contractions and relaxations in serial order, thus giving 

 rise to instinctive behaviour of an eminently adaptive 

 nature. 



In discussing the activities concerned in feeding, we 

 found that there was a similar congenital co-ordination 

 of motor responses for pecking at a small object within a 

 suitable distance. But, from the observations, it seems 

 that the selection of certain of these objects and the 

 rejection of others is a matter of individual experience. 

 We were not, however, prepared to found a sweeping 

 generalization on a limited number of observations on a 

 few species, and freely admitted that there may very 

 probably be cases where particular sensory stimuli give 

 rise to appropriate congenital responses ; in other words, 



