Heredity in Man. 325 



rise to the secondary automatism of habit, which is thus 

 to be distinguished from the primary automatism of 

 instinct. 



12. Impulse is the tendency of the organism to carry 

 out its instinctive or habitual activities under the appro- 

 priate internal conditions and external stimuli. The 

 accompanying consciousness is due to afferent currents. 



13. Imitative behaviour may be either (1) instinctive, 

 when the stimulus afforded by the results of the activities 

 of another gives rise to a congenital response of like 

 nature ; or (2) intelligent, where there is conscious selec- 

 tion of the activities or their results. The latter is 

 dependent upon an innate susceptibility to pleasure when 

 the results reached by the imitating individual resemble 

 the copy. 



14. Intelligence involves true selection or choice. And 

 the method of mental evolution, by the exercise of choice, 

 is to be clearly distinguished from the method of organic 

 evolution, by natural selection. 



15. Similar activities may be — (1) acquired de novo 

 by the individuals of successive generations through the 

 similar exercise of intelligent choice ; (2) handed on by 

 tradition through the instinctive or conscious imitation by 

 the young of their elders ; or (3) transmitted as congenital 

 instinctive behaviour. 



16. It is a matter of importance, but of no little difficulty, 

 to determine whether the similar activities of individuals 

 in successive generations are acquired de novo, are handed 

 on by tradition, or are directly due to hereditary trans- 

 mission. 



17. There is no conclusive evidence that the secondary 

 automatism of habit is transmitted by heredity, so as to 

 give rise to the primary automatism of instinct. 



18. At the same time there are cases in which 



