222 A STUDY IN HEREDITY 



and therefore of acquirement? When an insect secures its 

 proper food in the proper way, spins a cocoon, mates with an 

 individual of the opposite sex, or lays its eggs, with fit provision 

 for the future, in an appropriate place, does it not act solely by 

 virtue of inborn inherited knowledge and ways of thinking and 

 acting, and, since it is unguided by experience, not in the least 

 by virtue of knowledge and ways of thinking and acting which 

 are acquired ? To the mind of every naturalist will at once 

 occur innumerable instances of actions, some of them extremely 

 elaborate and complex, performed by insects and other com- 

 paratively low animals, in which experience can play no part ; 

 in other words, which are wholly independent of acquired know- 

 ledge and ways of thinking and acting. By means of instincts 

 animals are enabled to place themselves in harmony with an 

 environment infinitely more complex than that to which reflex 

 action alone can adapt them. The element of consciousness 

 and its outcome, choice, are introduced. The conscious animal, 

 unlike the unconscious, is enabled to choose between two or 

 more courses, to which two or more instincts impel him. Thus 

 the male spider approaches the gigantic female, guided by both 

 the mating and life-preserving instincts, and all the complications 

 of his subsequent conduct are due to his power of choice between 

 two or more courses. 



Higher in the scale, concurrently with the evolution of the 

 power of acquiring physical traits (properly so called), is evolved 

 the power of acquiring mental traits. It increases in successively 

 higher animals, and at length, in the highest animals, becomes of 

 such importance that it overshadows and replaces instinct, which, 

 since it rw longer holds a commanding place as a factor in 

 survival, undergoes great retrogression. If I can make my 

 readers grasp all that is implied in the above, I think they will 

 admit the vast importance I have claimed for my subject — an 

 importance which is vast not only from the standpoint of the man of 

 science, but from many other standpoints, such as those of the 

 moralist, the sociologist, the statesman, the philanthropist, the 

 physician, and others as well. Let us contrast two animals 



