662 THE POPULAR SCIENCE MONTHLY. 



with lines so deep as to determine the direction of conduct with tlie 

 greatest certainty. Then habit becomes instinct. The individual no 

 longer forms the structure, but inherits it ready formed. The actions 

 are no longer learned by practice, they are already predetermined by 

 the inherited structure. 



We see illustrations of this process in the artificial formation the 

 deliberate manufacture of instincts in domestic animals by human 

 training and human selection. We know that the instincts of the 

 pointer and the shepherd's dog have been formed in tliis way. The 

 great ancestor of all the pointers, before he was a pointer, was trained 

 with much coaxing and many beatings to do certain things. The re- 

 sult was doubtless any thing but satisfactory. Still a habit was formed, 

 and, as we must believe, a corresponding brain-structure. The pujis 

 of this dog were again trained, still with difficulty, but with less diffi- 

 culty than before, because the habit-structure was partially inherited. 

 The best-trained of this generation are selected, and their pups again 

 trained. The process is still easier, because the habit-structure is more 

 completely inherited, and the result is more satisfactory, because the 

 structure is more decided. Thus the improvement goes on from gen- 

 eration to generation, until finally, in the purest bloods, i. e., those 

 having the longest line of well-trained ancestry, without mixture with 

 effacing bloods, little or no training at all is required ; the habit-struct- 

 ure is almost perfectly transmitted. Perhaps in this case transmitted 

 habit never becomes perfect instinct ; probably the best-blooded pups 

 still require training. But this is because the process has not been 

 continued long enough, the breeding has not been true enough, and 

 the selection careful enough. 



Now, if pointers or shepherds' dogs should become wild, their in- 

 stincts would quickly be destroyed by natural selection, because they 

 are not useful, but, on the contrary, hurtful, in the wild state. But, 

 suppose they Avere useful in the struggle for life, then the habit thus 

 acquired would be transmitted, and become strengthened with every 

 generation, until it would become as perfectly fixed and invariable as 

 any, even the most perfect instinct. 



Now, it is precisely in this way that the wonderful instincts of 

 bees and ants and the wonderful instinctive coordination of muscles 

 in ruminants and gallinaceous birds have been formed, except that in 

 these cases natural training and natural selection have operated in- 

 stead oi human training and human selection. The great ancestor of 

 all the bees, before the distinctive characters of the bee yet existed, 

 was doubtless destitute of the wonderful instincts which we now find. 

 These have been gradually formed and improved from generation to 

 generation through many hundred thousands of years. 



It is difficult to imagine, much mor to express, all the steps of 

 this process. I will, therefore, illustrate it in the following manner: 

 We have seen that wise conduct is a product of intelligence and expe- 



