EXCURSIONS OF AN EVOLUTIONIST 



pie capacities thoroughly organized, man came 

 at last to be born with the germs of many com- 

 plex capacities which were reserved to be un- 

 folded and enhanced or checked and stifled by 

 the incidents of personal experience in each in- 

 dividual. In this simple yet wonderful way there 

 has been provided for man a long period during 

 which his mind is plastic and malleable, and 

 the length of this period has increased with civ- 

 ilization until it now covers nearly one third of 

 our lives. It is not that our inherited tendencies 

 and aptitudes are not still the main thing. It is 

 only that we have at last acquired great power 

 to modify them by training, so that progress 

 may go on with ever increasing sureness and 

 rapidity. 



In thus pointing out the causes of infancy, 

 we have at the same time witnessed some of its 

 effects. One effect, of stupendous importance, 

 remains to be pointed out. As helpless baby- 

 hood came more and more to depend on pa- 

 rental care, the correlated feelings were devel- 

 oped on the part of parents, and the fleeting 

 sexual relations established among mammals in 

 general were gradually exchanged for permanent 

 relations. A cow feels strong maternal affection 

 for her nursing calf, but after the calf is fully 

 grown, though doubtless she distinguishes it 

 from other members of the herd, it is not 

 clear that she entertains for it any parental feel- 

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