KOVEMBER 13, 1914] 



SCIENCE 



689 



weiglit of evidence is that it is not possible. Be- 

 ing an expert mathematician does not make one 

 an authority in law or medicine. The neural 

 pathways opened up in the pursuit of differ- 

 ent branches of learning are not the same. 

 . They may lie quite far apart and expertness 

 in one line does not imply even soundness of 

 judgment in another. This is an important 

 matter in education and will receive further 

 attention later. 



The formation of habit is common to all 

 animals, and habits have a marked influence 

 on behavior. We do things so often that it 

 becomes difficult to refrain from doing them 

 when the conditions under which they have 

 been done recur. The most forceful teacher 

 of my college days was wont to say : " Man is 

 but a bundle of habits and happy is the man 

 whose habits are his friends." At twenty, it 

 seemed to me that the force of this saying lay 

 in its sonorous quality. At sixty I realize 

 that its strength lies in its truth. The young 

 scout the idea that they can not indulge in a 

 vice occasionally without becoming a victim. 

 The chains forged in the smithy of habit are 

 strong in every link. They may safely hold us 

 in the heaviest storm or they may drag us to 

 the bottom of smooth seas. Another mistake 

 often made by youth is the belief that every 

 experience is helpful. There is no other com- 

 modity for which we pay so dearly and the 

 price often is health, happiness and even life. 



Some stimuli make such deep and lasting 

 impressions on the central nervous system that 

 the picture may be recalled without the recur- 

 rence of the original stimulus. This is mem- 

 ory. Jennings has shown that there is some 

 evidence of memory even in unicellular or- 

 ganisms. This becomes more marked as the 

 animal structures, especially the nervous sys- 

 tem, develop. Even a spider learns by experi- 

 ence and alters its behavior to its own benefit, 

 when repeatedly subjected to like conditions. 



Colvin says : 



Memory is a fundamental phenomenon of or- 

 ganic Ufe. In its widest sense it signifies the fact 

 that impressions onee received by an organism 

 axe retained for a greater or less period and that 

 this retention is indicated in the modified be- 



havior of the organism. The evidence of mem- 

 ory in animals is their ability to profit by experi- 

 ence. A white rat is placed at the entrance of a 

 maze at the center of which is food. The animal 

 moves about in an aimless manner until at length 

 it reaches the center. If on succeeding trials the 

 rat shows an improvement in the accuracy and 

 rapidity with which it moves about the maze, this 

 means that its earlier attempts have in some sense 

 left their effects; they have modified subsequent 

 conduct. Memory, when used in this widest sens© 

 of the term, lies at the basis of all learning. It 

 is a measure of educability. 



There are three important factors in mem- 

 ory. The impression must be " stamped in." 

 It must be correctly associated with other im- 

 pressions. It must be subject to recall and 

 proper recognition. The strength of the im- 

 pression is dependent upon many factors. 

 The brain may be so altered by inherited de- 

 fect, trauma, senility, fatigue, disease or toxie 

 agents, that effective and lasting impressions- 

 can not be made. So long as the brain re- 

 mains in the abnormal condition its receptiv- 

 ity can not be improved. The mentally de- 

 fective can be educated to a certain point, but 

 can go no farther. An impression may be 

 " stamped in " by the force or unusual char- 

 acter of the external stimulus. The external 

 world demands the attention of the individual 

 and an unusual sight, noise or other sensation 

 makes a never-to-be-forgotten impression. 

 This is knovsra as passive attention and is com- 

 mon to all animals. It is the basic principle 

 in all attempts to modify behavior through 

 hope of reward or fear of punishment and is 

 highly effective in the control and training of 

 the lower animals and ignorant men, but loses 

 in power with the development of intellect. 

 However, in this and other universities this 

 appeal to increased effort is employed in the 

 form of grades, admission to special societies, 

 the bestowal of insignia of distinction, etc., 

 and on most men in our stage of development 

 it is not without effect. The approval of our 

 fellows as shown by social, political and in- 

 tellectual preferment, still proves a potent in- 

 centive to increased effort. With the devel- 

 opment of intellect, passive attention is 

 largely supplanted by the active form. la 



