i 4 THE POPULAR SCIENCE MONTHLY. 



quent on this anatomical delimitation of brain areas is very im- 

 portant. Apart from this it is not possible to conceive of that 

 restriction of the attention to one kind of sensory impressions 

 that is essential to clear perceptions. All teachers know the im- 

 portance of securing attention ; but, unfortunately, this is too 

 often confounded with a constrained attitude and other non- 

 essential accompaniments. 



But a sound physiology and psychology should correspond to 

 Nature. About the best way to test them will be to ascertain how 

 they fit into human nature before it is influenced by any methods 

 whatever, for all methods are liable to hamper and modify. It 

 is hopeful to notice that so many psychologists of the modern 

 school are turning to infant psychology, or the study of the 

 mental development of the very young child, which is of course 

 closely related to its physical development. The behavior of the 

 infant is in accordance with the brain structure and function 

 of which I have been speaking. 



The infant from birth is the subject of almost constant move- 

 ments during the waking hours of its life — movements which are 

 spontaneous and not voluntary. Some of these movements, at all 

 events, are reflex — i. e., the nervous discharges from the central 

 cells of the brain and spinal cord which cause them are not due 

 to the will, but to some sort of external stimulus ; and so great is 

 the tendency to these nervous discharges in the young animal 

 that but the slightest stimulus is required. Some of these move- 

 ments may be considered a continuation of those of the pre-natal 

 period. 



It is doubtful if the newly born infant executes any voluntary 

 movements, because will proper it does not then seem to possess. 



Though the child at this stage neither sees nor hears probably 

 in the true sense of the term, it is not uninfluenced by light and 

 sound. Gradually it gets clear perceptions from all its'senses, and 

 then it becomes more than ever a reflex mechanism, its nervous 

 system being responsive to all external things, and its motor sys- 

 tem expressing this condition. In other words, sensations are 

 streaming in through all the avenues of sense, and these have 

 their outward expression in movements by which, as from the 

 first, the muscular sense on which all exact voluntary movement 

 depends, and the cutaneous sense, the most fundamental of all, 

 and that on which the perfection of all the others depend, are 

 exercised. 



At first, sounds though heard can not be localized. Objects 

 are perceived by the eye, but the infant has no idea of their dis- 

 tance. It will reach for a light across the room as readily as if it 

 were but a foot away. 



It is clear that the human being at this stage is on a par with 



