AX IXTRODUCTIOX TO THE STUDY OF GROWTH. 43 



an element as the individual man does to the social 

 organism. The architectural arrangement of these cells 

 is orderly, and must be realised, both for the better 

 understanding of the relations existing between the 

 different portions of the nervous system and the body 

 which it controls, as well as that the important fact of 

 the localisation of function in different portions of the 

 system may be intelligently discussed. Having pre- 

 sented the available facts under this head, the study of 

 the different functions of the several portions of this 

 system, or the study of localisation in the nerve centres, 

 will be undertaken. This completes the anatomical side 

 of the subject, and the remaining chapters deal mainly 

 with physiological problems. 



It is desirable at the start to understand the 

 manner in which the nerve cells react, and the 

 laws controlling the habits and rhythms, of which 

 they are capable. Of many of these processes we 

 are conscious, but, fortunately for us, there are also 

 many of which we are quite uninformed. Naturally all 

 reactions induce fatigue, followed by repose, which 

 permits recuperation. In this rhythm of fatigue and 

 recovery there are wide individual variations, and in 

 considering these variations we get a glimpse of tem- 

 perament. Finally there is a point in the history of the 

 individual when, both mentally and physically, the 

 capacity to feel and to act diminishes. The failure is 

 not necessarily equivalent in all directions, but there are 

 certain general features in these changes which it is 

 important to describe. With this foundation of anatomy 

 and physiology the significance of training and educa- 

 tional methods may be properly considered, and as a 

 division of this general topic it may not be amiss to 

 add a word concerning sex in education. Finally the 

 attempt will be made to summarise the facts most 



