276 THE GROWTH OF THE BRAIX. 



person. The reasons for these relations are, therefore, 

 not evident in the present way of regarding the 

 nervous system, according to which growth and in- 

 crease in size are associated with activity. The 

 anatomical arrangement, which was originally respon- 

 sible for this one-sidedness, has still to be investi- 

 gated, in order to determine whether the better 

 development of the afferent or efferent structures control 

 the matter in the first instance, and to discover, if pos- 

 sible, how far the physiological processes in the neglected 

 hemisphere may be duplicates of those in the one pre- 

 ferred. At the moment, however, it is not possible to 

 do more than state the difficulty. Yet it is possible that 

 since the relations between the outgrowths of one cell 

 element and those of another must be both very exact and 

 very close, a cessation of the growth processes just this 

 side of the best degree of approximation between the 

 two would produce a defect in organisation, not accom- 

 panied by differences in weight, since they might 

 easily be masked, in the sense that a slightly better 

 development of myeline might occur on the neglected 

 side. Such questions as are suggested by aphasia, the 

 analysis of which has contributed so much to our know- 

 ledge of brain processes, can be discussed more con- 

 veniently in the chapter on education, and will be there 

 treated after the activity, fatigue, and old age of the 

 central system have been reviewed. 



