THE NERVOUS SYSTEM ITS HIGHER WORK 259 



area is the place for the reception of the visual impulses, 

 and so on. In most respects the human brain has been 

 found to be organized in a manner closely corresponding 

 with what is traceable in the brain of the ape and hinted 

 at in the brain of the dog. 



Yet the distinctive accomplishments in which man ex- 

 cels the lower animals must be coupled in some way with 

 his cerebral equipment. One or two of these distinguishing 

 features seem to have quite definite positions. This is 

 especially clear in the case of the well-recognized "speech 

 center. " The belief is commonly held that the mechanisms 

 which are correlated with such acquired powers as speech, 

 reading, and writing are restricted to one-half of the 

 brain, usually the left. The right hand, which in most 

 subjects is so much superior in skill, is governed from the 

 left side of the cerebrum. A charming account of the 

 apparent relations between the human brain and human 

 capacities is given in W. H. Thomson's "Brain and Per- 

 sonality." The claims made for precise localization in 

 that book are regarded by many conservative writers as 

 extreme. It is certainly fair to say that at present the 

 most learned interpreters of brain physiology are placing 

 emphasis on the development of paths between centers 

 rather than on the organization of the centers themselves. 



The characteristic of early life is the ease and freedom 

 with which these paths are opened and the comparative 

 frequency with which they are changed. During the long 

 period of mature efficiency they are less subject to multi- 

 plication and are used with increasing regularity and with 

 rarer deviations. The man is becoming a creature of 

 habit and acquiring "ruts." In old age, as has been finely 

 said, the nervous system, instead of holding a prophecy 

 of what may be, contains a record of the past. It is a 

 fascinating fancy though it is nothing more that a 

 physician of surpassing insight might look upon the warp 

 and woof of fibers in a dead brain and tell us of the tastes, 

 talents, and pursuits of its former possessor. When we 

 walk through the rooms of a deserted house we can tell 



