268 DIVERSIONS OF A NATURALIST 



mechanism built up by the individual, as well as its 

 continuous elaboration and development, is what we call 

 " memory," unconscious or conscious. It is misleading 

 to speak of " inherited memory " or " rac^ memory," and 

 to apply it in any way to the inherited mechanisms of 

 instinct ; the word should be reserved in its ordinary 

 limitation to an individual's record. This new and 

 superior apparatus appears to require a much larger 

 bulk of brain-substance for its elaboration than that 

 which is sufficient for the inherited mechanisms of 

 instinct. It works in closer response to the innumerable 

 details of the individual case, and so must be much 

 more complicated, and we can well believe must require 

 a larger instrument. Obviously it is an advantage to its 

 possessor. He (be he animal or man) is provided not 

 with a simple response suitable for the average of 

 incidents in his life, but has, by the " education " due to 

 the circumstances in which his individual life is carried 

 on, formed an ever-increasing store of special little 

 mechanisms, giving the useful or advantageous response 

 which he has himself discovered to be appropriate to this 

 or that sign, sound, colour, shape, smell, touch, or what 

 not which may assail his senses. In proportion as the 

 brain increases in volume (especially that part of it 

 which is called "the cortex of the hemispheres") the 

 animal to which that brain belongs loses — gets rid of — 

 inherited mechanisms or instincts, and becomes " educable," 

 that is to say, capable of forming for itself new individual 

 brain mechanisms based on memorized experience. 



" Educability " is the quality which distinguishes the 

 brain of increased size. Dogs are more " educable " 

 than rabbits ; monkeys more so than dogs ; and men 

 more so — vastly more so — than monkeys and apes. 

 The human infant is born with a few inherited mechanisms 



