172 ARBOREAL MAN 



not concern us here, and we may rest content with the 

 usual clinical conclusion that the lodgment has been so 

 complete that damage of the whole of this kinsesthetic 

 area causes a total inability to perform all " voluntary " 

 or more accurately " pictured " movements. It 

 should be noted that, although in popular usage it is 

 commonly assumed that such oft-repeated things as the 

 movements of the legs and feet in walking become 

 " reflex," such an expression is totally inaccurate. No 

 repetitive pictured movement ever becomes reflex in the 

 sense that it is initiated anywhere than in the cortex of 

 the neopallium. Its site of initiation is lodged in the 

 neopallium, and it cannot be substituted by any " lower " 

 centre. Were walking, for instance, ever to be performed 

 as a true reflex, the power to walk would still be present 

 in cases of hemiplegia. It is this complete translation 

 of the initiating centre to the cortex which demands an 

 education of the human motor functions. A human 

 baby has to learn to walk, it has to learn all purposive 

 pictured movements. The newborn young of a lower 

 Mammal does not have to pass through the probationary 

 period necessary to an animal, in which such movement 

 is represented only in the cortex. There is a gradual 

 scale in this feature displayed in the mammalian series, 

 and to this we shall have to return in a subsequent 

 chapter, since it is concerned with the problem of infancy. 

 From the point of view of cortical representation of 

 motor impressions the arboreal habit has therefore 

 probably effected a great deal. It has permitted of 

 hand-testing, and it has enabled this testing to comprise 

 a correlated study by the hands and the eyes. It has 

 given scope for a wide range of fine hand movements, and 

 it has demanded a high degree of co-ordination of these 

 movements. It has also called forth a very special 

 co-ordination of movements in the balancing, necessary 

 in an arboreal life. And it has permitted the animal to 

 know, and to picture, all the outward features of its 



