THE FRONTAL LOBES 



231 



chain of neurons which form the final common path 

 for all sorts of intentional control mediated by the 

 cortex as a whole. It is only in the human brain that 

 the precentral cortex and pyramidal tracts approach 

 closely to the fulfilment of this process. And even 

 here they are not in undisputed possession of all 

 efferent pathways of intentional control (Franz, 

 Sheetz, and Wilson, 191 5; Oden and Franz, 191 7, 

 Franz, 1921). 



The frontal pole of the human cerebrum has often 

 been regarded as in some special sense the organ of 

 the higher or more abstract intellectual faculties 

 (Bianchi, 1922), but for this view there seems to be 

 no adequate foundation. The premotor functions of 

 this cortex, however, endow it with very special 

 significance for behavior patterns (Bolton, 19 14). A 

 part of this is the organization of efferent cortical dis- 

 charges into the specific synergic patterns necessary 

 for the phasic control of intentionally directed effort 

 to which reference has already been made. This func- 

 tion is represented in the frontal lobes of all higher 

 mammals, some more, some less, depending on the 

 fineness of the cortical control of motility and the 

 complexity of the acts so directed. Naturally these 

 functions are very highly developed in man as ex- 

 pressed in his manipulative skill, vocalization, and 

 other consciously directed acts. The apparatus in 

 question lies in the intermediate precentral field just 

 in front of the excitable areas. 



