CEREBRAL FUNCTION IN LEARNING 117 



tained from any one animal. These movements, with their 

 designation in the figure are listed above. Unless otherwise indi- 

 cated the movement is on the contralateral side. 



The stimulable area embraces all of the frontal pole in front 

 of the forceps of the callosum and the dorso-medial portion as 

 far back as the anterior margin of the hippocampal lobes. The 

 ^responses elicited correspond roughly to the antero-posterior dis- 

 tribution of the muscles involved, the head having the most 

 anterior representation. The responses are obtainable only 

 under light anesthesia and are less well coordinated than in 

 higher forms. 



The relation of the stimulable , cortex to paresis 



In primates destruction of the stimulable cortex produces 

 nearly complete paralysis, hi the dog the paralysis persists for 

 only a few days, in the rat destruction of this area produces no 

 discoverable disturbance. The data included in this and the 

 earlier studies contain a large number of cases of bilateral de- 

 struction of the motor cortex. Animals 4, 5, and 8, section III, 

 of this paper all show extensive destruction of the stimulable 

 areas of both hemispheres. Numbers 1, 3, 4, 20, and 28 of the 

 series of Lashley and Franz ('17) show similar superficial bilateral 

 lesions. None of these animals showed any persistent motor dis- 

 turbance, although in many the destruction of the stimulable 

 areas, either of one or both hemispheres, was practically complete. 

 The paresis described does not result from destruction of the motor t 

 cortex. 



The character of the lesions in paretic animals 



The animals showing paresis and the character of the lesion 

 in each are shown in table 9. Animals from the earlier series of 

 Lashley and Franz are included with those of the present series. 

 Since the experiment numbers of the two series are the same the 

 animals of the former series are indicated by an asterisk. For 

 detailed descriptions of the behavior and extent of the lesions 

 in those animals the reader is referred to the original paper. 



