LOCALISATION OF FUNCTION. 273 



Some movements like those for the eyes are repre- 

 sented by more than one point in. the cortex, from which 

 they may be aroused by direct stimulation. It appears 

 that the movements of the eyes, which follow stimulation 

 of the frontal region, are due to impulses, which, arising 

 there, pass to the lower centres, from which arise the 

 motor nerves controlling the muscles of the eyes; and in 

 the same way movements of the eyes, which follow 

 stimulation of the occipital region, depend on impulses 

 which pass directly from the point of stimulation to the 

 lower centres. It has been suggested that when the 

 sensory area in the occipital region was stimulated, and 

 movements of the eyes followed, they were due to im- 

 pulses which passed from the occipital to the frontal 

 region by way of the association fibres, and then through 

 the mediation of the frontal centres found their way to 

 the lower centres. But Schafer showed that in the 

 monkey's brain the two cortical T regions might be com- 

 pletely separated from one another, and yet the reaction 

 followed stimulation of the occipital cortex, thus proving 

 that they were not connected. At the same time, the 

 movements of the leg, for example, can be modified by 

 impressions received through the eyes, and in this case 

 the muscles are in part controlled by a sense organ 

 with which they are not associated at the periphery, and 

 whose cortical area is remote from that of the efferent 

 fibres. In the reactions of which this is a type, as when 

 one steps back before a wave of water, the reaction is 

 probably mediated by association fibres between the 

 sensory, visual, and motor, leg areas. This is very im- 

 portant as a fundamental arrangement, because, while 

 the primary condition puts each group of muscles into 

 relations with the sense organ with which it has the 

 most immediate peripheral associations, this second 



1 Schafer, Proc. Roy. Soc., London, 

 18 



