CHAP. IL] THE BRAIN. 1119 



greater importance. This indeed is shewn In the relations of 

 the motor region. We have already urged, that even as regards 

 the mere carrying out of a skilled movement (and we may 

 add whether that be voluntary or involuntary in the ordinary, 

 common use of the words) the motor region must have other 

 ties with the part moved than merely the efferent tie of the 

 pyramidal fibres ; it must have sensory afferent ties, and the 

 course of these, including even perhaps those which belong to 

 the muscular sense, we may regard as an indirect one along 

 the spinal cord and middle parts of the brain, though the 

 details are as yet unknown to us. It must moreover, as we 

 have also seen, have ties, at least in many cases, with parts other 

 than the part moved, for instance with the general coordinating 

 machinery. And the ease with which some, not very obvious, 

 change, will permit the stimulation of a limited motor area to 

 start epileptiform convulsions, shews how many and close are the 

 ties in another direction. Further, when we go beyond the final 

 phases of the process in the motor cortex, to those which precede 

 the issue of the efferent impulses, we find the ties multiplying. 

 For instance, since our movements are so largely guided by visual 

 sensations, there must be ties between the motor cortex and 

 the central visual apparatus, it may be of the occipital cortex, 

 but it may also be of the lower visual centres. As we insisted, 

 the motor area is only a link in a complex chain ; and what 

 we can see, dimly though it be, in reference to the cortical 

 motor processes, probably holds good for those other cortical 

 processes as well, of whose nervous genesis we know at present 

 nothing. Hence even the higher psychical events cannot truly 

 be spoken of as functions of the cortex, meaning that they are 

 simply the outcome of molecular changes in the cortical grey 

 matter; they are rather to be regarded as the outcome of 

 complex processes in which the parts of the brain below the 

 cortex play a part no less important than that of the cortex 

 itself. If so, the fibres passing down from the cortex to the 

 middle brain have functions by which they take part even in 

 our psychical life, functions for which neither the words motor 

 nor sensory are fitting. 



F. 



71 



