498 F. H. PIKE 
localization of all reflexes. As the matter appears to me now, I 
would say that the loss of or injury to any given region of the 
brain may be compensated for, in part at least, by an increase 
in the quantity (without any change in the quality), to use a 
suggestion of Hughlings Jackson’s, of the nervous energy pass- 
ing over the other afferent pathways or through other central 
stations which are normally involved in the functions of the 
injured part. Compensatory processes of this general nature 
should be considered in arriving at an estimate of the normal 
function of any injured or lost portion of the central nervous 
system. And if, as I believe has now been definitely shown, 
these processes do enter into the problem of the interpretation 
of cerebral function, the minimal deficiency of function observa- 
ble after a long period of recovery will be too low to serve as an 
accurate index of the normal function of the injured or lost part. 
Such a view is not in any way destructive of or antagonistic to 
von Monakow’s argument for cerebral localization. As I see the 
problem, it strengthens von Monakow’s general position inas- 
much as it shows that normal cerebral function may be even 
greater than he imagines. 
The view that more numerous and more widely separated 
groups of nerve cells and fibers are necessary for essentially the 
same sort of movement in higher animals than in lower and the 
view that afferent impulses from different sources are concerned 
in most of our neuromuscular reactions have a certain bearing 
on the hypothesis of circumscribed centers each having a definite 
and particular function. Von Monakow has taken the speech 
center as a test case and adduces evidence that the cerebral 
speech mechanism cannot be such a circumscribed center. 
Space does not permit a consideration of the evidence against 
such circumscribed centers urged by other physiologists (Leonard 
Hill). 
There are other systems or mechanisms in which the hypoth- 
esis of a definite circumscribed center is no longer satisfactory. 
One would expect to find such a definite circumscribed region in 
the lower levels of the nervous system in the portions which 
have become highly organized, as Hughlings Jackson expresses it, 
