MINUTE ANALYSIS OF CORTICAL CENTRES. 
165 
As is shown in this Table, the sequence in the movement of the joints is funda¬ 
mentally similar to that which had been arrived at from clinical observation by Dr. 
Hughlings Jackson in cases of epilepsy, in which he had recorded the “ march ” of 
the movements of the joints. 
As all the facts which we have accumulated on the subject of the primary repre¬ 
sentation of movement of joints and the representation of secondary, &c., movements 
are collated in a very demonstrative manner in the accompanying figs. 7 and 8, a 
detailed description is hardly called for, but we cannot leave this pathologically very 
important subject without dwelling for a moment on some of the more salient features 
of our results. 
We have already pointed out on page 163 why the shoulder, wrist, and thumb are 
the joints, par excellence, in which primary movement takes place. 
We will now, therefore, discuss the march, i.e., the order in which the movements of 
the various joints follow each other after the primary movement. The first and most 
fundamental fact concerning the successive invasion of the various joints has already 
been determined by Dr. Hughlings Jackson, viz., that when a movement emanating 
from the cortex, e.g., of the upper limb, begins in the shoulder it proceeds downwards, 
involving successively the elbow, wrist, and fingers; and inversely, when it begins in 
the thumb and fingers, the “march” proceeds up the limb. We are here referring 
to movements presenting the characters of deliberate purpose, “ voluntary ” efforts, 
which also can be evoked by electric stimulation of the cortex, besides being exhibited 
in convulsive and epileptiform seizures. The observation of these movements as 
produced in our experiments has enabled us to form certain definite generalisations 
concerning the order of their march. Among these generalisations, the following 
appear to us to be the most important. 
1, Movement of the upper limb, commencing with the shoulder, is not completed by 
a movement of the thumb ; and, while this result is obtained at the extreme upper 
limit of the area, on the other hand, we have the exact converse at the lowest limit, 
viz., movement of the limb, commencing in the thumb, and ultimately involving the 
elbow, which is not completed by movement of the shoulder. In fig. 8 is shown 
diagrammatically the order of the march of movements occurring at each point in the 
area for the upper limb. 
2. We wish next to point out the very remarkable constancy in the order of 
march in the centres 2, 2', 13 (fig. 8). Here we are dealing with the very nucleus of 
the upper limb area, i.e., that part of it in which the most frequent and most ordinary 
movement of the limb is represented, viz., preliminary fixation of wrist in extension, 
intended, as we think, for the purpose of permitting accurate movement of the digits ; 
following this, flexion of the digits; next flexion of the elbow and subsequent adduction 
and rotation out of the shoulder, producing the complex movement which has been popu¬ 
larly styled the hand-to-mouth action, and which is unquestionably one of the most 
