120 
THOMPSON YATES LABORATORIES REPORT 
flexed at the raetacarpo-phalangeal joints ; supination of the wrist and active flexion of the fingers were 
movements sometimes seen. 
Macaque brachial roots severed except Vth, Vlth and Vllth. The elbow was not held 
permanently flexed, but the fingers, except the thumb, were little used, although slight extension of the 
fingers was frequent as a willed movement. 
Macaque: — All brachial roots except the Vllth severed. The elbow was kept permanently 
extended. 
Fig. 14 
Macaque : — The Vth and Vlllth roots of the left side alone intact, the rest having been severed. 
Elbow and wrist and fingers could be flexed and extended ; abduction of the wrist to the ulnar side was 
often noticed. The impairment of the limb was not very great ! 
Macaque : — The Ilnd thoracic root alone, of all brachial roots, left unsevered. The animal flexed 
its fingers voluntarily at times. 
Moniceys in which the Vth, Vlth, Vlllth and 1st roots were singly in different individuals severed 
and allowed to degenerate, displayed no obvious impairment of the movements of the limb, either 
immediately after the operation nor when the operation wound had healed. 
From the foregoing, it is seen that by collating the combined movements obtained from 
each of the brachial series of roots, a sketch of the motor localization of the limb movements is 
indicated ; but the sketch is an imperfect one. As to the topographical order of the groups of motor 
nerve-cells executing the simple movements of the limb-joints, the analysis of the muscular fields 
of the motor roots carried out in my degeneration experiments yields a fuller and more accurate 
view of spinal localization, considered in its fore-and-aft arrangement. The information from 
the combined movements evoked by nerve-roots is complicated by algebraic summation of com- 
ponent antagonistic factors, which, as I have shown elsewhere, is not of physiological value. 
