1895.] Influence of Sensory Nerves upon Movement, fyc. 481 



fatigue. The measurements which were, taken of the rates of 

 velocity at different parts of the tracings afford somewhat varying 

 results, and the number of cases is too few for any definite conclu- 

 sions to be drawn from them. But it would appear that while the 

 diminution is gradual and uniform in the case of small weights, in 

 that of larger weights it occurs, as a rule, more rapidly, and that 

 the rate of diminution does not remain the same throughout the 

 tracing. 



VIII. "Experiments upon the Influence of Sensory Nerves upon 

 Movement and Nutrition of the Limbs. Preliminary Com- 

 munication." By F. W. MOTT, M.D., F.R.C.P., and C. 

 S. SHERRINGTON, M.D., F.R.S. Received March 7, 1895. 



In the 14th of the ' Le9ons sur la Physiologic et la Pathologic du 

 Systeme Nerveux,' Claude Bernard draws attention by experiments 

 on the frog and on puppies to the degree of impairment in movement 

 undergone by a limb that has been rendered insensitive by section of 

 the sensory roots of its spinal nerves. 



In a series of experiments carried out during the last eighteen 

 months, we have examined the same thing in the monkey, using 

 chiefly Macacus rhesus, and observing the animals for periods up to 

 four months from the time of operation.* We propose to give here a 

 brief account of the results obtained. 



Our experiments deal separately with the lower limb and with the 

 upper limb. The phenomena observed in the two limbs do not 

 essentially differ, but are rather more marked and much more acces- 

 sible to examination in the case of the upper limb. 



I. On Movement. 



(1.) Effect of Section of the whole Series of Sensory Roots belonging to 

 the Limb. By the "whole series" is meant in the brachial region 

 from the 4th cervical to the 4th thoracic inclusive ; in the lumbar 

 from the 2nd to the 10th post-thoracic inclusive. 



From the time of performance of the section onwards, as long as 

 the animal may be kept, the movements of the hand and foot are 

 practically abolished ; the movement of grasping, which is so fre- 

 quent and useful to the monkey, both with the hand and foot, never 

 occurs at all in our experience. On the other hand, the movements 

 at the elbow and knee, and especially the movements at the shoulder 

 and hip, are much less impaired. The fore limb hangs from the 

 shoulder partially flexed at the elbow ; the hind limb is flexed at hip 



* In all our operations the animals have been deeply anaesthetised with chloro- 

 form and ether. 



VOL. LVII. 2 M 



