Further Note on the Sensory Nerves of Muscles. 



247" 



" Further Note on the Sensory Nerves of Muscles." By C. S. 

 Sherrington, M.A., M.D., F.R.S., Holt Professor of Physio- 

 logy in University College, Liverpool. Received February 

 26,— Read April 8, 1897. 



In a former number* of these ' Proceedings' I drew attention to the 

 occurrence of reflex reactions evoked by mechanical and electrical 

 excitation of individnal eye-muscles and of their nerve-trunks. I 

 was later somewhat surprised when, after the sensory nature of the 

 structures originally termed muscle-spindles (Kiihne) had been 

 proved,f I was unable to find in the eye-muscles any examples of 

 these structures.;!; I had expected to find in those muscles, on 

 account of the great delicacy of their control and co-ordination, and 

 in view of the well-known richness of their innervation, a field pecu- 

 liarly favourable for the examination and study of " spindles." It 

 appeared to me possible, however, that spindles if of a very simple 

 type, e.g., containing a single muscle fibre not enveloped in a distinct 

 capsule, but with simply an unthickened perimysial sheath and with- 

 out any circumfusal lymph space, in short if reduced to a far simpler 

 type than I have ever met actually existent, might, although present, 

 yet escape recognition. I turned, therefore, to the production of 

 degeneration for further information. 



I had noted that the intrafusal muscle-fibres, of the "red" 

 variety as they are, undergo when the nerve-trunk of a muscle has 

 been severed, a much slower course of alteration than do extra-fusal 

 muscle fibres, § i.e., I found no pronounced degeneration for even two 

 years following section. I therefore cut through n. oculomotorius at 

 its origin, and examined the resultant degenerations in the eye- 

 muscles which it innervates and in their individual nerve-trunks. 

 The degenerative process was allowed scope for various periods. 

 This method of test failed, however, to give me distinct results 

 because (1) the muscle-fibres of the eye-muscles (in monkey) exhibit 

 normally a certain variable amount of fatty granulation, simulating 

 degenerative change ; and because (2) the resultant changes in the 

 muscle-fibres, although the fatty granulation distinctly increased, 

 did not even after a period of sixty days show the clearly distinctive 

 characters I had hoped. 



On the other hand, in the nerve- trunks, extra-muscular and intra- 



* ' Roy. Soc. Proc.,' vol. 52. April, 1893. Further note on the "Correlation 

 of the Action of Antagonistic Muscles." 

 f < Proc. Physiol. Society,' Kb. 3, 1894. 



% Ibid., and 1 Journal of Physiology,' vol. 17, 1894. " The Constitution of the 

 Nerves of Muscles." 



§ ' Journ. of Physiology,' vol. 17, 1894, ibid. 



