300 ON CUTANEOUS AND [BOOK in. 



left intact); if the stimulus is strong, the movement spreads to 

 neighbouring muscles. And we know that a muscle is supplied 

 by nerve fibres which do not end in end-plates in the muscular 

 fibres; some of these are vaso-niotor, but others are probably 

 afferent, more especially those described as ending in fine fibrils 

 around and among the muscular fibres, that is in the perimysial 

 and other connective tissue ; and of these while some may serve 

 for the impulses of pain, others may serve as impulses for the 

 muscular sense. 



Tendons and ligaments are also provided with afferent nerve 

 fibres, and a special mode of ending, a plexiforni arrangement of 

 fibrils terminating in minute end-bulbs, has been described in 

 tendons under the name of the " organ of Golgi." 



Both muscles on the one hand and tendons and ligaments 

 on the other may furnish the afferent impulses of which we are 

 speaking. \Ve must seek therefore other arguments to decide 

 whether the muscular sense is derived from the muscles or from 

 other parts. We cannot by an appeal to our own consciousness 

 localize the sensation so as to lodge it either in one tissue or 

 another, and must trust to indirect indications. On the one 

 hand there seems to be a close connection between the muscular 

 sense and the ' sense of fatigue ; ' and the latter appears to be 

 determined by the condition of the muscles. Again, in many of 

 our movements we only employ a part of a muscle, and it is 

 difficult to suppose that the afferent impulses which guide us in 

 using that part only, depend only on the effect w r hich the partial 

 use of the muscle produces in the tendons and the like. On the 

 other hand, when we have a muscular sense of the movements of 

 the fingers, we can hardly suppose that the sense is afforded by 

 impulses coming exclusively from the muscles moving the fingers, 

 distant as these often are from the joints which they move, And, 

 again, the movements of which we are most distinctly sensible, are 

 especially the movements affecting joints ; indeed we have some 

 difficulty in appreciating the amount and character of a movement 

 not necessarily involving a joint such as one caused by contrac- 

 tions of the orbicular muscle of the mouth or of the eye, even 

 though in these cases we are assisted by cutaneous sensations. 



We ought therefore probably to conclude that the muscular 

 sense though based in part on impulses derived from the muscular 

 fibres is also, and possibly to a large extent, based on impulses 

 derived from the tendons and other passive instruments of the 

 muscles, though we cannot as yet assign accurately the relative 

 share. If this be so the ' muscular ' sense is not a wholly appro- 

 priate term ; but it would be undesirable, at present at least, to 

 attempt to replace it by a new one. 



This muscular sense, using the term in its broad meaning, 

 enters largely into our life. By it we are not only enabled to 

 coordinate and execute adequately the various movements which 



