CHAP, iv.] FEELING AND TOUCH. 583 



carried. We are also conscious of the varying condition of our 

 muscles, even when they are at rest ; the tired and especially the 

 paralysed limb is said to 'feel' heavy. In this way the state of our 

 muscles largely determines our general feeling of health and 

 vigour, of weariness, ill health and feebleness. 



It has been suggested that since muscle possesses little or no 

 general sensibility, comparatively little pain being felt for instance 

 when muscles are cut, our muscular sense is chiefly derived from 

 the traction of the contracting muscle on its attachments; and 

 undoubtedly in many instances of cramp, the pain is chiefly felt 

 at the joints; and, as we know, Pacinian bodies are abundant 

 around the joints. Afferent nerves, however, having a different 

 disposition from the ordinary motor nerves which terminate in 

 end-plates, have been described as present in muscle ; and analogy 

 would lead us to suppose that these afferent fibres, though possess- 

 ing a low general sensibility, might be easily excited in a specific 

 manner by a muscular contraction ; but further investigations are 

 necessary before these can be accepted as the true nerves of the 

 muscular sense. 



In favour of the view that the muscular sense is peripheral and 

 not central in origin, may be urged the fact that the sense is felt 

 when the muscles are thrown into contraction by direct galvanic 

 stimulation instead of by the agency of the will. Many authors, 

 even while admitting the existence of a muscular sense of peripheral 

 origin, contend that w r e also possess and are very largely guided in 

 our movements by what might be called a ' neural ' sense of central 

 origin. That is to say, the changes in the central nervous system 

 involved in initiating and carrying out a movement of the body, so 

 affect our consciousness, that we have a sense of the effort itself. 



It has been observed that when the posterior roots are divided, 

 movements become less orderly, as if they lacked the guidance of a 

 muscular sense ; and although the impairment of the movements 

 may be due in part to the coincident loss of tactile sensations, it is 

 probable that it is increased by the loss of the muscular sense. 

 There is a malady or rather a condition attending various diseased 

 states of the central nervous system called locomotor ataxy, the 

 characteristic feature of which is that, though there is no loss of 

 direct power over the muscles, the various bodily movements are 

 effected imperfectly and with difficulty, from want of proper 

 co-ordination. In such diseases the pathological mischief is fre- 

 quently found in the posterior columns of the spinal cord and the 

 posterior roots of the spinal nerves, that is in distinctly afferent 

 structures ; and the phenomena seem in certain cases at least to be 

 due to inefficient co-ordination caused by the loss both of the 

 muscular sense and of ordinary tactile sensations. The patients 

 walk with difficulty, because they have imperfect sensations both of 

 the condition of their muscles and of the contact of their feet with 

 the ground. In many of their movements they have to depend largely 



