694 APPENDIX. 



are due to the foldings and stretchings of the skin when the muscles 

 contract*." Trousseau 'st view was very similar to that of Schiff. 



Wundt ('Menschen-u. Thier-Seele,' I. p. 222, 1863), thinks it 

 most probable that " the sensations accompanying the contraction 

 of the muscles arise in the nerve fibres that transmit the motor 

 impulse from the brain to the muscles." If it were due to sensory 

 nerves in the muscles, he says, "the muscular sensation would 

 constantly increase and .decrease with the amount of internal or 

 external work done by the muscle. But this ie not the case ; for 

 the strength of the sensation is dependent only on the strength of 

 the motive influence passing outwards from the centre, which sets 

 on the innervation of the motor nerves." A statement similar to 

 this was made by Hamilton, though it has now been shown to be 

 completely erroneous. The contrary condition of things is, indeed, 

 well illustrated by the cases of Demeaux, and Spaeth (pp. 698, 700). 



Bain's statements in the second edition of his work (1864) become 

 more explicit than they were in the first. He says: " Our safest 

 assumption is that the sensibility accompanying muscular move- 

 ment coincides with the outgoing stream of nervous energy, and 

 does not, as in the case of pure sensation, result from an influence 

 passing inwards by ingoing or sensory nerves." This opinion is 

 repeated and emphasized in the third edition (1868), in which he 

 adds (p. 76), in regard to the characteristic feeling of exerted 

 force, <( we are bound to presume that this is the concomitant 

 of the outgoing current by which the muscles are stimulated 

 to act." He considers it to be of immense consequence, from a 

 philosophical point of view, that such impressions should be asso- 

 ciated with the outgoing current, and not dependent upon ordinary 

 sensory nerves.J 



Bastian ('On the Muscular Sense,' Brit. Med. Journ., April, 

 1869) says: "All the evidence we can obtain from disease, and 

 also, as I think, the evidence which we can obtain from the most 

 careful examination of our own sensations, goes rather to support, so 

 far, the opinion of Landry that these impressions do not depend 

 upon our notions of the quantity of nerve-force liberated during a 

 volitional effort, or, in other words, upon the mind's consciousness 



* See his 'Muskel u. Nervenphysiol.,' pp. 156, ff. 



t ' Clinical Medicine,' art. ' Locomotor ataxy '. 



% The very existence of sensory nerves in Muscles was formerly held to be quite 

 \mccrtain. This doubt, however, no longer exists. The investigations of Sachs 

 (' Centralblatt fiir die Med. Wisseusch.,' 1873, and ' Archiv fur Anatomie,' 1874) have 

 shown conclusively that sensory fibres are abundant within the Muscle itself, and 

 that, having a course and distribution entirely distinct from the motor filaments, 

 they enter the Spinal Cord by the posterior or sensory roots of the spinal nerves. 



