CH. LI.] 



SENSORY ENDINGS IN MUSCLE. 



699 



The principal grounds for believing the n euro-muscular spindles 

 to be sensory, are first, that the nerve-fibres that supply them do 

 not degenerate when the anterior roots of the spinal nerves are 

 cut, and secondly, that they do degenerate when the posterior 



' /',/ T'/ .' / i ' 



Fig. 521. Termination of medullated 

 nerve-fibres in tendon near the mus- 

 cular insertion. (Golgi.) 



Fig. 522. One of the reticulated end-'plates 

 of flg. 521, more highly magnified, a, 

 medullated nerve-fibre ; b, reticulated 

 end-plate. (Golgi.) 



roots are divided (Sherrington). They also undergo degenerative 

 changes in locomotor ataxy, which is a disease of the sensory 

 nerve-unite, and remain healthy in infantile paralysis, which is a 



m.n.b. 



pr.t 



s.e 



Fig. 523. Neuro-muKcular spindle, c., capsule ; n.tr., nerve trunk ; m.n.b., motor nerve 

 bundle; pl.t., plate-ending; pr.t.. primary nerve-ending; s.e., secondary ending. 

 (After Ruffini.) 



disease of the motor cells of the anterior horn of the cord 

 (Batten). 



In addition to the special end-organs, sensory fibres may ter- 

 minate in plexuses, as in the sub-epithelial and the iutra-epithelial 

 plexus of the cornea (fig. 524). 



We may now proceed to the consideration of the sense of touch 

 itself ; it may be taken under three heads : 



i. Localisation of sensations. 



