THE CENTRAL NERVOUS SYSTEM 



by Sir Charles Bell. Bell observed that when, in an animal 

 just killed, he mechanically stimulated the anterior roots, 

 muscular contractions were obtained at each touch of the 



nuc/e 



,Pijramidal iCeli 

 *,. Ay&s-cultnder 



through re sri-, 

 form body /jij 



ft 



Fibre ofPt/ramJreic, 

 (cut short) 



Fillet 



Ne we Cells - 

 of grctcilt % 

 cutieate nuclei 



Fibre of Direct - 

 Ct rebel Jar* Tract. 



Fibre of G ell's Ccl- 



-Fibre of Growers'Tract 



L . . Nerve-cell ofPost.Horn (?) 



k ^S 



\ ^Pcsf-.Jtoflt of G an alien Utt 

 \@ 



Cell of Ant. Horn 



Ganglion-Cell 

 on Post. Ro9t--- 



Post.Root \^ 

 Fibres ^ 



T/ 



e rve - Cell of Clarke's Col 



Middle li?ie 



Po ssi Me Affe re n t Paths. 



FIG, 252. SOME POSSIBLE PATHS OF AFFERENT IMPULSES IN THE CENTRAL 

 NERVOUS SYSTEM (SCHEMATIC) 



forceps. He concluded from this that the anterior roots are 

 motor ; but although he is often credited with the discovery 

 of the functions of the posterior roots as well, he was not 



