Plate IV.— STRUCTURE Or A NERVOUS MECHANISM. 



?ig. 1. 



V 



Diagram to ebow the possible relation to one 

 another of various circuits traversing a single 

 caudate nerve cell, a may be a circuit connecting 

 a peripberal sensitive surface -witb tbe cell ; 6 may 

 be tbe path of a motor impulse : c and d other 



V circuits passing to other cells or other peripheral 



parts. A current passing along the fibre a might 

 induce currents in the three other tibrea 6, c, d. 

 which Lraveree the same cell. 



fig. 2. 



Diagram to show possible relation of fibres from caudate nerve cells of tbe spinal 

 cord, and fibres from cells in ganglia, as, for example, the ganglia on the posterior 

 roots, a is supposed to be the periphery ; the cell above b one of those in the 

 ganglion. The three caudate cells resemble those in the gray matter of the cord, 

 medulla oblongata, and brain. 



