110 



VETERINARY PHYSIOLOGY 



posterior root fibres which have their cells in the ganglion 

 upon the posterior root. 



(2) That the fibres which degenerate only after section of 

 the cord must have their cells in the cord itself, i.e. that 

 the incoming fibres of the posterior roots have formed 

 synapses with fresh neurons (fig. 48). 



B '- 



E 



Fig. 49. — To show Redistribution of Impulses in the Cord. 1 to 5, incom- 

 ing fibres of posterior root; A, tract of kinfesthetic sense and touch 

 for some distance before crossing ; B, tract of unconscious impulses 

 for muscular co-ordination and tone ; 0, same as B, but on opposite 

 side ; D, tract of impulses of pain, heat and cold ; E, tract of impulses 

 of touch and pressure. (Page May.) 



The degenerated fibres may be traced across the an- 

 terior white commissure to the opposite side of the 

 cord from cells situated in the posterior horn of grey 

 matter. 



