334 Restoration of Paralysed Muscles by Nerve Anastomosis. 



of the extensor muscles was made, and this showed that the movement of 

 extension was not made by the extensor muscles, as they were not able to 

 be stimulated. A platinum electrode was also inserted into the extensor 

 muscles through the skin, but no contractions could be produced in them 

 either by the galvanic or by the faradic current. 



The following are the conclusions from the research : — 



(1) In the limb of the dog when the nerve supply of one group of muscles 

 is eliminated, the nerve supply of its antagonistic group may be used to 

 supply both groups, and under these conditions co-ordinated movements may 

 be restored. 



(2) When two antagonistic groups of muscles in the limb of the dog have 

 their nerve supplies cut and both groups then made to derive their supply 

 from that of the one group, the group whose nerve supply is utilised probably 

 will be the first to recover. 



(3) Recovery of function of antagonistic muscles is slower to occur when 

 one nerve supply is eliminated than in the case of nerve-crossing experi- 

 ments where no nerve is eliminated, but where the supply of the two 

 groups is crossed : and this delay is caused by reduction in the former case 

 of the total volume of the nerves supplying the limb, and possibly by greater 

 difficulties of adaptation in the brain to the new conditions. 



(4) Where in the dog one nerve has been made to supply not only its 

 own but also the antagonist of its own muscle, the nerve fibres passing to 

 the two muscles in the nerve trunk proximal to the junction may be so 

 completely separated that it may be possible to stimulate each group without 

 affecting the other, producing thus at will contraction either of the one or 

 of the other muscle, both being now supplied by a single central trunk. 



(5) When two groups of antagonistic muscles in the limb of the dog are 

 represented by separate cortical areas, and when the nerve supply of one of 

 the groups is eliminated, both groups being caused to be innervated by the 

 remaining nerve supply, the cortical area corresponding to the eliminated 

 nerve supply becomes inexcitable, while the other cortical area on stimulation 

 causes contraction in both groups of muscles. 



(6) Where one group of muscles is paralysed, and a portion of an 

 antagonist muscle is detached from its insertion and attached to the tendons 

 of the paralysed group, this substitute for the paralysed group may enable 

 the function of that group to be performed to a certain extent, and the 

 function recovered by means of this procedure is probably controlled by 

 the same adaptation in the central nervous system as occurs in the case of 

 nerve anastomosis. 



(7) The adaptation in the central nervous system which allows restoration 



