PHYSIOLOGY OF NERVE 



273 



popliteal turned up out of the way, and the central end of the 

 internal popliteal slit up lengthwise for a short distance. The 

 peripheral ends of both nerves are then sutured to the two parts 

 of the central internal popliteal. 



It is found that regeneration takes place, and after the 

 appropriate interval the dog has the use of his hind limb with 

 little or no apparent defect, and such delicate co-ordinated move- 

 ments as the scratch reflex are performed to all appearance as 

 well as in the normal animal. Kilvington infers that the fibres 

 from the internal popliteal have grown downwards into both 



I.P E.P 



E.P. 



EP 



FIG. 5. Optimum arrangement for FIG. 6. Arrangement giving " axon 



restoration of function. I.P. Internal reflex." 

 and E.P. External Popliteal nerve. 



internal popliteal and external popliteal. If this inference is a 

 just one, it follows that the muscles formerly supplied by the 

 external popliteal (and from the corresponding cells in the anterior 

 horn of the spinal cord) are now supplied from cells that formerly 

 supplied the internal popliteal, and through the nerve trunk the 

 antagonistic muscles. As the co-ordination seems as good as 

 before, the cells that have been changed over must have learned 

 a new lesson, and this apparently applies, not only to the cells 

 in the spinal cord, but also, as Kennedy ( 43 ) has shown, to the 

 cells in the Kolandic cortex. 



The earlier experiments of Langley and Anderson and Kilving- 

 ton, and the later of Kilvington and Osborne, provide another 

 fact. If the connections at the time of suture were arranged as 



s 



