PriMcIpLes of veterinary StlRGERY 33 



tions in which the function of the nerve was restored the 

 conditions for growth were always the best. No part of the 

 nerve trunk was destroyed. The solution of continuity was 

 artificially restored at once. 



Quinn and Desperes claim to have restored the function 

 of the median nerve of an animal by grafting it to the ulnar. 

 After making this experiment they report that the "use of the 

 foot was recovered." This experiment becomes somewhat 

 inconsistent when it is known that the median nerve of ani- 

 mals at any available point of operation is purely sensory, 

 and that veterinarians repeatedly divide this nerve surgically 

 to relieve pain in the articulations below. The median nerve 

 of animals has motor fibres but jiot at any point where it 

 could be successfully grafted to the ulnar. It can be cut with 

 impunity far above the elbow, without impairing the function 

 of a single muscle. The fact is, these learned experimental- 

 ists grafted two sensory nerves to each other, both of which 

 might be cut without disturbing the use of the leg. 



In a word, cut nerves appropriately approximated will 

 promptly unite anatomically and will slowly resume their 

 function by the downward growth of their axis-cylinders, 

 while cut nerves not appropriately approximated resume 

 their function very imperfectly or not at all, according to 

 whether or not the axis-cylinders meet with any obstacle in 

 finding the old channel, which is indispensable to the re-in- 

 nervation of an area unnerved by the division of a nerve 

 trunk. 



EPITHELIUM. — New epithelium must spring from 

 pre-existing epithelial cells and the regeneration is usually 

 quite complete. The phenomena occurring immediately after 

 a wound are very similar to those which take place in the re- 

 action of other tissues to injury. The epithelial cells imme- 

 diately bordering the wound, die and degenerate, while the 

 cells in adjacent parts swell up and multiply (both by direct 



