432 l)r. II. Ki'imrdy. On (/,, I; J.,,<itwn oj 



were five in nunitar. The first four were of the same kind, and con- 

 sisted in uniting the central segments of the divided musculo-cutaneous, 

 niolian, and ulnsir nerves to the peripheral segment of the divided 

 musculo-spiral, and vice vcrsA. Thus the entire supply of the flexor 

 muscles of the forearm was crossed with the entire supply of the 

 extensor muscles. The musculo-cutaneous was included in the crossing, 

 as it sends a communicating branch to the median at the elbow, 

 which branch may contain efferent fibres to muscles. 



The nerves were divided above but near the ell>ow joint, and the 

 two points of union were therefore situated one on the outside and one 

 on the inside of the limb, with a bulky muscle between them, which 

 prevented any possibility of confluent reunion of all the divided ends. 



One of the experiments (Exp. I) was a failure on account of the 

 wound becoming septic, but in the remaining three (Exp. II, III, IV) 

 the animals regained almost completely the power of making voluntary 

 co-ordinated movements of the limb. Thus the leg was used constantly 

 and perfectly in walking and running, and in performing such co- 

 ordinated movements as giving the paw on request, using the paw to 

 hold a bone while gnawing, &c. The recovery of function commenced 

 about the 30th day after the operation, and was almost perfect from 

 the 45th to the 90th day. 



The physiological examination showed that the nerves which had 

 been crossed had united as they had been placed without one point of 

 union communicating with the other, and that the flexor muscles were 

 thus entirely supplied by the musculo-spiral, and the extensor muscles 

 entirely by the median, ulnar, and musculo-cutaneous. 



In two of the experiments (Exp. II and III) the musculo-spiral 

 stimulated above the seat of union gave flexion of the paw, and no 

 movement in the extensor muscles, while stimulation of the central 

 segments of the musculo-cutaneous, median, and ulnar gave extension 

 of the paw, and no movement in the flexor muscles. Stimulated on 

 the cerebral cortical centres of the sigmoid gyrus, it was found that on 

 the left hemisphere the centre which normally gives on stimulation 

 flexion of the paw, gave on the contrary extension, and no movement 

 whatever in the flexor muscles. Stimulation of the centre, normally 

 associated with extension of the paw, gave in one of the animals pure 

 flexion of the paw and no contractions of the extensor muscles (Exp. III), 

 while in the other animal the flexion centre was found to lie in the 

 normal extension area, but pure flexion could not be obtained free 

 from extension movements (Exp. II). 



In the other experiment (Exp. IV) the results of stimulation were 

 somewhat obscure. Stimulation of the central segments of all four 

 nerves gave contractions in the extensor muscles and no contractions 

 in the flexors. Yet the flexors were perfectly healthy in appearance 

 and possessed normal irritability to faradic stimuli. Stimulation of 



