No. 3.] PERIPHERAL NERVES. 693 



(4) Stimulating the peripheral ulnar at wrist excited movements of the 

 digits and reflex movements, showing a return of motor and sensory function 

 of ulnar branches in the foot. 



(5) The central ulnar stump, which was, as will be remembered, grafted 

 to the median, was cut 8 ctm. above the point of grafting, and then stimu- 

 lated by induction shocks at 5 ctm. S. C, but no movement could be 

 observed in the muscles supplied by the median or ulnar. 



(6) The peripheral stump of the median, which had been grafted to the 

 ulnar, was found to be degenerated. 



(7) Mechanical stimulation by cutting the median above its junction 

 with ulnar, by cutting the peripheral ulnar, and by cutting the muscular 

 branches, excited contraction of flex. carp. ul. and flex. prof. dig. 



(8) No contraction resulted after cutting the central ulnar and peripheral 

 median stump. 



Conclusion. — Complete regeneration of peripheral ulnar through fibres 

 of the central median stump. The engrafted stump of median was 

 degenerated. 



The nerves were hardened in Miiller's fluid, and stained in anilin blue 

 and safranin. 



Part III. — Histological. 



Methods. — Of the great number of methods employed by 

 the various writers who have made a study of degeneration and 

 regeneration of divided peripheral nerves, very few bring out 

 with clearness the changes undergone by the axis cylinder. 

 The fate of the myelin can be quite easily traced if the degen- 

 erating nerve is hardened in a fluid having osmic acid as one of 

 its constituents. The structural changes undergone by the 

 nerve nuclei can be readily followed in preparations hardened 

 in Flemming's or Hermann's solution, and stained in safranin. 

 After much experimenting with the various methods used for 

 staining the axis cylinder in peripheral nerves, the author came 

 to the conclusion that, as far as his experience goes, the best re- 

 sults were to be obtained with Stroebe's anilin blue and safranin 

 stain. This method, slightly modified, was used in preparing 

 the great majority of the histological preparations. In each 

 experiment the entire peripheral stump of the operated nerve, 

 the implanted piece, and about one inch of the central stump, 

 were removed and hardened from three to four weeks in Miiller's 

 fluid, at a temperature of forty degrees C; then washed in 



