No. 3-] PERIPHERAL NERVES. 64 1 



Haversian canals of the unabsorbed bone. In the peripheral 

 end new fibres were found between the degenerated old sheaths. 

 Other experiments of a similar character have from time to time 

 been reported by Vanlair. He recognizes in " bone drain 

 suture " a group of mechanical condition most favorable for aid- 

 ing regeneration of nerves after loss of substance, and has 

 gained the conviction that, experimentally, one could reproduce 

 a nerve segment which in length had no limit other than that 

 of the member containing the injured nerve. He was further 

 able to change the course of a nerve by placing the peripheral 

 end of the central stump of a resected sciatic into a bone drain 

 and imbedding the other end of the bone tube in a long, deep 

 incision made in the muscular tissue of the leg, where it was 

 retained by catgut sutures. The wound was then closed. The 

 animal died 6^ months after the operation. Up to that 

 time no return of function had been observed in the leg and foot 

 operated upon. At the post-mortem examination the end of the 

 central sciatic was found bulbous, and from this enlargement 

 could be traced a small cord ending in the muscle ; this con- 

 sisted of nerve fibres, the bundle becoming smaller and the 

 fibres less numerous the further away from the central sciatic 

 the observation was made. Vanlair was able to trace the new 

 fibres 6 ctm. from the bulbous enlargement, and states that he 

 might no doubt have followed them still farther had not the 

 scalpel cut them. The peripheral sciatic was degenerated. 

 This experiment seems to me to offer most convincing evidence 

 that the nerve fibres are an outgrowth from the fibres of the 

 central end ; any other explanation seems to me untenable. 

 The peripheral end could in no way take part in the develop- 

 ment of the new fibres, and it can hardly be believed that the 

 elements of a decalcified bone tube, or the connective tissue or 

 muscle surrounding it, could furnish any material from which 

 new nerve fibres might have been developed. 



Biinger, in two instances, united the resected ends of a dog's 

 sciatic, from which i ctm. of nerve tissue had been removed, 

 with a human brachial artery. At the end of forty-three 

 days the space which separated the nerve ends was filled with 

 new fibres. They were arranged in parallel order within the 



