No. 3.] PERIPHERAL NERVES. 639 



Quite recently Dr. De Forest Willard, in a communication 

 dealing with nerve sutures, reports fourteen experiments, two 

 of which have to do with implantation. 



In one of these ^ of an inch was removed from the left sciatic 

 of a dog. The segment was reinserted and sutured with fine catgut. 

 Twenty days later the right side was operated upon in the same way. The 

 dog was killed forty-four days after the first operation. On the left side the 

 sciatic was bulbous at the seat of operation, the bulbs being united by a 

 bridge about half the size of the nerve. On the right side there was a thick- 

 ening of connective tissue which included the graft. In the other experi- 

 ment ^ of an inch was removed from the sciatic of a dog, and a 

 segment of nerve yk of an inch was taken from the sciatic of another 

 dog, implanted, and sutured. The dog was killed on the thirtieth day. 

 A small bridge united the divided ends of the sciatic. Physiological 

 and histological examinations, if made, were not reported. 



The results obtained in the experiments reviewed may be 

 summed up in the table on the following page. 



Excluding the experiments of Gluck (for reasons already 

 given), we find only one instance where, after the removal of a 

 segment more than 3 ctm. long, followed by implantation, 

 recovery is reported. 



The above table also shows that Gliick is the only experi- 

 menter that has obtained union by first intention. 



The large number of failures and "doubtful" cases would 

 not speak encouragingly for the adoption of this method in 

 surgical practice. That much more favorable results may be 

 hoped for, if the animals are observed for a time long enough 

 to admit of regeneration, I hope to show in the experiments 

 recorded later on. 



{c) Tubular SiiUire. — Gliick experimentally tried implanta- 

 tion of substances other than nerve tissue, using bands of 

 Danish leather, a bundle of catgut threads, strips of muscle and 

 skin, and finally inserting the resected ends of a nerve into a 

 " Neuber's bone drain." In these experiments the implanted 

 substance now and then made " connective tissue union " with 

 the pineurium of the nerve. However, it was usually absorbed 

 or mummified. In no instance did regeneration of the periph- 

 eral end occur. 



