688 DR ROBERT KENNEDY ON THE 



fibres, which are to act as the guides for the growth of the new fibres to the terminal 

 organs, can scarcely be supposed to be brought by the suture into line with their proper 

 central segments. Also, if we take the view held by Vanlair and others, that the new 

 sprouting fibres simply run in the endoneural spaces, how can the new fibres be guided 

 to their appropriate terminal organs ? 



From these considerations I have been led to inquire if a difference in the resulting 

 return of function will obtain between reunion with the most accurate coaptation, and 

 reunion with the most extreme displacement of the one segment with reference to the 

 other. In two dogs I divided the sciatic nerve at the level of the trochanter, and after 

 rotating the peripheral segment to the extent of a semicircle, reunited it to the central 

 end.* To insure that this displacement was accurately carried out, the suture was 

 placed before the division of the nerve. The nerve having been raised from its bed on 

 the point of the finger, was transfixed by the needle threaded with chromicised catgut. 

 The needle was then carried through below the nerve, and the nerve again transfixed 

 at a lower level in the same direction as before. Next, the nerve was divided between 

 the two points of transfixion, and the suture tied, the result being that the peripheral 

 segment was rotated with reference to the central segment through a semicircle. Thus 

 the two segments were coapted so that the fibres of one side in the central segment 

 were brought into line with those of the opposite side in the peripheral segment, only 

 the fibres in the centre of the nerve being approximately correctly coapted. In a third 

 experiment, to serve as a control to the first two, the same nerve was divided at the 

 same point and accurately coapted, the suture being placed before the division, so as to 

 insure accuracy of coaptation in the normal position. 



Experiment I. — On 19th January 1898, a collie bitch, aged 15 months, having 

 been anaesthetised by means of a subcutaneous injection of 0'5 gram, sulphate of 

 morphia followed by inhalation of ether, the hair was shaved from a considerable 

 area around the trochanter and tuber ischii of the left side. The skin was then 

 thoroughly scrubbed with soap and warm water, next with turpentine, then with 

 alcohol, and finally with 5 per cent, carbolic lotion. The precaution taken to prevent 

 contamination of the wound during the operation was to fix round the body a jaconette 

 sheet with an oval aperture in its centre, sufficiently large to expose only the field of 

 operation. The instruments, dressings, ligatures, etc., to be used had all been previously 

 sterilised. The sciatic nerve was exposed as it passes between the trochanter and the 

 tuber ischii. The nerve held up on the point of the finger, was transfixed by a flat 

 needle threaded with chromicised catgut. The needle having been drawn through, was 

 passed underneath the nerve, and the nerve again transfixed parallel to the first trans- 

 fixion and in the same direction, but about 0*5 cm. lower down, and drawn through, 

 leaving the suture in place. The nerve was then transversely divided between the 

 two points of transfixion, and the suture tied. The result of the two ends having 



* I am indebted to Professor M'Kendrick for suggesting to me this form of experiment. 



