272 Drs. Mott and Halliburton and Mr. Edmunds. [June 12, 



central lumen. In some fibres, on the other hand, there is a distinct swelling 

 at the site of the nucleus, and here there is a considerable amount of proto- 

 plasm accumulated around the nucleus. There were no traces of nodes, and 

 nothing resembling an axis cylinder or fibrillar could be seen. The diameter 

 of the fibres varied from 2-5 to 3 fi. These appearances are illustrated in 

 figs. 1 and 2. 



Fjg.' 1. Fig. 2. 



The sections (some of which were stained by Cajal's new silver method) 

 showed merely the divided ends of these tubular structures cut across. It 

 is true that the appearance of the long nuclei in transverse section was at 

 first sight suggestive of axis cylinders, but their size, apart from the evidence 

 of longitudinal sections and teased preparations, disproves this view. 



The appearances, therefore, are merely those which have been so often 

 described in the peripheral segment of a divided nerve in which regeneration 

 has not occurred, and which all agree is due to neurilemmal activity. 



The remains of the nerves which had been transplanted under the skin 

 showed the same appearances. Here also a large uumber of well formed 

 blood-vessels were found. These grow in not only at the ends, but actually 

 break through the surrounding connective-tissue sheath into the interior. 

 The accompanying drawing illustrates how a blood-vessel breaks through the 

 sheath into the substance of a degenerated nerve bundle. 



From this irruption of blood-vessels it is a very small step to the intro- 

 duction of nerve-fibres into the interior of the transplanted nerve. It 

 seems reasonable to suppose that where the one could penetrate the other 

 would have no difficulty in doing likewise, and this would account for the 

 presence of the medullated nerve-fibres which Kennedy discovered. In our 



