238 



PHYSIOLOGY 



CHAP. 



the blood-clot of the wound and the clumps of leucocytes found 

 at the extremity of the central stump of the cut nerve. 



During the third or fourth days after section the process of re- 

 generation proceeds no less rapidly ; the central end is surrounded 

 by a mass of newly formed connective tissue which is permeated 



FIG. 151. Extreme end of central stump and portion of cicatrix (semi-diagrammatic) twenty 

 days after section. (Perroncito.) The regenerated fibrils from the nerve-fibres of the central 

 stump in the first zone of the cicatrix interlace and run in all directions ; in the next zone they 

 make a number of spiral formations ; lastly, they form a fibrillary interlacement like a network, 

 which fills the middle part of the cicatrix. This apparent network again gives rise, in the 

 outer part of the cicatrix, to slender bundles of new fibrils, which run singly in the longitudinal 

 direction, and begin to reconstitute the peripheral part of the divided nerve. 



in all directions by a great number of new fibres that run mainly 

 along the axis of the old nerve. Twenty to thirty days after the 

 section the regenerating fibres travelling towards the peripheral 

 stump are once more, to a large extent, made up into definite 

 bundles, while the spiral regenerative formations have attained 

 their maximal development (Fig. 151). Thus we have an 



