THE PHYSIOLOGICAL CHEMISTRY OF NERVES. 



537 



when the latter has been cut. Very suggestive, in this connec- 

 tion, are the following lines by Professor Barker 36 : "Waller 

 proved that if a motor nerve was severed there resulted com- 

 plete degeneration of the fibers in the peripheral end, even 



DIAGRAM OF RELATION BETWEEN LONGITUDINAL AND TRANSVERSE 

 SECTIONS, SHOWING CONES CUT ACROSS AT DIFFERENT LEVELS. 



1, at base of cone; 2, through middle of cone; 3, through apex of 

 cone; 4, through interval between two cones. In 1, 2, and 3 the cone 

 segments and protoplasmic sheaths are seen. In 4 only the thin pro- 

 toplasmic sheaths beneath primitive sheath and around axis-cylinder are 

 visible. (W. H. Wynn.) 



to the muscles which they govern, the central end remaining 

 apparently intact. As a matter of fact, the changes charac- 

 teristic of the Wallerian degeneration could not, as a rule, 

 be traced farther in the central end than to the first node 

 of Kanvier." Stewart 37 states that "in the degenerated nerve 



Barker: Loc. cit., p. 740. 



87 Stewart: "Manual of Physiology," p. 607. 



