ACUTE TRANSVERSE MYELITIS. 



437 



given rise to fatty degeneration of the exudate and of the 

 myelin-sheaths of the nerve-fibres. Microscopically, the 

 nerve-fibres are found to be swollen and granular, and the 

 myelin-sheaths filled with droplets of fat. Everywhere are 

 numerous leukocytes, and possibly some neuroglia-cells which 

 have taken up the disintegrated myelin, and on account of 

 their appearance have been designated compound granular cells. 

 The myelitis rarely goes on to suppuration, though the 

 affected area may undergo complete liquefaction (Fig. 208). 



FIG. 208. 



a, changes on the eleventh day after section of 

 a frog's sciatic (Gray). 



6, changes on the fifteenth 

 day after section (Gray). 



Usually, however, the fat is absorbed, and, the myelin- 

 sheaths having been entirely destroyed, a condition of gray 

 degeneration or softening remains. 



