44 LECTURES ON THE CENTRAL NERVOUS SYSTEM. 



covered, in working on the electric organ of the torpedo, that a single ganglion- 

 cell may send out two sorts of processes, of which only one, the axis-cylinder 

 process, is continued into a nerve ; and in 1854 Remak observed the same thing 

 in the great ganglion-cells of the spinal cord. Deiters, in 1865, proved that this 

 was true of all ganglion-cells. Our knowledge of these conditions has been in- 

 creased by the labors of Gerlach, Max Schultze, Waldeyer, Jolly, A. Key and G. 

 Retzius, Betz, Bevan Lewis, Obersteiner, Freud, and many others. So many 

 have turned their attention and efforts to this most difficult region of histology 

 that a memoir which appeared at the beginning of 1887 (Napsen) enumerated 

 341 works on nerve-fibres and ganglion-cells. More recent and profound works 

 on the neuroglia are those of Boll, Ranvier, and Gierke. 



