546 THE SYMPATHETIC SYSTEM OF NERVES, BY DR. S. MAYER. 



also been attempted to be maintained. Schwalbe describes a 

 case in which an isolated cell from the sympathetic of the Cat 

 exhibited such a division of its processes into several branched 

 processes and a single cylinder axis. Bidder also mentions 

 having seen similar instances. I have myself isolated a cell 

 from the cseliac ganglion of the Rabbit, which, besides possessing 

 several branched processes, also exhibited very distinctly two 

 other processes which, at a short distance from the cell, became 

 invested with nerve medulla, and were consequently to be 

 regarded as axis-cylinder processes. From this it would appear 

 that the axis-cylinder process is not always single. Auerbach 

 has called attention to a peculiar arrangement of unipolar cells, 

 which he has named " opposed " or " twin " cells (' opposite 

 Stellung der Zellen'). Here two cells are contained in a single 

 sheath, and each gives off a single process in opposite directions 

 from the poles which are averted from each other. Like 

 Schweigger-Seidel, I have not unfrequently met with this form 

 in various parts of the sympathetic. 



Fig. 266. 



Fig. 266. Ganglion cell, with spiral fibre. 



An important advance in the path of discovery in regard to 

 the nature of the processes of the sympathetic nerve cells was 

 made by the simultaneous discovery of L. Beale and J. Arnold, 

 that two processes are given off from the small end of the more 

 or less bell-shaped nerve cells in the sympathetic of the Frog. 

 One of these pursues a straight course, the " straight fibre " of 

 both authors, whilst the other forms a series of coils around 

 this, and constitutes their ^spiral fibre." Both the straight 

 and the spiral fibre lie within a common and usually nucleated 

 sheath, which represents the direct continuation of the sheath 

 of the ganglion cell. Nucleated enlargements not unfrequently 



