THE 



Journal of Comparative Neurology. 



Volume X — Number 2. 



observations on sensory NERVE-FIBERS IN 



VISCERAL NERVES, AND ON THEIR MODES 



OF TERMINATING. 



By G. Carl Ruber, M.D., 



Junior Professor of Anatomy and Director of the Histological Laboratory, 

 University of Michigan. 



With Plate XI. 



In a most suggestive paper " On the structure, distribu- 

 tion and function of the nerves which innervate the visceral and 

 vascular systems," Gaskell (i) drew attention to the fact that 

 physiological differences observed in peripheral nerves are 

 bound up with morphological differences, so that groups of 

 nerves of the same function can be grouped under the same 

 morphological laws of structure and distribution. In this com- 

 munication attention is drawn to the fact, that certain anterior 

 spinal roots — namely from the loth to the 25 th — contain a rel- 

 atively large number of medullated fibers varying in size from 

 \.% IX to 2. y ju and that these form the greater portion of all 

 the nerve fibers found in the nerves commonly known as white 

 rami ; and further, that these small, medullated nerve fibers 

 pass to the metameric sympathetic ganglia and in three main 

 streams — upwards into the cervical sympathetic ganglia, down- 

 wards into the lumbar and sacral ganglia, and outwards into 

 the prevertebral and terminal sympathetic ganglia. In the white 

 rami and in the splanchnic nerves a small number of larger 

 medullated nerve fibers were found, clearly shown in his figure 

 (8) of a cross section of a typical white ramus as seen when 

 stained with osmic acid. These observations corroborated in 

 part and extended those of Bidder and Volkmann (2) who had 

 reached the conclusion " that in the various typical nerves of 



