No. I.] SYMPATHETIC GANGLIA OF VERTEBRATES. 65 



of 20 /i. thickness, of one of the dorsal sympathetic ganglia, 

 is shown a sympathetic nerve cell with several dendrites. On 

 one of the branches, d, is shown the ending of a non-medullated 

 fiber, ti ; the non-medullated fiber being stained somewhat more 

 deeply than the dendrite. In a careful search of many prepa- 

 rations, only a few such endings have been found ; yet in rela- 

 tively thin sections, studied under yL-inch oil immersion, they 

 have now and then been quite clearly made out. 



Concerning the medullated fibers found in the sympathetic 

 ganglia of birds, the following observations have been made : 



It will be remembered that the sympathetic ganglia of the 

 bird lie on the ventral branch of the spinal nerve and partly 

 on the ventral side of the spinal ganglia, and are removed with 

 these structures. In such preparations, stained in methylene 

 blue and examined before fixing, even under a low power, the 

 multipolar-sympathetic cells may be made out with certainty, 

 and axis-cylinders of medullated fibers may now and then be 

 traced between such multipolar cells. Cajal, it will be remem- 

 bered, describes such fibers as coming from the anterior roots, 

 while Lenhossek regards them as coming from the posterior 

 roots, as may be gathered from the following statement made 

 by him : " In zwei Fallen, schien es mir, als handelte es sich 

 gerade umgekehrt um Fasern die aus dem Spinalganglion 

 kommen, also um sensible Fasern, doch kann ich dies nicht 

 mit voller Bestimmtheit vertreten." In ganglia removed as 

 above stated, and examined before fixing, and especially in those 

 where only a few nerve fibers were stained, I have several times 

 been able to trace axis-cylinders of medullated fibers ending in 

 the sympathetic ganglia toward the anterior root ; this may 

 also be seen in serial sections of the sympathetic ganglia and 

 the structures in connection with them. My observations, as 

 far as they go, are therefore in accord with those given by Cajal. 



There is no doubt that many of the medullated fibers end- 

 ing in the sympathetic ganglia of birds, do so in pericellular 

 plexuses, although Cajal, Retzius, and Lenhossek were unable 

 to see them in Golgi preparations of these structures. The 

 latter says in this connection: "Von einer faserkorbartigen 

 Anordnung im Inneren des sympathischen Ganglion ver- 



