66 HUBER. [Vol. XVI. 



mochte ich beim Hiihnchen nichts wahrzunehmen ; es handelte 

 sich immer um einfache Aufzweigungen." The pericellular 

 plexuses seen by me are the endings of collateral branches, 

 or ultimate endings of medullated fibers. A number of such 

 endings are reproduced in Figs. 20-22, In Fig. 20, from the 

 medullated fiber A, is given off at the node of Ranvier, x, a 

 non-medullated collateral branch, a, which may be traced into 

 two pericellular plexuses. Fig. 22 was sketched from a section 

 of a methylene blue stained, dorsal sympathetic ganglion of 

 a chicken, fixed in ammonium molybdate, the sections being 

 further stained in alum carmine. Here the relation of the 

 pericellular plexus to the cell body of the enclosed cell and its 

 capsule is clearly shown. 



The pericellular plexuses observed in birds are of a relatively 

 simple structure. The end branch, or collateral branch destined 

 to form such an ending, divides, just before or after it reaches 

 the capsule of a sympathetic cell, into a number of fine varicose 

 fibers which are woven into a very loose plexus and often end 

 free on the cell. 



My observations on the sympathetic ganglia of birds may be 

 briefly summarized as follows : 



i) The sympathetic neurons are multipolar, with one neu- 

 raxis and several dendrites. The cell body of such a neuron is 

 enclosed in a nucleated capsule. 



2) The non-medullated fibers entering the ganglia from with- 

 out, end, after branching, on the dendritic branches of the sym- 

 pathetic neurons. 



3) The medullated fibers of cerebro-spinal origin, which enter 

 the ganglia, most probably from the anterior roots, end, after 

 branching in the ganglia, in pericellular plexuses of a relatively 

 simple structure. These plexuses surround the cell bodies of 

 the sympathetic neurons and are intra-capsular. 



Sympathetic Ganglia of Mammalia. 



The sympathetic ganglia of Mammalia have been investigated 

 with the Golgi method by Kolliker (30-33), Ramon y Cajal 

 (34-36), Retzius (28), Van Gehuchten (37), Sala (38), d' Erchia 



