38 HUBER. [Vol. XVI. 



nuclei may belong to very much branched neuroglia cells, only 

 the nuclei staining in the preparations at my disposal. This 

 hypothesis is here only mentioned, and will be further discussed 

 subsequently. 



The medullated fibers ending in the pericellular plexuses may 

 now and then be traced into some nerve root coming to the 

 ganglion ; their further course has not been ascertained. 



A few very small medullated fibers are occasionally stained 

 in sections of the sympathetic ganglia of fishes. My observa- 

 tions on these do not allow of any definite statement concerning 

 them. 



The non-medullated fibers seen in the ganglia are no doubt, 

 to a large extent, the neuraxes of the sympathetic cells, con- 

 stituting the ganglia, although in sections it is an exceedingly 

 difficult task to trace such non-medullated fibers to a ganglion 

 cell ; I was able to do so only a few times. Small bundles of 

 them may be traced into the nerves leaving the ganglia. 



Sympathetic Ganglia of Amphibia. 



The sympathetic system of the frog comprises a series of 

 ganglia, lying on each side of the vertebral column, united 

 by intervening nerves to form the ganglionated chains. The 

 number of sympathetic ganglia usually corresponds to that of 

 the spinal nerves, ten pairs of ganglia being found. Numerous 

 smaller ganglia are found in the walls of the various organs — 

 Bidder's and other ganglia in the heart ; ganglia in the lungs, 

 the pharynx, the intestinal canal, and the bladder. Sections 

 were usually made of the larger ganglia — the first and second 

 (this being the largest), and seventh, eighth, and ninth. The 

 last three, on account of their size, the length of their rami, 

 and their exposed position, are very easily found. 



The methylene blue method was used to the exclusion of 

 other methods. The stain was injected into the circulation 

 of the living frog. The larger ganglia were fixed in ammo- 

 nium molybdate, sectioned, and some of the sections double- 

 stained in alum carmine. The smaller ganglia were fixed in 

 ammonium picrate and cleared in glycerine. 



