8o HUBER. [Vol. XVI. 



Such observations led Langley to conclude that the nerve 

 fibers, issuing from the cord and reaching the sympathetic 

 ganglia through the white rami, had each a sympathetic nerve 

 cell in its course, which sympathetic cell was paralyzed by 

 nicotin. Langley has suggested the term pre-ganglionic fibers 

 or pre-cellular fibers to designate the efferent meduUated fibers 

 before they reach the nerve cells, and post-ganglionic or post- 

 cellular fibers after they have traversed the nerve cells. Taking 

 these statements into consideration, it would seem reasonable, 

 to say the least, that the pre-ganglionic fibers are the medul- 

 lated fibers which end in the sympathetic ganglia in pericellular 

 plexuses, and the post-ganglionic fibers, the neuraxes of the 

 sympathetic neurons of said ganglia. 



It is not, however, to be supposed that such pre-ganglionic 

 fibers end only in the chain ganglia in pericellular plexuses. 

 Small medullated fibers may, as we have quoted from Gaskell, 

 be traced into the peripheral ganglia, and the mere fact that in 

 such ganglia pericellular plexuses, similar in structure to those 

 found in the chain ganglia, have been described as the endings 

 of medullated fibers, would warrant the conclusion that many 

 of the pre-ganglionic fibers reach also the peripheral ganglia. 

 Kolliker (33) has stated the fact so tersely that I may be 

 allowed to quote again from him: "Hierbei ist der Verlauf 

 derselben" (meaning here the pre-ganglionic fibers) "ein langerer 

 oder kiirzerer. Die einen enden an den nachstgelegenen Gang- 

 lienzellen, andere durchlaufen mehrere Ganglien, bevor sie zu 

 ihren Endigungen gelangen und konnen hierbei durch Colla- 

 teralen auf eine Mehrheit von Zellen einwirken. Noch andere 

 endlich finden erst an den am meist peripherisch gelegenen 

 Ganglien ihr Ende, wobei es unentschieden bleibt, ob sie in 

 ihrem Verlaufe auf zwischengelegene Zellen einwirken." 



These observations warrant, it seems to the writer, the fol- 

 lowing statements : the sympathetic neurons form the periph- 

 eral links in a nerve chain, of which the second link is formed 

 by a neuron, the cell body of which is situated in the cerebro- 

 spinal axis, the neuraxes of which form the pre-ganglionic fibers 

 ending in pericellular plexuses, which unite the two links 

 physiologically. 



