HuBER, Sympathetic Nervous System. 115 



far that the terminal fibrillae of the nerve fibers ending in these 

 structures are not always woven into a network. 



In E, of Fig. 8, is shown a nerve cell from a sympathetic 

 ganglion of a black bass. It may be seen that the nerve fibers 

 ending on the cell, (intra-capsular ending), break up into a 

 number of varicose fibrillae which only partly surround the cell. 

 The endings are often more complex, but the cell shown in the 

 figure may serve as an illustration. In fishes, as in other verte- 

 brates, the end basket, or the intra-capsular end-brush, as it 

 may be more correctly termed, represents the termination of a 

 medullated nerve fiber found in the sympathetic ganglia. 



From this review of the structure of the peri-cellular end-bas- 

 kets in the sympathetic ganglia of vertebrates, we may deduce 

 the following facts : 



1. These structures are found in the various classes of 

 vertebrates. 



2. In all vertebrates they are intra-capsular, and have es- 

 sentially the same structure. The fact that in some vertebrates 

 — amphibia and reptilia — the nerve fiber terminating in the end- 

 basket is wound spirally about the neuraxis of the ganglion cell, 

 does not modify this statement. 



3. In all vertebrates these peri-cellular baskets are the 

 mode of ending of medullated nerve fibers found in the sympa- 

 thetic ganglion, medullated fibers which often divide and give 

 off collateral branches, which in their turn end in the baskets. 



These questions may now be asked. Where do these med- 

 ullated fibers come from ; are they neuraxes or dendrites of 

 neurons ; are the cell bodies of such neurons found within or 

 outside of the ganglion ; and if outside of the ganglion, in some 

 portion of the cerebro-spinal axis ? 



In answering these questions, I may at the outstart state 

 that all the evidence we possess — experimental and histological 

 — goes to show that these medullated fibers enter the sympa- 

 thetic ganglia through the white rami communicantes. This 

 evidence is in brief as follows : 



In the first place let me draw your attention to the fact 

 that " all effects which can be produced by stimulating the sym- 



