76 HUBER. [Vol. XVI. 



made out. A very small non-medullated fiber, c, could be 

 traced with the utmost clearness to its ending on one of the 

 protoplasmic branches of the cell in question ; this non-medul- 

 lated fiber terminated in two very small nodular enlargements, 

 which were in contact with this dendrite, as shown in c' of this 

 figure. In a number of instances such endings were made out, 

 so that I feel justified in concluding that at least some of the 

 non-medullated fibers in the ganglia, possibly also the termi- 

 nal branches of the small medullated fibers, terminate in the 

 ganglia after this manner. 



In giving my own conclusions as to the nature of the fibers 

 ending in the sympathetic ganglia of Mammalia, I can do no 

 better than to quote the conclusion reached by Dogiel (40) 

 concerning this point, which is as follows: "Die feinen Fasern, 

 welche in den Ganglien mit intercellularem Geflechte endigen, 

 zu den sympathischen, augenscheinlich vorzugsweise markhalti- 

 gen Fasern gehdren, die dicken Fasern aber, deren Endverzwei- 

 gungen in den Ganglien pericellulare Geflechte bilden, zu den 

 markhaltigen Fasern zu rechnen sind, welche aus dem Cere- 

 brospinalsystem entspringen." These pericellular plexuses, as 

 already stated, are always intra-capsular. 



General Conclusions. 



In these general conclusions my aim is to be as brief as 

 possible. Two reasons may here be given in justification of 

 this : (i) the results obtained in each of the vertebrate classes 

 studied have to some extent been summarized in the foregoing 

 pages ; (2) the writer has, in a series of *' Special Lectures on 

 the Sympathetic Nervous System," given before the medical 

 students of Michigan University, and published in the JoiLvnal 

 of Co7nparative Neurology, Vol. VII, No. 2, September, 1897, 

 dwelt more fully on many of the questions which will here be 

 touched upon. 



From a study of the sympathetic ganglia of vertebrates the 

 following facts concerning the shape and structure of the sym- 

 pathetic neurons, and the nerves ending in the ganglia, may be 

 deduced : 



