424: NEKVOTJS SYSTEM. 



According to the latest researches, the filaments of the 

 sympathetic, at or near their termination, are connected with 

 ganglionic cells, not only in the heart and the uterus, but in 

 the blood-vessels, lymphatics, anal canals, the submucous and 

 the muscular layer of the entire alimentary canal, the sali- 

 vary glands, liver, pancreas, larynx, trachea, pulmonary tis- 

 sue, bladder, ureters, the entire generative apparatus, supra- 

 renal capsules, thymus, lachrymal canals, ciliary muscle, and 

 the iris. 1 In these situations, nerve-cells have been demon- 

 strated by various observers, and it is probable that they 

 exist everywhere in connection with the terminal filaments 

 of this system of nerves. 



Peculiarities in the Intimate Structure of tJie Sympa- 

 thetic Ganglia and Nerves. The peculiarities in the struct- 

 ure of the cells and fibres of the sympathetic system are 

 not numerous, nor do they possess very great physiological 

 importance. The free communications between the sympa- 

 thetic ganglia and the cerebro-spinal nerves, and the differ- 

 ences in the general appearance of certain of these anasto- 

 mosing branches, lead to the important question of their 

 origin. As a rule, the sympathetic nerves are softer and 

 more grayish in color than the spinal nerves. When there 

 are two branches of communication between a ganglion and 

 a spinal nerve, one of them is white and the other is gray- 

 ish, and we might infer from this that one, the white, is 

 derived from the spinal system, and the other, from the sym- 

 pathetic ; but this is a point not yet settled by microscopical 

 investigations. It has been conclusively shown, however, 

 by Courvoisier, that the communicating fibres pass in both 

 directions. Taking advantage of the degeneration of nerve- 

 fibres after separation from their proper centres, this ob- 

 server has demonstrated that, after division of the branches 

 between the spinal nerves and the sympathetic ganglia, cer- 



1 MATER, in STRICKER, Handbuch der Lelire von den Geweben, Leipzig, 1871, 

 S. 820. 



