436 



SYMPATHETIC NERVE. 



Ganglia. The ganglia occurring on the 

 sympathetic are, as has been already stated, 

 very numerous, constituting the most distin- 

 guishing character of this nerve. There are 

 also ganglia present on the posterior roots of 

 all the spinal nerves, as well as on several 

 of the cerebral nerves ; and by many these are 

 classified along with those of the sympathetic, 

 constituting what has been termed the gan- 

 glionic system of nerves. The ganglia present 

 the appearance of nodules or swellings oc- 

 curring on a nerve during its course. When 

 examined with the naked eye, they appear to 

 consist of opaque and more or less pellucid 

 portions, present a greyish colour, and are 

 possessed of considerable consistence. Some- 

 times they occur in the course of a single nerve, 

 as is the case with the ganglia in the posterior 

 roots of the spinal nerves. The sympathetic 

 ganglia commonly present the appearance of 

 masses of various sizes connected with several 

 nerve-branches which appear to pass off from 

 them in different directions. The ganglia 

 situated in different parts of the body are all 

 more or less connected by means of bundles 

 of nerve-fibres passing between them. As 

 already noticed, many of them are arranged 

 alongside the spinal column ; others are si- 

 tuated on the different plexuses which are 

 formed by the branches passing off from these, 

 while numerous others of smaller size occur 

 in the substance of the organs supplied by the 

 sympathetic. All of them consist essentially 

 of a number of bodies presenting peculiar 

 characters and termed ganglionic corpuscles, 

 and of nerve-fibres in more or less intimate 

 connection with these. 



Ganglionic Corpuscles, ganglion-vesicles 

 (Germ. Ganglienkugeln). These bodies ap- 

 pear to have been first noticed by Ehrenberg*, 

 and were afterwards more fully described by 

 Valentin. f They vary in size from the TgVo-th 

 to the ^o tn f an inch. Those in the ganglia 

 of the cerebro-spinal nerves are generally con- 

 siderably larger and not so delicate as those 

 in the ganglion of the sympathetic. They 

 commonly present a round or oval form; 

 sometimes they are more or less pear-shaped. 

 Their contents consist of a delicate clear fluid 

 holding in suspension numerous finely granular 

 particles, which give the cells a more or less 

 grayish aspect. This substance is possessed 

 of considerable viscidity, as shown by the fact 

 that when removed from the corpuscle it does 

 not separate into distinct particles, but remains 

 coherent in a single mass which flattens out 

 somewhat. Each of the ganglionic corpuscles 

 contains a distinct rounded nucleus which in 

 appearance resembles the corpuscle itself, 

 only its contents are clearer. These measure 

 from the ^oW tn to the ys-'o-oth f an incn in 

 diameter, and are commonly situated rather 

 towards one side of the cell. Within the 

 nucleus there is commonly a third body, which 

 presents a clear rounded appearance like the 



* PoggendorPs Annalen, band xxviii. p. 458., as 

 quoted in Brun's Anatomic. 



f Nova Acta, band xviii. p. 127., as quoted in 

 Brun's Anatomic. 



nucleus, and may be regarded as the nucleolus. 

 Sometimes there are two such bodies present. 

 In the ganglionic corpuscles there is also fre- 

 quently contained a mass of pigmentary 

 matter consisting of particles which are much 

 coarser and darker than the rest of the con- 

 tents. This mass is sometimes situated at a 

 little distance from the nucleus, at other times 

 it partly covers it, and occasionally it conceals 

 it entirely from view. Its quantity varies 

 much in different cells : it appears, as Kb'lliker 

 observes, to be more abundant in the ganglion- 

 corpuscles of old people than in those of the 

 young. Sometimes he has observed it present 

 in such quantity as to fill the entire cell. In 

 the Gasserian ganglion of a man aged about 

 sixty I observed several bodies present, which 

 in size and shape corresponded with the gan- 

 glionic vesicles : they appeared, however, to 

 be less delicate, and presented a dark-brown 

 colour, and in all probability were ganglionic 

 corpuscles filled with dark pigmentary matter 

 such as Kolliker notices. Connected with 

 many of the ganglionic corpuscles are one or 

 two delicate processes of different lengths, 

 and presenting the same delicate finely-gra- 

 nular appearance as the vesicle itself of 

 which they appear to be a prolongation. In 

 the corpuscles occurring in the ganglia these 

 do not present the same branching character 

 as they have been described to do in the brain 

 and spinal cord by Purkinje, Remak, Hannover, 

 and by Todd and Bowman, who in their de- 

 scription of these bodies, which by them were 

 termed "caudate nerve-vesicles," hinted at the 

 probability of the processes being continuous 

 with nerve-tubes. The actual continuity of the 

 process of the ganglion-vesicle with the nerve- 

 tube was, however, first observed by Kolliker * 

 in the ganglia of the amphibia. He found that 

 on tracing the process onwards from the cell 

 it became continuous with a nerve-tube pre- 

 senting distinct dark margins. The observa- 

 tion of Kolliker in regard to the connection 

 of the nerve-tube with the ganglion-corpuscle 

 has since been confirmed by many other ob- 

 servers, and especially by Wagner and others 

 in the ganglia of the fish. Some of the gan- 

 glionic corpuscles appear to be destitute of 

 any such process ; others have a single process 

 passing off from them, while others present two 

 such processes, passing off at either extremity 

 (A.G.^.286.). Occasionally the two processes 

 pass off from a round cell, not at either extre- 

 mity, but at a short distance from each other on 

 one side of the body (fig. 291 .). The ganglionic 

 corpuscles which are not connected with any 

 process, or, as may be safely said, with any 

 nerve-tube, have been termed by Stannius 

 apolar cells ; those from which one tube pro- 

 ceeds are termed unipolar, while the cells with 

 which two such are connected are called by him 

 bipolar ganglionic corpuscles or cells. The 

 nerve-tube which is connected with the uni- 

 polar cell is always found to run peripherically, 

 i. e. from the centre. In regard to the bipolar 



* Mikroskopische Anatomic, p. 508., zweiter 

 band. 



