4.38 



SYMPATHETIC NERVE. 



man and other mammalia, is proved by the with the walls of the included ganglionic cor- 

 observations of Schroeder van tier Kolk in puscle, and appears to hold much the same 



Fig. 287. 



Fig. 288. 



A. Spinal ganglion from the Ray. (40 diam.) 



B. Portion of the same more separated. 



regard to the cervical ganglia of man, as men- 

 tioned by Bonders and Harting. Schaffner 

 also describes a bipolar cell in the ganglion 

 Gasseri of the sheep ; and similar cells have 

 been observed by Cord* and Pappenheim in 

 the acoustic nerve of the pig, and by Frey in 

 the Gasserian ganglion of the cat. In the 

 common trunk of the pneumogastric and 

 sympathetic nerves in the middle of the neck, 

 in the young calf, oval cells may be seen which 

 have distinctly attached at their peripherical 

 extremity a nerve -fibre ; and some of them 

 also appear to be connected with one at the 

 opposite or central extremity. 



The different cells composing a ganglion are 

 each surrounded by a more or less clear, homo- 

 geneous substance, in which are contained a 

 number of round or oval nuclei. These are 

 seen to form a single or double row around 

 the margin of the ganglionic vesicle, their long 

 axis being directed in the axis of the cir- 

 cumference of the cell (fig. 288.)- They are 

 also seen upon the surface of the corpuscle (c, 

 fis.. 288.). This substance not unfrequently 

 presents a more or less fibrous aspect, as if 

 composed of spindle-shaped corpuscles. It re- 

 sembles much (as has been already stated) the 

 fibres of Remak. The nuclei measure from the 

 r Jj_th to the 4-oVoth of an inch in breadth, and 

 about ^n^th to -f^th of an inch in length. 

 The structure in question is closely connected 



* Kolliker's Mikroskopische Anatomic, band ii. 

 \ 519. 



From the gastric ganglion of the Ray, shewing 

 ganglionic corpuscles embedded in a nucleated 

 fibrous tissue. 



relation to it that the fibres of Remak hold to 

 the nerve-tubes. It has been termed the 

 capsule of the ganglionic corpuscle. The cap- 

 sules surrounding the different ganglionic cor- 

 puscles are also closely united to each other, 

 so as to form a kind of framework, in the loculi 

 of which the ganglionic corpuscles are placed 

 (jig.288.). It would appear also to be prolonged 

 along the nerve-tubes connected with the gan- 

 glionic corpuscles for some distance, forming 

 for them an investment or sheath similar to 

 that which it forms for the corpuscles them- 

 selves. The quantity of this substance which 

 is present varies in different circumstances. 

 It appears to be more abundant in some cases 

 than in others, and is commonly more so in 

 the sympathetic ganglia than in those on the 

 posterior roots of the spinal nerves. 



As regards the arrangement of the nerve- 

 fibres in the ganglia, when one of the enter- 

 ing branches in the ganglia of small animals, 

 such as the mouse, is traced into the point at 

 which it joins the ganglion, it is found to 

 spread out somewhat, and soon breaks up 

 into its component fibres. These separate 

 from one another, running amongst the gan- 

 glionic corpuscles, either singly or in bundles 

 of two, three, or more. The nerve-fibres be- 

 longing to one bundle leave it and join neigh- 

 bouring bundles, so that a more or less com- 

 plete interchange of the fibres contained in 

 the different bundles takes place; and at the 

 same time there is formed a sort of plexus or 

 network, in the meshes of which the ganglionic 

 corpuscles are imbedded (Jig. 28?.). Some- 

 times, as Valentin observed, one or more of 

 the fibres of one of the entering bundles are 

 seen to wind round the ganglionic corpuscles, 

 and appear again to pass into another entering 

 bundle, thus pin-suing apparently a retrograde 

 course. The fihres which thus surround the 

 ganglionic vesicles were termed by Valentin 

 umspinnende fasern ; whether they _again 

 really leave the ganglion in the direction in 

 which they entered it, and in this way may be 

 regarded as terminating in a looped arrange- 



