440 



SYMPATHETIC NERVE. 



tabes, and are evidently continuous with the 

 same (c, fig. 286.). Sometimes the granular 

 contents of the vesicle appear to be prolonged 

 downwards into the nerve-tube (A. fig. 289.), 



Fig. 289. 



appear on addition of acetic acid. In other 

 parts the ganglia contain corpuscles similar to 

 those already described as occurring in the 

 spinal ganglia, with the exception that they 

 are in general perhaps somewhat smaller. 

 They are imbedded in a fibrous structure, 

 which seems to hold the same relation to 

 them as the nucleated substance forming the 

 capsules of the ganglionic corpuscles in the 

 higher animals. It is difficult to ascertain 

 how far the ganglionic corpuscles in the ab- 

 dominal ganglia are unipolar or bipolar ; ac- 

 cording to Wagner, they are the same in this 

 respect as the corpuscles in the spinal ganglia, 

 being all bipolar ; one tube entering while 

 another leaves the corpuscle. The nerve- 

 tubes which are connected with them belong 

 both to the broad and fine varieties ; in ge- 

 neral, the narrower fibres are connected with 

 the smaller corpuscles, the broader fibres \\ ith 

 those of larger size (fig. 290.). 



Ganglionic corpuscles from the gastric ganglion of the 

 Torpedo. (After Wagner.) 



Showing, B, several of the cells still surrounded 

 by the fibro-nucleated tissue. A, other cells de- 

 nuded of it. 



while at other times, the oily contents of the 

 latter reach quite up to the corpuscle, and 

 seem either to become blended with the 

 granular contents of the same, or are pro- 

 longed into the clear space. Wagner* be- 

 lieves that the normal relation between the 

 nerve-tubes and corpuscles is, that each pri- 

 mitive nerve-fibre coming from the centre, 

 retains its appearance of double contour up 

 to the ganglion-cell, where its contents are 

 interrupted by the finely granular matter of 

 the latter; at the peripherical extremity of 

 the cell, the nerve-fibre commences in a quite 

 similar manner. Thus then, according to 

 Wagner, the oily contents of the nerve-tube 

 cease on reaching the ganglionic corpuscle. 

 Bidder-}-, on the other hand, regards the clear 

 white space between the cell-wall and the 

 granular contents as a thin sheet of nervous 

 matter, which serves as a connecting medium 

 between the contents of the nerve-tube on 

 either side of the ganglionic corpuscle. 



As regards the sympathetic ganglia in this 

 animal, they appear in some parts to be almost 

 entirely composed of a fibrous structure and 

 of a quantity of granular matter resembling, 

 as Wagner and Robin observe, the gray 

 granular matter of the nervous centres, and 

 containing a number of bodies of a brownish- 

 yellow granular appearance, which do not dis- 



* Handwb'rterbuch der Physiologie, bandiii. p. 

 361. et seq. 



j- Zur Leben von dem Verhaltnisz der Ganglien, 

 korper zu den Nervenfasern, Leipzig, as quoted 

 in Canslatt's Jahresbericht, 1847. 



Ganglionic corpuscles from the 2Gth spinal ganglion of 

 the Torpedo, drawn in utline in order to show the 

 different size of the nerve-lubes. (After Wagner.) 



It has been already seen that it is almost 

 certain that all the ganglionic corpuscles oc- 

 curring in the ganglia on the posterior roots 

 of the spinal nerves, at least in this animal, 

 belong to the bipolar variety ; it remains to 

 inquire whether all the nerve-fibres in the 

 posterior root are connected with ganglionic 

 corpuscles. When the ganglion, after addition 

 of dilute solution of soda, is examined with a 

 powerof about 30 or 40 diameters, itis observed 

 that while many of the fibres soon disappear 

 among the ganglionic corpuscles, several of 

 them can be traced from the point at which 

 they enter the ganglion almost to its opposite 

 extremity, without being connected with cor- 

 puscles ; but I have never been able to trace 

 them in this manner quite past the ganglion. 

 Wagner, who counted the nerve-tubes con- 

 tained in the posterior root of the nerve and 

 also the ganglionic corpuscles, found that the 

 number of each corresponded pretty closely, 



