SYMPATHETIC NERVE. 



437 



cells, when the nerve-tubes come off at either them runs towards the periphery, the one at 

 extremity, as they generally do, while one of the opposite runs towards the nervous centres. 



Fig. 286. 



Ganglionic corpuscles from one of the spinal ganglia in the Hay. 



In A, the granular contents reach quite to the margin of the vesicle ; B, ganglion-corpuscle with a 

 layer of clear round delicate bodies on the inner surface of its wall ; c, showing a clear space be- 

 tween the granular contents and the cell-wall, occupied by particles of oily matter similar to the 

 contents of the nerve-tubes ; D, a corpuscle which has been treated with chromic acid ; E, ganglionic 

 corpuscle of smaller size, with narrower nerve-fibre attached to it ; F, one intermediate in size between 

 the larger and smaller corpuscles; G, apparent apolar and unipolar corpuscles; H, collapsed mem- 

 brane of a ganglion-corpuscle ; j, liberated contents of the same. 



When both nerve-tubes pass off, not at op- 

 posite extremities, but from one side of the 

 corpuscle, they both run. according to Bidder, 

 in the direction of the periphery. As regards 

 the mode of connection between the ganglionic 

 corpuscle and nerve-tube, the cell-wall of the 

 former appears to be directly continuous with 

 the membrane of the latter, while the contents 

 of the vesicle seem to be prolonged ' down- 

 wards into the nerve-tube, becoming continuous 

 with its contents. The nucleated substance 

 forming the capsule of the ganglionic corpuscle 

 is also, according to Kolliker, prolonged along 

 the nerve-tube which arises from the corpuscle 

 itself (Jig. 288. and 289.). All the nerve-tubes 

 which are thus connected with the ganglionic 

 corpuscles in the ganglia of the sympathetic 

 belong to the finer variety of tubular fibres 



already described. In the spinal ganglia, 

 according to Kolliker, the nerve-tubes arising 

 from the corpuscles are at first fine, mea- 

 suring about 0-0015 0-0025 of a line ; but in 

 their further course many of them increase in 

 diameter up to 0*003 0'004 of a line, or even 

 to 0-0050-006 of a line, so as to represent 

 broad nerve-fibres, or fibres intermediate be- 

 tween the broader and finer varieties. 



Most of the cells which are seen in ex- 

 amining the ganglia of the mammalia belong 

 either to the apolar or bipolar variety. It is pos- 

 sible, however, that many of them, as Wagner, 

 Robin, &c. maintain, although apparently apo- 

 lar, are really unipolar or bipolar cells, from 

 which one or both processes have broken off 

 during the process of preparing them for ex- 

 amination. That the bipolar cell exists in 



F F 3 



