Royal Microscopical Society. , 7 



connecting the ganglionic bodies with each other, whence they 

 extend, while assuming a more oblong form, between the sympathetic 

 nerve iibres. 



The destination of those axis cylinders, arising from the processes 

 piercing the capsule, I have never been able to determine satisfac- 

 torily. Several times I have seen them isolated to a length of 

 ^V mm., and frequently I have traced them in thin transparent 

 sections to a considerable distance, without noticing any change in 

 their structure or even their diameter ; they always disappeared 

 between the bundles of sympathetic nerve fibres. Although these 

 axis cylinders run mostly, as already mentioned, parallel with the 

 sympathetic fibres, they nevertheless are observed to pass here and 

 there through the latter in an oblique direction, and as it appears, 

 toward the dark-bordered nerve fibres. In consequence of this 

 fact, I presume that, after a shorter or longer course, they are 

 surrounded by a covering and transformed into darh-hordered 

 nerve fibres. If this conjecture should prove to be true, as we 

 shall see farther on, the sympathetic ganghonic bodies would then 

 give rise to both kinds of nerve fibres, each of which might transmit 

 a nervous current of its own. 



The ganghonic bodies of the spinal ganglia show, with some 

 deviations, the same structure as those of the gangliated cords. 

 There are certain difficulties, however, in the way of examining 

 them accurately, produced by their more considerable size and a 

 greater thickness of their capsule, as well as by a number of dark- 

 bordered nerve fibres running between them. From the body 

 within the capsule, as in the former case, a number of processes of 

 difierent diameters arise ; some of them seem to pierce the capsule, 

 while the rest contribute to the formation of the capsule. The con- 

 struction of the latter, as also the reciprocal connection with the 

 neighbouring capsules, are the same as those of the ganglionic bodies 

 of the gangliated cords, with this difierence, that the meshes of the 

 network are, in proportion to the greater size of the whole body, 

 somewhat larger. The most essential difierence, however, consists 

 in a darh-hordered nerve .fibre, originating directly in the spinal 

 ganglionic body. The axis cylinder of this nerve fibre arises, as 

 usual, from the body, and pierces the capsule, while the tubular 

 membrane seems to terminate in the latter. Whether this dark- 

 bordered nerve fibre connects the sympathetic ganghonic body with 

 the spinal marrow, or whether it runs in an opposite direction 

 toward the periphery, is difficult to determine, especially, as it first 

 winds its way along for some distance between the neighbouring 

 ganghonic bodies before it joins the bundle of nerve fibres. But 

 judging from certain observations I made, I am inclined to think 

 that it belongs to the spinal marrow. A part of the fibriUae arising 

 from the network on the outer surface of the capsule go to contri- 



