254 NERVOUS SYSTEM. [sect. 1 24. 



cases, pass from the ganglia in various directions. According to 

 Memah, multipolar cells also occur in the ganglia of the sympa- 

 thetic. To trace topographically different fibres in the sympathetic 

 cord, with reference to their origin from determinate rami com- 

 municantes and ganglia, and their continuation into particular 

 branches — if more be required than what has already been stated 

 — is a problem as yet not to be undertaken, and which can only 

 be reserved for the future. 



Bidder and Volkmann have demonstrated, that in the frog the majority of 

 the fibres of the rami communicant cs are distributed with the spinal nerves 

 in the periphery, and, accordingly, only a small part, which, besides, is derived 

 from the spinal ganglia, is to be regarded as the root of the sympathetic. 

 However, I believe I have seen in man and in rabbits the rami communicantes 

 running principally in a central direction. 



This appears to be the proper place to make a few more remarks upon the 

 fine Jibres of the ganglionic-nerves. It has long since been known, that the 

 sympathetic contains far more of the thinner nerve-fibres than the cerebro- 

 spinal nerves; but it was first in 1842, that Bidder and Volkmann endea- 

 voured to show that they are not only thinner, but also otherwise anatomically 

 different, whence, in contrast to the thick tubes of the cerebro-spinal nerves, 

 they called them sympathetic nerve-fibres. In opposition to this, Valentin 

 (Repert. 1843, p. 103), and I {Symp., p. 10, et set/.), attempted to prove, and, as 

 I believe, successfully, that the fine fibres in the sympathetic constitute no 

 special class of fibres. 



§ 124. Peripheral Distribution of the Ganglionic Nerves. — From 

 the cord of the sympathetic, arise the branches going to the peri- 

 phery. These invariably receive both fine and thick fibres from the 

 main cord, but besides, at least in part, contain other special elements, 

 to which their difference of aspect is owing. Some of them, namely, 

 are white, as the trunk itself is in most places, the nervi splanchnici, 

 for instance ; others are greyish-white, as the nervi intestinales and 

 the nerves of the non-pregnant uterus ; others are grey, and at 

 the same time less firm to the touch, as the nervus caroticus internus, 

 the nervi carotid externi seu molles, the nervi cardiaci, the vascular 

 branches in general, the branches connecting the great ganglia 

 and plexuses of the abdominal cavity, the branches passing into 

 the glands, and the pelvic plexuses. The peculiar condition of the 

 latter nerves depends, in part, upon the paler colour of the fibres 

 of the sympathetic itself, chiefly, however, upon the presence of 

 RemaFs fibres, as they are termed after their discoverer (gelatinous 

 fibres, Henle), which were at first looked upon as a kind of nerve- 

 tubes, but which are only a form of connective tissue, although 

 there are still some authorities who have not been able to satisfy 



