442 



SYMPATHETIC NERVE 



fibres on the one side than they received on 

 the opposite side. So also in the septum 

 between the auricles of the frog's heart 

 Bidder has seen small ganglia, which gave off 

 on Hie one side eight nerve-fibres more than 

 they received on the other side. The obser- 

 vations of Bidder and Volkmann have been 

 confirmed also by Kolliker. Engel*, moreover, 

 describes a peripheral ganglion, to which no 

 nerve-fibres passed, while a number of fibres 

 left it; an observation which, if correct, places 

 beyond a doubt the question as to the origin 

 of nerve-fibres in the ganglia. The ganglion in 

 question he describes as being pear-shaped, 

 and about 0*096 of a line in diameter ; it oc- 

 curred in the perichondrium of the tracheal 

 cartilage, and consisted of fourteen ganglionic 

 corpuscles, with seven efferent nerve-fibres, 

 each measuring about 0*0012 of a line in 

 diameter. Even in regard to the bipolar gan- 

 glionic corpuscles, it does not appear to be at 

 all certain that they are all merely organs deve> 

 loped on the course of a nerve-fibre arising in 

 the brain and spinal cord. On the contrary, 

 it would appear that several of the cells be- 

 longing to this variety must also be regarded 

 as giving origin to nerve-fibres in the same 

 manner as the unipolar cell. Thus Bidder 

 has seen bipolar cells, the nerve-tubes con- 

 nected with which did not run in opposite 

 directions, one towards the brain and spinal 

 cord, the other towards the periphery, but 

 both ran in the latter direction (fig. 291.) : so 

 also Stannius, as mentioned by Kolliker, has 



Fis. 291. 



Bipolar ganglionic corpuscle, Loth nerve-fibres con- 

 nected with which run peripherically. From the 

 spinal ganglion of a Fish. (After Bidder.} 



seen in the ciliary ganglion of Trigla, a bi- 

 polar cell, both nerve-fibres of which were 

 directed peripherically. The same observer 

 has also seen ganglionic corpuscles in the fish 

 which gave origin to or had three nerve-tubes 

 connected with them. 



That most of the bipolar cells are, how- 

 ever, as Robin maintains, organs developed 

 on nerve-fibres of cerebro-spinal origin, in 

 their course towards the periphery, there is no 



* Engel in Zeitschrift der Wien. Aerzte, iv. p. 307., 

 as quoted in Kolliker's Mikroskopische Anatomic, 

 p. 532. 



reason to doubt; and moreover that several of 

 these may occur in the course of a single 

 fibre between its central and peripherical ter- 

 mination is also shown by the observations of 

 Stannius on [the fish, and by Valentin on 

 the frog. Wagner has also observed two 

 ganglion-corpuscles occurring in the course 

 of a single nerve-fibre, at short distances from 

 one another. 



Robin* divides the ganglionic corpuscles 

 into two distinct classes, a larger and a smaller : 

 the larger he finds always occur on broad nerve- 

 fibres, or fibres of animal life, while the smaller 

 are always connected with nerve-fibres be- 

 longing to the finer variety, or fibres of or- 

 ganic life ; and in this way, according to him, 

 we have a good mark by which to distinguish 

 the animal from the organic nerve-fibres. In 

 the ray, according to Robin, the larger variety 

 of corpuscles measure 0'095 to 0*150 mm. in 

 diameter, are spherical, and often flat at both 

 poles; the smaller measures 0*080 to 0*115 

 mm. in length, and 0*050 to 0*070 mm. in 

 breadth, and are commonly oval. , In the 

 larger cells there is a layer of clear round 

 bodies, without nuclei; in the smaller gangli- 

 onic corpuscles the outer membrane is finer, 

 and each of the cells, on their inner sur- 

 face, . is provided with a central dark nu- 

 cleus. Bidder f also agrees with Robin in 

 separating the ganglionic corpuscles into two 

 groups. In the pike the one set measure 

 O'O^"', while the other set do not measure 

 more than 0*0 18 //r : the former chiefly occur 

 in the ganglia of the cerebro-spinal nerves, 

 the latter in the ganglia of the sympathetic ; 

 the former are always connected with broad 

 fibres, the latter with fibres belonging to the 

 fine variety. The views of Robin and Bidder 

 are opposed by Kolliker, Valentin, and ap- 

 parently also by Wagner. The latter admits 

 that in general the ganglionic corpuscles are 

 smaller than those occurring in the spinal 

 ganglia, and that the smaller corpuscles have, 

 as Robin observes, an oval shape, while the 

 larger are more or less spherical : there are, 

 however, according to him, cases where broad 

 nerve-fibres are seen passing off from small 

 cells, and where the large cells are connected 

 with small or narrow fibres. Sometimes, in- 

 deed, the ganglionic corpuscle has a narrow 

 tube on one side, and a broad one on the op- 

 posite side (see fig. 290.); and sometimes the 

 broad, sometimes the narrow, runs peripheri- 

 cally. Stannius has, as mentioned by Kolliker, 

 observed in Petromyzon cells present, of the 

 fibres connected with which the one was six 

 times broader than the other. Although, how- 

 ever, there does not appear to be a distinct de- 

 marcation between the ganglionic corpuscles 

 belonging to the two sizes, there can be little 

 doubt that the cells occurring in the sympa- 

 thetic ganglia are generally smaller than those 

 occurring on the cerebro-spinal nerves, both 

 in the fish and also in the higher animals. 

 The larger cells in the spinal ganglia of the 



* Annales des Sciences Xaturelles, torn, septieme, 

 1847, p. 282. ; also Canslatt's Jahresbericbt, 1847. 

 f See Causlatt's Jahresbericht, 1847. 



