THE NERVOUS SYSTEM. 44-3 



larger blood-vessels are supplied by them, and these may convey 

 them throughout the frame. There is no reason to say that the 

 ganglionic nerves merely arise from the encephalo-spinal : they 

 give branches evidently to the encephalo-spinal a , and conse- 

 quently we may presume that they are as extensively distributed; 

 and the ganglionic nerves are very fine and at length must be in- 

 visible. The property they give must be supposed similar to that 

 of sensibility: and we see, therefore, why they have ganglia 

 exactly like those of nerves of sensation, inasmuch as they consist 

 of grey and white substance inextricably mixed, and their white 

 matter is exceedingly soft like those nerves, whereas in nerves of 

 motion it is hard ; and we are not surprised to find them convey 

 galvanism badly, like nerves of sense, while nerves of volition 

 conduct it well ; nor to find that, as narcotics applied to nerves 

 of sensation destroy the sensibility of the parts which these 

 supply, so, when applied to ganglionic nerves, narcotics destroy 

 the excitability of the parts supplied by them. The filaments of 

 ganglia are declared by Lobstein b to be different according to 

 the organs which they supply, just as we know the vital properties 

 or excitability of every organ to differ. Hence we cannot wonder 

 at the continuance of the organic functions during inactive states 

 of the encephalo-spinal system, in sleep and coma; nor even 

 when the brain is removed, or the muscle itself is detached from 

 the body : we cannot wonder at the division of the principal trunks 

 belonging to a muscle not preventing its irritability from being re- 

 newed after exhausting stimulation has been intermitted. Lastly, 

 when the encephalon, or both it and the spinal chord, are wanting 

 in monsters, the ganglionic system almost always, if not always, 

 exists ; and is said never to be absent, if a monster is not far 



a This is shown by Mr. Mayo, 1. c. p. 265. ; and Mr. Swan conceives that 

 there is no doubt of the branches of the sympathetic proceeding to the sixth, 

 instead of arising from it. (On the Nerves.) But, above a century ago, Petit 

 demonstrated the error of those who derived the sympathetic from the fifth and 

 sixth pairs (Mem. de V Acad. Roy. des Sc. 1727) ; and Fontana, according to 

 Girardi, argued against the origin of the sympathetic from the third or fifth pair, 

 because the twigs were not detached from these pairs, but ran to them ; so that 

 they should be called the end and not the origin of the sympathetic. Professor 

 Panizza declares that the branches of the sympathetic which ascend with the 

 carotid artery merely entwine around the sixth pair, and may be detached with- 

 out injury to their continuity. (Ricerche Sperimentali, p. 6.) 



b De Nervo Sympathetico. 1835. 



