GANGLIONS. 327 



Besides the ganglia of the encephalon and of encephalic and 

 spinal nerves at their origin, there are, on each side, several 

 ganglia in the head ; the ophthalmic or lenticular, the spheno-pa- 

 latine or Meckel's, and the cavernous, the otic, and sub-maxillary ; 

 there are three cervical ; twelve dorsal ; five lumbar ; and five 

 or six sacral ; one at the heart, called cardiac ; and two in the 

 abdomen, called semilunar. Branches connect them with the 

 encephalic and spinal nerves. Single branches run longitudinally 

 between them all, connecting their whole series ; and the lines 

 unite in a single ganglion on the os coccygis. Old anatomists 

 gave the whole the name of sympathetic or intercostal nerve, 

 and supposed it to arise from the encephalo-spinal nerves. The 

 ganglionic nerves are less firm than the encephalo-spinal, and of 

 a less clear white. 



We must not forget that every part of the nervous system 

 throughout the body is directly connected with others, and in- 

 directly with all the rest, just as is every blood-vessel in regard 

 to its system. 



Nerves subdivide and soften till they are lost, with the excep- 

 tion of the optic, which expands into a membrane called retina, 

 and of the coalition of nerves. The diameters of branches are 

 said usually to exceed that of a trunk. 



I have used the words prolongations, arise, &c., but merely for 

 the purpose of ocular description ; since Gall has shown that the 

 nerves and spinal chord do not arise from the brain, but only 

 communicate with it ; nor the spinal nerves from the spinal chord : 

 for, when the brain is absent, the foetus may equally possess ence- 

 phalic nerves and spinal chord P ; and, when the chord is absent, 

 the foetus may equally possess spinal nerves ; and the brain and 

 spinal chord, and the brain and encephalic nerves, are in no pro- 

 portion to each other in the various species of the animal kingdom, 

 nor the spinal nerves to the spinal chord, nor does the latter 

 diminish as the nerves go off. 



The idea of the nerves proceeding from the brain is as un- 

 founded as that of the arteries proceeding from the heart, or one 

 portion of an extremity from another. Foetuses are seen with an 

 arterial system, and no heart; others born with no arms, but 



Writers say cerebro-spinal. But, if cerebrum is not allowed its classical 

 meaning the whole cranial nervous mass as well as its scientific application to 

 a portion only, the term cerebro-spinal must be replaced by encepbalo-spinal. 



P Gall, 4to. t. ii. p. 77. sqq. j 8vo. vol. i. sect. ii. For spinal nerves without 

 chord, see Hist, de V Acad, des Sciences, 1746, p. 42. 



