271 



of all the muscles of the interior life, as well as over those of the loco- 

 motive apparatus; and while the brain, reserved for the most noble and 

 most important functions, seems exclusively charged \vilh the operations 

 of intelligence and thought, the spinal marrow holds under its controul 

 all the contractile organs, and it is by its influence that all their contrac- 

 tions are executed*. 



Thomas Bartholin had already acknowledged that the brain was more 

 particularly the organ of sensation, and the spinal marrow that of mo- 

 tionf. He v/as equally sensible, that the best way of proceeding in the 

 dissection of the brain, was to advance from the base to the vertex, and 

 not from the summit to the base, as was the custom until our times. 



If we take a view of the graduated scale of the animal creation, says Dr. 

 Gall, in his Researches of the Nervous System, Sec. the sensible substance, 

 which is merely gelatinous pulp in the polypus, gradually becomes dis- 

 posed into nervous filaments and cords hi the more perfect animals. In 

 order to establish a more extended intercourse with the external world, 

 Nature has added more complex organs, according as the relation of the 

 species with the surrounding creation become more numerous : it is thus 

 that, by the successive addition of new organs, and the perfection of 

 others, the animal creation is elevated to man himself. 



The brain, a simple tubercle added to the anterior extremity of the 

 spinal marrow, of which it seems to be nothing else than an accessary 

 part, an appendix, in the insects, because amongst them it is but little 

 larger than one of their numerous ganglions, becomes more complex and 

 more perfect in the higher animals : in the fishes it but little exceeds the 

 spinal cord ; whilst in the mammalia it possesses the same parts as in 

 man, and is disposed nearly in the same form ; but, in no animal is the 

 double appearance of diverging and converging fibres better developed 

 than in him ; in no other animal w the brain properly so called, that is to 

 say, the superior part of the encephalon, or the hemispheres, possessed 

 of a greater volume in proportion to the size of the animalj. The brain 

 proper seems to be the seat of the nobler functions of intelligence, whilst 

 in the cerebellum the medulla oblongata, and the spinal cord, those fa- 

 culties and manifestations that are common to us and the lower animals, 

 appear to reside. 



The nervuos system ought not, therefore, to be compared to a tree, the 

 trunk of which f represented by the spinal marrow, has its roots in the 

 brain, and expands its branches through all parts of the body; but ought 

 rather to be considered as a net-work whose threads communicate with 

 each other, separate, re-unite, and join several masses or dilatations of 

 greater or less size: these masses or ganglions ought to be viewed as 

 being the centres of communication. 



The brain should not be considered as a ganglion, or even as a collec- 

 tion of ganglions, as the common ganglion of the nerves of the cranium, 

 as some physiologists have done; the nerves which detach themselves 

 from its base, or from the medulla oblongata, have their origins distinct 



* See the above Note i 

 f " Et id quidem manifestius fit inspicientibus anatomen piscium; ibi enim medulla? 

 caput et caucla insij.niis est magnitudinis; processus vero medullas ad cerebrum admo- 



nocl pisces motu magis quam sen 

 cortex, ad motum plus medulla i 



dum exigunm, cujus rei causa est, quod p'isces motu magis quam sensu utantur, ac sic 

 ad sensum plus conferat cerebrum vel 



See APPENDIX, Note D I). 



