TtiE LAWS OF ORGANIC 



possess the same powers ; and as these are com- 

 bined in every thoracic or abdominal plexus or 

 ganglion, it is reasonable to suppose, that the 

 connexion of the various fibres cannot in the 

 least change their individual properties : before 

 they contribute these properties, they exhibit 

 sensibility and motion ; and if they are conjoin- 

 ed, the centres which they form will be sources 

 of sensibility and motion. 



CCXXXVI. If then the whole of the ganglions 

 and plexuses be centres or combinations, partici- 

 pating in the endowments of nerves whose func- 

 tions have been ascertained, it follows that the 

 viscera of the thorax and abdomen, the extremi- 

 ties and surface of the body, are supplied with 

 nervous energy composed of one or both of these 

 qualities. If this view be taken, we leave no 

 nerves to perform secretion or excretion, except 

 it be allowed to the physiologist that the nerve 

 which performs motion in one part of the body 

 is a nerve indispensable for secretion in another. 

 This idea has been embraced by WILSON PHILIP 

 and others, who believe that the formation of 

 the gastric juice depends on the eighth pair of 

 nerves. 



CCXXXVII. When I speak of sensibility 

 and motion, I do not, by any means, confine 

 those terms to the limits of their ordinary accep- 

 tation. I look upon every organ as possessing 

 sensibility and motion corresponding to its office. 

 The contraction of the heart, iris, or sphincter 



