AND ANIMAL LIFE. 215 



investigation particularly concern the physiolo- 

 gist it is sufficient for him to observe that dif- 

 ferent acts of the system are accomplished by the 

 simple volition of the mind. 



CCXL. Whether the sympathetic nerve arise 

 from the brain, or only be connected with it, 

 or whether the system which it forms is to be 

 regarded as independent of the cerebrum and 

 spinal cord, or as constituted to combine and 

 communicate the same influence in the more per- 

 fect animals, are subjects which will continue to 

 perplex as long as anatomy be appealed to as the 

 only guide. 



If the ganglionic system in the lowest orders 

 of animated nature be supposed to preside over 

 the functions of secretion, absorption, and nu- 

 trition, as there is no other system of nerves 

 present, it may be justly asked whence those 

 powers are derived which bestow sensibility and 

 motion ? MECKEL and WEBER remark, that the 

 sympathetic nerve and par vagum are developed 

 in the inverse ratio of each other. In the lower 

 gradations of animal life, the sympathetic nerve, 

 or ganglionic system, is the only nervous struc- 

 ture which is present for sensation and motion ; 

 and, as we ascend in the scale of being, we per- 

 ceive the additional contribution of the par va- 

 gum to supply the multiplied wants of the ani- 

 mal. It is, therefore, probable that these two 

 nerves possess endowments precisely of the same 



