PART III 



NERVOUS OPERATIONS UNCONNECTED WITH 

 CONSCIOUSNESS 



Those nervous operations of which man is necessarily 

 conscious and which are directly concerned in his useful- 

 ness and happiness, cannot continue to minister to his 

 higher nature without the assistance of another set of 

 actions of which he is in health almost wholly uncon- 

 scious. The complicated mechanisms for producing sen- 

 sation and voluntary motion are constantly worn away at 

 every point, and every tissue must- be as constantly re- 

 newed. Through the action, at every moment of life, of 

 nerves and nerve cells whose office it is to preside over 

 what are called the vital processes, the body is kept in 

 condition for the exercise of its conscious -powers. Those 

 vital processes are included under the general term nutri 

 tion, that is, the growth, waste, and repair of tissue. 

 Nutrition is effected by means of the circulation of the 

 blood, digestion (including absorption and assimilation), 

 respiration, and excretion. Because these operations are 

 wholly dependent upon nervous influences, and because 

 they go on through life without necessary connection 

 with consciousness, they are grouped here as unconscious 

 nervous operations. 



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