ANIMAL LIFE ASSIMILATION. 



cycles ; the self-direction of the Cerebrum, of 

 the total Brain, and of the total Organism. 

 Still the latter is not governed directly always 

 from the three brain centers, but has its own 

 center, a sort of second or subordinate Brain 

 situated almost wholly in the Trunk itself. 



(b) This secondary System of centralizing 

 and directing the Organism or parts of it, has 

 many ramifications, but may be looked at 

 in three main divisions the Spinal Cord, the 

 so-called Sympathetic Nerve, and the Nerves 

 proper, or the Neural differentiation, which 

 embraces the peripheral System on the sur- 

 face of the body. The general character of 

 this secondary System is meditational, lying 

 as it does between the immediate organs of 

 Assimilation and the supreme organs of con- 

 trol. In fact the whole sphere is one of intri- 

 cate division and specialization; the Nerves 

 are indefinitely specialized for each little part 

 or purpose. Every region of the body's sur- 

 face has a different degree and kind of sensa- 

 tion for instance, and this is a neural differen- 

 tiation. 



The Spinal Cord has the double duty of re- 

 flex action and at the same time of transmis- 

 sion of the stimulus to the Brain. It is itself 

 a reflex center of afferent and efferent nerves, 

 yet is also connected with and subordinate to 

 the cerebral center, to which likewise there 



