646 Dynamic Theory. 



sense, and with slight variations these parts have been handed down 

 from remote generations. It is perfectly reasonable to suppose that the 

 nervous connections between the members and the brain are as definite 

 and constant as the other parts are, and this probability is confirmed by 

 the facts of comparative anatomy, as far as they have been ascertained. 



Furthermore, it is reasonable to infer that the same parts of the brain 

 are connected with their same corresponding muscles, glands, sense or- 

 gans, &c. , now as in the generations gone by. The existence of organs 

 in the brain, therefore, is antecedently probable, but more than that it 

 is experimentally proved, as will be seen further on. But the nature of 

 these organs is very different from that assumed by the phrenological 

 philosophy. As assumed by that system, the brain is the organ of the 

 Mind ; as proved by scientific research it is the organ of the Environment. 



In the simplest animal forms there is no perceptible nervous system. 

 The animal is moved by external stimuli directly applied to move the 

 whole body of the infinitesimal animal, or some part of him. When, 

 by evolution, the animal attained such a size that a stimulus applied on 

 one side was too far away to affect the opposite side by direct contact, 

 the stimulus made for itself a pathway across the bod} r of the animal. 

 This pathway constitutes the earliest form of the nervous system, but it 

 involves the entire principle upon which all the subsequent developments 

 of it are founded. No matter how extensive and complicated the ner- 

 vous system becomes, it is never anything more than a pathway between 

 the body in the environment from which the stimulus is projected, and 

 the muscle which is adapted to be moved by it. The fact of the im- 

 mense development of the brain as a part of this pathway, does not al- 

 ter the principle. The development of the brain has come about by the 

 great number anfl variety of the stimuli on one side, and the great num- 

 ber and variety of the muscular movements possible on the other. The 

 brain may be compared ( remotely ) with the central office of a city tele- 

 phone system. If there were but two subscribers to the telephone, no 

 "central " would be required. But when there are three, a simple gan- 

 glion of switches is necessary to shunt the message and enable one to 

 communicate with either of the others. This shunting arrangement, 

 acting under the direction of the sender, no matter how many sub- 

 scribers, never becomes anything more than an inserted adjunct in the 

 pathway of communication, qualifying the pathway but in no manner 

 affecting the message. The comparison is general, and is incomplete in 

 important particulars. The body is a community of parts having gen- 

 eral identical interests. The stimuli from different parts and from the 

 environment, meeting in the brain, modify, neutralize and reinforce each 

 other, so that the stimulus, starting from any given source, may reach 

 a different muscle and accomplish a different motor action from what it 



