2»(5 THE EVOLUTION OF A MOTHEB. 



added, and bye lanes and loops between the older high- 

 ways must be thrown into the system. The stations 

 upon these roads from which the travellers set out 

 are cells ; the roads are transit fibres ; the travellers 

 themselves are in physiological language nervous dis- 

 charges, in psychological language mental processes. 

 Each new mental process involves a new redistribu- 

 tion of nervous matter among the cells, a new travel- 

 ling of nervous discharge along one or many of the 

 transit fibres. Now in every new connection of ideas 

 multitudes of cells and even multitudes of groups of 

 cells may be concerned, so that should it happen that 

 a combination of these precise centres had never been 

 made before, it is obvious that no routes could pos- 

 sibly exist between them, and these must then and 

 there be prospected. Each new Thought is therefore 

 a pioneer, a road-maker, or road-chooser, through the 

 brain ; and the exhaustless possibilities of continuous 

 development may be judged from the endlessness of 

 the possible combinations. In the oldest and most- 

 used brain there must always remain vast territories 

 still to be explored, and as it were civilized ; and in all 

 men multitudes of possible connections continue to the 

 last unrealized. When it is remembered, indeed, that 

 the brain itself is very large, the largest mass of 

 nerve-matter in the organic world ; when it is further 

 realized that each of the cells of which it is built up 

 measures only one tenth-thousandth of an inch in 

 diameter, that the transit fibres which connect them 

 are of altogether unimaginable fineness, the limitless- 

 ness of the powers of Thought and the inconceivable 

 complexity of these processes will begin to be under- 

 stood. 



