192 Journal of Comparative Neurology. 



both be seats of consciousness, or the one may predominate, 

 receiving from the other as much assistance as one eye gives to 

 the other ; or for all we know, one may do the entire work 

 alone, as the center of speech is unilateral while the correspond- 

 ing region of the other hemisphere is differentiated for some 

 other purpose. It is to be hoped that future experiences will 

 throw more light on these problems. 



The unity of aim arises from the practical needs of life, 

 and originates, necessarily, through the common interest of the 

 whole organism as a unity. Whatever the mechanism be which 

 produces this mental convergence of many feelings in one con- 

 sciousness, it is natural that it works automatically in normal 

 brains as does the co-operative adjustment of the motions of our 

 eyes. This, of course, does not exclude that the concentration 

 of attention can be trained, and that our consciousness can be 

 greatly intensified and rendered more and more lucid by educa- 

 tion and self-control so as to reach a higher and ever higher 

 grade of perfection. 



