282 UNIVERSAL EVOLUTION 



present time. This integration of organic matter 

 occurs by a multiplication of cells, and a differentia- 

 tion of the growth, into the heterogeneousness of organ- 

 isms. Thus, the great variety of species, now existing, 

 have been produced by the adaptation of an occasional 

 variation in the anatomy, and a corresponding varia- 

 tion in the physiology, of the hereditary form. "When- 

 ever the variation proved of benefit to its possessor, in 

 its struggle for existence, that organism proved more 

 likely, than its less favored companions, to live and 

 multiply. This is the principle of natural selection, in 

 the struggle for existence, and is the theory now gener- 

 ally held by scientists, as the one most likely to ac- 

 count for the origin of new species. 



The evolution of what is called physical life has long 

 been recognized, and acquiesced in, by the scientifically 

 educated, but for a long time after this acquiescence, 

 the psychical life was still deemed unexplainable by 

 natural laws. Modern psychology, however, has dem- 

 onstrated the dependence of psychical, or as formerly 

 called mental life, upon the physical, and that these 

 phenomena are as much under the operation of natural 

 law, as is physical life. This is so, whether psychology 

 is to be considered a science in itself, or a branch of 

 physiology. Whether we view mentality as like, or 

 unlike, the condition we call matter, yet the facts show 

 that they are inseparably connected in function. They 

 so perceptibly fuse that it is impossible to distinguish 

 the line of separation. Matter, whether in body tis- 

 sue, or in brain cells, is made up of centers of energy. 

 The explosion of these centers, in the brain, releases 

 the energy in the form of psychical phenomena. The 

 substrate of mental operations, as Wundt calls the 

 nervous structure, is a form of specialized matter, and 



