184 FKAGMENTS OF SCIENCE. 



a subject so profoundly suggestive. Besides the physical 

 life dealt with by Mr. Darwin, there is a psychical lift - 

 presenting similar gradations, and asking equally for a 

 solution. How are the different grades and orders of 

 Mind to be accounted for ? What is the principle of 

 growth of that mysterious power which on our planet 

 culminates in Keason ? These are questions which, 

 though not thrusting themselves so forcibly upon the 

 attention of the general public, had not only occupied 

 many reflecting minds, but had been formally broached 

 by one of them before the ' Origin of Species ' ap- 

 peared. 



With the mass of materials furnished by the phy- 

 sicist and physiologist in his hands, Mr. Herbert 

 Spencer, twenty years ago, sought to graft upon this 

 basis a system of psychology ; and two years ago a 

 second and greatly amplified edition of his work ap- 

 peared. Those who have occupied themselves with the 

 beautiful experiments of Plateau will remember that 

 when two spherules of olive-oil suspended in a mixture 

 of alcohol and water of the same density as the oil, 

 are brought together, they do not immediately unite. 

 Something like a pellicle appears to be formed around the 

 drops, the rupture of which is immediately followed by 

 the coalescence of the globules into one. There are organ- 

 isms whose vital actions are almost as purely physical 

 as the coalescence of such drops of oil. They come into 

 contact and fuse themselves thus together. From such 

 organisms to others a shade higher, from these to others 

 a shade higher still, and on through an ever-ascending 

 series, Mr. Spencer conducts his argument. There are 

 two obvious factors to be here taken into account the 

 creature and the medium in which it lives, or, as it is 

 often expressed, the organism and its environment. Mr. 

 Spencer's fundamental principle is, that between these 



