THE EVOLUTION OF THE MIND. 



259 



United States. Its adjustments, checks, and balances 

 are more perfect. It should in its changing relations be 

 compared rather with the great unwritten constitution 

 of civilized society. The laws of society spring from 

 the laws governing the development of the single cell. 

 If we knew the latter "all in all," as Tennyson says 

 of the flower, " we should know what God is and 

 man is." 



If we could follow any life problem to its uttermost 

 detail, we should have the clew to all life. 



Among the protozoa, as already stated, all activities 



are centred in the single cell which forms the animal 



unit. Each cell is sufficient unto itself. 



Activities of It ig i ndependent and free but it is at 



protozoa. 



the same time unspecialized and in- 

 effective. Its career offers no wide play for volition, 

 for a single life unit can not control the elements which 

 surround it. It is the sport of the wind and the wave. 

 But the recognition of self and non-self, which in one 

 form or another is the attribute of all life, is not want- 

 ing among the protozoa. Some of them develop this 

 sense to a large degree. It is said that among the 

 rhizopods are those whose appendages or pseudopodia 

 are at once cast off if they come in contact with the ap- 

 pendages of another of the same species. This recog- 

 nition of self and non-self is not intellect, but it is 

 homologous with the impulses on which in the higher 

 types personality depends. 



All sensation has reference to action. If a creature 



is not to act it can not feel. Wherever motion exists 



there is some sensitiveness to external 



Sensation re- conditions, and this is of the nature of 



lated to action. . . 



mind. In a compound organism the na- 

 ture and position of the sensorium or mind centre de- 

 pends on what it has to do, or rather on what were the 



