258 FOOT-NOTES TO EVOLUTION. 



and degree of response variations occur. Those varia- 

 tions favourable to the division of labour and the adap- 

 tation of the animal to its surroundings 

 Irritability the afe seized and fixed b natur al selection, 

 basis of mind. 



In this way, on the basis of a diffused 



function, an organ is built up and the organ itself is 

 specialized and perfected. 



The mind and consciousness of man is an outgrowth 

 from the irritability of the lower animals, developed 

 through series of " successive differen- 

 The brain tiations and integrations." All the 



adequate for the . . , , 



. , higher animals are colonies of co-oper- 



ating and co-ordinated cells. In such 

 colonies of units the functions of sensation, thought, 

 and motion are relegated to series of the most sensitive 

 and most highly organized cells. This alliance of cells 

 is adequate for the work it has to perform. The brain 

 is always adequate for the mind, for the one is the 

 organ, the other the function, and the development of 

 the two must go on together. 



The intellect of man can not be regarded as the 

 crowning marvel of the "great riddles of life." A mar- 

 vel is no greater for its bigness. Life is 

 e ma one continuous marvel, without break or 



end. The human mind is one of life's 

 manifestations. The marvel appears in great or small 

 psychic powers alike, for the great powers of the many- 

 celled brain are produced by the co-operation and spe- 

 cialization of the small powers of the single cell. Na- 

 ture knows neither great nor small. " God works finer 

 with his hands than man can see with his eyes." The 

 single cell is far from simple. The egg or germ cell 

 carries within itself the whole machinery, as well as the 

 whole mystery, of heredity. The simplest organism we 

 know is far more complex than the constitution of the 



