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 
are seized and fixed by natural selection. 
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- 
Irritability the 
basis of mind. 
The hvala tiations and integrations.” All the 
adequate for the hie er ee f 
ratte igher 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 
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 
The marvel 
of life. 
