1880.] A Review of the Modern Doctrine of Evolution. 267 
still further development. Thus the vegetable kingdom died, so 
to speak, that the animal kingdom might live; having descended 
from an animal stage to subserve the function of food for 
animals. The successive types of animals have ‘first stimu- 
lated the development of the most susceptible to the conflict of 
the struggle for existence, and afterwards furnished them with 
food. Doubtless in the occupation of the world’s fields, the 
easiest and nearest at hand have been first occupied, and succes- 
sively those which were more difficult. The digging animals are 
generally those which first abandoned the open field to more 
courageous or stronger rivals; and they remain to this day gen- 
erally of low type compared with others of their classes (e. g., 
Monotremata, Rodentia, Insectivora). All occupations have been 
filled before that one which requires the greatest expenditure of 
energy, č e., mental activity. But all other modes‘ of life have 
fallen short-of this one in giving the supremacy over nature. 
Automatism then represents a condition of “lapsed intelli- 
gence” and diminished life. The unconscious automatism of 
animals is a condition of still greater lapse. On the contrary, 
‘sensibility is the condition of development, and the susceptibility 
and impressibility which is the extreme reverse of automatism is ° 
the especial character of youth. Here the “doctrine of the 
unspecialized”’ finds justification again. - 
What the future has in store for us in the history of inorganic 
force and its results, we can not now foresee, but I call attention 
in this connection to the important part played by life in the dis- 
tribution of minerals, It has long been known that the carbon of 
the earth’s crust was once in a living state, and it is admitted that 
the limestone once circulated in the fluids of animals. We have 
recently been compelled to believe that siliceous rocks are com- 
posed of the consolidated shells of minute plants, which they 
have elaborated from the water of the ocean, Silver and gold 
are segregated and deposited by seaweeds. The principal i a. 
material, whose relation to life has not been ascertained, is alu- 
mina. How far the processes which now characterize dead mat- 
ter were once related to life is a problem for the future. 
IV. The Morals of Evolution. 
The doctrines of the struggle for existence and siai of the 
fit i in human ie have a two-fold — r n a a 
