LUTHER BURBANK 
This term, natural selection, has obvious pro- 
priety because it connotes a process closely akin in 
its results to the artificial selection through which 
man determines that certain races of animals and 
plants under domestication shall be preserved, and 
that others shall be destroyed. But artificial selec- 
tion is after all only a phase of natural selection, 
in which man becomes an active influence or a 
deciding element in environment. 
Because of man’s power to transform the con- 
ditions of soil, to supply artificial heat, and to 
bring together and hybridize plants and animals 
that would not come in contact in the state of 
nature, the results of artificial selection, epitomiz- 
ing within certain bounds the results of natural 
selection, may be produced with unexampled 
celerity. 
Man, for example, eliminates a species in a few 
decades, where nature would have found no way of 
correspondingly rapid elimination. The black 
walnut, for example, has been almost extermi- 
nated throughout eastern America because man 
prized its wood for the making of furniture. But 
for the presence of civilized man the black walnut 
would doubtless have maintained its position for 
ages to come, just as it had maintained it through- 
out the ages of the past. 
Yet we must not forget that on occasion there 
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