272 THE HISTORY OF CREATION. 
of animals and plants are variable, and possess the capability 
of adapting themselves to different places or to local rela- 
tions. The varieties or races of each species, according to 
the laws of adaptation, deviate all the more from the original 
primary species, the greater the difference of the new con- 
ditions to which they adapt themselves. If we imagine 
these varieties—which have proceeded from a common 
primary form—to be disposed in the shape of a branching, 
radiating bunch, then those varieties will be best able to 
exist side by side and propagate which are most distant 
from one another, which stand at the ends of the series, or 
at the opposite sides of the bunch. Those forms, on the 
other hand, occupying a middle position—presenting a state 
of transition—have the most difficult position in the struggle 
for life. The necessaries of life differ most in the two ex- 
tremes, in the varieties most distant from one another, and 
consequently these will get into the least serious conflict 
with one another in the general struggle for life. But the 
intermediate forms, which have deviated less from the 
original primary form, require nearly the same neces- 
saries of life as the original form, and therefore, in com- 
peting for them, they will have to struggle most with, and be 
most seriously threatened by, its members. Consequently, 
when numerous varieties of a species live side by side on the 
same spot of the earth, the extremes, or those forms deviating 
most from one another, can much more easily continue to 
exist beside one another than the intermediate forms which 
have to struggle with each of the different extremes. The 
intermediate forms will not be able to resist, for any length 
of time, the hostile influences which the extreme forms 
victoriously overcome. These alone maintain and propagate 
