DISCRIMINATE AND INDISCRIMINATE ACTION. 135 
in such cases are liable to be of importance, through the original 
average character of the species not being fully represented and 
through the fact that this initial bias often leads to some new 
form of selection, which continues to act with cumulative force 
through subsequent generations. No single pair can exactly repro- 
duce the average character of the species in all its aptitudes 
and habitudes, and therefore the methods of dealing with the environ- 
ment adopted by the descendants are liable to be different. 
(2) In isolation and partition there is less opportunity than in 
selection and election for cumulative effects in each generation. 
Moreover, in many of the cases, the isolation is indiscriminate till 
divergent forms of selection codperate. But it should be noted that 
the isolation of a small number of the species is of frequent occurrence, 
and the failure of these small groups to represent the average charac- 
ter of the group or race either in habitudes or aptitudes introduces 
slight divergences determining new forms of autonomic selection 
which are of great importance in molding new types. And even 
when large masses are indiscriminately isolated all selection pro- 
ducing codrdinations between the members of the separate groups 
ceases; and the probability is that in the course of many generations 
divergent forms of selection will arise, through different methods of 
coérdination between members as well as through different methods of 
dealing with the environment adopted by different isolated groups. 
This probability rests not so much on the probability of a difference 
in the average character of the two large sections as on the probability 
that in one section some new habitude will arise that does not arise in 
the other section. The importance of isolation in producing diver- 
gence is seen not only in its being the absolute condition on which 
divergent forms of selection become of avail in producing divergence, 
but in the fact that the isolation of a few individuals often introduces 
from the first a divergent form of autonomic selection, though the 
environment is the same, and in the fact that the isolation of a large 
section of a species opens the way for a similar divergence of selection, 
though it may require many generations for the result to become 
apparent. Moreover, discriminate isolation (as when different indus- 
tries have led individuals to form intergenerating groups according to 
their aptitudes), leads from the first to divergence in adaptations and 
to the intensification of adaptations. 
The table on page 136 will be useful in enabling us to keep in mind 
the importance of these distinctions when applied to some of these prin- 
ciples. Discriminate survival, which is usually called selection, is of 
such importance that many terms have been needed to present the 
