SO ANALYSIS OF THI} FOUR PRINCIPLES. 
These six conditions all relate to reproduction. The first and 
second are that there must be reproduction, and that it must be 
sufficient with the aid of adaptation to perpetuate the race. The 
third and fourth are that the reproduction must result in individuals 
more or less departing from the average character of the parents, but 
corresponding with them in their fundamental character. The fifth 
is that reproduction involves the codperation of separate individuals 
and binds the intergenerating group together in a common heredity. 
The sixth is that divergence of character depends on the prevention 
of free intergeneration, loosening the bond of common descent be- 
tween the isolated sections, and so opening the way for the divergent 
forms that variation and heredity controlled by segregation are per- 
mitted to produce. ‘The causes preventing free intergeneration, and 
opening the way for divergence, may lie in the organism or be imposed 
from without. 
2 Six Conditions on which the Evolution of Habitudinal Types must rest. 
First, the power of influencing associates; second, success (that 
is, the number of the socially endowed individuals must be sufficient 
to keep up the organization); third, innovation (that is, tentative 
diversity in the action of individuals in invention and initiation by 
means of experiment, comparison, and repetition of the best); fourth, 
tradition (that is, influence by means of example and imitation) ; fifth, 
free association and communication within the social group; sixth, 
segregate association setting limits to the sphere of free association 
and so controlling innovation and tradition. 
3. The Modes of the Four Princtples. 
In the classification which I have found most convenient, each of 
the four principles of segregation is presented under two main forms 
or modes, besides a third covering the reverse or regressive aspects. 
I also recognize that the indiscriminate action of any one of the four 
principles may produce results that should not be overlooked. The 
indiscriminate principle sometimes producing racial intensification is 
indiscriminate elimination of all but a few, and the indiscriminate 
principle sometimes producing habitudinal intensification is indis- 
criminate failure of all but a few. Under selection we have first 
the two modes, 7, reflexive selection, determined by the direct influ- 
ence of members of the ‘species upon each “other, as im sexual 
selection and social selection, and k, environal selection, deter- 
mined by the relations between the environment and the species. 
But each of these modes may be presented in its regressive aspects 
