THROUGH CUMULATIVE SEGREGATION. 
205 
“ will generally lead to the most different or divergent varia- 
tions being preserved and accumulated by natural selection.” 
Now it cannot be doubted that ability to appropriate unused 
resources would be an advantage to any members of a com- 
munity pressed for food ; but I do not see bow the divergence 
that would enable them to appropriate, for example, a new kind 
of food can be accumulated while free crossing continues ; and 
Natural Selection cannot prevent the free crossing of competitors 
w r ho leave progeny. 
Having found that the evolution of the fitted is secured 
through the prevention of crossing between the better fitted 
and the less fitted, can we believe that the evolution of a 
special race, regularly transmitting a special kind of fitness, 
can be realized without any prevention of crossing with other 
races that have no power to transmit that special kind of 
fitness ? Can we suppose that any advantage, derived from 
new powers that prevent severe competition with kindred, can 
be permanently transmitted through succeeding generations to 
one small section of the species while there is free crossing 
equally distributed between all the families of the species P Is 
it not apparent that the terms of this supposition are inconsis- 
tent with the fundamental laws of heredity P Does not inheri- 
tance follow the lines of consanguinity ; and when consanguinity 
is widely diffused, can inheritance be closely limited? When 
there is free crossing between the families of one species will not 
any peculiarity that appears in one family either be neutralized 
by crosses with families possessing the opposite quality, or being 
preserved by natural selection, while the opposite quality is 
gradually excluded, will not the new quality gradually extend to 
all the branches of the species ; so that, in this way or in that, 
increasing divergence of form will be prevented ? 
If the advantage of freedom from competition in any given 
variation depends on the possession, in some degree, of new 
adaptations to unappropriated resources, there must be some 
cause that favours the breeding together of those thus specially 
endowed, and interferes in some degree with their crossing with 
other variations, or, failing of this, the special advantage will in 
succeeding generations be lost. As some degree of Independent 
Generation is necessary for the continuance of the advantage, it 
is evident that the same condition is necessary for the accumu- 
lation through Natural Selection of the powers on which the 
LINN. JOURN. — ZOOLOGY, VOL. XX. 17 
