SOCIAL AND FILIO-PARENTAL SELECTION. 203 
accord with the new habits till, in the case of most species, there are 
but few individuals that fail through lack of appropriate social in- 
stincts. Nevertheless, in the branches of the human species that have 
‘attained the highest civilization the process is still far from complete, 
for the instincts of many individuals are in conflict with civilized 
habits. 
We find that the natural faculties that are best fitted to secure indi- 
vidual success, and a numerous and long-continued descent, are 
different under different forms of civilization. Social habits in a 
great measure determine the food and clothing of a community and 
_ thus deeply affect the qualities of the race. The degree of exposure 
to which the young are habitually subjected is also largely determined 
by social custom, and so the quality of the constitution that is per- 
mitted to survive. In other words, the form of parental selection 
that prevails in any community is often determined by social selec- 
tion, as the form of social selection is sometimes determined by nat- 
ural selection. Many matters which, amongst irrational animals, 
are determined by instincts guiding the individual directly to the 
needed resources, and showing what provision must be made, are, 
with man, determined by social instincts, leading the individual to 
follow the general experience or traditional habits of his clan. 
As in countries where there are no beasts of prey the gregarious in- 
stinct of cattle ceases to be a necessity for the preservation of life, it 
is no longer maintained by natural selection, but it may be preserved 
by social selection; for though occasional stragglers appear, they are, 
through lack of adaptation to the social organization, specially liable 
to fail of finding mates, and, therefore, to fail of propagating their kind. 
Between the capacities of a community and its social organization 
there is a constant action and reaction which tends with more or less 
rapidity toward transformation; and this tendency is increased when 
a small community, during a long separation from other communities, 
gradually increases in strength, independently constructing a civili- 
zation of its own. In other words, independent social selection tends 
toward divergent evolution of capacities and of social organization. 
(12) Ftho-parental selection is the exclusive breeding of those 
better adapted to the relations in which parents and offspring stand 
to each other, through the failure to live and propagate of those less 
adapted. How the power of giving suck and the corresponding instinct 
for sucking were first developed it may be impossible to tell; but it is 
evident that having once been established as the method of sustenta- 
tion for the young of mammals, any young lacking the instinct would 
perish without leaving descent. Thereis every reason to believe that, 
