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 is no longer maintained by natural selection, but it may be preserved 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) Filio-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. There is every reason to believe that, 



