On the contrary, they react unfavorably upon his personal gains, if, through too great development, they interfere with his activity or render him a conspicuous mark for enemies. Such development would constitute excessive sex-distinction, and this is precisely the condition of the human race. Our distinctions of sex are carried to such a degree as to be disadvantageous to our progress as individuals and as a race. The sexes in our species are differentiated not only enough to perform their primal functions; not only enough to manifest all sufficient secondary sexual characteristics and fulfil their use in giving rise to sufficient sex-attraction; but so much as seriously to interfere with the processes of self-preservation on the one hand; and, more conspicuous still, so much as to react unfavorably upon the very processes of race-preservation which they are meant to serve. Our excessive sex-distinction, manifesting the characteristics of sex to an abnormal degree, has given rise to a degree of attraction which demands a degree of indulgence that directly injures motherhood and fatherhood. We are not better as parents, nor better as people, for our existing degree of sex-distinction, but visibly worse. To what conditions are we to look for the developing cause of these phenomena? Let us first examine the balance of forces by which these two great processes, self-preservation and race-preservation, are conducted in the world. Self-preservation involves the expenditure of energy in those acts, and their ensuing modifications of structure and function, which tend to the maintenance of the individual life. Race-preservation involves the expenditure of energy in those acts, and their ensuing modifications of structure and function, which tend to the maintenance of the racial life, even to the complete sacrifice of the individual. This primal distinction should be clearly held in mind. Self-preservation and race-preservation are in no way identical processes, and are often directly opposed. In the line of self-preservation, natural selection, acting on the individual, developes those characteristics which enable it to succeed in “the struggle for existence,” increasing by use those organs and functions by which it directly profits. In the line of race-preservation, sexual selection, acting on the individual, developes those characteristics which enable it to succeed in what Drummond has called “the struggle for the existence of others,” increasing by use those organs and functions by which its young are to profit, directly or indirectly. The individual has been not only modified to its environment, under natural selection, but modified to its mate, under sexual selection, each sex developing the qualities desired by the other by the simple process of choice, those best sexed being first chosen, and transmitting their sex-development as well as their racial development.