And, in fact, only the universality of that passion transcends the importance of its direction. For, while the sexual instinct, per se, guarantees the perpetuation of the species, the instinct of selection refers to the composition of the next generation, of which it thus determines the quality as the other determines the quantity. And just as the vital powers of the individual organism strive back from disease to health, the genius of the species seeks to reëstablish the perfection of the type, and to neutralize the effects of degenerating influences. We accordingly find that the individuals of each sex seek the complement of their own defects. Small women prefer tall men; fickle men worship strong-minded women; dark grooms select fair brides; practical business men are attracted by romantic girls; city belles admire a rustic Hercules, and vice versa. Exceptional intensity of mutual passion denotes exceptional fitness of the contemplated union, or rather the results of that union; for, here as elsewhere, Nature, in a choice of consequences, will sacrifice the interests of individuals to the interests of the species. Passionate love, accordingly, is ever ready to attain its purpose at the price of the temporary advantages of life, nay, of life itself; and the voluntary renunciation of such advantage is, therefore, in the truest sense a self-sacrifice for the benefit of posterity, a surrender of personal interests to the welfare of the species. In spite of the far-gone perversion of our ethical standards, we accordingly find an instinctive recognition of such truth in the popular verdict that applauds heroic loyalty to a higher law when lovers break the fetters of sordid interest or caste restrictions. In their hearts, the very flatterers condemn the decision of a bride who has sacrificed love to wealth, even in obedience to a parental mandate, or the monitions of Nature-estranged moralists. In extremes of adverse circumstances, love itself, however, will often voluntarily withdraw its claim. Hopeless inequality of station, disease, and irremediable disabilities will extinguish the flame of a passion that would have defied time and torture. A lover struck with a cureless malady will shrink from transmitting his affliction; a proud barbarian will refuse to make a refined bride the witness of his humiliations. The perils of consanguinity may reveal themselves to a sort of hereditary (if not aboriginal) instinct; and the discovery of an unsuspected relationship has more than once deadened desire as if by magic, and turned love into self-possessed friendship. B.—REWARDS OF CONFORMITY.