In the Norwegian mercantile marine the customs contrast happily with those we have just mentioned, and permit officers to live on board with their wives. In all respects the Norwegian serves as a model in the sexual question; does he not favor conjugal life by only charging half-price on the boats for women who travel with their husbands! Other classes have a less obvious influence on sexual life. On the whole, however, all sexual isolation of castes has an unfavorable influence. Wherever the prejudices of a caste compel its members to intermarry, certain special degenerations are produced. Good quality in man is not derived from class or position, but from true innate or hereditary nobility of character, and this alone should be the object of positive selection, without any distinction of classes. =Individual Life.=--There is no doubt that the mode of life of the individual exerts an influence on his sexual life. High living combined with little bodily exercise generally increases the sexual appetite, while insufficient food combined with severe muscular work diminishes it. Intellectual work acts in a variable manner. A distinguished psychologist assured me that intense intellectual work excited his sexual appetite; others have said the opposite. As a rule, a sedentary life increases the sexual appetite; a life full of occupation and muscular activity diminishes it. But the question is complicated by other influences. Alcohol diminishes sexual power, while exalting desire or even perverting it. The artificial excitants of the sexual appetite, cultivated by modern civilization by interested speculation, act in rather a different way. Erotic pictures, obscene novels and dramas, etc., constitute an unhealthy medium in our centers of civilization, which overexcites and corrupts the sexual appetite. The more delicate and poisonous the perfume of this atmosphere and the more æsthetic the refinement by which it titillates the senses, the greater is its destructive action. The question of the reunion or separation of the sexes plays an important part. Life in common among girls and boys from infancy usually diminishes sexual excitation, in the same way as among brothers and sisters. We find something analogous in different branches of human activity where the two sexes live together; for instance, at college, in the fields, and in general where work and play is common to both sexes.