When in human families, especially under civilized conditions, we see large families we are in the presence of a reversion to the tendencies that prevail among lower organisms. Such large families may probably be regarded, as Näcke suggests, as constituting a symptom of degeneration. It is noteworthy that they usually occur in the pathological and abnormal classes, among the insane, the feeble-minded, the criminal, the consumptive, the alcoholic, etc. 4
This tendency of the birth-rate to fall with the growth of social stability is thus a tendency which is of the very essence of civilization. It represents an impulse which, however deliberate it may be in the individual, may, in the community, be looked upon as an instinctive effort to gain more complete control of the conditions of
life, and to grapple more efficiently with the problems of misery and disease and death. It is not only, as is sometimes supposed, during the past century that the phenomena may be studied. We have a remarkable example some centuries earlier, an example which very clearly illustrates the real nature of the phenomena. The city of Geneva, perhaps first of European cities, began to register its births, deaths, and marriages from the middle of the sixteenth century. This alone indicates a high degree of civilization; and at that time, and for some succeeding centuries, Geneva was undoubtedly a very highly civilized city. Its inhabitants really were the "elect," morally and intellectually, of French Protestantism. In many respects it was a model city, as Gray noted when he reached it in the course of his travels in the middle of the eighteenth century. These registers of Geneva show, in a most illuminating manner, how extreme fertility at the outset, gradually gave place, as civilization progressed, to a very low fertility, with fewer and later marriages, a very low death-rate, and a state of general well-being in which the births barely replaced the deaths.