Man begins his career as a child of Nature: he completes it as a creature of Art. When Aristotle said, "Man is by nature a political animal," he meant that essential human qualities are developed in civil society. Izoulet makes the same point in stating that the mind is the child of the city.2 Modern psychologists agree that social environment is a basic factor in the development of personality. If this be so, then the complex life of our great cities must profoundly affect the mentality of their inhabitants and result in reactions different from those characteristic of a rural population. How such modification comes about, it is the purpose of this paper to consider. Urban life is marked by its heightened stimulation. When many people are brought close together contacts are multiplied and reactions are greatly increased.3 Men are assailed at every sense by the presence of their neighbors. The sound of footsteps and hoof-beats, the rattle of wagons and rush of cars, the clang of bells and hoot of whistles, the stroke of hammers and whir of machinery, cries of children and peddlers, strains of music, shouts and laughter swell into a dull roar as the city wakes to its day's work. One who watches the torrent of people pouring through the boulevards of Paris, or who struggles for a foothold in the rush at Brooklyn Bridge, becomes aware of innumerable prods at his attention. The crowd sets a pace. The individual must hurry with it or be pushed aside. Such excitement deeply stirs the nervous system. Architects tell us that tall buildings are set vibrating by the jar of street