Few kinds o of labor develop the body in a symmetrical manner. This is true even in an elementary division of labor. The carpenter and the blacksmith usually have strong, large shoulders and arms, but small and weak legs. The farmer, from excessive bending over his work, loses, in a greater or less degree, his elasticity of body, and often becomes stoop-shouldered. If such defects result from the more primitive forms of labor, it is not at all strange that the laborers of the modern industrial world show bodily peculiarities and variations that correspond, in a marked degree, to their respective trades.