In an elaborate discussion of beauty of movement Stratz summarizes the special characters of the gait in woman as follows: "A woman's walk is chiefly distinguished from a man's by shorter steps, the more marked forward movement of the hips, the greater length of the phase of rest in relation to the phase of motion, and by the fact that the compensatory movements of the upper parts of the body are less powerfully supported by the action of the arms and more by the revolution of the flanks. A man's walk has a more pushing and active character, a woman's a more rolling and passive character; while a man seems to seek to catch his fleeing equilibrium, a woman seems to seek to preserve the equilibrium she has reached.... A woman's walk is beautiful when it shows the definitely feminine and rolling character, with the greatest predominance of the moment of extension over that of flexion." (Stratz, _Die Schönheit des Weiblichen Körpers_, fourteenth edition, p. 275.) An occasional development of the idea of sexual beauty as associated with developed hips is found in the tendency to regard the pregnant woman as the most beautiful type. Stratz observes that a woman artist once remarked to him that since motherhood is the final aim of woman, and a woman reaches her full flowering period in pregnancy, she ought to be most beautiful when pregnant. This is so, Stratz replied, if the period of her full physical bloom chances to correspond with the early months of pregnancy, for with the onset of pregnancy metabolism is heightened, the tissues become active, the tone of the skin softer and brighter, the breasts firmer, so that the charm of fullest bloom is increased until the moment when the expansion of the womb begins to destroy the harmony of the form. At one period of European culture, however,--at a moment and among a people not very sensitive to the most exquisite æsthetic sensations,--the ideal of beauty has even involved the character of advanced pregnancy. In northern Europe during the centuries immediately preceding the Renaissance the ideal of beauty, as we may see by the pictures of the time, was a pregnant woman, with protuberant abdomen and body more or less extended backward. This is notably apparent in the work of the Van Eycks: in the Eve in the Brussels Gallery; in the wife of Arnolfini in the highly finished portrait group in the National Gallery; even the virgins in the great masterpiece of the Van Eycks in the Cathedral at Ghent assume the type of the pregnant woman.