The student of pelvic morphology is compelled sooner or later to consider the two main functions of the girdle, those of weight-bearing and parturition. These functions Inevitably guide his Investigations. Comparatively little work has been done on the pelvic mechanics of erect posture. The evolution of man's erect posture, on the other hand, has been considered by Friedenthal (1910), Weidenreich (1913), Keith (1923), Morton (1926), Westenhofer (1929), and Reynolds (1931)* The last author's disappointing paper succeeds only in demonstrating the difficulty of establishing the principles underlying the orthopaedist's approach to the mechanics of man's posture.
