Four different mammals; rabbit, cat, fruit bat and man were chosen in this study. Each mammal has its own locomotion habit and posture. A total number of fourty animals, ten for each mammal, was used.
The bony pelvis possesses different relation to the vertebral column. It is horizontal in rabbit and fruit bat, vertical in man and oblique (midway between the horizontal and vertical positions) in cat. These different positions acquired by the bony pelvis in relation to the vertebral column depend upon the angle present between the sacral and iliac axes which consequentely depend upon the habits of the animal during locomotion.