“Birthing posture” in Nimba toads. A: gestating Nimba toad; the grey shading indicates the size and position of the enlarged distal parts of the oviduct (uterus), B: shows the “birthing posture”, in which females build a double W with their legs and increase pressure on their uteri. Compare the position of legs on the photograph on the right (C) of a female giving birth, showing likewise the double W, of the legs. A and B are redrawn after Vilter (1956a).