Kammerer mated a number of generations of toads in a fishtank full of water.Eventually he announced that he had succeeded and he presented a group of midwife toads with black bumps on their hindlimbs.

• 卡摩尔在盛满水的鱼缸里交配了好几代的蟾蜍，最后他宣布他成功了，并展示了一组带有黑色指垫的产婆蟾。