Consisting of 23 individual models showing the development of a fertilised frog's egg to a tadpole. Enlarged approx 50 times. Diameter of a natural egg approx. 1.5 mm. A. Stages of division (8 models), B. Stages in the formation of the nuclear membrane (4 models), C. Formation of the neural channel (2 models), D. Development of the tapole (6 models), E. Swimming tadpole (3 models). Each model individually mounted on a stand with base and in one piece.