Sir James Gray took How Animals Move as his topic for the series of lectures he gave at the Royal Institution in 1951, and brought in horses, bears, snakes, fishes, birds, and desert rats of the living illustrations of the characteristic which defines the animal kingdom. Here the same result has been achieved by pictures: drawings by Edward Bawden and photographs taken in the author's own laboratories and elsewhere.
The author describes certain simple laws of mechanics which apply to inanimate as well as living movement; he shows how evolution may account for the development of increasingly efficient organs of locomotion - fins, legs, and wings - ranging from an amoeba to an eagle. He explains how to watch and interpret the movements of snakes and fishes, grasshoppers and kangaroos, bats, birds, flies, horses and men, in a series of instances based on experiment. The variety, fitness, and beauty of moving animal life is impressive.