FROGS AND TOADS. The frog or toad is a lunar animal par excellence. Its shape or behavior is reminiscent of the moon; it swells and shrinks, submerges under water but emerges again, and hides under the ground in winter but reappears in spring. The frog lives according to the lunar rhythm. In fact, a great many myths speak of a frog in the moon. According to the Chinese, the moon has not only an evergreen cassia tree and a rabbit but also a frog inside it. Thus the Tianwen section of the Chuzi (fourth or third century BCE) asks: "What is the peculiar virtue of the moon, the brightness of the night, which causes it to grow once more after its death? What does it advantage to keep a frog in its belly?"

The frog, then, is naturally associated with all sorts of aquatic...