cf. C.A.S. Williams, Outline of Chinese Symbolism and Art Motives, pp.253-255, where the author states that the "lion was indigenous to China, but was introduced in connection with Buddhist art as the defender of law and protector of sacred buildings. Sculpted lions were often placed at the gates of temples and porticos of houses, and sometimes they graced the pinnacles of tombs".
Williams also states that "there is an ancient legend relating that the lion produces milk from its paws, and therefore hollow balls were placed in the hills by the country people, with the result that the lions, who enjoyed sporting with the balls, would leave some of their milk in them, which the people would receive. The male lion is usually represented playing with the ball, however, and the lioness is generally accompaied by its young".