Though Europe was thus undoubtedly indebted to India for its mediæval literature of fairy tales and fables, the Indian claim to priority of origin in ancient times is somewhat dubious. A certain number of apologues found in the collections of Æsop and Babrius are distinctly related to Indian fables. The Indian claim is supported by the argument that the relation of the jackal to the lion is a natural one in the Indian fable, while the connection of the fox and the lion in Greece has no basis in fact. On the other side it has been urged that animals and birds which are peculiar to India play but a minor part in Indian fables, while there exists a Greek representation of the Æsopian fable of the fox and the raven, dating from the sixth century B.C. Weber and Benfey both conclude that the Indians borrowed a few fables from the Greeks, admitting at the same time that the Indians had independent fables of their own before. Rudimentary fables are found even in the Chhandogya Upanishad, and the transmigration theory would have favoured the development of this form of tale; indeed Buddha himself in the old Jataka stories appears in the form of various animals. Contemporaneously with the fable literature, the most intellectual game the world has known began its westward migration from India. Chess in Sanskrit is called chatur-anga, or the "four-limbed army," because it represents a kriegspiel, in which two armies, consisting of infantry, cavalry, chariots, and elephants, each led by a king and his councillor, are opposed. The earliest direct mention of the game in Sanskrit literature is found in the works of Bana, and the Kavyalamkara of Rudrata, a Kashmirian poet of the ninth century, contains a metrical puzzle illustrating the moves of the chariot, the elephant, and the horse. Introduced into Persia in the sixth century, chess was brought by the Arabs to Europe, where it was generally known by 1100 A.D. It has left its mark on mediæval poetry, on the idioms of European languages (e.g. "check," from the Persian shah, "king"), on the science of arithmetic in the calculation of progressions with the chessboard, and even in heraldry, where the "rook" often figures in coats of arms. Beside the fable literature of India, this Indian game served to while away the tedious life of myriads during the Middle Ages in Europe.