The following lectures, presented to the public as the fourth course of Madras University Special Lectures in the Department of Indian History and Archaeology, formed the subject on which the author intended to send a paper to the International Congress of Orientalists, which was to have been held at Oxford but for the outbreak of the War. It was suggested as worth doing as the result of a discussion on the subject which the author had with Sir George Grierson, who at the time was interesting h