The first 19 chapters of the "Grammar" present key examples of ornament from a number of sources which were diverse both historically and geographically – examining the Middle East in the chapters on Arabian, Turkish, Moresque (Alhambra) and Persian ornament. The final chapter, titled 'Leaves and Flowers from Nature' acknowledges the underlying principle that dictates the design of ornament around the world, which is the form found in nature: "in the best periods of art, all ornament was based upon an observation of the principles which regulate the arrangement of form in nature" and that "true art consists of idealising, and not copying, the forms of nature".