The purpose of this note is to examine the method by which N. S. B. Gras establishes his thesis concerning the evolution of the English grain markets. According to his book, grain, markets evolved through several distinct stages, culminating in the “metropolitan market.” Although the influence of the London market by the sixteenth century can be demonstrated without reference to the existence of the early stages, it is nevertheless they that constitute the essential novelty of Mr. Gras's approach and, presumably, the main contribution of the book to the study of economic history. It will be contended below that the existence of certain of these early stages is at least doubtful and that, in any case, their economic significance is either negligible or not provable.