THE PRIMARY aim of this book is to explain the remarkable rule which regulated the succession to the priesthood of Diana at Aricia. When I first set myself to solve the problem I thought that the solution could be propounded very briefly, but I soon found that to render it probable or even intelligible it was necessary to discuss certain more general questions. Thus, for example, on the crucial question of the practice of putting kings to death either at the end of a fixed period or whenever their health and strength began to fail. If in the present work I have dwelt at some length on the worship of trees, it is not, I trust, because I exaggerate its importance in the history of religion, still less because I would deduce from it a whole system of mythology; it is simply because I could not ignore the subject in attempting to explain the significance of a priest who bore the title of King of the Wood, and one of whose titles to office was the plucking of a bough-the Golden Bough-from a tree in the sacred grove. But I am so far from regarding the reverence for trees as of supreme importance for the evolution of religion that I consider it to have been altogether subordinate to other factors, and in particular to the fear of the human dead, which, on the whole, I believe to have been probably the most powerful force in the making of primitive religion. J. G. FRAZER.