J.G. Frazer 
Golden Bough [PDF ebook] 
A Study in Magic and Religion

Sir James George Frazer originally set out to discover the origins of one ancient custom in Classical Rome — the plucking of the Golden Bough from a tree in the sacred grove of Diana, and the murderous succession of the priesthood there — and was led by his invetigations into a twenty-five year study of primitive customs, superstitions, magic and myth throughout the world. The monumental thirteen-volume work which resulted has been a rich source of anthropological material and a literary masterpiece for more than half a century. Both the wealth of his illustrative material and the broad sweep of his argument can be appreciated in this very readable single volume.