"It's an expolration of the descent of fertility ritual, from human sacrifice down to the scarecrow, an effigy substituting for the human. Taking in Morris dancers on the way (12 jolly dons). A bit Golden Bough."

Except morris dancers wear white. The celebration is May Day, certainly, and the "to a stake they tied a child new born" is certainly a reference to human sacrifice, either symbolic or genuine.

Isn't there some sort of May ritual in the university towns? Perhaps they are the 'dons' refereed to.