Proof that academicians can turn any subject into a scholarly study; Legman, an anthropologist, catalogs dirty jokes by type, then traces their history back to ancient folklore, explaining the sources, variations and history. This is a book that works on two levels; if you're really interested in learning that farmer's daughter jokes have a precedent in 12th Century literature, then you won't be disappointed. On the other hand, if you just want to read the good parts and skip the analysis, the book's format makes that easy to do, too. It's unfortunate that both volumes of the "Rationale" are out of print, because they belong in the collection of anyone who's interested in the "more things change the more they stay the same" theory of history, as well as those who just want good jokes to tell people around the water cooler or via email.