This lecture was written on shipboard in an untidy sea, and, if its matter and its T sentiment pitch and toss a trifle, you may properly expect me, as an archaeologist, to blame environment. I belong in fact to a generation of students who have learned to make something of a fetish of environment, even at the expense of forgetting occasionally the extent to which we are the authors of that same environment. It is not difficult to think of examples where mankind has created a desert and called it civilization; and when in the long run the desert wins, as is its habit, we once again short-circuit logic and arraign environment.