Given the diversity of talents who over the years contributed cartoons to The New Yorker, it may be surprising to learn that everything in our large cartoon bank has, for the sake of easy reference, been reduced to a dozen or so categories...The categories were as follows: arts and galleries; bars and drinking; birds, fish, and animals; businessmen; cars and road signs; cavemen; children, babies, clergymen; cocktail parties; criminals, cops, jails, and judges; doctors and hospitals; heaven, hell, gods, devils, and so forth; olden times (royalty); old people; politicians and generals; musicians; restaurant and food; tourists, vacations; and finally TV and movies. As far as I know, we've never had anything in the bank that couldn't be easily fit into one of those categories. I'm sure the current bank contains a disproportionate number of TV and movie gags. whereas the cocktail party category is rather thinner than it used to be. Desert island and caveman jokes, of course, go on forever.
Lee Lorenz, The Art of The New Yorker 1925-1995, Knopf, 1995