The foundation of swamp cooking is foursquare—crawfish, oysters, shrimp, and crab—and of these four, the crawfish is king. So fecund are the creatures in the waters of the delta that there are scarcely nets enough to catch them or mouths to eat them. The brackish bayous and marshes are also ideal for oysters, wild or farmed, and more of them are produced and eaten in Louisiana than in any other state. Because the oysters are half the size of their northern cousins, you have to eat them in quantity. There are still a number of oyster bars in New Orleans where you stand at a marble counter, sauce them up, and slurp them down as fast as your man can shuck them. In more innocent days saloon bars were heaped with oysters raw and pickled, boiled crawfish and shrimp, red snappers and roast beef, all for free. Only plenitude can account for the number of oyster dishes named by New Orleans restaurant cooks desperate to distinguish their bivalves from the po’ boy oyster loaves of the bars by adding watercress and Pernod to make oysters Rockefeller; mushrooms and cream for oysters Bienville; shrimp, mushrooms, and garlic for oysters Rossignac.