ONCE UPON a time, all ducks were free spirits, flying in tight V-formations over the world, navigating precisely over thousands of miles in the fantastic phenomenon of migration. Not long ago, there was a display of that grandeur now rarely seen by Americans. While I was lunching at the Robert Morris Inn in Oxford, a waterfront village on the eastern shore of Maryland, the dining room darkened suddenly as if a thundercloud had covered the sky. We rushed onto the terrace facing the water. A migrating flock of canvasback ducks was coming in -- wave after wave, with hundreds upon hundreds splashing down. The roar of their gabbling drowned out our voices. It was a scene of powerful beauty that only the wild can create.

The duck might forever have remained a rare game bird had it not been for the good sense and gustatory greed of the ancient Chinese emperors in their palaces in Peking. They decided it was too much trouble to hunt for ducks. Why not catch the beautiful white birds alive, clip their wings and domesticate them? It would be so simple to fatten them up and then just grab one whenever there was a longing for duck. The Chinese succeeded in doing just that, but that was thousands of years ago, and still many questions about duck remain. Are all breeds cooked in the same manner, are they equally lean, which breeds are available now, what is the best duck of all time? Of course, I am assuming the reader buys cultivated duck; conservation laws in almost every country forbid the commercial sale of wild duck. But if you are a hunter you will experience magnificent eating from the mallard, wood duck, baldpate, blue-wing or green-wing teal, scaup, scoter, eider redhead, ringneck or pintail.

Which is the greatest of all duck dishes? I believe that, apart from the extraordinarily complex Peking duck, the finest preparation within the capacity of a good amateur cook is that invented by the turn-of-the-century French giant of gastronomy, Auguste Escoffier. He was greatly admired by Kaiser Wilhelm of Germany. In the summer of 1914, just before World War I, as part of the political maneuvering, the French millionaire chocolate tycoon, Henri Meunier, took his big steam yacht to the German beach resort of Kiel with Escoffier aboard as chef de cuisine so that the kaiser could be lured to lunch. Among Escoffier's unpublished private papers are his notes for that lunch. The main course was a preparation of duck he had created especially for the occasion.

Escoffier browned and then braised a very small, young, almost entirely fatless, baby duckling in sweet butter. At the same time, he sauteed separately an array of tiny young vegetables: white onions, potatoes, artichoke hearts and peeled cherry tomatoes, plus hazelnuts, garlic and black olives. In a third saucepan, he simmered slices of black truffles in Spanish sherry. He adjusted the temperatures so that they were done at the same moment. The brown duck was placed in its nest of vegetables and "wore the truffles on its breast like jeweled decorations."

The kaiser was so delighted that he asked Escoffier to be brought in and said: "Monsieur Escoffier, that was an unforgettable duck. I may be the emperor of Germany, but you are the emperor of the world's kitchens."

Perhaps you may want to try your hand at some of the more exotic breeds. They are more expensive, but there are good buys because of the much higher yield of edible, lean breast meat. For these, we all depend mainly on the "odd man out" of the American duck industry, a charmingly offbeat character named Ben Kropp, who ships his ducks under the unbelievable label, Sleepy Eye Farms, from a village actually named Sleepy Eye (believe it or not) in Minnesota. Kropp's main business is raising capons and geese, but "to fill in the time" he plays around with ducks. Not Pekings. He thinks they are "dull and tasteless."

Kropp began an experimental breed by domesticating a group of great wild mallards. When I roasted one of these I found it had an intense, lively, magnificent taste and negligible fat. Next, Kropp began breeding the South American Muscovy. These big birds have a distinctive, slightly gamey flavor, with dark, juicy, meaty flesh and twice as much breast meat per pound as the Peking, with no excess fat.

But Kropp's great experiment is an American version of a rare French breed, the mullard -- a crossmating between a male Muscovy and a female mallard. The result is a duck shaped almost like a goose, with an enormous breast and with lovely tender, intensely flavored, juicy meat -- a bird that should wear a little red cape and call itself Superduck! But Kropp is having problems with it. His Muscovy gentlemen are being temperamental and are refusing to associate with the mallard ladies. He is going to try again, the other way around -- with mallard gentlemen and Muscovy ladies. He will let me know the results after mating time, next spring.

And now for Escoffier's notes for the duck he served Kaiser Wilhelm, followed by a recipe adapted in our test kitchen. Duck IMPERATOR FOR KAISER WILHELM II (From Escoffier's notes)

"I selected a plucked and drawn 3-month-old baby duck that had been killed 12 days before. When a lump of sweet butter, with salt and freshly ground pepper, had just begun to bubble in the first casserole, the duck was put in, turned around to be well covered by the butter, the lid put on and the bird left to braise gently. Meanwhile, in a second casserole, there were, also cooking gently, tiny white onions hardly larger than pearls, with potatoes virtually no bigger! Now starts the race between the vegetables and the duck as carefully as any of the great horse races of the world. These are tender creatures and the heat of the fire is something that has to be watched carefully and continuously, or the final magic results will be lost. Remember, first the butter, when it's hot enough to conquer, then those miniature onions, then the baby potatoes, a few whole hazelnuts or filberts, a heart or two of artichoke . . . If you use, as I do, an entire clove of garlic, be sure, before serving, to recover it -- if it is to be served to an emperor! Then add 1/2 dozen ripe black olives with their stones left in to help them resist the ordeal by fires. Next, put on a couple of peeled and seeded tomatoes, each the size no bigger than can be crowded into your mouth. Finally, cook some slices of black truffles in a tiny pan wetted with a small glassful of sherry. When all this is done, at least 40 minutes will have gone from your life, but your duck should be ready for his nest of vegetables, and, like jeweled decorations, the truffles." DUCK IMPERATOR FOR KAISER WILHELM II (2 servings) 1 duckling (about 4 1/2 pounds) Salt and pepper 3 tablespoons butter or melted duck fat 1 cup each: peeled small boiling onions, small peeled potatoes 1/4 cup blanched hazelnuts 1 large clove garlic 1/4 cup sherry 14-ounce can artichoke hearts, drained 10 peeled, seeded cherry tomatoes 6 large black olives Truffles for garnish (optional)

Rub duck inside and out generously with salt and pepper. Heat butter in large dutch oven; brown duck, turning until brown on all sides.

Remove duck to rack set over drip pan. Put in 450-degree oven; reduce heat immediately to 350 degrees; cook until tender. (The test kitchen favors roasting to braising because today's ducks are larger and more fatty than they were in Escoffier's time.) Meanwhile, remove all but 1 tablespoon fat from dutch oven. Add onions, potatoes, nuts and garlic. Cook, covered, until potatoes are tender, in about 5 minutes. Add sherry, artichoke, tomatoes and olives. Cook gently until heated through. Remove garlic from pan. Arrange vegetables on warm platter. Put duck on top; decorate breast with truffles.