YANKEES CUT watermelon funny. The way a man (or woman) cuts a watermelon is an infallible test of whether he hails from north or south of the Mason-Dixon line.

Never mind those scholarly dissertations dealing with regional speech patterns, just watch how he attacks that good old Southern delicacy, the watermelon. A fellow who has grown up far from the sprawling vines of a watermelon patch is liable to commit the basic error of cutting the melon indoors.

Any Southerner worth his grits in melon knows that just as pasta should be al dente , watermelon should, for optimum ease and pleasure, be al fresco . A watermelon is full of sugary water that flows freely over the cutting surface when the first slice is made. Only a plebe would carve a melon on a linen tablecloth or mahogany sideboard, even with adequate splash guards. Ant will find one drop of watermelon syrup that is undetectable to the human eye as surely as a hummingbird finds blossom nectar. So show me a fellow (or gal) wrestling a plump watermelon onto a dining room table, and I'll show you a Yankee.

I discovered this infallible test for geographic origin by watching my husband carve a watermelon. He launched the project, not on a picnic table in the yard, but on a kitchen counter. We had invited friends for a casual supper on the porch, and watermelon is the most casual dessert in the world. It is at its most casual when you are in the watermelon patch and you pick up the ripe melon, drop it (thereby cracking it), and reach inside for the seed-free heart.

On a scorching summer day, this may seem savage pleasure to city slickers, but I can say that anyone who tries it is an instantaneous convert.

Robbing a watermelon patch is another matter entirely, and while it has its thrills, it is not a pastime I recommend. Irate farmers have been known to pepper thieves with light shot, and I am told it is painful in the extreme to remove pellets from the rear end.I wouldn't know about that, of course. But the justifiable outrage of man who has lavished effort, time and love on the cultivation of a field of healthy "rattlebacks" is not something the fainthearted should provoke. But that is digression into watermelon ethics, as opposed to cutting a watermelon.

So back to it. My husband heaved the fat, two-toned, green-stripped melon onto the kitchen counter. He approached it with a thin-bladed chef's knife.

"Good grief!" I said, astounded. "What are you doing?"

"Gonna cut the melon," he answered, unconcerned.

"Not with that thin knife, you won't," I suggested.

He glared in my direction, stood the watermelon on end like a man approaching a softboiled egg in an egg cup. As the melon wobbled and protested at this indignity, he sawed away at one end, trying to cut off a "cap."

"You planning on serving watermelon RINGS?" I gaped, horried and amused simultaneously.

"We don't have a plat in the house that will hold a slab of watermelon like that," I persisted.

"We'll cut the circles in triangles or rectangles, or rhomboids, for all I care!" he roared, trying to extricate the thin blade from the melon's interior. He succeeded, and juice poured freely from the melon and ran down the knifeblade, over the handle, onto his arm and dripped from his elbow to the floor and the toe of his shoe.

"Dammit!" he protested.

"Don't you have a better knife to cut this thing? And," he continued, "don't you Southerners have some special dish to use when you cut a watermelon?"

"Sort of like a chafing dish or something like that?" I asked.

"Something along those lines," he said, "though I was thinking more of a well-and-tree platter."

Unable to resist, I said, "Well, there are a few examples among pre-1860 Southern silver of the watermelon prong. Though not many survive."

"Are you kidding?" he asked, not turning from his task, therefore missing my grin.

"Of course not. The watermelon prong was widely used at plantation parties. A large melon, either round or oblong, was skewered lengthwise on the fancy watermelon prong, much as you skewer a weenie the long way on a coathanger. Then a special circular knife, much like egg scissors, was lowered over the melon's rotundity and discs were sheared to the prong, at which point they were lifted from the watermelon prong and serve to guests. This watermelon prong was stepped up like a mast in a large silver bowl, heavily gadrooned. The watermelon prong itself was usually finely wrought, and often bore the crest of the plantation family."

By now the kitchen was spatter painted with melon juice and polka-dotted with watermelon seed. "Ah, you're nuts," he said, heading for the porch with a geometric puzzle of watermelon pieces.

As we all attacked the melon with fruit knives and forks (another infallible test of Yankee ingenuity at work), we continued the discussion of how to cut a watermelon.

"In the yard," chorused the Southern guests, like protagonists in a Greek play. "And in wedges," some of us added. "Hooey!" said my husband, spitting a seed with Southern precision, "Next time I'm borrowing the neighbor's chain saw!"

So there you have it, good neighbors, the sure test of a person's origins. Just watch them cut a watermelon. A Southerner, it goes without saying, cuts a watermelon into matching wedges with accuracy, nonchalance and grandpa's ham knife.

One final word in this scholarly vein: If anybody buys a watermelon and asks to have it "wrapped up," take off, because you can be sure the Martians have landed.