In case you were confused, the frogs in those big garbage pails on Mott Street are meant for your dinner table, not your kid's aquarium. Yes, live frogs have returned to fish markets in Chinatown, a portent of summer that puts smiles on old women's faces, fills the viewfinders of tourists' cameras and creates a vague churning in most New Yorkers' stomachs. "You mean they EAT that crap?" muttered one New Yorker, rushing away from a Chinatown fish market the other day. Rather than water, his mouth compressed into a tight clench, like a baby trying to prevent the entry of a spoonful of strained spinach. For New Yorkers like him, Chinatown's live frogs are a symbol of a neighborhood whose cultural barriers have always seemed insurmountable. Even as Mall-hattan has become increasingly generic thanks to eight years of unrelenting "clean-up," Chinatown guards its impenetrable customs -- and remains as unfathomable to the rest of us as the unidentifiable animal carcasses hanging in every restaurant. When my translator and I tried to pierce the wall of secrecy, fish mongers ignored me. One even pulled his barrels of frogs into a back room when I stood in front of his shop scribbling notes (full disclosure? I was only writing a note to remind myself to pick up some dishwasher detergent). "He thinks you're a cop," offered Garner Wong, a 27-year-old passerby (me, a 90-pound weakling with the Crown Heights good looks, a cop? Has the NYPD started recruiting nebbishes?). But if the fish sellers wouldn't talk, at least their customers did. "This is my happiest time of the year," said Michael Lee, as he shopped for amphibians on Mott Street. Lee was reluctant to talk, but did reveal that he cooks frogs with hot peppers and black beans (which, despite my Western prejudices, made me hungry). Lee said he only picks male frogs (identified by the bump under their chin), but others dismissed this as just an old wives' tale. These people -- some of them genuine old wives, no less -- choose the liveliest specimens. So when one frog managed to jump out of the barrel onto the slimy sidewalk, a woman chased him down and bought him. The would-be escapee was then unceremoniously relieved of his skin (and, no, there aren't more than one way to skin a frog. The knifeman makes a deep, v-shaped cut behind the head, then rips off the skin in one piece and then beheads the victim. The result looks like a beheaded, naked GI Joe doll). While waiting, she engaged in some superstition of her own, praising the healing power of frog meat. The Department of Agriculture denies any medicinal quality, but its website disclosed that "The Other Green Meat" is a healthy food. Three and a half ounces of frog meat has 73 calories and 3 grams of fat, compared to the 287 calories and 23 g of fat in the same size portion of beef brisket. But not all Chinese shoppers are fans. "Frogs are for old ladies," said Wong, the 27-year-old. "I mean, there's just no meat on them. And the legs jump around even after they're dead. It's unpleasant." That's not the only thing that's unpleasant. Every few hours or so an unlucky worker must change the murky frog water by spilling it onto Mott Street while trying to preventing a massive jailbreak. It's not only the workers who hate the chore. Despite the prevailing sense that Chinatown stays the way it is because the locals like it that way, there are plenty of residents -- and not just Yuppie newcomers -- who resent gutters filled with fish juice. "The city can't clean up Chinatown," said Peter Eng, a Mott Street resident for all of his 40 years, "because whenever they try, the local business groups cry `Racism.'" (On this score, Chinatown is like any other neighborhood: Most businessmen would rather make money than make waves.) But the last question is: How good ARE these frogs? I mean, what would happen if I went to a fine French restaurant and replaced the frogs they USUALLY serve with these Chinatown sidewalk jumpers? To find out, I brought two Mott Street frogs to Scott Campbell, chef at the always excellent Avenue Bistro on the Upper West Side. Campbell, who knows about disquieting food (he's eaten SQUAB, after all!), often serves frog legs, but typically gets them from seafood wholesalers, not garbage pails in Chinatown. Yet after he'd worked his magic -- he dunked the legs in milk and flour, deep-fried them and then finished them in a little olive oil, sauteed tomatoes and lots of garlic -- Campbell was impressed (by the way, they don't "taste like chicken"; they taste like fried calamari). "They're very fresh and sweet," said Campbell, "but I'm not surprised. Chinatown is the best for fresh produce or seafood. I mean, I know a place where you can get fresh pig uterus." Damn! Too bad it's not the season. --30-- email: gershny@yahoo.com