Pam Bailey was having none of this cheesecake business.

Here she was, surrounded by everything from spicy Jamaican "jerk" chicken to magenta-hued Central American pickled cabbage, and Terron Bailey, her 9-year-old son, was whining for a slab of pale, plain cheesecake.

"Try something different, that's what we're here for," she said, thrusting a paper plate of "bolany" at him. He recoiled.

"It's nasty," he said, squinting at the Afghan dish, a deep-fried, vegetable-filled sandwich dipped in herbed yogurt sauce.

But Terron took a bite, and another, and a third, and soon the new bolany aficionado had forgotten the existence of cheesecake.

The Baileys' cross-cultural experience was one of thousands taking place yesterday at Montgomery County's seventh annual Ethnic Heritage Festival, a celebration of the county's exuberant, dynamic multiethnic community.

Held along the shady trails of Wheaton Regional Park, the festival brought together participants from dozens of countries whose people have been streaming into the county during the past two decades.

As in the past, the festival featured a staggering array of food vendors, costumed entertainers and craftspeople. Participants wore saris, dashikis, chadors, mariachi band outfits and turbans -- every imaginable form of national dress. There were so many languages being spoken that, at times, walking from booth to booth was like flipping the switch on the headsets at the United Nations.

"I can't get over how different these guys sound," said Manuel Ortiz, a Spanish-born Takoma Park resident who was enjoying the variations on his native language. "I've met people from Mexico, Salvador, Colombia, Nicaragua, you name it."

Organizers said about 25,000 people showed up before late afternoon rain washed over the festival.

Montgomery County's foreign-born population nearly doubled during the 1970s. Preliminary projections from the 1990 census indicate that about one-quarter of the county's population is nonwhite, said Jose C. Manduley, director of the county's Office of Minority and Cultural Affairs.

The census will show about 62,000 blacks, 54,000 Hispanics, 47,000 Asians and 12,000 to 13,000 "others" in a total county population of 750,816.

Manduley said the population is no longer organized into distinct enclaves. "Now you see a conglomeration, not just pockets," he said. "There's Asians, Chinese, Salvadorans and blacks all together."

The juxtaposition often is beneficial.

"Hey, the Koreans are okay, they're buying our juice," said Francisco, a Colombian operating a food booth for his company, Tropical Splash. He was hesitant to give his last name, he said, because he didn't want to jeopardize his government job, but he was enthusiastic when it came to his dream of putting tropical juices in every American refrigerator.

Manduley said his office, along with festival sponsors at the Committee on Ethnic Affairs and the Maryland-National Capital Park and Planning Commission, is hoping the festival will promote better understanding of ethnic minorities. So was Gurmeet S. Gahunia, a Sikh representing the Guru Nanak Foundation of America.

Since the Iraqi invasion of Kuwait, he said, some Washington area Sikhs have been heckled and teased by people who think Sikhs are Arabs.

"Sometimes it gets ugly," he said, recalling similar problems experienced by Sikhs when American hostages were being held in Iran. "I tell people, 'We have nothing to do with Muslims and Arabs, we are Sikhs.' "

"Then," he sighed, "they say, 'Sikhs? Never heard of 'em.' "