That "The Originals: Women in Art," the seven-part series that begins tonight at 10:30 on WETA, is being broadcast is yet another sign of the great and growing power of the women's movement in the world of art.

"No question, this series is directly connected with the women's movemnt," says Perry Miller Adato, its executive producer. It is not only about art: it is also about politice, both sexual and practical.

"The Originals" avoids polemics. Tonight's show is a mild profile of Mary Cassatt, the Philadelphian who went to Paris and there joined the avant-garde, earning in the process the enthusiastic praise and the friendship of Degas. "Then it really is a woman who paints as well as that," he said.

The Cassatt show will be followed in succeeding weeks by programs on Louise Nevelson, the sculptor, portraitist Alice Neel, collage-maker Betye Saar, painter Helen Frankenthaler, and one previously broadcast on Georgia O'Keeffe. The seventh program in the series, "Anonymous Was A Woman," will discuss early American makers of coverlets and quilts.

In the past, artists and art professionals, though notoriously independent, have had little clout. But many of them are women, and the women have organized. The new national Coalition of Women's Art Organizations, formed last week in New York, represents 100 women's art groups with a combined membership of approximately 100,000.

"If 75 percent of the graduates who emerge from American art schools are women, what happens to them after graduation? she asked in her keynote address. "If more than 50 percent of the Ph.Ds. in art history are awarded to women, where are the women museum directors? If almost every art organization you can name is staffed largely by women, where are the women at the policy-making levels?"(See ORIGINALS, B5, Col. 2)(ORIGINALS, From B1)

Feminist artists and art historians, who feel they've been ripped off by male-dominated college, galleries and museums, already have made their presence felt in professional art organizations, in the National Endowment for the Arts (which paid for "The Originals"), in museums and the White House.

"Women's art organizations have described what they believe to be patterns of discrimination against women artists," Margeret (Midge) Constanza, the president's assistant for special-interest groups, last fall wrote the GSA, the arts and humanities endowments, and the Smithsonian Institution. "Their complaints seem to be substantial . . . I am writing to urge you to look into the situation . . . and, where warranted, to initiate remedial procedures.

Many curators, infuriated by her reference to their "exhibition policies," charged "political interference." Was the White House telling them to use sex as a criterion for evaluating art?

Should the federal government organize exhibits that, like "The Originals," are women-only shows? Should the nation's art museums adjust the art history they show us to include more women?

Yes, would be the answer of the more outspoken feminists, a number of whom note that in his standard college textbook H.W. Janson surveys the history of Western art without citing a single woman artist. Claiming that "art by women differs from art by men in fundamental ways," critic Lucy Lippard writes that she is "all in favor of a separatist art world for the time being - separate women's schools, galleries, museums." Lippard feels she has detected "a lot of sexual and gyno-sensuous imagery in women's art - circles, domes, eggs, spheres, boxes, biomorphic shapes . . ."

The women's movement has already led to the discovery of gifted female painters who were, for years, neglected. "Why Have There Been No Great Women Artists?" asked historian Linda Nochlin in a 1971 essay that encouraged such researches.

"The fact, dear sisters, is that there are no women equivalents for Michelangelo or Rembrandt, Delacroix or Cezanne, Picasso or Matisse . . . The fault, dear brothers, lies not in our stars, our hormones, our menstrual cycles or in our empty internal spaces, but in our institutions and our education . . ."

Calling Nochlin "as brainwashed as the rest of the male historians," writer Cindy Nemser responded that most women artists are "great." "It will become clear that the highest accomplishment, greatness, in female artists is a rule rather than an exception."

Neither H.W. Janson, who excludes female artists, or Nemser, who as indisriminately applauds them, has a lock of truth. The women who have organized so effectively are telling us, correctly, that women deserve more opportunities in the art establishment. In the past, artists, both female and male, often have been arbitrarily neglected. One need not claim, as Lippard does, that "the time has come to call a semisphere a breast," to welcome efforts that increase our exposure to - and our understanding - first-rate women's art.