In the auditorium of Saint Ann's Infant and Maternity Home, the members of the Xerox Community Involvement Program and the Emmanuel Seventh Day Adventist Church sat in plastic chairs by long bare tables and waited in nervous charity for their guests to appear.

The visitors came out of the bitter cold of a Saturday night to give a Christmas party for the children of Saint Ann's because, as the party's organizer, Alonzo Bethea, put it, "If not for the grace of God, I could very well be one of these orphans," and because, as Merle Thompson, who is a member of Bethea's Sabbath school class said, "Just the thought of orphaned kids at Christmas is so touching."

Most of the children of St. Ann's are not exactly orphaned: Some have been abandoned, and others were surrendered, and some had the bad luck to be born to parents whose concepts of life's responsibilities have long been dulled by a needle or a bottle. They range in age from the first days of their infancy to 6 or 7. The littlest ones, up for adoption, don't stay long; the list of prospective parents is a long one. The average stay for the older ones is about three months, although there are many who stay longer as they wait to be placed in a foster home, or for a chance to be reunited with their mothers or fathers.

"Where's my mommy?" asks a little Hispanic boy whenever he sees Sister Genevieve, a member of the order of the Sisters of Charity, which operates St. Ann's. Alarmed brown eyes engulf his face. "Let me tell you about your mommy," Sister Genevieve tells him. "Your mommy loves you and she misses you, and she's going to come and see you, do you believe me?" The little boy nods his head, and sits quietly until he catches sight of Sister Genevieve again. "Where's my mommy?" he asks.

While the sorrow for some is that they have no home to go to, the pity for others is that they do. They are victims of abuse or neglect; they have been placed at St. Ann's only on an emergency basis. It is hoped that in a month or two they can return to their parents; it is feared that in a month or two after that they will be back, left alone again.

And so the occupants of the St. Louise and the Guardian Angel units of the St. Ann's Infant and Maternity Home came gravely to the good time that had been arranged for them. It is the season for such parties, and there have been a number of them. The Sisters of Charity are grateful and the kids, of course, enjoy themselves. But as one 6-year-old says, with a little tough-guy shrug, there's only one problem: "When the party's over, everybody goes away."

About 17 children came downstairs to the party. The youngest was about a year old, the eldest was 9. The older ones walked in first, finding comfort in sticking as close together as possible, while the littlest ones made their entrance in a laundry cart, all dressed up in ruffly dresses and fresh T-shirts, eyes wide in wonder. "Oh, I'm going to fall in love," said Caroline Lambright, who had come with the Xerox group, as the little procession halted in the middle of the room. Soon the youngest children were safely ensconced in the laps of their benefactors while the older ones hung back in shyness. "Go ahead, go talk to the people," one of the little boys was urged by a staff member. "But I've never seen these people before in my life," he said with some astonishment.

The reluctance began to disappear when the caroling began and they all gathered around the upright piano, near the manger scene that was arranged on the small stage, flanked by the presents that had been bought (with money provided by Xerox) and wrapped by the group the week before. They sang "Joy to the World," and "Rudolph the Red-Nosed Reindeer," and "Santa Claus is Coming to Town" -- the three Spanish-speaking brothers, whose mother brought them to St. Ann's because she is too sick to care for them and there is no heat in her apartment; the little boy who, when he is asked how long he has been there, says "three days, this time," and this time, it turns out, is the fourth time; the 2-year-old, a victim of fetal alcohol syndrome, who wears a bonnet on her head, because in her hyperactivity she tends to pull her hair out.

Suddenly Santa Claus was there and just as suddenly there were at least six children clinging to his legs, making it almost impossible for him to walk. Santa Claus, known also as Michael Brant, Xerox branch manager, managed a very creditable "ho-ho-ho," and gave a present to each child as one by one they sat on his knee. "Oh, I knew you'd come," said one little boy. "I knew it."

Afterward, they had cookies and ice cream and punch and the room was filled with errant footballs and screeching race cars and red wagons. In an hour it was over. "The people are the best part," said a 6-year-old as he threw his arms around a visitor. "Are you coming back tomorrow?"