SHE KNEW her parents had been having martial difficulties recently, but when her mother called her at work one day in July 1977 to announce their decision to divorce, she couldn't believe it -- couldn't accept it -- didn't want to believe it. All the hard-won wisdom and maturity she had achieved at age 28 were of no consequence in the face of this bizarre crisis.

Her parents? She had heard about other couples divorcing in their later years, but Mother and Dad? After 36 years? The ones who always instigated and coordinated the annual family reunions? People of her own generation were old hands at divorce these days; she herself had married, right after college, but that mistake lasted only 3-1/2 years, and the divorce was relatively painless.

However, her parents' generation had taken permanent vows, "'til death did them part." How could they separate now, in their late sixties, with all the children fully grown and gone -- now, just when they should relax finally and enjoy each other's company in their twilight years?

The signs had been there for a long time, as it tuned out. The seeds of discontent were planted with two events: her father's retirement, and her younger brother's wedding.

In January 1974, Dad viewed his retirement with apparent anticipation. After commuting 60 miles a day to the Pentagon for 30 years, it was time to take it easy and do the things he wanted to do. He offered to help out around the house, but his efforts were usually rebuffed. A faithful practitioner of the Royal Canadian Air Force exercises to keep in shape, he took more care now with his physique and appearance, dabbling with health foods and other regular forms of exercise. He colored his hair periodically with Grecian Formula. To some, he appeared more and more obsessed with maintaining a youthful appearance, as if that would, in fact, make him young again.

Mother had dreaded Dad's retirement from civil service for several months before it occurred; the reality fulfilled her worst expectations. Suddenly he was around the house all day, meddling here and there in her daily routine. It seemed that if she asked him for constructive help, he was glad to -- right after his daily noontime sunbath and martini, or as soon as he returned from his daily constitutional. Otherwise he spent his time (unproductively, to her) reorganizing his stamp and postcard collections, or puttering around the yard. They still lived in the big old white frame house where all the children had done most of their growing up. The echo of voices must have been disquieting.

About a year later, while Dad and Mother adjusted to this new arrangement, the youngest son announced his engagement and imminent wedding. A senior in college, he and his fiancee couldn't wait -- and so the last offspring left the nest. Mother's "golden boy," her baby, was one no longer, and his marriage signaled to her the breaking of the final tie between herself and her children. She felt betrayed: She had spent most of her adult life raising them, and they had dated to leave her to go out and lead their own lives. What purpose could there be now in her life?

The following year, during the Bicentennial summer of 1976, Dad celebrated another kind of anniversary. He traveled to Massachusetts to attend his 50th high school reunion. Mother, viewing this affair as a monumental bore, declined his invitation to accompany him. He, in turn, discovered that his old high school flame would be there, and so he and his former flame arranged, with Mother's knowledge and blithe approval, to go together.

Dad and his former sweetheart had a wonderful time.

During the following year, it became painfully evident to friends and relatives that all was not well between them. Their bickering was becoming more and more unpleasant to witnesses, though to Mother's mind they were no worse than many of their long-married friends. But to the children, who had never observed it before, there was something terribly wrong. Of course, they would have good spells and bad spells -- not exactly cyclical, but there was an uneven pattern to them. Cocktail hour habitues as long as anyone could remember, their drinking now resumed after dinner, when they would put their feet up and read the paper, or watch television, highball in hand.

Finally, they made their annoucement.

As she listened to her mother on the phone that hot July day in 1977, she felt numb. Sure, it was easier to talk about than to do, and perhaps that was all it was -- talk. Mother was bitter. "Can you believe it?" she asked. "I never thought I would be in this situation." Apparently he had handed her a letter that morning, outlining all the reasons for his unhapiness and stating his intention to leave.

After the phone call, she went up onthe roof of the office building where she worked to mull things over. It still didn't seem possbile. Her parents' breakup seemed to symbolize the breakdown of their entire family unit, and that thought was untenable.

When you came right down to it, that's what was really bothering her, this whole business about family. As far back as she could remember, she had thrived on it. When the children were still young, hadn't they all gotten together every Saturday night for "Kids' Night," to play cards and eat popcorn and invite friends in? Kids from all over the neighborhood would "drop by," knowing full well what to expect, and everyone loved it. And those family vacations, alternating summers visiting relatives in Kentucky and Massachusetts. Comic books for the kids, newspaper spread all over the back of the old station wagon for their faithful canine companion, ever panting. Later it was the reunions, complete with spouses and (grand)children. And didn't the four grown children, even now, periodically circulate a round-robin letter among themselves?

Accompanying this realization was an overwhelming regret caused by this unexpectedly sudden wrench from childhood to adulthood, a wrench she hadn't anticipated experiencing until one of her parents died. Parents are, after all, custodians of childhood memories, and the final break of that tie signals the arrival at adulthood, whether one is ready for it or not.

How could the same parents who had created and fostered such strong family ties -- how could they, especially Dad, selfishly think of only themselves and their own happiness, when it meant the betrayal and destruction of those bonds?

Her meeting with her father was terse. He was early, so she hadn't finished her laundry when he arrived. Everything was askew, it seemed. She wanted to yell and scream, to shake some sense into him, as if by doing so she could restore the comfortable reality she had known before. But there was no big, dramatic scene -- only her father, reciting a tale of general unhappiness. They hadn't loved each other for a long time, he said. They had stayed together for the sake of the children, and for social convenience. He honestly felt they would be happier apart, and he also felt that Mother would come to that realization sooner or later herself. As for him, he had a vague plan to move to New England in the fall, and establish himself there.

She tried to reassure him that she understood his need for happiness, that he was deserving of it and that he would always be her father, no matter what. But it was hard.

Mother and Dad continued together for the next few months, into the fall of 1977, as if nothing had happened. They went out on their wedding anniversary, as usual; went out on her birthday, as usual; entertained friends for dinner and bridge, as usual. The daughter couldn't believe their seemingly normal behavior. Why didn't Mother throw him out immediately, angry as she was at what he was doing to her? The daughter asked once about a marriage counselor. Well, they had tried one, but he suggested that much of the discord lay with Mother. They stopped going.

Now, however, began a new phase. Mother: "Don't you think it's absolutely awful what he's doing to me? After all the years I worked making a home for him and raising the children, this is what we've finally come to." Father: "We just don't get along anymore. We don't love each other anymore." The children, hard as they tried not to be, were drawn into the fray. Of course it never happened when the parents were together -- only when they happened to be alone with one of the children. The children didn't want to be forced to take sides, but that's what each parent was asking. The daughter tended to side with her mother, but felt she owed her father -- whatever.

Finally, in October, he left. He announced his departure date, and that weekend several family members got together, as they always did whenever relatives came to town. It was hard to maintain the kind of festive atmosphere that always marked these reunions, because everyone knew it was "the last one." As they said goodbye at the end of the evening the daughter felt bewildered. He wouldn't really leave, and this wouldn't be the last time she would ever see him. But that night she had a long, mournful bout of crying.

It was the last time, for a long time. The day before he left, he called her at work to bid a final farewell. There was not much else to say, and so the conversation was brief.

The sudden, deep pain she felt realy took her by surprise. She had imagined herself so sophisticated and mature, and had believed she would be able to deal with the situation in her accustomed adult manner. But the great gulping sobs that reverberated through her apartment in the evenings belied her daily, public calm. She felt abandoned, deceived -- almost as if he had left her, not her mother. There was no rational explanation for it.

And Mother -- trying to keep her together too, bolstering her so she could pull herself together. Without the support Mother had derived from Dad throughout their marriage, Mother felt adrift and frightened. She felt his absence physically. He had left the responsibility for selling the house to her, to handle alone -- what did she know about real estate? She was left without a bridge partner, a dinner companion, a resonance, and so she turned to those nearest her for help. The daughter, understanding all that must be going on within her mother, nevertheless resented this sudden dependence, this sudden responsibility. She had her own life to live; Mother would just have to learn to manage by herself sooner or later. What was taking her so long? The daughter spent many evenings listening to her mother's bitter lament. The resentment didn't fade for a long time.

The sessions with the phychologist helped some. It was the intermittent crying jags, which could be induced by the merest suggestion of emotion, that drove the daughter to seek help. Through the therapist she came to relize how much she had depended on her father. He had been a good father, there was no denying that. He had spent a lot of time with his children, taking them mountain climbing, on picnics, to concerts -- occasions when Mother had declined to go along. No, there was no denying that he had been an involved parent. That hadn't helped explain why she felt so close to him, but the knowledge did not do much to relieve the pain. Since he had left, she hadn't heard from him at all -- he had cut all communications. In case of emergency, there was a post office box number. It was as if he had died, except that she knew he was alive, and that was worse.

It has been 2-1/2 years now since Dad left. The remaining family unit -- Mother and four children -- is still intact an going strong. The daughter's fears about its disintegration had proved groundless. That familial closeness that had been instilled by the parents in the children is now even stronger, as a result of this shared crisis.

Mother now lives in a comfortable 2-bedroom apartment, with pictures of children and grandchildren all over the walls. She is now enjoying her new life, however; she has learned to cope alone, and she now realizes the pleasure to be derived from cooking whatever she wants to eat, in spending her money in ways she wants to, in having her friends over for bridge. Mother and daughter visit each other periodically, and they enjoy shopping and going out to dinners and shows. They call each other on the phone a fewtimes a week.

Dad has remarried, this time to his high school sweetheart, to no one's great surprise. They live in New Hampshire. The daughter's first verbal communication with her father since he left was a phone call last spring, announcing his marriage. In fact, they met, not long after the phone call, over dinner: Dad, his new wife and daughter. It was somewhat awkward: idle conversation about the daughter's newly acquired contact lenses, the neighborhood where he and his wife live, his trim figure. He asked the daughter if she had anything to say about all that had transpired, and she tried to explain her anger, but the words didn't have much punch. What had happened could not now be undone; the unraveling of his first marriage had been a natural inevitability.

The daughter no longer has great crying jags, although she is still suggestible. She went to therapy for about seven months, until she felt she had gotten about all the benefit she could and would now have to cope on her own. Her contact with her father now consist of occasional typed, Xeroxed newsletters which he sends to all friends and relatives, indicating their copy by circling their name at the bottom of the letter. This bothers her: she feels reduced to a name of the bottom of a distribution list. She writes chatty letters to him infrequently, and still remembers his birthday and Father's Day, though not without a twinge. (Mother feels she shouldn't, and doesn't hesitate to let her know, in little ways. "Do you ever write to him?" "Sometimes." "You do?" [Translation: How could you?] The pain is greatly reduced now, but the memory of it has not faded. Mostly she regards him now as a nonperson: Yes, he is still her father biologically, but he is not her father anymore.