Critic John Mason Brown once likened Alfred Lunt and Lynn Fontanne to Adam and Eve: "Theater was their Eden and they never left the garden."

Yesterday morning, shortly after four o'clock, Lunt died at Chicago's Northwestern Hospital.

Girding for what friends described as "her life's Gethsemane," Fontanne, his stage partner and wife of 54 years, was resting at the time at their Genessee Farms, Wis., estate, aware that her husband was unlikely to live.

He had undergone surgery for bladder cancer July 21 and had awakened from a coma only twice, for the final time very briefly last Friday.

Announcement of his death was made by their longtime friend and legal adviser, Donald Seawell, president of The Denver Post. He said that private funeral services will be held Friday afternoon in a Genesee Depot chapel, with only family members present. They will include George Bubbee, Lunt's brother-in-law who lived at their home, Ten Chimneys, and nieces and nephews. Lunt and Fontanne had no children.

For over 50 years, the Lunts personified the finest of the American theater, and even their ages had a mystique. The records do not vary about days and months - his birthday was Aug. 19, hers is May 19 - but about the years there are wide discrepancies, Lunt's age ranging from the announced 84 to 89, Fontanne's from 90 to 96.

Last year, impeccably groomed, they looked to be a couple in their early 60s, and kept any facts of ill health to themselves, though his sight had failed badly in recent years and they never were certain how their vitality would be on any given day. She observed: "There's one good thing about growing old. You no longer mind the heat."

It was like the tricks they mastered for their mind-reading roles in "The Great Sebastians," wherein he roamed the audience while she, blindfolded on stage, "read" his mind. The mystery of their ages was part of the Lunts' magic.

In the public mind - even of those who never saw them act - and in their own minds, Lunt and Fontanne were inseparable. Peleas and Melisande, Arthur and Guinevere, Tristan and Isolde, Lynn and Alfred, Alfred and Lynn.

Until two summers ago, when Fontanne entered a Chicago hospital to heal a leg injured while gardening, they never had spent a night apart since their marriage on May 26, 1922.

Lunt was a handsome 6-foot-2, Fontanne a beautiful whatever height she decided the moment called for. Whatever they did, on stage or off, became, through assiduous care, glamorous perfection. They persistently worked on their roles even after playing them for years.

If Fontanne's taste exceeded a producer's wardrobe budget, the couple paid the difference from personal funds. In their early years they came home from the Paris couturiers with just enough to pay their taxi fare from ship to home.

They first acted together June 9, 1919, at Washington's National Theater in "Made of Money," by Porter Emerson Browne and Richard Washburn Child for the George C. Tyler stock company, whose other members included Helen Hayes, Emily Stevens, Cornelia Otis Skinner and Glenn Hunter.

The next week, they were together again in "A Young Man's Fancy" by John T. McIntyre. Separate successes for both - "Dulcy," the George S. Kaufman-Marc Connelly comedy for Lynn and Booth Tarkington's "Clarence" for Alfred - kept them professionally apart. For the first six years of their marriage, they appeared both separately and together, but from 1928 they always starred together. They appeared in 27 plays together from 1923 to 1958.

Only 27 plays?

All but "Point Valaine," written by their pal Noel Coward, were such hits that the Lunts would perform them for seasons at a time, alternating in mini-repertory throughtout the United States and Great Britain to a degree matched only by their peers, Helen Hayes and Katharine Cornell. There was not a theater in the English-speaking world they did not know and remember.

Shortly before his death, Lunt was on the phone with Carol Channing, who was about to play the Muny Opera in St. Louis. Lunt described the trees on its stage, where he had appeared 60 years before in "As You Like It." He remarked; "We used the trees for the forest of Arden."

Critics wrote that they would be content to have Lunts read the phone book, but the Lunts had reason to be proud of their record. They were together in Shaw's "Arms and the Man," "Pygmalion" and "The Doctor's Dilemma," in Dostoevsky's "The Brothers Karamazov" and in Chekhov's "The Sea Gull."

Robert E. Sherwood, who was to reach the White House as Franklin D. Roosevelt's speechwriter, wrote three of the Lunts' lasting hits, "Reunion in Vienna." "Idiot's Delight" and "There Shall Be No Night." They rehearsed as Benedick and Beatrice for "Much Ado about Nothing," but the play never reached the stage because they were so successful as Essex and Elizabeth the Queen." They subsequently linked up with Shakespeare for "The Taming of the Shrew" in 1935, to which they returned occasionally during the next five seasons.

Their last official Washington date came a year ago when Queen Elizabeth II invited them to her dinner for President and Mrs. Ford at the British Embassy during the queen's Bicentennial visit. First, they went to the Kennedy Center to see the one-woman performance of Eugenia Rawls, who had appeared with the Lunts in "The Great Sebastians."

After the play, Fontanne advised. "A little more pink in the Number Two. dear," meaning a more gentle effect in a particular light. That reminded Lunt of one of their sofa love scenes when Fontanne hissed his ear: "You're in my light."

They later paid a backstage visit to congratulate James Whitmore and his wife, Audra Lindlay, for "The Magnificent Yankee," which the Lunts had played on television and, staying at the Embassy Row Hotel, they chatted with Alice Roosevelt Longworth next door.

Queen Elizabeth's invitation stemmed from her girlhood memory that for fours years, beginning in 1943, the Lunts had chosen to perform in Britain, sternly playing on even after a German bomb burst at their stage door during a performance. For Elizabeth's father, King George VI, the Lunts had acted "There Shall Be No Night" at Windsor Castle without scenery or props for an audience of 50 persons crowded into a royal drawing room. Elizabeth was there.

In those wartime days when manpower was thin, Lunt lead a secret London life. On non-matinee days he worked as a hospital orderly, telling no one about the role, which he acted while using his stepfather's name. Only when a released patient saw him on stage did it sink in that the courteous daytime orderly had less prosaic night.

He was born in Milwaukee, the son of descendants of an old New England family. "Think of it." he marveled in 1976. "My grandfather was born in 1805. I almost span our nation."

Because his widowed mother. Harriet, was to choose a Finnish-Swede for her second husband, it later was assumed that Lunt had Scandinavian blood. Another error about his past is contained in "Who's Who in the Theater," which says Lunt dropped out of Harvard University to join E.E. Clive's Castle Square company in Boston. "Not Harvard," Lunt said, "but Bostons' Emerson School of Oratory, my college drama teacher's school."

After three years at Castle Square, Lunt became leading man to Margaret Anglin, known for her Greek classic revivals in those pre-World War I days. He also toured with Lily Langtry and made his Broadway bow in 1917 in "Romance and Anabella."

Fontanne was English-born, officially in the same year, as Lunt, although she is said to be 93. About that, she tosses her reddish hair and says, "I was born the year I met Alfred. When was that? I can't imagine."

After a bow under the tutelage of Ellen Terry in a Drury Lane pantomine in 1905, she came to the United States at the suggestion of Laurette Taylor, with whom she made her American bow in 1916 in "The Wooing of Eve." After seeing each other on different stages and at parties, Lunt and Fontanne were professionally linked by George C. Tayler, then a leading producer, for the National Theater's summer series.

The Lunts were kept apart after their engagement was announced in December, 1921 as Lunt went on tour with Billie Burke, wife of Florenz Ziegfeld. Referring to Mrs. Ziefeld's train entourage of a nurse for her daughter, chauffeur for her limousine that was carried in the baggage car, a chef, two maids and three dogs, and thinking of circus traditions, Lunt said, "All we need now is a calliope and a Shetland pony for a morning parade."

When Fontanne completed her tour in "Dulcy" and Lunt had a week off before returning to the Billie Burke comedy in Atlantic City, they sat one beautiful May morning on a bench in Central Park.

"Let's get married," he said. "Today?" She asked. "Now. Immediatley," Lunt said. They took a subway to the marriage bureau, filled out the forms and conralled two strangers as witnesses. "That will be two dollars," said the marriage clerk. Between them, the Lunts had 95 cents. The witnesses produced two dollar bills.

The Lunts spent their honeymoon in Atlantic City but later decided that a religious wedding service was more fitting. An Episcopalian minister performed the ceremony, Mrs. Ziegfeld tossed a wedding reception and Lunt wired his mother of Lynn." That night he blew his lines.

They made only three films together - "Second Youth," a silent of 1924; Molar's "The Guardsman," a talkie of 1931, and "Stage Door Canteen" of 1943, in which they played themselves. Kirk Douglas was to meet them and say to Lunt: "We used to wash dishes together . . . at the Stage Door Canteen."

When MGM offered them $1 million to make more movies, Lunt replied: "We can be bought, but we can't be bored." They consciously chose stage insecurity rather than movie money.

They never were bored at Ten Chimneys, their farm at Genesee Depot, Wis., into which they poured their savings, including MGM's money for "The Guardsman." That built their swimming pool just as the play's stage profits had built their studiolodge.

A few years ago they sold their New York home, just off Gracie Square, your which designer Stewart Cheney had created mirrored walls to disguise the 15-foot width.

Through the years they built an army of friends and admirers in all branches of the profession, from grips to stars, from unknows to the famous, so that virtually everything that found an American stage had a Lunts veteran in its company. In this way, by mail and phone, they maintained an efficient network of news and theater gossip.

They were not enthusiastic about the books written about them, although they had high praise for George Freedley's slim volume of 20 years ago. In 1972, one of their stalwarts, actor Alan Hewitt, produced a staggeringly complete list of their appearances, separately and jointly, for a West Coast tribute by the American National Theater and Academy. "How on earth did you dig that out?" Lunt asked about a reference to their two weeks in a Washington summer stock company.

Each worried constantly about the other. After a separation of a few hours, there would follow several hours of catching up on what had happened while they were apart. "Lynnie's got a broken arm but hides the cast in her gown and flails it about." Lunt complained one night in his dressing room. Next door, a few minutes later, Fontanne would be exercising her arm and saying, "I don't like that condition in Alfred's stomach." Holding separate court at parties they would look over to see what the other was doing. As recently as last year, anyone would know the two were Somebody, even if unaware they were The Lunts.

About their work they were exhaustingly serious. They could spend hours rehashing a performance, to the fascination of their colleagues.

The night they closed a three-season tour in Sam Behrman's "I Know My Love" at Washington's Shubert (Gayety) Theater, they introduced some movements into a final scene that never had satisfied them. "We DID it," Lunt whispered to Fontanne after they felt the audience response.

For some years they kept the nucleus of a company together and, although Lunt rose to become a member of the Theater Guild board, they never managed to finance a permanent company. They relished the successes of such young proteges as Montgomery Cliff and Uta Hagen. When "The Lunts in" whatever was announced, ticket racks emptied across America. They knew train schedules, sleeper jumps and freighter routes and relished their touring.

They were especially known for "overlapping," meaning that the other would begin a line while the first was completing its lead-in. Actors marveled at this, and some dubbed them "technicians."

That word offened them. "We are just the opposite of tricks," Lunt said. "We play naturally and truthfully. People do overlap when they're talking. Listen to them. Carefully. Once in 'Arms and the Man' I worried because of not getting a laugh. Lynnsaid, 'Why don't you try looking at me?' I did, and the laugh came. It was right because it was the natural thing to do.

"Technique is our weapon, the inner truth is our essential. We never mind long runs, in fact enjoy them, because each audience is a different challenge and we keep working on our performances. I can't imagine anyone ever tiring of acting a good part."

Their final play together, prior to some television work they did, was Duerenmatt's "The Visit." At its try out in Brighton, England, such old friends as Noel Coward, Terence Rattigan and Beatrice Lillie tried to dissuade the Lunts from the symbolic story of the world's richest woman, now old and finally getting revenge on the man who had raped her in their youth.

Fontaine worked on her characterization to become a glamorous but chilling woman. Lunt produced a vomiting action that was the essence of the playwright's meaning. For their New York opening in "The Visit," Robert Dowling and Roger L. Stevens renamed Brodway's renovated Globe "The Lunt-Fontanne Theater." They did the play for three more years.

Lunt turned to direction in their busiest years, not only of their own productions but of such actresses as Helen Hayes in "Candle in the Wind," which did not work," and Audrey Hepburn in "Ondine," which did. For the Metropolitan Opera he staged "Cosi Fan Tutti" and "La Traviata."

The appreciation of other performers was exceptional and warm, cutting across all area of the art.

When Charles F. Love, Carol Channing's husband, introduced the Lunts to George Burns and Gracie Allen, Lunt came up with line he had heard Burns use more than 20 years earlier in vaudeville. Allen immediately picked up her cue, and they containued the sketch for another 10 minutes, all collapsing in laughter on the floor.

Scarcely a month went by at Ten Chimneys without visit from such luminaries as Laurence Olivier, Cathleen Nesbitt, Helen Hayes, Burns, and Channing, plus the Lunts' longtime legal adviser, Donald Seawell and his wife, Eugenia Rawls. In the theater, an invitation to Ten Chimneys was equivalent to one from the White House.

Dinner was black tie and often the cooking was by Lunt, famous among his friends and magazine readers as a chef. When his sight began to fail. Lunt said, "I'm writing a book called 'Cooking by Ear.''"

Their approach of life carried with it the wit that they personified on stage and that was the spice of their era. When Lunt's sight was fading, Noel Coward, who had written "Design for Living" for the Lunts and himself, arrived for a visit.

"What should I do about my eyes? Lunt asked Coward during dinner. "I'll tell you at breakfast," Coward said. When he came down the next morning, Coward said: "Alfred, never eat white fish on white china."

The sequal to the story is that in a recent printing of the anecodote an editor changed the phrase to "black china," observing that "white china" made no sense. Lunt asked, "Has humor gone out of style?" For although truth was their impelling motive, style was the brilliant motif of the unique, ageless, romatic Lunts. CAPTION: Picture 1, Lunt and Fontanne, shown here in Shakespeare's "The Taming of the Shrew," first appeared in it in 1935, and performed the comedy over the next five seasons. AP; Picture 2, The Lunts are shown in 1972 in Beverly Hills, just after their golden wedding anniversary. They had borrowed $2 from a stranger to pay marriage fee. AP; Picture 3, The famous couple, wearing modern dress, starred in "Amphitryon 38" in New York in 1937, in the S.N. Behrman adaptation of the comedy by Jean Giraudoux., AP