Irving Wallace, 74, the best-selling author whose lively novels, including "The Prize," "The Man" and "The Chapman Report," were strong on plot and background detail and were read by millions, died yesterday of pancreatic cancer at Cedars-Sinai Medical Center in Los Angeles.

By one estimate, Mr. Wallace's 33 books, both fiction and nonfiction, written alone or with members of his family, sold more than 194 million copies and made him one of the world's most widely read authors.

A pipe-smoking former screenwriter, Mr. Wallace based many of his bestsellers on traditionally popular themes: sex, politics, religion. Painstaking in his research, he offered vivid behind-the-scenes glimpses of celebrated institutions such as the Nobel prizes or the American presidency.

He was recognized as one of the most skillful practitioners of converting current events into fiction, and was recognized also for his effort to inject serious ideas and thoughtful discussion into the mass-market novel. Many of his books became movies.

However, he was not universally admired by professional book critics, a good number of whom complained that his work was something less than true literature and who condemned his topics as lurid, his sentences as pedestrian and his characterizations as often wooden.

Mr. Wallace viewed himself as an entertainer, a spinner of yarns, an heir to the spellbinding tradition that, as he once put it, went back to the days in which "stories were told in wayside inns or around fires before men could read or had bound books.

"You tell a tale . . . so that the listener will exclaim 'But what happened next?' or 'What happened to her?' "

One of two children of a Russian immigrant couple, Mr. Wallace was born in Chicago on March 19, 1916, and was taken at age 1 to Kenosha, Wis., where his father bought a general store.

He recalled growing up as a voracious reader, a member of the junior high school track team, and a nationally ranked high school debater, who was also editor of his school's weekly newspaper.

"I always wanted to be a writer," he wrote recently. "Nothing else, ever. I started with magazines because there were so many of them."

After high school, he moved to California to study writing, to continue the magazine freelancing he had already begun, to turn out plays, and to make an effort at breaking into Hollywood as a screenwriter.

After the outbreak of World War II, he enlisted in the Army Air Force and was assigned to a motion picture unit, where he wrote training films.

After the war, his screenwriting career flourished in a Hollywood he once described as "a plush hell . . . where the writer suffered indignity, disrespect, disdain, and where he could make more money than he could possibly make in any other salaried medium of writing."

Moonlighting, in an effort to break free, produced three well-received nonfiction books: The Fabulous Originals in 1955, a collection of biographies of real-life inspirations for fictional characters; The Square Pegs in 1957, which told of nine little-known American eccentrics; and a P.T. Barnum iography titled The Fabulous Showman in 1959.

His first novel, "The Sins of Philip Fleming," was published in 1959, and won him a $25,000 advance on two future books that enabled him to abandon screenwriting.

The first novel, which detailed the struggle of a young writer, suggested the reality-based themes that would follow. Mr. Wallace's next book was also based on a real-life topic, but a livelier one.

The book, "The Chapman Report," published in 1960, discussed the effect on the lives of nine suburban women of a sex survey similar to the Kinsey Report, a landmark social study of the postwar period.

The Chapman report, which became a hit movie in 1962, was the first of a long string of best-selling novels for Mr. Wallace.

They included "The Prize" (1962) about the Nobel Prize; "The Three Sirens," (1963) about anthropologists studying South Sea sexual practices; "The Man" (1964) about a black man as president; "The Plot" (1967), about intrigue at an international summit meeting; "The Seven Minutes" (1969) which has a sexual theme, and "The Word," (1972) about the effects of the discovery of a new gospel.

He and his son, David Wallechinsky, who adopted his grandfather's original last name, collaborated on The People's Almanac, a reference work. With Mr. Wallace's daughter, Amy Wallace, they edited The Book of Lists. Mr. Wallace's wife, Sylvia, whom he had met when she was a magazine editor, collaborated on the sequel to that.

His wife, son and daughter were at his side when he died yesterday, according to a spokesman for the hospital where he died.

RAY GUSTIN JR.

Landscaper and Nurseryman

Ray Gustin Jr., 87, a landscaper and nurseryman in Gaithersburg and a past president ofthe Landscape Contractors Association of Washington and the Maryland Nurseryman's Association, died of cancer June 23 at the Asbury Methodist Home in Gaithersburg.

Mr. Gustin was the owner of Gustin's Greenery Inc., a greenhouse in Gaithersburg. He was the founder and former owner of Gustin Gardens Inc., a landscaping business, and Gustin Gardens Tree Service Inc., both of which were taken over by other members of his family.

A native of Troy, Pa., Mr. Gustin moved to the Washington area in 1929. He worked for other nurserymen and landscapers until World War II, when he served in the Army Corps of Engineers in the Pacific. He went into business for himself in 1946. Among the projects on which he worked was the Lyndon B. Johnson Memorial Grove on the Potomac River near the Pentagon.

Mr. Gustin was a past president of the International Shade Tree Conference, the National Arborists Association and the Silver Spring Rotary Club, and he was a founding member of the Council of Tree and Landscape Appraisers.

Survivors include his wife, Janet E. Gustin of Gaithersburg; two children, Doris Belle Shullenbarger of Cambrdige, Md., and Ray Gustin III of Gaithersburg; a sister, Bessie Cairns of Zelienople, Pa.; a brother, Richard M. Gustin of Charles Town, W.Va.; seven grandchildren; and four great-grandchildren.

RICHARD DEE BARKER

Treasury Official

Richard Dee Barker, 78, a retired official of the Treasury Department and a recipient of the Albert Gallatin Award, the department's highest honor, died June 27 at his home in Potomac. He had a stroke.

Mr. Barker served in the Treasury from 1942 until he retired in 1968. He spent the early part of his career in the Bureau of Accounts, and during World War II he was responsible for overseeing the establishment of about 365 branch banking facilities at military bases.

In 1947, he was assigned to the Office of the Assistant Secretary for Fiscal Affairs, where he became a management analyst. That office supervised the Bureau of Accounts, the Bureau of the Public Debt and the Office of the Treasurer.

Mr. Barker was executive assistant to the secretary of the Treasury when he retired.

In addition to the Albert Gallatin Award, which was conferred on him at retirement, his honors included two Superior Service Awards, two Meritorious Service Awards and the Exceptional Service Award.

A native of Ogden, Utah, Mr. Barker graduated from the University of Utah in 1934. He began his federal career that year with the Farm Credit Administration in Salt Lake City.

In 1935, he moved to Washington and joined the Federal Emergency Relief Administration and the Works Progress Administration. From 1938 until the end of 1941, he was with the Federal Housing Administraiton. He then joined the Treasury.

In retirement, Mr. Barker was a private investment counselor. He was a member of the Potomac Ward of the Church of Jesus Christ of Latter Day Saints.

Survivors include his wife, Frances Hodge Barker of Potomac; two children, Richard Francis Barker of Palm City, Fla., and Vail, Colo., and Elaine Barker Dismuke of Rockville; two sisters, Maude Marion Barker Bevan and Edith Barker Harris, both of Salt Lake City; two brothers, Reese Dee Barker of Orinda, Calif., and James Taylor Barker of Coronado, Calif.; and two randsons.

YUILL BLACK

Allergist

Yuill Black, 61, an allergist in the Washington area for nearly 25 years who had offices in Washington, Vienna and Manassas, died of cancer June 25 at his home in McLean.

Dr. Black was born in Falkirk, Scotland. He graduated from the medical school of the University of Glasgow. He came to the United States in 1952 and served in the U.S. Army in Korea during the war there.

In 1966, after further medical training in the Detroit area and elsewhere in this country, he moved to the Washington area and opened his medical practice. He was a staff physician at Arlington and Fairfax hospitals.

He also studied environmental allergies for the Department of Labor and the Environmental Protection Agency, and for 25 years he volunteered through the D.C. Medical Society to take the pollen counts that are included in daily weather reports.

Dr. Black was a diplomate of the American Board of Allergy and Immunology, a fellow of the American Association of Clinical Immunology and Allergy, and a member of the American College of Allergists, the American Medical Association and the American Academy of Allergy and Immunology. He also was a member of Toastmasters International.

His marriages to Jane Black and Michelle Shaver ended in divorce.

Survivors include his wife, Dorothy Helen Black of McLean; four children from his first marriage, Jeffrey Ian and Stephen Arnold Black, both of Fort Lauderdale, Fla., and Laura Marie and John Frederick Black, both of McLean; a child from his second marriage, Christopher Jean-Paul Black of Alexandria; a brother, Lyall Black of Alberta, Canada; a sister, Margaret Gregg of Richmond; and two grandchildren.

HELEN SIPHERD REMIGAILO

Art Teacher

Helen Sipherd Remigailo, 85, a retired elementary school art teacher in Arlington and a former deacon of the National Presbyterian Church in Washington, died of cancer June 27 at the home of her daughter in Ardsley-on-Hudson, N.Y.

Mrs. Remigailo was born in Pittsburgh and grew up in Orange, Calif. She graduated from the University of California at Los Angeles and did postgraduate study in art, dancing and children's theater at the Art Institute of Chicago, Columbia University, the University of Wisconsin and Northwestern University. In the early 1930s, she toured Italy and Eastern Europe to do research on peasant art and design.

Later, she taught children's theater and art in Seattle.

In 1938, she married Vladimir M. Remigailo and moved to the Washington area. He died in 1978.

While her children were growing up, Mrs. Remigailo was a substitute art teacher in Arlington. She also did volunteer art work with children at Arlington Hospital. In the 1960s and early 1970s, she was a full-time art teacher in Arlington, and she worked at several elementary schools.

She was a member of Rock Spring Garden Club and the Neighbors Club in Arlington. She had been director of the women's art workshop at the National Presbyterian Church.

She moved from Arlington to Ardsley-on-Hudson three years ago.

Survivors include her daughter, Anne R. Myers of Ardsley-on-Hudson; a son, Richard V. Remigailo of Atlanta; and six grandchildren.