The London Daily Telegraph yesterday reported that many works attributed to John Constable, the English master, are actually the work of Lionel, his son. Has a shadow fallen on that most revered of British landscape painters. Can old England take the shock?

The reattribution story - with its juicy implications of masterworks demoted and art experts deceived - was treated by the Telegraph as a revelation. "It was our second lead on Tuesday and we're splashing it on Wednesday," said an editor there yesterday. "We're running photographs of Constables on the top of the front page." In America, however, specialists in English art look the news in stride.

"This sort of thing," said Susan Casteras, assistant curator of paintings at the Yale Center for British Art, Paul Mellon's new museum, "happens all the time."

The Daily Telegraph's account cites a scholarly report which will be published in September by the Burlington Magazine. Its authors, Leslie Parris and Ian Fleming-Williams, both of London's Tate Gallery, have taken 14 "Constables" most small, unsigned and slightly known - and after years of study assigned them to his son.

Reuter news service, however, yesterday cited the "doubt thrown" on "some of 1300 works." "It will take a generation of research to sort out the confusion," said Hugh Leggatt, the London dealer. "This discovery will have repercussions all over the world."

"Some of the most important oil paintings involved are in American collections, notably at Yale," said the Associated Press.

But those "important" oils are not all that important. Their authorship has long been questioned, and that is one reason the three at Yale have never been publicly displayed.

The Yale Constables - "The Old Barn," "Looking Over to Harrow," and "Brook, Trees and Meadows" - were described more than a year ago as "an awkward group" in a letter written by Malcom Cormack, curator of paintings at Yale's British Center, to Leslie Parris at the Tate. "Stephen Somerville thought 'Looking Over to Harrow' was only 'in the manner of,'" wrote Cormack, "and it was not accepted by Charles Rhyne (another Constable scholar), who thought it might be by one or other of the sons, Alfred or Lionel. Certainly it looks very weak."

Yet another questioned Constable is now in the collection of the Philadelphia Museum of Art. Titled "Bridget on the Mole," it is just 10 inches high. And like the Yale oils, it is not on display.

One source of the confusion is that John Constable (1776-1837) was prolific both as a painter and a father.

Constable enjoyed reclining in the fields making small and speedy sketches of the shifting clouds above, recording, as he put it, the "natural history of the sky." He rarely signed such sketches. And he was the father of four sons, John Charles, Charles Golding, Alfred and Lionel, all of whom were painters who learned their skills at home. His daughter, Isabel, painted too.

Many pictures by John Constable, and a number by his children, passed to his grandson, Hugh, who, financially embarrassed, sold 177 of them through a Londan dealer in 1899. From that batch of paintings come all the 14 Constables that are now in dispute.

It seems that no fraud was intended. "Hugh," say his descendants, "assumed a work was by his grandfather if he thought it good enough."

British painting, until recently, rarely received the scholarly scrutiny that has long been given Dutch, French and Italian art. That relative neglect is one of the reasons that Paul Mellon, who began buying seriously only after World War II, was able to acquire the 64 works attributed to Constable that he has since given to Yale. His collection, he observed, may "require in the future a certain amount of judicious pruning."

That process has begun.

A large Constable retrospective was organized by the Tate in 1976. Among that museum's Constables is one, "Near Stokes-by-Nayland," that was reassigned to Lionel Constable ater the gallery closed Monday night. The son, note Parris and Fleming-Williams, applied paint more thinly than did his father. He also had a penchant for "pinky-mauve tones in the sky," the Daily Telegraph reported.

Lionel Constable, who was only 9 when his father died, was an amateur photographer. The trees in "Bridge on the Mole," the Philadelphia picture, appear to be an exact copy of those in one of Lionel Constable's photographs. Had the oil been painted by his father - 30 years earlier - the trees would have been younger and much smaller.

Three Constables in university collections - "Looking Over to Harrow," a drawing at the Fogg at Harvard; "Cornish Coastal Scene," an oil at Oxford's Ashmolean Museum; and "View Near Dedham" at the Smith College Museum of Art - as well as sketches now in Munich and Berlin should now be assigned to Lionel Constable, the Tate's two scholars feel.

"Lionel Constable," says Yale's Susan Casteras, "is not about to be promoted. He will always be what he has always been, a relatively minor follower of Constable, a painter 'in the circle of.' The number of works assigned to him may grow, but they won't get any better and their value will not change."