UNDATED: Irene Dunne.

10/03/98 02:18:03 PM

At 18, he was still playing the role of a child. Realizing that acting as a boy did not bear "any relation to acting as an adult," he moved to New York to study acting. He made his stage debut in Young Woodley at the Westport Country Playhouse in Connecticut and was soon working on Broadway in Shaw's Misalliance and playing in Shakespeare at the Stratford Festival in Connecticut.

In 1955 he did three plays, The Doctor's Dilemma at the Phoenix Theater, The Tempest at Stratford (he played Ariel to Raymond Massey's Prospero) and No Time for Sergeants on Broadway.

Often he had to fight typecasting. After playing a Southern soldier in No Time for Sergeants, he had difficulty getting roles as Englishmen. After acting in Compulsion on Broadway, he was typed as a psychopath. That was followed by Look after Lulu, The Fighting Cock and the stage musical Camelot, in which he played Mordred.

He also acted on television, and after about five years he returned to the movies, eventually acting in movies as varied as Orson Welles' production of Macbeth (he played Malcolm both on stage and on screen), Cleopatra (he played Octavian) and the Planet of the Apes series of films.

His other films included The Subterraneans, The Longest Day, The Loved One, Lord Love a Duck, Evil Under the Sun, Fright Night, Dead of Winter, Last Summer in the Hamptons and The Grass Harp.

At one point, the actor who had once played such warm-hearted, well- behaved children was in demand to play villains.

As a collector of performances, he was outspoken about such favorites as Laurette Taylor and Bette Davis and also about actors who were trapped by their stardom. "Celebrity sometimes is the most dangerous component in the continuance of a career," he said. "Certain people are wildly talented but their legend becomes the currency in the marketplace." Among those underrated actors he named Mae West, Jean Harlow, Alice Faye, Alan Ladd and Tuesday Weld.

Last year, he was back on stage in New York as Scrooge in the musical version of A Christmas Carol, a role of the greatest distance from him and from the character of Huw in How Green Was My Valley, but one that he approached with his customary diligence. As always, he looked incredibly young -- until makeup transformed him into Dickens' elderly miser. He gave an assured performance as the centerpiece of an otherwise overblown production.

He is survived by his sister Virginia, who lives at the Actors Home in Los Angeles, where McDowall often visited elderly actors.

Although Roddy McDowall never turned his back on his childhood acting, it also became something to overcome. It was, he said, a "demon walking with you." He added, "My whole life I've been trying to prove I'm not just yesterday." The fact is he had to keep reinventing himself in his many guises as an actor.

But as a student of film he also knew that yesterday's treasure, like How Green Was My Valley and Lassie Come Home, was eternal. Because of all his personal attachments and his memories connected with those films, he had difficulty watching them again. In common with other moviegoers, he would weep at the grief of the little boy on screen.

NYT-10-03-98 1516EDT