Hitchcock and/or his writers start weaving allegories in his films or, worse still, neglect to spring surprises after the ground has apparently been prepared, the consequence is something less than cheering. And the mental anguish he can thereby create, apparently in the minds of his characters but actually in the psyche of you, is of championship proportions and-being hokum, anyhow- a sheer delight.But when Mr. Hitchcock folds suggestions very casually into the furrows of his film, the way he can make a torn newspaper or the sharpened inflection of a person's voice send ticklish roots down to the subsoil of a customer's anxiety, is a wondrous, invariable accomplishment. And now he is bringing in another bumper crop of blue-ribbon shivers and chills in Jack Skirball's diverse production of 'Shadow of a Doubt,' which came to the Rivoli last night.Yes, the way Mr. He did it quite nicely in 'Rebecca' and again in 'Suspicion' about a year ago. You've got to hand it to Alfred Hitchcock: when he sows the fearful seeds of mistrust in one of his motion pictures he can raise more goose pimples to the square inch of a customer's flesh than any other director of thrillers in Hollywood.

Teresa wright shadow doubt