Not surprisingly, since it's a six-chapter novelization of a six-part British television series, this tracking of a few artistic types, from Cambridge University in the Fifties, to the onset of middle age twenty years later, consists almost entirely of dialogue and also not surprisingly, the dialogue is smart, quick, chic or true, Raphael being the screenwriter for Darling and others as well as a veteran storyteller. Three of the episodes belong to Adam Morris, an openly autobiographical figure--the Jewish cynic-outsider, quick to take offense (lots of offense to take), who befriends a dying to-the-manor-born classmate, marries outside his religion, and wrestles with the art-versus-commerce paradox as his novelist career plods and his screenwriter career catapults. The minor characters in Adam's sequences become the stars of the others, more flamboyant drama-society stand-outs who wind up swapping lovers, junking loyalties, and, later on, comparing career choices: a vivacious hanger-on who eagerly settles for pastoral marriage to a reform-school teacher. . . until her old lover (father of her oldest child), now a TV star, re-sparks her ambition; a nonconformist professor who brings his black American second wife to meet his old colleagues in the new English academia, industry-supported and besieged with US-style student insurgence. All these situations are intriguing, and the badinage (though monotonous in such bulk) rips along, but the colors and depths of absorbing fiction simply don't exist in such sketchy surroundings; presumably when this series is aired here (beginning January 9 in the N.Y. area), flesh-and-blood actors and color photography will supply precisely those missing ingredients.