Tonight we pair candidates for the two greatest thirties family melodramas-Stella Dallas and Imitation of Life-astonishing items both, if only for the way they half acknowledge and half disguise the devoted self-effacement of mothers. Stella Dallas is the purer "weepie," though both are object lessons in social striving and class ambition that are guaranteed to leave you gape-mouthed. King Vidor's 1937 version of Stella Dallas is in many ways a slavish copy of Henry King's 1925 silent, also produced by Samuel Goldwyn. But the subtle adaptations for sound include Vidor's closer identification with this brassy Stella, brilliantly incarnated by Barbara Stanwyck. Her "low-class" vibrancy brings off what by rights should be a thoroughly archaic storyline in which Stella's marriage is ruined, it seems, by her dimestore fashion sense. As in most "women's weepies," the men are a pathetic lot-either too much (Stella's pal Alan Hale, "a good judge of horseflesh") or too little (Stella's husband John Boles, an actor who elsewhere perfected spinelessness for director John Stahl). Stella's daughter (Anne Shirley), for whom she sacrifices all, is unworthy, though that is part of the point: no doubt the excesses of mother love in the thirties weepie can be taken today as appallingly degrading. And yet there is something so self-contained, so strong, in Stella's sacrifice that it can also be understood as her triumph over society. That's the universal trick of the best "women's weepies." That's what makes them so watchable still. If you can't change the rules of a man's world, you can create a world elsewhere where those rules don't apply. Stella Dallas marks the epitome of this triumph. Scott Simmon