In contrast to many television adaptations of stage presentations, the Zoe Caldwell "Medea," to be broadcast tonight at 8 on Channel 26, is not diminished by a transfer to the small box.

This fortuitous pairing of medium and story may be due in part to the essential intimacy of the Robinson Jeffers adaptation of Euripides. Although the passions are enormous, they are contained by the form of the play. The cast, with the exception of Jacqueline Brooks, who replaced Rosemary Murphy as the First Woman of Corinth, is essentially the same as the company that played at the Kennedy Center a year ago, and at least two of the performances have improved.

Caldwell is still incomparable in her Tony Award-winning performance as the awesomely vengeful Medea. Her intensity, panther-like fury and agonizing heartbreak are those of a woman driven mad by the emotional violence done to her by her husband Jason, who leaves her for a younger woman and then seems surprised that she might be upset. One of the strengths of Caldwell's performance is that her madness is not used as an excuse for her actions, but seems a plausible reaction to her husband's behavior. The grandeur of Medea's agony, and the horror of her revenge, are the cathartic elements of this play, and Caldwell makes the catharsis accessible.

Judith Anderson, playing the nurse, is shown to perhaps better advantage in this version than she was on the stage. Her performance is clean and wonderfully simple, and the close-ups of the camera allow her more subtlety. Jason, one of the world's all-time heels, seemed stiff and stupid when Mitchell Ryan was playing him here. Now Ryan plays Jason with the arrogance of a male who can discard a woman like a used chariot. And he doesn't make you wonder how Medea could ever have been so in love with him that for his sake she killed her brother, betrayed her father and left her own country for "this land of chattering Greeks."

The main flaws are technical: Caldwell's makeup seems too heavy and gives her a skin color startling in contrast to her pale children, and Ben Edwards' set is somewhat lost on the small screen. But the performances are there; not light entertainment, to be sure, but theater at its most serious.