The Chalk Garden; Starring Irene Worth, Constance Cummings, Donal Donnelly. Comedy by Enid Bagnold. Directed by John Stix.

Enriching is the word for Enid Bagnold's ''The Chalk Garden'' in the exceptionally satisfactory revival at Roundabout Stage One. Constructed around a central situation involving strong and fascinating characters, this serious 1955 comedy of manners and relationships compels the attention and stimulates the imagination.

The play opens on a windy June day as the quietly enigmatic Miss Madrigal (Irene Worth) waits to be interviewed by the patrician, headstrong Mrs. St. Maugham (Constance Cummings). Mrs. St. Maugham is considering applicants for the post of companion to her granddaughter, Laurel (Sallyanne Tackus). A precocious, fantasizing, badly spoiled teen-ager with a propensity for lighting fires, Laurel has proved more than previous companions could handle.

Once on the job, Miss Madrigal begins taming Laurel and reclaiming the inhospitably chalky soil of Mrs. St. Maugham's ill-cultivated garden. With a mixture of acquired wisdom and quiet common sense, she gains the sometimes reluctant respect of her employer. Miss Madrigal also wins the devotion of Maitland (Donal Donnelly), the family's houseman-of-all-work. Maitland -- a person of temperament like the rest of the menage -- has served five years in prison as a conscientious objector.

Employing epigram, metaphor, and superb dramatic craftsmanship, Miss Bagnold has created a comedy with attendant elements of mystery and morality play. Says the cavalier Mrs. St. Maugham: ''Love can be had any day. Success is far harder.'' Says the sadder and wiser Miss Madrigal: ''The dangerous thing about hate is that it seems so reasonable.''

''The Chalk Garden'' is not merely absorbing stage fiction. It is also a parable about stubborn self-will rationalizing itself as disinterested concern and about the danger of falsehoods that go unchecked. While the argument can be subtle and complex, the play's compassionate conclusion is stated with shining clarity. At its intelligent best, the Roundabout production matches the play's virtues.

Miss Worth's Madrigal embarks on her Sussex manor house adventure from a point of controlled inner stillness achieved in isolation and confinement. The actress then completes the portrait of a woman whose psychological insights and green thumb combine to prepare her for making the play's ultimate, crucial decision. Miss Worth illumines the comedy as she reveals the character. Her performance requires an adversary of mettle. This is supplied by Miss Cummings's superb portrayal of the traditionally autocratic and eccentric Mrs. St. Maugham.

The production also owes much to Mr. Donnelly's testy but touching Maitland, the temperamental mainstay of the establishment. Though not ideally cast as Laurel, Miss Tackus does succeed in conveying the insecurity and emotional hunger that underlie the adolescent's self-dramatization and calculated hysteria.

The well-tempered performance staged by John Stix is strongly served by Elizabeth Owens as Mrs. St. Maugham's beleaguered daughter, I.M. Hobson as an aging pillar of the judicial establishment, and by other members of an admirable cast. The handsome and glistening production has been designed by Roger Mooney (setting), Judith Dolan (costumes), and Martin Aronstein (lighting).