Every year, thousands of light-skinned and straight-haired negroes cross the line. Not the Mason Dixon line but another border of far greater significance--the line which divides white from colored in American society.

"Lost Boundaries," currently playing at the University Theater is the story of such a negro. After graduating from medical school, Dr. Carter (Mel Ferrer) reluctantly decides to "pass" when he finds that no negro hospital will accept him because he is too light and no white institution will take him because he frankly admits he is a negro.

Along with his attractive young wife (Beatrice Pearson) Dr. Carter settles down in the little New Hampshire town of Keenham, where he raises his children and wins the affection of the community through his untiring medical service. For 20 years, he is completely accepted; then, abruptly exposed. The impact of this exposure on the little New England village is like that of flint on stone. Sparks fly--the sparks of bitter reaction--and the result is keen drama.

This movie succeeds, even more effectively than other recent efforts such as the play "Deep are the Roots" or "Home of the Brave" in making the casual spectator think hard about the negro "problem." This is true mainly because the negroes it depicts as central characters are intelligent, sensitive, attractive people whose problems the audience does not hesitate to share. You will catch yourself wondering what you would do in a similar predicament.

The film gets across the hard-to-grasp concept that being a negro is, like everything else, a relative thing. It does not insist that all negroes are bright, pleasant people. It shows along with the neat, smart negroes, the ugly, stupid negroes, demanding of the audience only a degree of intellectual honesty in separating the two kinds, just as it would separate acceptable whites from unacceptable.

Mel Ferrer and Beatrice Pearson deserve great credit for their natural and absorbing performances, particularly Ferrer, who the movie magazines tell us hates acting worse than castor oil. Also memorable are the performances turned in by Susan Douglas and Richard Hilton, the two young stars who play the parts of the doctor's children.

If you like well paced and stimulating films, try this.