FOUR STORIES (245 pp.)Sigrid Undset Knopf ($3.75).
THE LITTLE KAROO (188 pp.)Pauline SmithVanguard ($3.50).
The short stories in these two collections have widely separate backgroundsNorway and South Africabut they both deal with the early 20th century, and the societies described in both are like cocoons with no hint of the world outside or the tumultuous sprawl of history.
The late, famed Nobel prizewinner Undset (she died in 1949) writes of desperate Norwegian spinsters who are roughly used by all who know them, of babies who bring brief happiness to love-starved households and then sicken and die, of people who hesitate to rescue others...