The Effect of Gamma Rays on Man-in-the-Moon Marigolds, a genuinely depressing play broken only by extremely black humor, is a societal reflection of the phenomenon of the dysfunctional single-parent family in the latter half of the twentieth century. In fact, the work is vaguely autobiographical. Beatrice (Betty) Frank was the maiden name of playwright Paul Zindel’s mother. During his high school years, his mother, who was separated from Zindel’s father, also boarded and cared for terminally ill patients. Zindel himself was a high school chemistry teacher, so it is no great stretch to equate the character of Tillie, with her love of science, to Zindel. He admitted that he based the character of Beatrice, although with exaggeration, on his mother.

The most pervading image of the play is that of the mutations that derive from exposure to radiation. Tillie’s science experiment is the literal representation of this theme. The extension of this image is how exposure to difficult issues in life has mutated Beatrice and how, in turn, her actions have mutated Tillie and Ruth. Tillie points out that seeds too close to the point of radiation die, seeds a moderate distance from the source mutate, and seeds farthest from the source are unchanged. Ruth, who is too close to Beatrice, is stunted—some part of her killed in the same way that some vital part of Beatrice was blighted—but Tillie has become the hybrid mutant, beautiful in her synthesis of the cruel and the creative.

The work explores the world of parent/child relationships and seems to reach the conclusion that children must create their own identities. Beatrice probably believes that her verbal and emotional abuse of her children toughens them, helping them face the real world. In actuality, this abuse simply isolates them from that world, so that, eventually, reality resolves itself into the sordid, removed environment in which they all exist.

Both Ruth and Tillie need to love Peter, the pet rabbit. The pet is central to their existence. Beatrice sees the rabbit as coming between herself and her children. The rabbit offers them the comfort and acceptance withheld by their mother. After many threats, Beatrice kills the rabbit in retaliation for Ruth’s cruelty. The result destroys Ruth, who has lost her only source of love, but that same act strengthens Tillie, with her newly found senses of personal importance, acceptance, and self-worth and her love of science and the atom.