The effects of x‐radiation on limb development and regeneration in Amblystoma

The regeneration of the early fore limb bud of Amblystoma larvae has been prevented by exposure to x‐radiation. Histological studies show that the failure to regenerate is due to a destruction of the undifferentiated mesenchyme cells which normally furnish the materials for regeneration. Data have also been gathered as to the minimal dosage of x‐rays necessary to prevent the regeneration of the early limb bud.