Abstract
Male mice from the BALB/c strain were irradiated with increasing doses of X-irradiation. Ten weeks after the treatment, meiotic preparations from the testes were made by an air-drying technique. The reciprocal translocation was the most frequent chromosome rearrangement seen. No relation was found between the nature of the rearrangements and the X-ray dose. The relationship between the X-ray dose and the rate of abnormal cells appears to be linear with a regression coefficient b = 0.017121 [plus or minus] 0.001048.