Abstract
By means of phase-contrast microscopy, vital staining, and fluorescence culture method, cytological and tissue culture observations were carried out with the leukemic cells of RF strain mice after X-irradiation. As the result the characteristics of lymphoblasts and myeloblasts were confirmed and also from the growth patterns of the cells from various organs of the leukemic mice it was possible to differentiate the two classifications of the thymoma type and the non-thymoma type of lymphocytic leukemias as already described in a previous report (Part 2). The results of this study support the view of the author on the onset mechanism of leukemia induced in RF mice by X-irradiation; namely, in the case of thymoma type lymphocytic leukemia leukemic changes originate in the thymus, whereas in non-thymoma type lymphocytic leukemia the leukemic changes originate in the spleen or in lymph nodes.
