Abstract
After the Yoshida sarcoma was transplanted into B-strain rats, one of them developed a tumor which was characterized by having a high percentage of tetraploid tumor cells.
Using this tumor material, the facility of invading the lung tissue of the diplo-and tetraploid karyotypes, was examined. The result of observations indicates that the infiltration ability of tetraploid tumor cells into the lung tissue was much stronger than that of the diploid cells. On the other hand, the vast majority of tumor cells forming the solid tumor which had developed in the peritoneal cavity were of the diploid type.
