Abstract
1. In order to gain information on artificially induced translocations in rice, dormant seeds, germinating seeds and panicles just before blossoming of two varieties were X-rayed. More than two hundreds strains thus obtained were observed from the second to the fifth generations after the treatment with regard to fcrtility and other characters. 2. In a greater part of strains, fertile and semisterile plants were found in approximately I : I ratio, while in sorne other strains, either fertile or semisterile plants were predominant : in a few strains. the fertility variation seemed to be continuous. In strains segregating into fertile and semi-sterile plants, the fcrmer produced no sterile plant in their offspring, while the latter continued segregation. In strains showing continuous variation, the progeny of semi-sterile plants generally showed a similar continuous variation.
