Abstract
The writer has already indicated that the Japanese barley varieties are classified into four main ear-types, and also that these ear-types differ each other as to various quantitative characters of young and adult pIants. This paper dealt with the results on their genetical behaviors in the hybrids. 1. It was proved that two pairs of independently inherited genes, Uz-uz and L-1, were chiefly concerned with the determination of these ear-types. 2. As expected from the previous studies, marked differences in the coleoptile and culm lengths as weIl as in the lengths of ear and rachis-internode were recognized among the F2 phenotypes with diffaent combination of Uz, uz and L, 1 genes. These phenomena were here explained as the pleiotropisms of these genes. 3. The quantitative effects of the "dominant" genes, Uz and L, over the "recessive", uz and l proved to be somewhat incomplete, although the degree of incompletion was unnoticedly slight. 4. It was pointed out that the "coleoptile method" would serve to facilitate the breeding procedure of Japanese barley improvement, because some important characters of adult plants, such as ear-types, culm length, geographical adaptability and etc. could be predicted by the coleoptile length in their sdedling stages.
