Abstract
1. The fertility of the Edgeworthia fJapyrffera, which had been considered as selfsterile, was tested in the fQllowing way. a) Self pollinatiation was conducted with 2 different varieties, namely, "Kochl shu" and "Shizuoka-shu. " b) Both cross pollihation among the same variety and intra-specific, pollination bctween 2 different varieties, were darried out. Thus the relative fertility of each of the above mentioned groups was tested. 2. As the result of the test, it was found out that both of the above 2 varieties are sterile due to their self incompatibilities. 3. It may be ascribable to the cross pollination among the same variety that "Shizuokashu" has a good fruitsetting in the plantation. 4. "Kochi-shu" seldom bears fruit though itblooms. This is probably due to the fact that this is a variety of asexual propagation by suckers. Therfore, though cros pollination is made, the tre-es belong to the same clone and the result is sterility as in the case of self po1lination. 5. Intra-specifc pollination such as ("Kochishu" x "Smzuoka hu " "Shl'uoka shu" x "Kochi-shu") always results in good fr'ditsetting. But as "Kochi shu" blooms earlier than" Shl u oka-shu", there is little c'nance of a crossing comirg out though their plantations may be closs to each other. As a matter of course, therfore, their fertility is very low.
