The different part of the hypocotyl in cucumber seedlings exhibited different effect on the floral formation of excised cotyledons cultured in vitro. The percentage of the floral buds raised directly on the cultures was different when the heat shock treatment was taken on the cucumber seedlings with or without roots and with different length of hypocotyl. Among them the rootless seedlings got the highest percentage of floral formation, the rootless+1/2 hypocotyl the lowerest, and the control and rootless +3...