Abstract
According to the results of Cucurbita-crosses the author has investigated, bud pollen grains; at 5 p. m. of the day before anthesis were found to have already high germination power. but to be unable to germinate and grow on styles, because they were contained in anther wall and wet. If only anther dehiscence had been hastened by some way, bud pollen grains would be able to germinate and grow on styles even at 5 p. m. of the day before anthesis. In this experiment the author attempted to make successful pollination in the evening with bud pollen grains from artificially dehisced anthers and futhermore to elucidate the relation between the preparation for ger'mination and anther dehiscence by artificial methods. In hastening anther debiscence, two lrLethods were found to be effective : the high temperature treatment of bud male flowers from two d.ays before anthesis and the placement of bud male flowers in the laboratory in summer after the longitudinal cutting of anther wall at noon of the day before anthesis.
