[in Japanese]

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Chrysanthemums are self-sterile. Statistical studies about this fact were reported by the author under the title of “Pollination and Self-sterility of the Chrysanthemum” on the Report of Japanese Association for the Advancement of Science
Vol.VI in 1930.
This report describes the structure of the embryo-sac in the pistil of the chrysanthemum and the result of the investigations into the self-sterility and the crossfertility of the plant through the observation under microscope about the state ofthe embryo-sac of the pistils pollinated eighther by themselves or by crossing to clarify the structure of the embryo-sac in the ovary of the plant.
The results obtained by this observation are as follows:
(1) The tubular florets of the chrysanthemum are proteandrous.
(2) It tekes pistils 2 to 30 hours to grow over the top of the tubular florets.
It takes stigmas 1 to 2 days to ripen dichotomously. The differentiation of the time of growth is caused by weather and temperature in Tokyo in the first few weeks of November.
(3) The pistils of the chrysanthemum have an anatropous ovule wrapped by integument of one lobe.
(4) By observations under microscope on the embryo-sac in the mature pistil selfpollinated in strict seclusion from pollens of other flowers (of different variety), the author found that the embryo-sac began to wither on the 20th day after pollination, and that after more than 30 days the cells consisting of the tissues had lost the turgordruck and withered completely without any symptom of fertilization.
(5) Mature stigumas grow over tops of tubular florets contract down to, or a little lower than upper rims of them in about 5 hours after cross-pollination.
(6) Following facts were obtained as the results of observations under microscope about embryo-sacs of mature pistils (of chrys.) made every 2 hours after cross -pollination.
(A) Pollens of other flowers (of different variety) on the mature stigma germinate easily and soon.
(B) Pollen tubes pass inside the style, and some of them reach the micropyle as soon as 2 hours after pollination.
(C) Within 14 to 15 hours after pollination the egg cell finish fertilization.
(D) In 29 hours after pollination embryo with considerably mature albumen is generated.

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