1. The number of chromosomes in the pollen-mother-cells of
Tropaeolum majus (SUTTON′s Scarlet Tall) is 14.
2. In the postsynaptic phase there are 4, paired chromosomes forming 44 rings telosyndetically and some bivalent chromosomes forming long rods, the other univalent ones forming shorter rods in irregular forms.
3. In the diakinesis both chromosomes paired and unpaired, somewhat contract and are arranged in pairs.
4. The wall formation in the dividing pollen-mother-cells is centripetal and usually it begins at once when the second division is over and 4 spores are formed. But sometimes it begins in an earlier stage, even at the end of the first division, first dividing the cell horizontally, and after that the second wall being formed crosswise to the newly formed cell wall.
5. The pairing of the chromosomes in the somatic cells is also demonstrated in
Tropaeolum.
6. In the cortical parenchyma of
Tropaeolum there are found amitotic figures, often 3 or more nuclei being present in a cell.
In conclusion, I wish to express my acknowledgment and gratitude to Prof. K. Fujii of the Botanical Institute of Tokyo Imperial University for the kind advice and criticism throughout the work. My cordial thanks are also due to Dr. Y. Noda, the director of The Osaka High School, for the equipment of required instruments, and other facilities given for the present research.
抄録全体を表示