The present work is a study of the chromosome behaviour during meiosis of Rumex acetosa after the treatment with colchicine. In addition to the special effect of colchicine on spindle mechanism, chromosome distribution and cell division, pollen derived from treated pollen-mother-cells were used for pollination. Pollen-mother-cells derived from the affected archesporial cells were found to be tetraploid. But no tetravalent in doubled pollen-mother-cells was observed during the 1st metaphase, and a few univalents and many bivalents were seen. In the same materials, the number of X-Y complexes was greater than that of X-X. In the 1st meiotic division of treated pollen-mother-cells so called c-bivalents were not observed, but univalents were seen scattered all over the cell. In both the 1st and 2nd divisions, various irregularities due to the after-effect of colchicine were found, which gave rise to polynucleate cells or asymmetric polyads. The giant cells carrying a large number of small chromosomes found among young pollen grains were supposed to be induced by the primary or secondary effect of colchicine. The pollination of pollen involving many large grains induced by colchicine treatment, and that of pollens containing many small grains induced by over-treatment resulted in large and small seeds respectively.
The pigments occurring in the violet-red and the blue flowering variety of Japanese Iris (Iris ensata THUNBERG var. hortensis MAKINO et NEMOTO) have been isolated and studied. After purification the pigments from the petals of these two garden varieties were found to be identical with each other. The colouring matter is an anthocyanin, which yields, on hydrolysis with boiling 20 per cent. hydrochloric acid, glucose and a sugar-free pigment. The latter was identified as malvidin chloride, C17H15O7Cl. The number of glucose molecules in the glucoside as well as the positions of the glucosidic linkage will be investigated later.