On the Starch of Evergreen Leaves and Its Relation to Photosynthesis during the Winter

The starch contents of evergreen leaves differ much at a given time according to the different species. Monocotyledons generally contain less starch than dicotyledons, gymnosperms, and pteridophytes, or even none in some species. 2. The starch in evergreen leaves, generally speaking, begins to decrease in November, reaching its minimum during January and the beginning of February, and increases again from the end of February. 3. Many evergreen leaves in Tokyo and other parts of middle and southern Japan contain more or less starch in the mesophyll, while it is entirely absent in some species in the coldest time of winter. 4. The starch found in evergreen leaves in winter is generally very little compared with that observed at other times of the year, but in a few species the starch is quite abundant. 5. This starch is formed by photosynthesis in winter, though feebly, and its translocation occurs in the same season. 6. The starch in the guard-cells becomes less or even entirely disappears in many species, while a few species contain a moderate amount throughout the winter. 7. The majority of evergreen leaves in the northern part of Japan nearly lose the starch from the mesophyll and guard-cells in winter, while a little starch is still found in some species. 8. The starch content of evergreen leaves is generally more abundant in spring than in late summer or early autumn. 9. The opening of the stomata in winter was observed in some evergreen leaves in Tokyo. 10. The entire absence of calcium oxalate crystals from the leaves in winter, as stated by Lidforss, could not be verified in the present investigation.