クロモの葉と莖とに於ける Chlorosis の相違及これに及ぼすHormone の影響

Abstract

1. In Hydrila the chloroplast of the leaf shrinks by dark-treatment, but does not disappear.2. The addition of artificial hormone makes the chloroplast in the leaf shrink more than the control both in the light and in the dark owing to the accelerating effect of hormone on the consumption of nutrient for growth.3. The degree of shrinkage of chloroplast in the leaf effected by hormone is proportional to the hormone concentration within the experienced range of 10-8-10-5.4. The chloroplast number in unit area is inversely proportional to the hormone concentration 10-8-10-5.5. When the chloroplast of the leaf which has shrunk by etiolation is exposed in the light it does not immediately recover its normal size but shrinks more for a while.6. The nutrient supplied by the photosynthesis of the chlorophyll which has recovered from chlorosis after the reexposure in the sun causes the recovery of the normal size of chloroplasts.7. The nutrient given in solution keeps chloroplast from shrinking and helps to maintain its size.8. On the stem the shrinkage of chloroplast in chlorosis proceeds until the chloroplast vanishes.9. The recovery of chlorosis in the stem by the exposure in the light, appears to be the recapitulation of the size of chloroplast.10. The chloroplasts in the leaf and in the stem are divided in two types, that is, the true chloroplast type in the leaf and the amyloplast type in the stem.