The Correlation of Physiological Differences and Varions Leaf Forms of an Aqnatic Plant

An analysis of the celluar constituents of the leaves of an aquatic fern, Marsilea vestita , was done after and during the formation of different leaf forms. Land leaves of Marsilea produced almost twice as much dry material, soluble carbohydrate, insoluble protein and soluble peptides compared to submerged leaves on a fresh weight basis, but on a dry weight basis there is tittle difference between the two types of leaves. the submerged leaf soluble nitrogen fraction consisted mostly of ammonia and free amino acids, while that of the land leaf probably con tained mostly peptides. Free arginine was present in large quantities in megaspores and as the plant matured, at the expense of the megaspore, the amount of arginine left in the pool diminished. A correlation was found between soluble sugar increase and leaf elongation, Just prior to the production of submerged leaves the developing leaves contained low levels of protein and soluble sugar, but high levels of soluble nitrogen and an increased amount of starch. A theory which involves metabolism was proposed to account for the leaf form changes in Marsilea.