. Research methods in ecology. Plant ecology. HYDROHARMOSE 127 tion of them has been found but recently. This explanation has come from the work of E. S. Clements already cited, in which it was found that certain sun plants underwent no material structural change when grown in the shade, and that the same was true also of a few species which grew in two or more habitats of very different water-content. In accordance with this, it is felt that the xerophytic features found in amphibious plants are due to the persistence of stable structures, which were developed when these species were growing
. Research methods in ecology. Plant ecology. HYDROHARMOSE 127 tion of them has been found but recently. This explanation has come from the work of E. S. Clements already cited, in which it was found that certain sun plants underwent no material structural change when grown in the shade, and that the same was true also of a few species which grew in two or more habitats of very different water-content. In accordance with this, it is felt that the xerophytic features found in amphibious plants are due to the persistence of stable structures, which were developed when these species were growing in xerophytic situations. When it is called to mind that monocotyledons, and especially the grasses, sedges, and rushes, are peculiarly stable, it may be readily understood how certain ancestral characters have persisted in spite of a striking change of habitat. Such a hypothesis, can only be confirmed by the methods of experimental evolution, and a critical study of this sort is now under way. 171. Hydrophytic types. Hydrophytes permit a fairly sharp division into three groups, based primarily upon the relation of the leaf surface to the two media, air and water. In submerged plants, the leaves are con-. Fig. 36. Hippuris vulgaris: 1, submerged leaf; 2, aerial leaf. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Clements, Frederic E. (Frederic Edward), 1874-1945. Lincoln, Neb. , University Pub. Co.
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectplantec, bookyear1905
