Nature and development of plants . riant beds on the damp ground,especially where logs and brush have been burnt. The thallusshows the same general features that we have noticed in Riccio-carpus, being rather fleshy and creeping over the ground, to whichit is attached by numerous rhizoids. The simple air chambersnoted in Ricciocarpus are much enlarged and appear £b diamond-shaped or rhomboidal plates on the surface of the thallus (). Thin sections across the thallus shows that these airAiam-bers have a complex structure (Fig. 188). They origiirate inthe upper cells of the thallus and as
Nature and development of plants . riant beds on the damp ground,especially where logs and brush have been burnt. The thallusshows the same general features that we have noticed in Riccio-carpus, being rather fleshy and creeping over the ground, to whichit is attached by numerous rhizoids. The simple air chambersnoted in Ricciocarpus are much enlarged and appear £b diamond-shaped or rhomboidal plates on the surface of the thallus (). Thin sections across the thallus shows that these airAiam-bers have a complex structure (Fig. 188). They origiirate inthe upper cells of the thallus and as they enlarge they becomecovered by a well-developed epidermis which forms a chimney-like pore over the center of each cavity. From the bottom ofthe chamber numerous delicate chlorophyll-bearing cells arrangement of the tissues is again suggestive of the chlor- 256 REPRODUCTION OF MARCHANTIA enchyma of the leaf and it is manifestly protective and adaptedto photosynthesis. The structure of the lower cells of the thallus. Fig. 188. Section through the center of the thallus of Marchantia, show-ing one of the air chambers and chimney-like air pores in the epidermis—ch, palisade-like chlorenchyma arising from bottom of air chamber. Thelower cells of the thallus are nearly colorless and filled with watery solu-tions or mucilage, r, rhizoids; I, leaf-like plates of cells. and the distribution of the rhizoids and ventral plates are essen-tially as in Ricciocarpus.
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Keywords: ., bookcentury1900, bookdecade1900, bookpublisher, booksubjectplants
