. College botany; structure, physiology and economics of plants. Botany. 290 COLLEGE BOTANY gins and tlie upper surface is marked into rather definite ai'cas which give it a superficial resemblance to an animal liver (Fig. 138) and therefore the common name "; In the center of each area is a small opening into a chamber which corresponds to the, area. The epidermal cellsi are transparent, but arising from the floor of this chamber ai'e many delicate chlorophyll-bearing cells. However, ohlorophvll is not restricted to these cells, but is also foimd in other cells. On the low
. College botany; structure, physiology and economics of plants. Botany. 290 COLLEGE BOTANY gins and tlie upper surface is marked into rather definite ai'cas which give it a superficial resemblance to an animal liver (Fig. 138) and therefore the common name "; In the center of each area is a small opening into a chamber which corresponds to the, area. The epidermal cellsi are transparent, but arising from the floor of this chamber ai'e many delicate chlorophyll-bearing cells. However, ohlorophvll is not restricted to these cells, but is also foimd in other cells. On the lower axial region are numerous hair-like structures known as rhizoids and corresponding to- the root hairs of the higher plants. They Fig. 137. fiq. i38. absorb Water and other raw food materials. The air has free access to the cells within the chambers and affords the necessary stip- ply of carbon dioxide. The sunlight passes through the upper epider- mal cells (Fig. 13 9). Therefore, it will be seen that the plant has all tbe factors necessary for pho- tosynthesis. The anterior end of the plant is notched, and it is from this point that the gTOwth occurs. The non-sexual reproduction is by means of small buds or gemmce which are borne in tiny cups or cupules, along the axial line of the upper surface. They are capable of growing into new gametophvtes (Fig. 137). The sexual organs (Fig. l-tO) are borne in receptacles or special branches arising from the upper surface of the thallus or gametophyte body. The archegonial and antheridial branches are borne on different gametophj-tes and therefore the plant is dicEcious. The archegonial branch (Fig. 110, a) bears a star- shaped body which gives rise to the archegonia. The archegoTiium is flask-shaped and the egg cell is borne in. Fig. 137.—Marchantia polymorpha showing two cupules bearing gemmule. Fig. 138.—Surface view of Marchantia poly- morpha very much Please note that these images are extracted from scanned page i
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