. Elementary botany. Botany. Fig. 255- Nearly mature sporogonium of Riccia crystallina; mature spore at the right. Fig. 236. Riccia glauca; archegonium containing neariv mature spo- rogonium. j,v, spore-producing cells surrounded bv single layer of sterile cells, the wall of the sporogonium. fours are the spores. At this time the wall of the spore-case dis- solves, the spores separate from each other and fill the now en- larged venter of the archegonium. When the thallus dies they are liberated, or escape between the loosely arranged cells of the upper surface. 481. A new phase in plant life.—
. Elementary botany. Botany. Fig. 255- Nearly mature sporogonium of Riccia crystallina; mature spore at the right. Fig. 236. Riccia glauca; archegonium containing neariv mature spo- rogonium. j,v, spore-producing cells surrounded bv single layer of sterile cells, the wall of the sporogonium. fours are the spores. At this time the wall of the spore-case dis- solves, the spores separate from each other and fill the now en- larged venter of the archegonium. When the thallus dies they are liberated, or escape between the loosely arranged cells of the upper surface. 481. A new phase in plant life.—Thus we have here in the sporogonium of riccia a very interesting phase of plant life, in which the egg, after fertilization, instead of developing directly into the same phase of the plant on which it was formed, grows into a quite new' phase, the sole function of which is the development of spores. Since the form of the plant on which the sexual organs are developed is called the gamelophyte, this new phase in which the spores are developed is termed the sporo- phyie. Now the spores, when they germinate, develop the gamelo- phyte, or thallus, again. So we have this very interesting condi-. 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 Atkinson, George Francis, 1854-1918. New York : H. Holt
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