. Plant life and plant uses; an elementary textbook, a foundation for the study of agriculture, domestic science or college botany. Botany. 420 THE VASCULAR PLANTS. Fig. 211. — Shows the method by which the sporangium, by means of its an- nulus, discharges the spores. ture is produced by a spore, it is, of course, a gametophyte. The prothallia of true ferns are small, heart-shaped, flat, green bodies. (See Figure 212.) They produce their archegonia and antheridia on the under surface. (See Figure 213.) The sperms of pteridophytes are larger than those of bryophytes and have many cilia. The arc
. Plant life and plant uses; an elementary textbook, a foundation for the study of agriculture, domestic science or college botany. Botany. 420 THE VASCULAR PLANTS. Fig. 211. — Shows the method by which the sporangium, by means of its an- nulus, discharges the spores. ture is produced by a spore, it is, of course, a gametophyte. The prothallia of true ferns are small, heart-shaped, flat, green bodies. (See Figure 212.) They produce their archegonia and antheridia on the under surface. (See Figure 213.) The sperms of pteridophytes are larger than those of bryophytes and have many cilia. The archegonia have short necks and their venters are em- bedded. (See Figure 214.) After fertilization, the sporophyte (the fern plant) grows out of the archego- nium and up from the prothallium, the first leaf usually appearing just above the notch of the heart. Where very young ferns are found you may often find prothallia either still attached to them, or without the sporophyte yet showing. (See Figure 212.) Pro- thallia are often found on damp brick walls and on flower pots in old green- houses in which ferns are grown. The growth of new fern leaves from their underground stems is more conspicuous than their growth from prothallia, and when ferns are planted in yards or gardens the underground stems are used. They send up new fronds each season. 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 Coulter, John G. (John Gaylord), b. 1876. New York, American Book Co
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectbotany, bookyear1913
