. Textbook of botany. Botany. 114 TEXTBOOK OF BOTANY lengthened and new branches and leaves are formed during the growing season. At the coming of winter, growth stops and scale leaves covered with resin are formed that protect the bud. When growth begins again in the spring, the scale leaves drop off; but their bases remain, forming a ring that looks like a thickening of the stem. By means of this ring one can see where the growth of one year ended and that of the next year began. From the thickened ring grow one or more branches, which have developed from buds in the axils of the fallen scal
. Textbook of botany. Botany. 114 TEXTBOOK OF BOTANY lengthened and new branches and leaves are formed during the growing season. At the coming of winter, growth stops and scale leaves covered with resin are formed that protect the bud. When growth begins again in the spring, the scale leaves drop off; but their bases remain, forming a ring that looks like a thickening of the stem. By means of this ring one can see where the growth of one year ended and that of the next year began. From the thickened ring grow one or more branches, which have developed from buds in the axils of the fallen scale leaves. If the terminal bud is destroyed or killed, the growth of the trunk ceases ; but commonly, in such a case, one of the branches near the top of the tree bends and grows up- ward, so that the tree continues to become taller. The stem of the fern grows only in length; but that of the pine grows both in length and in thickness. The trunk is slenderest at the top and gradually thicker toward the base, because the base is the oldest part and has been growing in thickness for the longest time. Inner Structiire of the Stem. — At the verj^ tip of. Fig. 65. — A pine tree that grew in a forest. Photograph by L. S. Cheney. 140. the stem (Fig. 66) are many small cells, which, during the growing season, are continually growing and dividing. In this region, too, are some very small swellings; these are the beginnings of new leaves and branches. Below the tip the cells are larger; farther down tliey are still larger, and dif- ferent groups of them are gradually taldng on the forms that. 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 Allen, Charles E. (Charles Elmer), b. 1872; Gilbert, Edward Martinius, joint author. Boston, New York [etc. ] D. C. Heath & co
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectbotany, bookyear1917
