. Textbook of botany. Botany. 13^ TEXTBOOK OF BOTANY. Fig. 8i. — A small part of a cross sec- tion through a young portion of the stem of a bean; a, epidermis; b, cortex; c, bast; d, cambium; e, wood; /, pith. end to swing about in a way that will be ex- plained more ftally in Chapter XV. In all va- rieties the stem branches freely, each branch begin- ning as a bud in the axil of a leaf, and practically all that will be said about the stem applies also to the branches. 162. Inner Structxu'e of the Stem. — For this study we may use a cross section through the youngerpart either of the main stem
. Textbook of botany. Botany. 13^ TEXTBOOK OF BOTANY. Fig. 8i. — A small part of a cross sec- tion through a young portion of the stem of a bean; a, epidermis; b, cortex; c, bast; d, cambium; e, wood; /, pith. end to swing about in a way that will be ex- plained more ftally in Chapter XV. In all va- rieties the stem branches freely, each branch begin- ning as a bud in the axil of a leaf, and practically all that will be said about the stem applies also to the branches. 162. Inner Structxu'e of the Stem. — For this study we may use a cross section through the youngerpart either of the main stem or of a good-sized branch (Fig. 8i); the section should be cut between the points of attachment of two leaves. In such a section we shall observe that the vascular bundles are arranged, like the bundles of the pine, in a hol- low cylinder, which in the cross section looks like a ring. Between the wood and the bast of each bundle are one or two layers of cambium cells. In a section through an older part of the stem (Fig. 82), we find that the cambium makes a complete ring, and that its cells have begun to divide so as to form more wood on the inside and more bast on the outside of the ring. The bean stem therefore grows in thick- ness just as the pine stem does; but since the bean plant lives only one season, its stem never grows to be very 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
Size: 1726px × 1448px
Photo credit: © The Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1910, booksubjectbotany, bookyear1917
