. Botany, with agricultural applications. Botany. ANATOMY OF THE OLDER PORTIONS OP THE ROOT 149 equal in number to those on the outside. The new cells next to the xylem become modified into xylem, at first filUng in between the strands of the primary xylem, and the cells formed next to the phloem are changed into phloem. In this way the vascular. Fig. 132. — Diagrams showing how the xylem and phloem of roots are increased. A, cross section of a root showing xylem {x) and phloem (p) before the cambium is formed. B, cross section of root showing xylem (x) and phloem (p) after the cambium ring (c
. Botany, with agricultural applications. Botany. ANATOMY OF THE OLDER PORTIONS OP THE ROOT 149 equal in number to those on the outside. The new cells next to the xylem become modified into xylem, at first filUng in between the strands of the primary xylem, and the cells formed next to the phloem are changed into phloem. In this way the vascular. Fig. 132. — Diagrams showing how the xylem and phloem of roots are increased. A, cross section of a root showing xylem {x) and phloem (p) before the cambium is formed. B, cross section of root showing xylem (x) and phloem (p) after the cambium ring (c) is formed. C, cross section show- ing the xylem (x) and phloem (p) shown in A and B and the new xylem (a) and new phloem (6) which have been formed by the cambium (c). Adapted from J. M. Coulter. cyhnder is increased in diameter as shown at C. In roots which five many years, like those of trees, the layers of xylem formed each year form annual rings like those occurring in woody stems; and the outer layers of the phloem, with the cortex and other tissues outside of the phloem, constitute a bark hke that of woody stems. In fact, it is only by the presence of their early root anatomy that sections of such roots can be told from sec- tions of stems. In some fleshy roots, as Beets illustrate, a num- ber of cambium rings form outside of the first one, and the growth resulting from each appears as a ring when a cross-section of the root is 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 Martin, John N. (John Nathan), b. 1875. New York, John Wiley & sons, inc. ; [etc. ,etc. ]
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Keywords: ., bookcentury1900, bookdecade1920, booksubjectbotany, bookyear1920
