. Lessons in botany. Botany. PART OF MOVEMENT Of LIQUIDS IN PLANTS. 67 irough which a colored solution has been lifted by transpiration, we can le small groups of the minute cells in the cambial ring which are col- red. These groups of cells which form strands running through the stem are rocambium strands. The cells divide and increase just like the cambium :11s, and the older ones thrown off on either side change, those toward the :ntre of the stem to wood vessels and fibres, and those on the outer side to ast cells and sieve tubes. 123. Fibrovascular bundles in the Indian corn.—In fig. 54 i
. Lessons in botany. Botany. PART OF MOVEMENT Of LIQUIDS IN PLANTS. 67 irough which a colored solution has been lifted by transpiration, we can le small groups of the minute cells in the cambial ring which are col- red. These groups of cells which form strands running through the stem are rocambium strands. The cells divide and increase just like the cambium :11s, and the older ones thrown off on either side change, those toward the :ntre of the stem to wood vessels and fibres, and those on the outer side to ast cells and sieve tubes. 123. Fibrovascular bundles in the Indian corn.—In fig. 54 is repre- ssed a. fibrovascular bundle of the stem of the Indian corn. The large :11s are those of the spiral and reticulated id-annular vessels. This is the woody artion of the bundle, or xylem. Oppo- te. this is the bast portion or phloem, arked by the lighter colored tissue at i. he larger of these cells are the sieve bes, and intermingled with them are nailer cells with thin walls. Surround- g the entire bundle are small cells with ick walls. These are elongated and the pering ends overlap. They are thus :nder and long and form fibres. In eh a bundle all of the cambium has .ssed over into permanent tissue and the indie is said to be closed. 124. Rise of water in the vessels.— uring the movement of the water or. Fig- 54- Transection of fibrovascular bundle of Indian corn, a, toward periphery of stem ; g-, large pitted vessels ; j, spiral Ltrient solutions upward in the stem the vessel ; r, annular vessel; /, air cavity . r ,. , ,. j. . formed by breaking apart of the cells; ssels of the wood portion of the bundle i, soft bast, a form of sieve tissue ; p, certain plants are nearly or quite filled, ^in-walled parenchyma. (Sachs.) root pressure is active and transpiration is not very rapid. If, however, on y days transpiration is in excess of root pressure, as often happens, the ssels are not filled with the water, but are partly filled with certain gases cause the air or ot
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