False colour scanning electron micrograph of a longitudinal section through the stem of a pea plant, Pisum sativum. The micrograph shows xylem vessels, or water conducting vessels, which form part of the vascular system of the plant. Xylem cells are dead cells. They have lost their cytoplasm & the cross walls separating individual cells have broken down to form a continuous tubelike structure. Xylem cells form a large part of the stem. Their walls are strengthened, or lignified, to provide support for the plant. In annual plants, such as the pea, the strengthening is usually laid down in a spiral pattern (centre coiled spring). Magnification: X 63 at 35mm size. Original is bw print B725/128.