200x Magnification

In the 200x view, thin-walled parenchyma cells of the cortex stand to the right. Note the nuclei in these cells indicating they are living. Just to the left of these living parenchyma cells are the vascular tissues. Now you should be able to see some of the pits between cells. Spiral thickenings of xylem are also becoming visible in this region. These are a good diagnostic feature of xylem to look for in longitudinal sections of plant tissues.

400x Magnification

In the 400x view, the boundary between parenchyma cells of the cortex and vascular tissues is clearly evident. Patterned secondary walls of the xylem cells are now visible. Note these are spiral to the left and more scalariform or pitted to the right. Remember, xylem cells are sclerenchyma types. They lack nuclei because they are dead at maturity. The dead cells, whether tracheids or vessel members, provide continuous tubular pathways for water transport through the plant.

1000x Magnification

In this 1000x view, xylem cells cut in cross-section now clearly show the numerous pits between adjacent cells. Look closely to right center where some cell walls are cut in a median plane. Here, you can see how the walls alternate between thick and thin regions. The narrower regions of the walls are pits where primary cell wall material alone is the barrier between two adjacent cells.

100x Magnification

At 100x magnification, note the thin primary walls of cortical parenchyma tissues to the right. As you move deeper into the stem, cells of the vascular bundle cap sectioned here narrow. The open vertical space just to the left of these narrowed cells is a large xylem vessel. You should watch for these in longitudinal stem sections as they can indicate where the xylem vascular tissues are located. The perforation plate or boundary between two vessel members of the vessel is visible here. Just to the left of this are narrowed cells that are probably tracheids.