Electron microscopic picture of a cross-section through style cells of Strelitzia reginae. The secondary walls are extremely thickened and interspersed by pits of wide lumina. N Nucleus, P Plastid, V Vacuole. (E. KRONESTEDT, B. WALLES, 1986)

Connecting intercellular strands between cells of the palisade parenchyma of Phaseolus vulgaris. The strands seem to be made up from an intercellular substance (pectin ?). They are no plasmodesmata. Their diameter is 0.1 - 0.2µm.
(C. E. JEFFREE, J. E. DALES, S.C. FRY, 1986)