In cotton seeds, epidermal layers (outer and inner) surrounded both integuments at most parts of the seed, except at the chalaza. Dye movement studies using carboxyfluorescein showed that the epidermal layers (palisade layer, fringe layer) separated the outer integument from the inner integument and the inner integument from the nucellus symplasmically. Dye movement from the outer integument to the nucellus occurred through the integumentary connective and the transition zone. The phenol-containing cells of chalazal cap could protect the primary solute pathway (between integumentary connective and hypostase) against pathogens. The hypostase appears to be a control site for solute transfer to the endosperm.