A study of permeable seeds soaked in water containing stains showed that there were no local regions through which the water passed. The stains passed through all regions of the seed coat. Coating the micropylar region with vaseline retarded germination, but had no effect upon the percentage of germination at the end of three days. In seed coats through which the stain had passed, the light line was not stained. Some stain was found in the canals which crossed the light line, and much more in the cell cavities. There was no evidence that the stain had permeated the substance of the light line. It was able to cross the light line only when pores were present. In impermeable seeds the stains passed readily to the light line. (Pl. V, fig. 7.) It was evident that the absorption of water was not prevented by either the cuticularized layer or the cone-shaped structures of the Malpighian layer, but by the light line. The region outside of the light line became stained in a few hours, but there was no trace of the stain within the light line after the seeds had remained a week in the stains. Alcohol did not penetrate the seed coat more readily than water. A COMPARISON OF PERMEABLE AND IMPERMEABLE SEED COATS. No difference in chemical structure was found between the coats of permeable and impermeable seeds. The principal differences were in the character and amount of thickening of the cell walls. In many of the permeable seeds some of the canals were found to extend across the light line, but this was not true for all permeable seeds. (Pl. V, fig. 8.) Oblique sections of permeable seed coats showed that the cell cavities, although reduced to mere pores by the thickening of their radial walls, extended across the light line into the base of the cones, thus forming a passageway through which the stains passed to the larger portions of the cell cavities below the light line. (Pl. V, fig. 4.)