It has long been known that variations in the skin of fruits influence their keeping quality. This is particularly true in the case of apples (3, 4) where skin condition is recognized as a determining factor in the amount of wilting in storage, susceptibility to scald and other physiological troubles, as a mechanical protection for the underlying tissues, and as a partial regulator in connection with gaseous exchange. That different varieties of apples differ in skin thickness, amount of waxy coating, and permeability of the skin to gases, especially water vapor, is known in a general way, but little is recorded with respect to their quantitative differences. While the work of Cummings and Lombard (1), Magness and Diehl (4), Riviere and Pichard (5), and of Heinicke (2) is of value in indicating the water loss in relation to the original weight of the whole fruit, it throws but little light on skin permeability because the various workers, with the exception of Heinicke who worked on a single variety only, failed to calculate their data on an area basis or to account for the loss through the stem and calyx ends. An opportunity was presented in 1929 to determine under comparable conditions the skin permeability, as measured by evaporation loss, of sixteen varieties of apples, eleven of which were available from two different localities. The fruit used in each case was part of the material assembled for quantitative studies of the cutin and waxy-coating of apples which we have had under way for some time. While the data represent material collected in one season only, it is believed they portray fairly accurately what limits of variation and what varietal differences may be encountered, since all the material was examined under comparable conditions. In these experiments determinations were made of evaporation losses from normal fruit and from fruit in which the stem and calyx ends were blocked by means of paraffin. The results of these determinations are of interest and importance in that they provide quantitative information upon the varietal differences with respect to the total evaporation loss from the whole apple surface and from the skin exclusive of the stem and calyx openings. Data are given for varieties grown in two dissimilar apple regions,