AbstractUntreated and chloroform-washed leaf surfaces of forty-three species of mosses have been examined with the scanning electron microscope. Of these, twelve species showed well developed superficial wax comparable with the epicuticular wax of flowering plants. A further eight had at least traces of surface wax of similar character. All the species which display a glaucous bloom to the naked eye have strongly developed surface wax, and all the species with demonstrable wax are endohydric in their adaptation to water use and movement.