Development of the structure of the normal, smooth cuticle of the apple “Golden Delicious”

The epidermal and cuticular layers of the apple “Golden Delicious” during growth were studied electron microscopically with special reference to the cutin containing layer. The structure of the cuticle does not change essentially during the increase in thickness of the cuticle. A fibrillar structure of electron dense material occurs in the cuticle, most clearly in the young apple or in older stages when the wax is extracted. The cutinous substance expands inwardly during growth and in the full-grown stage the epidermal cells can be surrounded with cutinous material. Below a damaged cuticle a very strong cutinization has been observed.