An analysis of the dermis and a study of collagen and lipid biosynthesis by fibroblast cultures were carried out in one case of epitheliogenesis imperfecta in a new born calf. This was found to be not only an epidermal disease with fissures and blisters within basal cells on the basement membrane but also a metabolic disease affecting the dermal fibroblasts. These fibroblasts showed a significant decrease in collagen biosynthesis with an increase in the percentage of type III collagen and also a decrease in the biosynthesis of lipids, especially glycerides and cholesterol.