A study of the effect of initial drying temperature on the apparent lignin content of various succulent plant tissues has been made. Air-drying, drying in vacuo at 60 °C., air-drying after removal of constituents soluble in cold water and in cold dilute ethanol, and oven-drying at 105 °C. have been compared.Drying of immature or succulent tissues at 105 °C. results in a markedly higher apparent lignin content (as determined by the 72% sulphuric acid method) than is obtained after drying under the other conditions specified. This difference may be of especial importance when it is desired to compare the lignin contents of tissues of different degrees of maturity, or which have received different treatments, as in comparison of ensiled with non-ensiled materials.The nitrogen and methoxyl contents of the lignin preparations isolated indicate that drying at 105 °C. results in the inclusion of nitrogenous or carbohydrate materials, or both, in the lignin fraction. Evidence that the interfering substances are mainly easily soluble and removable prior to desiccation was obtained. It is indicated that non-lignin methoxyl may be present in lignin preparations prepared from tissues dried at 105 °C.