ONE of the most important chemical functions of plant-cells is that synthesis of albuminous matter which serves for the formation of protoplasm. The living protoplasm, however, is composed of proteids entirely different from the ordinary soluble proteids, as well as from the proteids of dead protoplasm. In other words, if living protoplasm dies, the albuminous constituents change their chemical character. We observe that in the living state a faculty of autoxidation (respiration) exists, which is wanting in the dead condition; and Pfluger, in 1875, drew from this the conclusion that in protoplasm the chemical constitution of the living proteids changes at the moment of death.