chapter XV

before undertaking the study of the proteins (this order is actually followed in some texts on Physiological Chemistry). But from the standpoint of the consideration of the various groups of organic components of plants, it seems a better arrangement to consider these groups in sequence, and then to discuss the various physical-chemical phenomena which govern their activity. However, it is recommended that the student refer at once to Chapter XV for an explanation of any terms used here, which may not be familiar to him; and that after the study of