Definition; general structure; hydrolysis of the natural glucosides; general properties; the phenol glucosides; the alcohol glucosides; the aldehyde glucosides; the oxycumarin glucosides; the cyanophoric glucosides; the mustard-oil glucosides; the pigment glucosides; the digitalis glucosides; the saponins; physiological uses; biological significance; references 76-93 CHAPTER VII--TANNINS General properties; occurrence; chemical constitution; classes; some common tannins; physiological uses; biological significance of tannins in fruits; references 94-101 CHAPTER VIII--PIGMENTS Types and classes; the chlorophylls, chemical constitution, similarity of chlorophyll and hæmoglobin, properties of the chlorophylls; the carotinoids, carotin, xanthophyll, lycopersicin, and fucoxanthin; phycoerythrin and phycophæin; the anthocyans; the anthoxanthins; the production of ornamental pigments in flowers, etc.; the functions of pigments; references 102-123 CHAPTER IX--ORGANIC ACIDS, ACID SALTS, AND ESTERS Chemical constitution; some common organic acids; physiological uses of organic acids; biological significance of fruit acids and esters 124-128 CHAPTER X--FATS AND OILS, WAXES, AND LIPOIDS General composition; fats and oils, occurrence, chemical constitution, acids which occur in natural fats, alcohols which occur in natural fats, hydrolysis and synthesis of fats, extraction of oils from plant tissues, identification of fats and oils, physiological use; the waxes; the lipoids, lecithin, other plant phosphatides, plant cerebrosides, physiological uses of lipoids; references 129-145 CHAPTER XI--ESSENTIAL OILS AND RESINS Definitions, classes, occurrence; the essential oils; the resins; physiological uses and biological significance of essential oils; references 146-150 CHAPTER XII--THE VEGETABLE BASES Composition and groups; the plant amines; alkaloids; the purine bases; the pyrimidines; the nucleic acids, composition and uses; references 151-163 CHAPTER XIII--PROTEINS Importance; general composition; amino-acids and peptid units; individual amino-acids; composition of the plant proteins; general properties of proteins; classification; differences between plant and animal proteins; extraction of proteins from plant tissues; synthesis in plants; physiological uses; references 164-180 CHAPTER XIV--ENZYMES