e 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

Reaction velocities; enzymes as catalysts; general properties;
extracellular and intracellular enzymes; chemical nature;
nomenclature and classification; occurrence and preparation;
general and individual enzymes; nature of enzyme action;
accelerators and inhibitors; coenzymes and antienzymes; zymogens;
physiological uses; further studies needed; references 181-201

CHAPTER XV--THE COLLOIDAL CONDITION

"Colloids" and "crystalloids"; the colloidal condition a
dispersion phenomenon; nomenclature and classification;
conditions necessary to the formation of sols; gel-formation;
general properties of colloidal solutions; suspensoids and
emulsoids; adsorption; catalysis affected by the colloidal
condition; industrial applications of colloidal phenomena;
natural colloidal phenomena; references 202-220

CHAPTER XVI--THE PHYSICAL CHEMISTRY OF PROTOPLASM

Heterogeneous structure of protoplasm; protoplasm a colloidal
gel; water; salts; osmotic pressure; surface boundary phenomena;
electrical phenomena; acidity and alkalinity; summary; vital
phenomena as chemical and physical changes; references 221-238

CHAPTER XVII--HORMONES, AUXIMONES, VITAMINES, AND TOXINS

External and internal stimulants; hormones; vitamines; auximones,
toxins 239-248

CHAPTER XVIII--ADAPTATIONS

General discussion; adaptations, accommodations, and adjustments;
chromat