Introduction. The Structure of Milk: Implications for Sampling and Storage. The Milk Lipid Globule Membrane. Particulate Constituents in Human and Bovine Milks. Sampling and Storage of Human Milk. Sampling and Storage of Bovine Milk. Physical Properties of Human and Bovine Milks. Determinants of Milk Volume and Composition: Lactogenesis in Women: A Cascade of Events Revealed By Milk Composition. Milk Volume and Caloric Density of Human Milk. Milk Volume and Caloric Density of Bovine Milk. Regional Variations in the Composition of Human Milk. Effects of Gestational Age at Delivery on Human Milk Components. Miscellaneous Factors Affecting Composition and Volume of Human and Bovine Milks. Carbohydrates in Milk: Analysis, Quantities and Significance. Nitrogenous Components of Milk: Human Milk Proteins. Nonprotein Nitrogen Fractions of Human Milk. Enzymes in Human Milk. Hormones and Growth Factors in Human Milk. Nucleotides and Related Compounds in Human Milk. Protein and Amino Acid Composition of Bovine Milk. Nonprotein Nitrogen Compounds in Bovine Milk. Enzymes Indigenous to Bovine Milk. Hormones and Growth Factors in Bovine Milk. Human Milk Lipids. Bovine Milk Lipids. Minerals, Ions and Trace Elements in Milk: Ionic Interactions in Milk. Major Minerals and Ionic Constituents of Human and Bovine Milks. Microminerals in Bovine and Human Milks. Vitamins in Milk: Water Soluble Vitamins in Human Milk. Water Soluble Vitamins in Bovine Milk. Carotenoids, Retinoids, And Vitamin K. Vitamins D and E in Human Milk. Fat Soluble Vitamins in Bovine Milk. Defense Agents in Milk: Defense Agents in Human Milk. Defense Agents in Bovine Milk. Comparative Analysis of Non-Human Milks: Phylogenetic Variation in the Gross Composition of Milks. Comparative Analysis of the Fatty Acid Composition of Milks. Comparative Analysis of Milks Used for Human Consumption. Infant Formulas. Contaminants in Milk: Drugs and Contaminants in Human Milk. Contaminants in Bovine Milk. Summary.