Includes morphology and development of the yeasts, cytology of yeast, physiology, nutrition, respiration, and alcoholic fermentation, origin of the yeasts, their position in classification of the fungi and their systematic relationships, methods of culture and isolation of yeasts, procedures for observation, methods for the characterization and identification, variation of species, classification of the yeasts, family of non saccharomycetes or doubtful yeasts, pathogenic yeasts and fungi related.