CONTENTS xi 



PAGE 



Physiological Conditions of Budding 112 



Particular Types of Budding. Scums and Rings. Physiological Condi- 

 tions for their Production 112 



Physiological Conditions of Sporulation 114 



Parasitism of Yeasts. Pathenogenic Properties. Symbiosis 120 



a. Parasitism 120 



b. Pathenogenic Properties of Yeasts 122 



c. Symbiosis of Yeasts 124 



CHAPTER V 



ORIGIN OF THE YEASTS; THEIR POSITION IN CLASSIFICATIONS OF THE FUNGI 

 AND THEIR SYSTEMATIC RELATIONSHIPS 



1. Historical 131 



a. Experiments on the Transformation of Molds into Yeasts 131 



6. Studies in Life Cycles of Yeasts in Nature 134 



c. Morphological and Cytological Studies on Yeasts 137 



2. Phylogeny of the Yeasts. Their Affinities in the Group of Ascomycetes. 139 



CHAPTER VI 



METHODS OF CULTURE AND ISOLATION OF YEASTS. PROCEDURES FOR 



OBSERVATION 



1. Methods of Culture 147 



a. Culture media 148 



6. Methods for Obtaining Sporulation 150 



2. Methods of Purification and Isolation of Yeasts 153 



a. Physiological Methods 154 



6. Dilution Methods for Separating Yeasts 154 



1. Hansen's Method 155 



2. Lindner's Method 157 



3. Determination of the Number of Cells in a Culture and a Study of the Power 



of Multiplication of Yeasts 157 



4. Methods for Studying the Yeasts 15$ 



a. Observation on the Development in Moist Chambers 158 



6. Methods for Examining the Cytology of Yeasts 158 



c. Methods for Determining the Action of Yeasts Towards the Carbo- 



hydrates 161 



d. Determination of Efficiency of Yeasts 163 



5. Preservation of Yeasts . . 164 



CHAPTER VII 

 METHODS FOR THE CHARACTERIZATION AND IDENTIFICATION OF YEASTS 



1. Character of the Vegetation in the Sediment 167 



2. Shapes and Dimensions of Cells 167 



3. Optimum Temperatures and Temperature Limits for Budding 167 



