yjij CONTENTS 



CHAPTER PAGE 



IV. MORPHOLOGY AND CLASSIFICATION OF THE YEASTS 43 



Size, shape, and grouping of yeast cells Structure Cell 



contents Vegetative multiplication of yeast cells 



Development of spores The classification of yeasts 



f Relationships of true yeasts Classification of the 



yeasts Saccharomyces Schizosaccharomyces. 



V. MORPHOLOGY AND CLASSIFICATION OF THE M'OLDS 50 



Structure of mold hyphse Structure of the mold cell 

 Mold growth Multiplication in molds Sexual repro- 

 duction in molds Asexual reproduction in molds 

 Sporangium formation Conidia Classification of the 

 molds Key for differentiation of common genera of 

 molds Rhizopus Mucor Key to species of Mucor 

 Oospora Aspergillus Key to Aspergillus Species 

 Penicillium Key to some common species of Penicil- 

 lium Trichotheciuin Hormodendrum and Clados- 

 porium Alternaria . 



SECTION II 

 METHODS OF STUDY 



VI. CULTURAL METHODS 71 



- Methods of sterilization Sterilization by heat Sterili- 

 zation by light Sterilization by filtration Culture 

 media Nutrient substances used in preparation of 

 media Solid media Adjustment of the reaction of the 

 medium Pure culture methods Study of growth char- 

 acters. 



VII. METHODS OF STUDYING PHYSIOLOGIC CHARACTERS 92 



Determination of changes in hydrogen ion concentration 

 Color changes of Clark and Lubs indicators Deter- 

 mination of acid production Determination of alcohol 

 production Determination of aldehyde Production 

 of acetyl methyl carbinol Determination of oxygen re- 

 lationships Determination of gas production Deter- 

 mination of reduction changes Determination of indol 

 Digestion of starch and other insoluble carbohy- 

 drates Digestion of proteins Fixation of atmospheric 

 nitrogen Oxidation of ammonia and of nitrites. 



VIII. MICROSCOPIC METHODS 106 



The oil immersion objective Microscopic observation of 

 colonies and cultures Unstained preparations Stained 

 preparations Spore stain Study of acid fast bacteria 

 Gram's stain Staining of Flagella. 



