CONTENTS 



Chapter Page 



Selection versus Hybridization 10-6 



Span of Life Cycle 10-6 



Hybridization Procedures for the Practical 



Yeast Worker 10-7 



Hybridization in Unfavorable Media 10-7 



11 Genetical Characters 11-1 



Terminal Characters 11-1 



Rough Colonies 11-4 



Quantitative Characters 11-5 



Lethal Genes 11-6 



Biochemical and Physiological Characters . 11-6 



Fermentative Ability 11-7 



The Fermentation Test 11-7 



Galactose -Melibiose Combinations 11-8 



Tests for the Presence of Galactose in 



Fermentation Tubes after Ten Days. . . 11-14 



Raffinose 11-14 



Production of CO2 When Different Sugars 



are Used in the Fermentation Tubes. . . 11-15 



Alpha Glucosides 11-15 



Vitamin, Amino Acid, and Nucleic Acid 



Component Deficiencies 11-16 



Mating Type Specificity. 11-17 



Suppressors 11-17 



Plus and Minus Modifiers 11-18 



12 A Comparison of Sexual Reproduction in Yeasts 



and Other Microorganisms 12-1 



Mucors 12-2 



Schizomycetes 12-2 



Hymenomycetes 12-3 



Paramecium 12-7 



Smuts 12-8 



Rusts 12-10 



Neurospora 12-12 



Venturia 12-15 



Glomerella 12-16 



Penicillium and Aspergillus 12-17 



Cross -Fertilization in Saccharomyces and 



Other Organisms 12-18 



Self -sterility alleles 12-18 



Sexual Dimorphism 12-18 



Plus-Minus Factors 12-18 



Xlll 



