Contents 



Page 

 Introduction 1 



The Founder of the Boyce Thompson Institute • Aims and Scope of Work 

 of the Institute • Organization and Purpose of Book • Acknowledgments 



Chapter 



1. Early Problems 10 



Yellows and Virus Diseases of Plants • Duck Food Problem • Stiidy 

 of Aquatic Plants 



2. Life Span of Seeds 28 



Seeds of Long Life Span • Seeds of Short Life Span • Life Span of 

 Seeds in Soil • Dormancy and Delayed Germination in Seeds of Wild 

 Plants • Why Seeds Remain Dormant in a Germinator or in Soil • 

 Hard Seeds Best Adapted for Long Life Span • Storage of Seeds • Why 

 Seeds Degenerate with Age 



3. Dormancy in Seeds 67 



Significance of Dormancy in Seeds • Categories of Dormancy: Hard 

 Coats; Light as a Factor in Dormancy; Oxygen Deficiency and Dormancy; 

 Moist Low-Temperature Stratification • Two-Year Seeds: Seeds with 

 Resistant Coats and Dormant Embryos; Dormant Epicotyls; Seeds Re- 

 quiring Two Low-Temperature Exposures • Period of Dry Storage 

 After-Ripens Many Seeds • Temperature a Factor in Overcoming Dor- 

 mancy • Quick Vitality Tests for Dormant Seeds • Chemicals as Forc- 

 ing Agents far Dormant Seeds • Summary 



/> 



Physiological Effects op Ethylene and Other Unsat- 

 urated Carbon-Containing Gases 139 



Early Experiments • Responses Induced by Gases Containing Un- 

 saturated Carbon: Epinasty of Leaves; Proliferation of Tissues; Abscis- 

 sion of Leaves, Flowers, and Fruits; Other Metabolic Changes in Living 

 Plant Tissues; Root and Root-Hair Initiation; Color and Ripening of 

 Fruits; Other Physiological Effects • Respiring Plant Tissue Produces 

 Ethylene • Summary 



Effect of Certain Lethal Gases Upon Plants and Animals 172 



Injury to Trees and Shrubs from Leaks of Artificial Illuminating Gas • 

 Injury to Plants in a Greenhouse by Mercury Vapor • Effect of Sulphur 

 Dioxide on Plants • Sulphur Dioxide of Atmosphere as a Sxdphur 

 Source for Plant Nutrition • Effect of Sulphur Dioxide on Animals • 

 Effect of Hydrogen Sulphide on Plants • Effect of Chlorine Gas and 

 Chlorinated Water on Plants and Aniynals • Comparative Effect of 

 Ammonia, Chlorine, Hijdrogen Cyanide, Hydrogen Sulphide, Sulphur 

 Dioxide on Plants and Animals • Summary 



«' 62169 



