CONTENTS 
Page 
Summary 
Introduction 
Character of corn embryo and process of germination 
Freezing injury not due to arrested development of the 
embryo 
Moisture content of corn 
Old corn 
New corn 
Physical effects of freezing 
Ice formation in kernels 
Effect of freezing on color of embryo 
Effect of freezing on embryonic tissues 
Chemical effects of freezing 
Probable cause of death from freezing 
Historical review 
Crushing of plant tissues or rupturing of cell structures 
Too rapid thawing 
Desiccation of the protoplasm 
Physical and chemical disorganization of the proto- 
plasm and other cell contents 
Personal interpretation 
Effects of freezing upon the viability of seed corn 
Vitality of corn frozen under control conditions 
Apparatus 
Selection of material 
Method of handling. . . . . 
Moisture tests 
Subjection to freezing temperatures 
Germination 
Observation of ice in seed 
Color of embryo 
Relation between moisture content and injury at 
various degrees of freezing 
Freezing at temperature range 82 to 28 F 
Freezing at temperature range 24 to 20 F 
Freezing at temperature range 16 to 12 F 
Freezing at temperature range 8 to 4 F 
Freezing at temperature range 0 to -5 F 
Summary of germination tests made under con- 
trolled conditions 
Effect of freezing on dry corn 
Natural resistance of green corn to cold 
Vitality of corn exposed to freezing temperatures in 
the field 
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