TABLE OF CONTENTS xL 



PAGES 



Maturity, 234; Sap concentration, 235; Rate of freezing a 

 factor, 236; Protection of bud-scales, 237; Relation of crop 

 the preceding season, 238; Correlation of wood structure 

 and hardiness, 239; Influence of type of soil, 240; Proxim- 

 ity to bodies of water, 241; Topography of land, 242; 

 Winds, 243. Orchard Practices: Cultivation, 244; Pruning, 

 245; Protecting trees and buds, 246; Securing hardier 

 fruits, 247; Treatment of frozen trees, 248; Variation in 

 hardiness of fruits, 249; Hardy and tender varieties, 250; 

 The grape, 251. 



CHAPTER XII 



Pollination and the Sterility Problem 282-310 



Investigations in pollination, 252; Causes of unfruitful- 

 ness, 253; Development of pollen, 254; Germination of the 

 pollen, 255; Longevity and viability of pollen, 256; Length 

 of receptive condition of the stigma, 257; Fertilization, 

 258; Cross-pollination, 259; Means of effecting cross- 

 pollination, 260; Nature's methods of avoiding self- 

 pollination, 261; Effect of cross-pollination on the fruit, 

 262; Effect of seed-bearing on the fruit, 263; Artificial 

 pollination, 264. The Sterility Problem: Definition of 

 terms, 265; Sterility not a constant factor, 266; Causes of 

 sterility, 267; The cherry, 268; The almond, 269; The 

 grape, 270; The plum, 271; The peach, 272; The quince, 

 273; The apple, 274; The pear, 275. 



CHAPTER XIII 



The Origin and Improvement of Fruit 311-338 



Theory of Van Mons, 276; Work of Knight, 277; Selec- 

 tion as a means of securing new fruits, 278; Mass-selec- 

 tion, 279; Line-selection, 280; Clonal-selection, 281; Bud- 

 selection, 282; Individuality of fruit-trees, 283; Results of 

 selecting bud variations, 284; Plant introduction, 285; 

 Chance seedlings, 286; Work in Canada, 287; Work of 

 Peter Gideon and other pioneers in the United States, 

 288; Hansen hybrids, 289; Burbank's work, 290; Inheri- 

 tance of characters in the apple, 291; The heterozygous 

 nature of fruits, 292; Pedigreed nursery stock, 293; Graft- 

 hybrids, 294; Breeding the grape, 295; Inheritance of self- 

 sterility in grapes, 296; The inheritance of sex in the grape, 

 297; Rogers' hybrids, 298; Breeding disease-resistant 

 fruits, 299; Stocks for pears, 300; Stock for grapes, 301. 



