CONTENTS. 



Page. 



Intro ".uetion _.... . ... .. 7 



General observations on plant breeding; 10 



Relaiiou of plant breeding to wealth _. 10 



Examples of results of breeding _... 13 



The "Wealthy Apple . 13 



The race horse, Messenger 13 



Minnesota No. 169 wheat _. .. . 14 



The value of large numbers in breeding experiments _ . 15 



General facts concerning heredity .. ... 16 



The use of variation illustrated 17 



Records and score cards 24 



Percentage score cards ., 25 



Graphic score cards _ 27 



Methods of plant breeding ...... . 28 



Relation of plant introduction to plant breeding 2S 



Choice of foundation stocks . , 30 



Names and numbering of varieties 31 



Breeding by selection . .. . _. 33 



Sele'^tion of seedling plants 33 



Bud selection . . . . , 3.5 



Breeding by hybridization and selection 37 



Degree of relationship in crosses .. .. . 38 



Hybrids and crosses defined .... . 40 



Im])ortance and methods of hybridizing. 40 



Breeding for special and new uses ^ ... 41 



Breeding nitrogen into field crops. .. ._.... 42 



Illustrations of work in plant breeding 44 



Breeding wheat . . .... . 44 



Improvement by selection alone, 44 



Wheat flowers.. .. _. 50 



Formation of varieties by hybridizing. ... 50 



Experiments in wheat breedinir . 54 



Hybridizing as a cause of variation in wheat 56 



Breeding corn . 57 



Selecting seed corn .. . 58 



Hy])ridizing varieties of corn ... 60 



Breeding timothy 61 



Brei 'ding potatoes . .. . 63 



Breeding apples 64 



How to hybridize apples 65 



Breeding black walnuts. 68 



Breeding fla.\ 69 



