TABLE OF CONTENTS 



IX 



swine, 90 ; Influence of age of sow on size of litter, 91 ; Re- 

 lation of age to fertility in sheep, 92 ; Influence of age 

 of ram on fertility of ewes, 93 ; The effect of the age of 

 poultry parents on the offspring, 94 j Age and fecundity, 

 95 ; Nutrition and fertility, 96 ; Excessive food supply 

 and nutrition, 97 ; Other factors affecting fertility, 98 ; 

 Relation of number of mammse in swine to fertility, 99 ; 

 Twins, 100 ; Characters correlated with fertility, 101 ; In- 

 breeding and fertility, 102 ; Cross-breeding and fertility, 

 103 ; Unusual fertility, 104 ; Unusual fertility among 

 horses, 105 ; Unusual fertility among cattle, 106 ; Un- 

 usual fertility among sheep, 107 ; Unusual fertility 

 among swine, 108 ; Unusual fertility among poultry, 109. 



CHAPTER VI 

 STERILITY .......... 



The causes of sterility, 110 ; Causes of sterility in the 

 male, 111 ; Sterility in the female, 112 ; Closure of the 

 cervix, 113 ; Obstruction of Fallopian tubes resulting 

 from excessive fatness, 114 ; Other causes of barrenness, 

 115; Sterility from fatty degeneration, 116; Sterility 

 caused by abortion, 117 ; Contagious abortion and ste- 

 rility, 118 ; Treatment for contagious abortion, 119 ; 

 Diagnosis of contagious abortion, 120 ; The complement 

 fixation test, 121 ; Sterility of free-martins, 122. 



113-130 



CHAPTER VII 

 HEREDITY . . . . . . . . 



Development, 123 ; Heredity defined, 124 ; Heredity 

 and variation not antagonistic, 125; The kinds of he- 

 redity, 126 ; Blending inheritance, 127 ; Alternative in- 

 heritance, 128 ; Particulate or mosaic inheritance, 129 ; 

 Mendelian inheritance, 130 ; The experiments of Men- 

 . del, 131 ; The law of dominance, 132 ; The law of seg- 

 regation, 133 ; Unit characters, 134 ; Gametic purity, 

 135 ; Application of Mendel's law, 136 ; The complexity 

 of animal characters, 137 ; The inheritance of polled and 

 horned character in cattle, 138 ; Theory of pure lines, 



131-156 



