Xll 



TABLE OF CONTENTS 



CHAPTER XII 



CROSS-BREEDING ......... 



Permanent and temporary results of cross-breeding, 

 226 ; Advantages from cross-breeding, 227 ; Grading, 

 228 ; Cross-breeding to increase fertility, 229 ; Cross- 

 breeding to increase size and restore constitution, 230 ; 

 Crossing and heredity, 231 ; First cross and improve- 

 ment, 232 ; Cross-breeding as a cause of variation, 233 ; 

 Crossing species, 234 ; Crossing bison and cattle, 235 ; 

 The mule hybrid, 236 ; The hinny hybrid, 237 ; Cross- 

 ing the horse and the zebra, 238 ; Crossing cattle and 

 zebu, 239 ; Sheep-goat hybrid, 240. 



PAGES 



243-254 



CHAPTER XIII 



DEVELOPMENT 



255-279 



Growth, 241 ; The growth impulse, 242 ; Factors in- 

 fluencing growth, 243 ; Growth and food supply, 244 ; 

 Capacity to grow, 245 ; Growth and the cell, 246 ; When 

 the growth impulse is strongest, 247 ; Development of 

 the foetus, 248 ; Heredity and foetal development, 249 ; 

 Birth weight of lambs, 250 ; Effect of protein and ash in 

 ration on foetal development, 251 ; High calcium rations 

 for pregnant swine, 252 ; Size and vigor of totus as in- 

 fluenced by corn and wheat rations, 253 ; The perma- 

 nent effect of retarded growth, 254 ; Early stunting and 

 the capacity to grow, 255 ; Climate, 256 ; The age factor 

 in animal-breeding, 267 ; Premature breeding decreases 

 size, 258 ; Decreased size due to early breeding not in- 

 herited, 259 ; Influence of early pregnancy on the 

 mother, 260 ; Gestation and lactation in relation to 

 growth, 261 ; The Missouri experiments, 262. 



CHAPTER XIV 



THE PRACTICE OF BREEDING 



Improvement in size, 263 ; Improvement in function, 

 264 ; The milking function, 265 ; Improvement in wool 

 production, 266 ; Improvement in tendency to lay on fat, 



280-303 



