vi PREFACE 



The author has made no attempt to write a book on 

 genetics or evolution ; but the principles of genetics as 

 they apply to the practice of animal-breeding are dis- 

 cussed, in accordance with the conclusions of biologists. 

 The problems of the animal-breeder are in many im- 

 portant particulars widely different from those of the 

 plant-breeder; and the emphasis has been placed on 

 those principles and practices that belong peculiarly to 

 the province of the animal-breeder, while not neglecting 

 the lessons and illustrations to be drawn from the other 

 field. 



It has been the purpose to make a practical book 

 which shall be directly useful to the student and to the 

 breeder of animals, and the lessons and examples of 

 which can be applied in the laboratory and on the farm. 



F. B. MUMFORD. 



COLUMBIA, Mo. 



November, 1916. 



