Bulletin No. 29. V. P. P.-83. 



U. S. DEPARTMENT OF AGRICULTURE, 



DIVISION OF VEGETABLE PHYSIOLOGY AND PATHOLOGY. 



ALBERT F. WOODS, Chief. 



PLANT BREEDING. 



BY 



WILLET M. HAYS, 

 Prof essor of Agriculture , University of Minnesota. 



WASHINGTON: 



GOVKKNMKNT PRINTING OKI'ICK. 

 I 9 O I . 



