Vlll PREFACE 



Stocking of Cornell University, for reading the 

 proof and for valuable criticisms, and to Prof. Ed- 

 ward H. Webster, Chief of Dairy Division, U. S. 

 Department of Agriculture, and Dr. E. B. Voorhees, 

 Director of New Jersey Experiment Stations, 

 through whose courtesy the writer obtained a num- 

 ber of valuable illustrations. 



Washington, D. C, October I, 1908. 



