Public Document No. 31 



TWENTY-FIRST ANNUAL EEPORT 



OF THE 



MASSACHUSETTS AGRICULTURAL 

 EXPERIMENT STATION. 



Part XL, 



Being Part IV. of the Forty-sixth Annual Report 

 OF THE Massachusetts Agricultural College. 



January, 1909. 



BOSTON: 



WEIGHT & POTTER PRINTING CO., STATE PRINTERS, 



18 Post Office Square. 



1909. 



