BULLETINS OF THE BUREAU OF PLANT INDUSTRY. 



The Bureau of Plant Industry, which was organized July 1, 1901, includes 

 Vegetable Pathological and Physiological Investigations, Botanical Investiga- 

 tions and Experiments. Grass and Forage Plant Investigations, Pomological 

 Investigations, and Gardens and Grounds, all of which were formerly independent 

 divisions, and also Seed and Plant Introduction, The Arlington Experimental 

 Farm, Tea Investigations and Experiments, and the Congressional Seed Distribu- 

 tion. Beginning with the date of the organization of the Bureau, the independent 

 series of bulletins of each Division was discontinued and all are now published as 

 one series of the Bureau. 



The reader's attention is called to the following instructions for obtaining the 

 publications of the Bureau: 



•The serial, scientific, and technical publications of the United States Depart- 

 ment of Agriculture are not for general distribution. All copies not required for 

 official use are by law turned over to the Superintendent of Documents, who is 

 empowered to sell them at cost. All applications for such publications should, 

 therefore, be made to 



"The Superintexdent of Documents, 



"Union Building, 



''Washington, D. C" 



The bulletins published in the Bureau series prior to this number are: 



No. 1. The Relation of Lime and Magnesia to Plant Growth, 1901. 



No. 2. Spermatogenesis and Fecundation of Zamia. 1901. 



No. 3. Mpcaroni Wheats, 1901. 



