PARAGRAPHS FOR THE TEACHER xi 



Every opportunity should be taken to send the 

 pupils to the fields to see the plants naturally as they 

 grow. 



Remember that garden plants and field crops are 

 as "botanical" and as well worth the attention of 

 botanists as are wild plants. 



Many persons have aided in the making of this book 

 as it has gone through its various editions. In this 

 present revision the author has had the help of Lewis 

 Knudson, Assistant Professor of Plant Physiology, and 

 acting head of the department, in the New York State 

 College of Agriculture at Cornell University, assisted 

 by M. F. Barrus, Assistant Professor of Plant Pathology 

 in the same institution, who have reviewed the work 

 from first to last with much care. 



L. H. BAILEY. 



ITHACA, NEW YOBK, 

 MAY 20, 1913. 



