PREFACE 



Of all plants grasses are the most important to 

 man. The different kinds are known by very few 

 even among botanists. This is largely because they 

 are supposed to be very difficult. When the struc- 

 ture of grasses is clearly understood, they are not 

 more difficult to study than are other plants. The 

 method here offered has been used by the author for 

 some years in teaching special students. 



The introduction explains the method followed. 

 The body of the primer consists of twelve lessons, 

 graded from the simplest to the most complex. 

 Each lesson is accompanied by figures bringing out 

 the facts in the text. The difference in the size 

 of the flowering organs is so great that the figures 

 are not drawn to the same scale. The organs are 

 enlarged as much as necessary to illustrate the char- 

 acter discussed. 



Grasses of the United States are used for the lessons 

 and the commoner ones are selected so far as possible; 

 however, our native grasses cover so wide a range 

 that the principles laid down in the lessons are ap- 

 plicable to grasses generally. 



AGNES CHASE. 



Washington, D. C., August 10, 1922. 



494313 



