LIST OF ILLUSTRATIONS xi 



Page 



A Good Type of a Four-year-old Alfalfa Plant . 171 

 x\lfalfa Plant and Roots Showing Bacteria Nod- 

 ules ig6 



Tubercles on Clover Roots 197 



Peculiar Nodules in Groups on Small Rootlets 206 



Alfalfa Roots Showing Normal Nodules . . . 207 



And There's Still ]\Iore to Follow 220 



Dead Prairie Dogs 221 



Pot Culture Experiments at University of Illinois 230 



Six Months' Growth of Alfalfa Foliage . . . 231 



Cutting Alfalfa in Southern California . . . 256 



Baling Alfalfa in Southern Oklahoma . . . 256 



A 400-ton Rick of Alfalfa 257 



A Cable Derrick, Provided with a Grapple Fork 257 



Sweet Clover {McliloHis alba) 288 



Yellow Trefoil (Mcdicago liipulina) .... 289 



