LIST OF ILLUSTRATIONS XIX 



FIGURE PAGE 



23. Slender wheat-grass (Agropyron tenerum) : a, glumes; 



b, spikelet with glumes removed ..... 220 



24. Sheep's fescue (Festuca ovina) : a, glumes ; b, spikelet with 



glumes removed ........ 224 



25. Crested dogstail (Cynosurus cristatus) : a, b, fertile spike- 



lets ; c, sterile spikelet . . . . . . . 235 



26. Bermuda-grass (Cynodon dactylon} : a, spikelet; b, floret . 238 



27. Paspalum dilatatum : a, showing arrangement of spikelets ; 



b, a single spikelet ; c and d, floret .... 252 



28. Rescue-grass (Bromus unioloides) : a, glumes ; b, lemma ; 



c, palea .......... 257 



29. Foxtail millet (Setaria italica} : a and b, dorsal and ventral 



views of a spikelet ; c, lemma ..... 287 



30. Texas millet (Panicum texanum) : a and b, dorsal and ven- 



tral views of a spikelet ; c, lemma ..... 297 



31. Canary grass (Phalaris canariensis) ..... 300 



32. Map of the United States, showing production of alfalfa hay 



by tons in 1909. Each dot equals 2000 tons . . .311 

 83. Map of the United States and Canada, showing acreage of 



alfalfa. Figures equal acres ...... 312 



34. An implement for harrowing fields of alfalfa . . . 341 



35. A well-set cluster of alfalfa pods 347 



36. Alfalfa seeds : a, individual seeds, showing variation in 



form ; b, edge view of a seed, showing scar ; c, natural 

 size of seeds ......... 349 



37. Dodder or love- vine growing on alfalfa .... 355 



38. Adult form of the alfalfa weevil (Phytonomus posticus) : 



Adults clustering on and attacking a spray of alfalfa. 

 (Slightly enlarged) 359 



39. Red clover 362 



40. Map showing acreage of red clover in the United States, 



1909, and Canada, 1910 363 



41. Stages in the development of red clover seed : a and c, flower 



in prime and ripe ; b and d, immature and mature seed 

 vessel ; e, mature seed 388 



