14 
Part I11.—SratisticAL FARM WoORK. 
Page 
CHAPTER XIII. THE CROPS AND CLIMATES OF THE UNITED STATES- -----_- 351 
Variability of results from plat experiments -------------------------- 352 
Effect of variations in method of cultivation and in quality of seed for 
different resions and! years. 222528 ose sae ee a eee ee See 355 
Effect of variations in dates of seeding and harvesting --___-.--. ---.-- 358 
Brief SUMMATYAOL CONCLUSIONS oe ee eee 362 
Part IV. 
CHAPTER XIV. AUTHORITIES: 
Catalogue of periodicals aud authors referred to -..-.-..-------------- 365 
General index 
