viii TILLERS OF THE GROUND 



CHAP. PAGE 



14. MAKING NEW PLANTS ..... 165 



15. THE STRUGGLE WITH DISEASE . . .178 



16. THE STORY OF RUST IN WHEAT . . .190 



17. PLANT FOOD AND THE TJTILISATION OF THE SOIL 200 



18. THE GAINS THAT KNOWLEDGE HAS BROUGHT . 212 



