8 DISEASES OF CROPS. 



anatomy and physiology of all the plants he grows, or to 

 be perfectly familiar with the life-history of every assail- 

 ing parasitic fungus or destructive animal, any more than 

 a householder should know all abotit the exact nature of 

 typhus, or diphtheria, or bacteria, bacilli, and disease 

 germs ; but as every householder at length begins to know, 

 amongst other facts, that an open drain is likely to prove 

 fatal to life, so every farmer should know, amongst other 

 things, that imperfectly drained fields and rotting vege- 

 table refuse mean disease and destruction to his crops." 



