58 PLANT DISEASE 



... It certainly may be laid down as one of 

 the principles or laws of nature to deviate 

 under certain circumstances. " The interest of 

 this science, says Buckle, depends simply on 

 the fact that when it is completed, it will 

 explain the aberrations of the whole organic 

 world.' " Encyclopaedia Britannica, vol. xviii. 

 p. 362. 



I think I have made it clear that there is 

 variation in plants and they produce corres- 

 ponding variations in animals eating them. 



Yet we go on defying nature, for many foods 

 that nature would destroy by blights, etc., are 

 brought to a so-called maturity by spraying or 

 fumigating, to perpetuate in animal life those 

 deficiencies already existing in these vegetable 

 foods, by these means building up the con- 

 ditions suitable to the development of disease 

 in animal life. 



