DISEASES OF COBK 



IN the history of tins plant disease is scarcely 

 known. Occasionally some rnoYbid indication, as a 

 rust on the leaves or stalk, or an unnatural secretion, 

 is witnessed ; arising probably from wounds in culti- 

 vation, or from long-continued extremes of weather; 

 but otherwise its history is marked with health and 

 vigor, and it still remains untouched with any serious 

 malady. The contrast in this respect with wheat 

 and most other grains is so strikingly in favor of corn, 

 as to justify the conclusion that the exemption of the 

 latter is purposely ordered by a beneficent Providence. 



The principal disease of this cereal appears in the 

 form of a dark spongy growth, sometimes of a blue 

 black or purple tinge, that occasionally shows itself 

 on the stalk or leaves, but is more apt to take the 

 place of the blighted ear. This substance increases 

 gradually in size, sometimes reaching six or seven 

 inches in diameter, and is generally regarded as a rank 

 and luxuriant species of fungus. The kind of para- 

 sitic growth to which this fungus belongs, it has been 

 found, may be in most cases effectually destroyed by 



