THE CORN SMUT 205 



plowed under with the stalks. The third season the 

 ground was planted as before, and this time fully two- 

 thirds of the ears were affected with smut. In fact, the 

 smut was so abundant that but little corn was gathered, 

 and the crop was practically abandoned. The ground 

 was found to be now so filled with smut as to unfit it 

 for further use for corn, and it was consequently assigned 

 to other uses. The lesson is very obvious. Smut left 

 on the ground will produce smut the next year." 



After the mycelium of the smut fungus has pene- 

 trated the corn plant it grows along with the latter, 

 pushing its way through the tissues of the stem, and 

 finally develoj^ing extensively, by means of many 

 branches, in the ear or tassel. From this mass of 

 branches the spores develop, the latter absorbing so 

 much of the substance of the former that the mass of 

 mycelium becomes gelatinous, and finally disappears, 

 leaving in its place the familiar blackish, powdery mass 

 of spores. Up to the time of maturity the smut mass is 

 surrounded by a dull white membrane, which finally 

 bursts and allows the spores to escape. 



Many farmers believe that corn smut is very injuri- 

 ous to cattle when eaten by them. Cases of death at- 

 tributed to this cause are not uncommon ; but feeding 

 experiments made by Professors Gamgee, Henry, and 

 others, indicate that the amount of smut cattle are likely 

 to eat, under ordinary circumstances, Avould do little, if 

 any, injury. The only plant besides Indian corn upon 

 which this kind of smut is known to develop, is a coarse 

 grass called Teosinte, which is sometimes used as a for- 

 age plant in the Southern States. 



Microscopic Characters. — The spores of corn 

 smut are so minute that it has been estimated that from 

 30,000 to 50,000 of them will adhere to the moistened 

 head of a common pin ; that 25,000 of them, laid side 

 by side in a straight line, would measure an inch ; and 



