Bui. 1417, U. S. Dept. of Agriculture 



Plate 4 



Detailed View of Part of the Circumference of the Spot of 

 Root Rot Shown in Plate 3 



Note that the cotton plants in the center of the spot are healthy. The diseased plants are 

 at the periphery of the spot. This illustration shows th3 sprjad of the fungus outward 

 through the soil and also that the active mycelium persists only at the outer edge of a spot 

 from season to season. Photographed by H. F. Loomis 



