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



Plate 



Longitudinal Sections of Cotton Roots 



A, Longitudinal section of the cork cells of a cotton root, showing the branching 

 of Ozchium strands to form accumulations or wefts of the invading hyphse (X 75). 

 B, Longitudinal section through a lenticel of a cotton root, showing the mycelial 

 mass and the penetration of the hyphal wedge between the cells. Below can be 

 seen the formation of a wall of cork cambium apparently trying to wall off the 

 lenticel (X 73). C, Longitudinal section of a cotton root, showing a typical de- 

 pression in which an accumulation of the hypha? appears (X 25) 



