PLATE 69 
Plasmodtophora brassicae: 
A. —A longitudinal section through a cabbage stem that became infected after 
the vascular elements were well differentiated. Note that the disease is confined 
•to a definite band of tissue between wood and bark. X70. 
B. —A section through one of the knoblike branch roots that are produced on in¬ 
fected roots. X60. 
