PLATE 9 



A, B. — Beets showing typical lesions produced by artificial inoculation. Needle 

 punctures through which the fxmgus entered permitted of rapid drying out of the 

 diseased tissue and of an early ruptiure of the outer layer of cells at the margin of the 

 lesions. A number of the lesions, however, show the concentric rings so character- 

 istic of the disease produced by natural infection. Cross sections of these lesions 

 are shown in C and D. 



C, D. — Cross sections of the lesions in A and B. The lesions in C disclose the more 

 advanced stage of the disease wherein the outer layers of cells are broken down. In 

 D the outer layers of the lesions are more or less entire. 



E, F. — Cross sections of cankers resulting from natural infection in the field. A 

 more advanced stage is shown than in C and D; otherwise the lesion produced by 

 the natural and artificial method of inoculation appeared identical. 



