BACTERIA 



513 



Potato bacteriosis. A very distinct and well marked 

 bacterial disease, caused by Bacillus solanacearum (E. F. 

 Smith), has been recorded in the north of England and in 

 Scotland. The disease has been known for some time in 



Fig. 155. Bacteriosis of potatoes. Potatoes cut in half show- 

 ing the disease. Fig. i, early stage ; 2, later stage. 



the United States, and has been carefully studied by Dr. 

 E. F. Smith. A marked characteristic of the bacterium 

 causing this disease is the production of a brown colouring 



2 K 



