PLATE 30 



Bacterium viiians: 



A. — A field of 3>^ acres of diseased lettuce at Beaufort, S. C. By actual coimt there 

 are two good plants in a hundred. Photographed by Dr. J. Rosenbaum. 



B. — A field of healthy lettuce at Beaufort, S. C. This field was planted with seed 

 from the same lot as that sown in the field sho\\Ti in A, but the land received 

 different treatment previous to planting and afterward. 



