<);5 



During the early growth of the plants no difierence can be seen between 

 the diseased and healthy ones, but as they develop the outer leaves of the 

 diseased plants wither, while the heart leaves curl up much more than the 

 normal, are dull in color, and the under side has a mottled appearance, 

 causing the leaves to resemble somewhat those of the Savoy cabbage. As 

 the season advances the differences between the diseased and healthy plants 

 become more and more accentuated. In the early season the bacteria are 

 found in parts of the plant only, but that may be any part from the leaves 

 to the extreme end of the tap root ; on account of this it is diflBcult to sur- 

 mise how the plants become diseased. In the late season the bacteria are 

 found permeating every part of the plant. 



Examined microscopically the bacteria are found to the greatest extent 

 in the parenchymatous tissue, but the tissue is not broken down by them. 

 They are found imbedded in the substance of the protoplasm as well as be- 

 ing in the cell sap. 



In form the beet bacterium is shortly cylindrical, being about twice as 

 long as broad. They occur mainly as isolated cells, though they are some- 

 times found in pairs. When vegetating rapidly the bacteria are very active, 

 moving in and out among one another with great rapidity. From their ar- 

 throsporous character the bacteria of the sugar beet very probably belong to 

 the genus Bacterium. 



The pure germ is easily obtained by the ordinary gelatine or agar plate 

 separation method, if a piece of the root that has no contact with the 

 surface be used for inoculation. This gives the disease germ only, free from 

 soil and air contamination. 



Very good development of the bacterium has been obtained by test tube 

 cultures of acid and neutral nutrient gelatine. Upon acid gelatine, using 

 spot cultures, the bacterium forms round, irregular-edged, greyish-yellow 

 masses, having beautiful iridescent surfaces. This iridescence is a peculiar 

 characteristic of the organism grown upon solid acid media. The masses 

 retain this iridescence for about two weeks; then the surfaces become crust- 

 like and dry, and the masses decidedly yellow in color. The bacteria liquefy 

 the gelatine, gradually forming hemispherical depressions into which they 

 drop. In neutral gelatine cultures they form, in most respects, the same 

 kind of growth as in acid, but the surface has simply a shiny appearance, 

 and as the masses ages they do not form crust-like surfaces. They liquefy 

 the neutral gelatine much more rapidly than the acid. 



A curious feature of this organism is that it causes the gelatine to become 



