16 A SOFT ROT OF THE CALLA LILY. 



In a 24-houi-okl beef-hroth culture they mea.sure about 0.5yu in width. 

 In the same culture the length varies from 2/^ to Sm- The very short 

 ones, as shown by the measurements, are round, or nearly so; these 

 eventuall}^ elongate, becoming rods. After the organisms have elon- 

 gated, cross walls are formed and as a rule they soon 

 break in two, forming separate organisms; but occa- 

 sionally they remain intact until a long chain is formed, 

 which may finally l)reak up into individual cells (PI. II, 

 fig. 1). This organism moves with a gliding motion, 

 Ficx. b.—Bariiins and upou staiuiug for flagella it is found to possess 

 geiiatTabouteoo. from two to eight wavy fiagella scattered over the sur- 

 face of the body (PI. II. fig. 1). The fiagella vary in 

 length from 4/^ to 18//, i.e., two to six times the average length of the 

 bodv. No spores belonging to this organism have been found in any 

 of the artificial cultures or in the diseased plants. 



PHYSIOIiOGICAL CHARACTERS OF THE ORGANISM. 



Certain ph^-siological characters of the organism have been deter- 

 mined by growing it on dilierent media and under various conditions 

 of light, heat, etc., as described in the following pages. 



NUTRIENT MEDIA. 



In studying the physiology of this organism the following media 

 have been used, viz, beef broth, agar, gelatin, Uschinsky's solution, 

 Dunham's peptone solution, peptone water with rosolic acid, peptone 

 water w\th methylene blue, simple peptone water," milk, litmus milk, 

 indigo-carmine peptone, and egg albumen. All these culture media 

 were carefully prepared. The beef-broth stock was made from lean 

 beef, the chemicals were "c. p.," and only distilled water was used. 

 In addition to these media the following vegetables and fruits were 

 used, viz, potatoes, onions, turnips, celery, cucumbers, peppers (green 

 fruits), pieplant, beets, radisJies, caulifiower, cabbage, eggplant, toma- 

 toes, salsify, carrots, parsnips, apples, pineapples, and bananas. 



In nearly all cases both the fruits and vegetal)les were used raw, 

 but in some instances the vegetables were cooked. Usually the raw 

 fruits and vegetables were sterilized by removing the outer la^^er with 

 a sterile knife and washing thoroughly with corrosive sublimate (1 

 part in 1,000) and then Avith sterile water. They were then cut in 

 thick slices and placed in deep petri dishes and inoculated with one or 

 more loops of a 21-hour beef-broth culture of the organism. When 

 the vegetables were cooked they were cut into cylinders and placed in 

 test tubes with distilled water, then thoroughly sterilized, and when 

 cool inoculated with fresh cultures of the organism. 



f'Witte's Peptonum skcum was the only peptone used. 



