24 A SOFT ROT OF THE CALLA LILY. 



Bair /v/r7/.s7/.— Several red, so-called ''white tip,"; round radishes 

 were obtained from the market. These were washed and the surfaces 

 sterilized in the same manner as the raw potatoes. They -were then 

 pared with a sterile knife, cut in half, and placed in petri dishes, four 

 halves in each dish. Immediatel}' after preparing these specimens, 

 two in each dish were inoculated with the calla-rot organism, using a 

 24-hour-old beef -broth culture, and in eighteen hours at 20^ to 25^^ C. 

 all the inoculated pieces showed slight discoloration. In forty-eight 

 hours the disease had advanced so that the whole of each inoculated 

 piece was discolored. None of the uninoculated pieces showed any 

 signs of disease. Some of the inoculated pieces were inoculated by 

 contact and others by stab. The disease progressed as rapidly in 

 the contact as in the stal) cultures. The inoculated pieces only were 

 affected; color, Cinnamon, No. 20, Plate III, Ridgway, a little lighter 

 than Saccardo's Umbrinus, No. 9, Table I. In reaction the discolored 

 pieces were strongly alkaline to litnuis, and had the very disagreeable 

 odor of decaying vegetal)les. All the inoculated pieces were involved 

 (see PI. y, lig. 1). gradually disintegrated, and settled down upon the 

 bottom of the petri-dishes, as shown in Plate V, figure 2. 



Rem cucwnljers^ sliced. — A green cucumber about .5 inches in length 

 was thoroughly w^ashed w^ith distilled water and the surface sterilized 

 with corrosive sublimate (1 part in 1,000). The outer rind was peeled 

 off with a sterile knife, and the material was then cut into slices from 

 1\ to 2 cm. in thickness. Each slice w^as divided into two parts and 

 placed in sterile petri dishes, four pieces in each dish. Two of these 

 pieces in each dish were inoculated with the calla disease germ, using 

 a 24:-hour-old beef-broth culture. All the inoculated pieces began to 

 show slioht discoloration in eighteen hours at 20-^ to 25° C, and in 

 forty-eight hours the disease had progressed rapidly, having discolored 

 in some cases the whole of each inoculated piece. The color of the 

 inoculated pieces at this time was light brown or yellowish, closely 

 resembling Kidgway's Buff, No. 13, Plate V, or Saccardo's Ochroleucus, 

 No. 28, Table II. The inoculated pieces had a peppery, pungent odor, 

 and were stronglv alkaline to litmus. 



Raui cucuvihers, ^vhole. — The effect of the calla germ on whole 

 cucumbers fresh from the vines was tried by taking nearly ripe cucum- 

 bers, sterilizing a spot near the stem b}" washing with corrosive sul)ii- 

 mate (1 part in 1,000), and then washing w^ith sterile water. Several 

 punctures were made in the sterilized spot with a sterile needle to the 

 depth of from one-half to 1 inch, and two 1-mm. loops of a 21:-hour- 

 old beef-broth culture of the calla organism were applied to the sterile 

 surface over the piuictures. For control several cucumbers were 

 treated in exactly the same manner, except that the organism was not 

 applied. At the end of twenty-four hours at 20- to 25 - C. a water}" 

 spot about one-half an iiuli 'v.\ diamc^trr appc:ired around the punctures 



