10 A SPOT DISEASE OF CAULIFLOWER. 



means of one to five polar flagella, wliich are two to three times the 

 length of the rod. (Stained by Van Ermengem's method; also by- 

 Hugh WilUams's method.) MotiUty occurs in most artificial metha. 

 In beef-bouillon cultures grown and kept at 0.5° to 1.5° C. for four 

 months the organism is still motile. Involution forms were found in 

 alkaline beef bouillon (—17 on Fuller's scale). Pseudozoogloese 

 occur in Uscliinsky's solution and in acid beef bouiUon. 



REACTION TO STAIXS. 



The organism does not stain by Gram. Modified Gram, using 

 amyl alcohol, gives a deep blue stani. It stains readil}^ and strongly 

 with carbol fuchsin, 'with an alcohohc solution of gentian violet, and 

 with a stain obtained from Dr. Kinyoun wliich contains methylene 

 blue, silver nitrate, azure I, and azure II. It is not acid fast. 



CULTURAL CHARACTERS. 



Agar 'plates (+15 peptonized heefhouillon with 1 per cent agar). — 

 The colonies are visible on the second day as tiny wliite specks 

 (temperature 23° C). 



In three to four days the colonies are 1 to 3 millimeters in diameter, 

 white (opalescent in transmitted light), round, smooth, flat, shining, 

 and translucent, mth edges entire. Structure, under hand lens, 

 coarsely granular ^^•ith internal reticulations. Bm'ied colonies small, 

 lens shaped. With age the colonies become dull to dirty white, 

 slightly irregular in shape, the edges undulate, slightly crinkled, and 

 with indistinct radiating marginal lines. The internal reticulations 

 disappear and the coarsely granular appearance changes to finely 

 granular. In thinly sown plates 7-day-old colonies are 6 to 8 milli- 

 meters in diameter; 15-day-old colonies are 12 to 15 millimeters in 

 diameter. 



Agar stabs. — The surface of the agar is covered in two days (22° to 

 24° C.) by a thin white growth. For several days the stab shows a 

 moderate growth in the upper 8 to 10 millimeters, but tliis does not 

 continue. Finally, the stab is almost, if not quite, invisible. Crystals 

 appear in the stab and on the surface. 



Agar slants. — In smear cultures the surface is covered in two days 

 (temperature 19° to 21° C.) with a thin white growth, glistening, 

 coarsely and irregularly pitted. White sediment in the V. 



In streak cultures in two days (temperature 19° to 21° C.) the 

 streak is 3 to 5 millimeters \\ade, white, margins slighth' undulate. 

 The internal reticulations seen in colonies on plates are present in 

 the streak cultures. At right angles to the streak are fine lines 

 extending from center to margin. 



Agar cultures become slightly greenish. 



225 



