56 Walter H. Burkholder 



three-days-old culture is filiform, white, translucent, smooth, and glisten- 

 ing. Freshly isolated cultures produce a marked green fluorescent 

 pigment. The ability to produce this pigment diminishes in strains 

 grown long in culture. 



Beef-infusion agar slants (pH 7.0). A very good whitish transparent 

 growth occurs along the streak, similar to that on beef-extract agar. 

 A very marked yellow-green fluorescent pigment is produced. 



Beef-extract agar plates (pH 7.0). Seven-days-old colonies are white to 

 hyaline, smooth, amorphous, with edges entire. They are butyrous in 

 consistency, and not more than 5 millimeters in diameter. Q strain 

 appears bluish to opalescent by transmitted light. Older colonies may 

 show a zonation. 



Beef-extract bouillon (pH 7.0). The broth becomes cloudy in twenty-four 

 hours, and very cloudy within two days. A light flocculation is produced 

 in seventy-two hours, and within a week a whitish granular sediment is 

 formed. 



Gelatin stab (pH 6.6). (Temperature 21° C.) Growth appears along the 

 stab within twenty-four hours, with slight liquefaction at the surface. 

 This liquefaction is at first turnip-shaped, but it proceeds rapidly and 

 soon loses any characteristic shape. Complete liquefaction occurs in 

 about ten days. The liquefied gelatin becomes cloudy, and a heavy 

 sediment forms within it which is slightly yellowish. A green fluorescent 

 pigment is produced. With the Q strain, liquefaction proceeds more 

 slowly and is not complete for six weeks. 



Milk. Separation begins on the fifth day, and occurs throughout the 

 culture on the sixth day. Further changes are slow, but at the end of 

 six weeks the culture appears as a muddy yellow liquid. With the Q 

 strain, clearing is very slight. 



Litmus milk. A slight blue clearing appears at the top of the culture in 

 two days. This clearing continues, and is nearly complete at the end 

 of eight days. Litmus is reduced from the bottom of the tube upward. 

 In eleven days a muddy purple appearance is evident, and at the end 

 of six weeks the culture is muddy brown. The Q strain is much slower 

 in reaction. 



Brom cresol purple milk. Procedure is similar to that in litmus milk, with 

 the exception of the color. A clear and purple zone appears at the top 

 and extends throughout the tube. The color is a reddish purple by 

 transmitted light. At the end of six weeks the culture is a fairly clear 

 wine-colored liquid. 

 Uschinsky's solution. There is a slight clouding in twenty-four hours, and 

 the culture becomes very cloudy, with a pellicle, in forty-eight hours. 

 In one week a light flocculation appears, and in five weeks the culture 

 is turbid, with a very heavy sediment. At the end of the fourth day a 

 light greenish color may be observed, which deepens and appears in 



