398 APPLICATION OF METHODS OF BACTERIOLOGY 



continuous, but appears in isolated, round, dense white 

 clumps or beads, which do not develop beyond very small 

 points. 



It does not liquefy gelatin. 



Upon plates of nutrient agar-agar the colonies appear as 

 small, almost transparent, round points, which have about 

 the same color and appearance as a drop of egg-albumen; 

 they are very slightly opaque. They are moist and glisten- 

 ing. They rarely develop to an extent exceeding 1 to 2 

 mm. in diameter. 



Upon agar-agar as stab- or slant-cultures the surface 

 growth has more or less of a mucoid appearance. It is 

 moist, glistening, and irregularly outlined. The outline of 

 the growth depends upon the moisture of the agar-agar. 

 It is slightly elevated above the surface of the medium. 



In contradistinction to the gelatin stab-cultures, the 

 growth in agar-agar is continuous along the track of the 

 needle. 



The growth on potato is a thick, irregular, slimy-looking 

 patch. 



The transparent mucilaginous substance which is seen 

 to surround these organisms renders them coherent, so 

 that efforts to take up a portion of a colony from the agar- 

 agar or potato cultures result usually in drawing out fine, 

 silky threads, consisting of organisms imbedded in the 

 mucoid material. 



The organism grows best at from 35° to 38° C, but can 

 be cultivated at the ordinary room-temperature — about 

 20° C. 



The growth under all conditions is slow. 



It grows both in the presence of and without oxygen. 



It is not motile. 



