METHODS USED IN SYSTEMATIC BACTERIOLOOY 365 



Colour. — Colour by reflected and transmitted light ; fluorescent, iridescent, opal- 

 escent, self-luminous. 



Opacity. — Transparent, translucent, or opaque. 



Consistency. — Butyrous, viscid, friable, membranous. 



Emulsifiahility . — Easy or difficult ; forms homogeneous, granular, or membranous 

 suspension when rubbed up in a drop of water with a platinum loop. 



Differentiation. — Differentiated into a central and a peripheral portion (Fig. 57). 



Growth on Stroke Culture. 



Degree. — None, scanty, moderate, abundant, profuse ; discrete, or confluent. 



Form. — Filiform, spreading, rhizoid. 



Elevation. — Effuse or raised. 



Surface. — Smooth ; contoured ; beaten-copper ; rough ; finely, moderately, or 



coarsely granular ; papillate ; heaped-up ; dry or moist. 

 Edge. — Entire, undulate, lobate, crenated, erose, fimbriate ; curled, effuse. 

 Colour, Opacity, Consistency, and Emulsifiahility. — As for colonies. 



Odour. — Absent, decided, resembling . 



Medium. — Coloured ; digested ; crystal formation (Fig. 57). 



Growth in Stab Culture. 



Degree. — As for stroke culture. Also position of optimal growth. 



Form. — Filiform, beaded, with or without branching. 



Extent. — Depth in tube to which growth occurs. 



Surface. — Surface growth present or absent ; if present, diameter, surface, and 



edge. 

 Colour and Opacity. — As for stroke culture. 

 Liquefaction. — Present or absent ; if present, crateriform, napiform, infundibuli- 



form, saccate, or stratiform. 

 Medium. — As for stroke culture (Fig. 57). 



Growth in Shake Culture. 



Position.— \Jn\ioxm. growth throughout tube ; or position of optimal growth. 



Surface. — Surface growth present or absent. 



Colonies. — Size, shape, colour, opacity, outgrowths from periphery, if any. 



Gas. — Present or absent ; medium disrupted. 



Medium. — Coloured, digested, or rendered turbid. 



Growth in Fluid Medium. 



Degree. — None, scanty, moderate, abundant, or profuse. 



Turbidity. — Present or absent ; if present, slight, moderate, or dense ; uniform, 



granular, or flocculent. 

 Deposit. — Present or absent ; if present, slight, moderate, or abundant ; powdery, 



granular, flocculent, membranous, or viscid ; disintegrating completely or 



incompletely on shaking. 

 Surface Growth. — Present or absent ; if present, ring growth around wall of tube ; 



or surface pellicle, which is thin or thick, with a smooth, granular, or rough 



surface, and which disintegrates completely or incompletely on shaking. 

 Odour. — Absent, decided, resembling . 



