54 
B. Cultural Characteristics 
1. Gelatin Stab. Draw the culture. 
(a) Growth: uniform, best at top, best at bottom. 
(b) Line of puncture: filiform, beaded, papillate, villous, arbores¬ 
cent. 
( c ) Liquefaction: none, crateriform, nap if orm, infundibuliform, 
saccate, stratiform. 
2. Agar Slope. Draw the culture. 
(a) Growth: scanty, moderate, abundant, none. 
(b) Form of growth: filiform, echinulate, beaded, spreading, 
arborescent, rhizoid. 
(c) Elevation of growth: fat, effuse, raised, convex. 
(d) Lustre: glistening, dull. 
(e ) Topography: smooth, contoured, rugose. . 
(0 Optical Characters: opaque, translucent, opalescent, iridescent. 
( g ) Chromogenesis: - photogenic, fluorescent. 
(h) Odor: absent, decided, resembling _ 
(«) Consistency: butyrous, viscid, membranous, brittle. 
(J) Medium: grayed, browned, reddened, blued, greened. 
3. Broth Culture. 
(a) Surface growth: ring, pellicle, flocculent, membranous, none. 
(b ) Clouding: slight, moderate, strong, transient, presistent, none, 
fluid, turbid. 
(c) Odor: absent, decided, resembling _ 
(d ) Sediment: compact, flocculent, granular, flaky, viscid, on 
agitation, abundant, scant, none. 
4. Agar Colonies. Draw a colony. 
(a) Growth: slow, rapid. 
( b) Form: punciiform, circular, irregular, myceloid, filamentous, 
rhizoid. 
(c) Surface: smooth, rough, concentrically ringed, radiate. 
(d) Elevation: flat, effuse, raised, convex, pulvinate, umbinate. 
(e) Edge: entile: undulate, lobate, erose, filamentous, curled. 
(0 Internal structure: amorphous, finely, coarsely-granular, 
filamentous, curled, concentric. 
5. Milk Culture. Draw the litmus milk culture. 
(a) Reaction to litmus. 
( b ) Curd: hard or soft; solid or porous. 
(c) Whey: little or abundant; clear or turbid. 
(d ) Digestion of curd: (Examine the plain milk culture). 
(e) Odor. 
(0 If curd has not formed, will if form on heating the culture 
to 100° C? Use tube I. 
(g) Percentage of acid formed. 
Note: Titrate 10 cc. of the milk from tube K with N/10 NaOH and using 
phenolphthalein as an indicator. Calculate the per cent of acid using the 
following formula: 
cc. N/10 NaOHX0.009X100 
Per cent acid = 
cc. milk used. 
