354 BACTERIOLOGY 



Agar slant. Growth abundant, moist, creamy, becoming a deep yellow. 

 Loffl.er's blood serum. Growth in 24 hours at 37° abundant, moist, light 



cream-colored, becoming a decided yellow. 

 Bouillon. Slightly turbid, with a granular sediment, becoming clear and 



tinged with yellow ; no pellicle. 

 Glucose bouillon. Rendered decidedly acid. 

 Milk. Not coagulated ; rendered a deeper cream color. 

 Potato. Growth a narrow stripe, becoming raised, dry, granular, and deep 



yellow. Non-pathogenic to guinea pigs. 

 Jiabitat. Found commonly in milk and cheese. 



See Klein Jour. Path, and Bact., 1894, 441,, and Henrici Arbeiten aus dem 

 Bact. Inst. Tech. Hochsch. Karlsruhe, 1894, Heft i. 



9. Mycobact. diphtheriae (Klebs) 



B, diphthericB Klebs : Verhandl. Congr. fiir inneren Medicin, 1883, 143. 



Bacillus bei Diphtheric des Menschen Loffler: Mitteilungen Kaiserliche Gesundheit- 



samte, II, 1886, 421. 

 Corynebacterium diphtherics Lehmann-Neumann : Bak. Diag,, 1896, 350. 



Morphology. Bacilli slender, rather long, straight or somewhat bent, com- 

 monly swollen at one or both ends, wedge-shaped (cuneate) or clavate, 

 or various irregular forms, rarely those which show true branching. 

 With alkaline methylene blue a beaded appearance due to irregular 

 staining. Stained by Gram's method. Grow best in the presence of 

 oxygen, and at body temperatures. 



■Glycerin gelatin colonies. Deep: round, light yellow, granular, border entire 

 — rough. Surface: delicate, grayish white — light yellowish, translucent, 

 darker and finely granular in the centre, coarsely granular on the border. 



■Gelatin stab. A scanty development ; no liquefaction. 



Glycerin agar colonies. Deep : round — oval, dark gray — greenish, entire, 

 amorphous. Surface : delicate, grayish white, translucent ; micro- 

 scopically, round, entire, yellowish, translucent, granular. 



Agar slant. But scanty development. 



Glycerin agar slant. Growth delicate, white — yellowish white. 



Blood serum or Loffler''s blood serum. Opaque whitish colonies, or a dull 

 whitish, granular streak. 



Bouillon. Turbid, due to granular particles, either immersed or often form- 

 ing a film on the surface. Medium at first acid, then alkaline. 



Milk. Not coagulated, amphoteric. 



-Potato. On acid potato growth scanty, when medium is rendered alkaline a 

 delicate glistening growth which can be raised by the needle and which 

 has the color of the potato. 



