MICROCOCCUS PYOGENES. 183 



Water of condensation cloudy. Precipitate whitish- 

 orange (8, ii). 



Bouillon Culture. — Marked uniform cloudiness. On 

 the surface a delicate pellicle is formed. Sediment mod- 

 erate and upon agitation it breaks up into tiny flocculi. 

 In sugar bouillon the same. 



Milk Culture. — According to Passet's and our own 

 observations it is gelatinous or firmly coagulated in from 

 one to eight days. According to Tavel it is flaky. 



Potato Culture. — Limited to the streak, at first whit- 

 ish, later pale orange-yellow, somewhat elevated and 

 crumbly, shining. Old cultures are wider, deep orange, 

 and dry (8, ix). 



Viability and Resistance. — (a) In body: Many cases 

 in which the Micr. pyogenes has been found after very 

 long periods (from ten to thirty-five years), in areas 

 (osteomyelitis) where they had been encapsulated during 

 this time, appear to prove a long viability. 



(6) In cultures : Very tenacious of life. Even after many 

 months are always alive, still there are no resting forms. 



Resistance to — (a) Drying: According to Hiigler, they 

 are alive after from fifty-six to one hundred days in dried 

 pus. 



(b) Dry heat : According to Liibbert, they are killed in one 

 hour at 80°, and killed rapidly only at from 110° to 120°. 



(c) Moist heat: Seventy degrees kills very quickly. 



(d) Cold: Are alive after sixty-six days in ice (Prud- 

 den). 



(e) Disinfecting agents act rather slowly. In bouillon 

 cultures T-jnTT sublimate does not kill them within five 

 minutes. 



Chemical Activities. — (a) Pigment production : Pro- 

 duces orange-yellow pigment of the carotin group (compare 

 p. 66), but only if oxygen is admitted. According to 

 Liibbert and F. Gartner, pigment production is greater, the 

 more oxygen is contained in the air. 



(6) Substances that are smelt or tasted : Agar cultures 

 smell like glue or spoiled yeast or paste (Becker, Passet). 



(c) Gas and acid formation from carbohydrates : 



Rather abundant formation of acid from grape- and milk-sugar, but 

 no gas-formation. It forms from milk-sugar : lactic acid and volatile 



