174 RELATIONSHIPS OF THE COCCACE^E 



the transformation of a white staphylococcus to an orange 

 one, and back again to a white one ; but the possibility of 

 mixed cultures is too great to permit the acceptance of 

 such a statement without strong confirmatory evidence. 

 In no other case, as far as we are aware, has the acquisi- 

 tion of the power of forming orange pigment been recorded. 

 The change from a chromogenic to a non-chromogenic 

 form has, on the other hand, been demonstrated by many 

 observers. Lubinski (1894) noted that the orange staphy- 

 lococcus. lost its chromogenic power under anaerobic con- 

 ditions, and that the recovery of this property on subse- 

 quent transfers to aerobic cultures was sometimes delayed 

 or abolished. After cultivation in an atmosphere of 

 carbon dioxid, three days' growth in air was sufficient to 

 restore the chromogenic power; while after cultivation in 

 hydrogen, aerobic cultures showed, after fifteen days, a 

 notably paler color than those which had not been exposed 

 to unfavorable conditions. After ten transfers under an- 

 aerobic conditions the chromogenic power was appar- 

 ently destroyed, and even after transfers in air the culture 

 could not be distinguished from the white staphylococcus. 

 Lubinski attempted to produce chromogenic power in 

 strains of the white staphylococcus, but without success. 

 Kolle and Otto (1902) note that heating to 85 degrees 

 produces a non-chromogenic strain of the orange staphylo- 

 coccus, and that the same loss of chromogenic power 

 follows prolonged cultivation on artificial media, or re- 

 peated passage through animals. Konradi (1904) pointed 



