500 NON-PATHOGENIC MICROCOCCI. 



166. DIPLOCOCCUS FLUORESCENS FCETIDUS (Klamann). 



Obtained from the posterior nares. 



Morphology. Diplococci, about 1.4 n in diameter (the pair), often ar- 

 ranged in chains containing from six to ten elements. 



Biological Characters. An aerobic and facultative anaerobic, liquefy- 

 ing, chromogenic micrococcus. Grows in the usual culture media at the 

 room temperature better at 37 C. Upon gelatin plates the superficial 

 colonies are at first gray or brownish circular masses, which soon sink be- 

 low the surface of the liquefying gelatin and later form a crater-like de- 

 pression, in the centre of wnich is seen a brownish-gray sediment, while 

 the surrounding gelatin has a grass-green or violet color. In gelatin stick 

 cultures a circular, shallow, pale-gray, saucer-shaped cavity forms at the 

 surface, and a purse-like pouch along the line of puncture ; a shining, iri- 

 descent film floats upon the surface of the liquefied gelatin, and a greenish- 

 gray sediment accumulates at the bottom ; finally the gelatin is completely 

 liquefied and has a green color above, while a violet-colored film floats upon 

 the surface. Upon agar a granular, brownish-gray layer is quickly devel- 

 oped. Upon potato a finely granular layer, which after a time acquires a 

 dark, bluish-green color, while the potato around it is colored blue. The 

 color is changed to red by acids. 



167. DIPLOCOCCUS LUTEUS (Adametz). 



Found in water, 



Morphology. Micrococci, usually in pairs, of 1.2 to 1.3 fit in diameter ; 

 sometimes observed in chains of eight to ten elements or in irregular groups. 



Biological Characters. An aerobic, liquefying, motile, chromogenic 

 micrococcus. Grows in the usual culture media at the room temperature. 

 This micrococcus is described by Adametz as actively motile. Upon gelatin 

 plates, at the end of three days, circular, pale-yellow, viscous colonies are 

 developed, which have a diameter of about one millimetre. Under a low 

 power they are seen to be granular and brownish-yellow in the centre, while 

 the margins are pale-yellow ; at the end of six days the colonies are of an in- 

 tense yellow color and about three millimetres in diameter. In gelatin 

 stick cultures growth occurs rapidly upon the surface only, at first as a cir- 

 cular, lemon-yellow layer marked with concentric circles; at the end of 

 about ten days the gelatin at the surface acquires an intense brownish-red 

 color, which extends downward in a cloud-like manner, gradually dimin- 

 ishing in intensity ; liquefaction commences at the end of several weeks. 

 Upon the surface of agar a viscid yellow layer is formed along the impf- 

 strich, and the medium acquires a brownish-red color. Upon potato a dirty- 

 yellow layer, which subsequently has a brownish color, is developed ; this 

 gives off the characteristic odor of penicillum cultures. In milk coagula- 

 tion of the casein is produced in about five days. 



168. DIPLOCOCCUS ROSEUS (Bumm). 



Found in the air. 



Morphology. Diplococci resembling the " gonococcus, " the elements of 

 a pair being hemispherical and separated by a tolerably broad cleft; the 

 diameter, measured from pole to pole, is from 1 to 1.5 n. 



Biological Characters. An aerobic and facultative anaerobic, liquefy- 

 ing, chromogenic micrococcus. Grows in nutrient gelatin at the room 

 temperature. Upon gelatin plates slightly elevated, pink colonies are de- 

 veloped, which under the microscope are seen to be finely granular and ir- 

 regular in outline. In gelatin stick cultures an abundant development oc- 

 curs upon the surface and along the line of puncture ; this has a pink color ; 

 the gelatin is slowly liquefied after a considerable time. 



