266 THE PYOGENIC COCCI 



with a tendency for the proximal ends to be slightly flattened and the 

 distal ends to be somewhat pointed. In this respect Micrococcus 

 ovalis resembles the pneumococcus very closely. In fluid media, par- 

 ticularly sugar broths, the pairs of organisms remain adherent in chains 

 of greater or lesser length giving rise to a diplostreptococcus arrange- 

 ment which is precisely like that exhibited by the pneumococcus under 

 the same conditions. 



Micrococcus ovalis is non-motile and possesses no flagella. It forms 

 no spores. According to Lewkowicz 1 and others, capsules are produced 

 when the organism is isolated directly from lesions. The organism 

 stains readily with ordinary anilin dyes, and it is Gram positive. 



Isolation and Culture. Micrococcus ovalis grows with moderate vigor 

 on agar plates, better in dextrose or lactose agar. The colonies after 

 forty-eight hours' incubation at 37 C. are round, translucent, color- 

 less, and measure about 1 to 2.5 microns in diameter. They are not 

 distinctive. Colonies on gelatin plates are very small and develop 

 slowly. The medium is not liquefied. Blood agar appears to be a 

 better medium for isolation of Micrococcus ovalis than any other; 

 the colonies are 1 to 3 mm. in diameter even after eighteen hours' 

 incubation, grayish and succulent. No hemolysis takes place. A 

 slight turbidity, which soon settles, forms in plain broth; the addition 

 of dextrose or lactose greatly enriches the growth. Milk is usually 

 coagulated in one to three days (acid coagulation), but the coagulum 

 does not become digested. 



Micrococcus ovalis is an aerobic, facultatively anaerobic organism. 

 The lower limit of growth is about 8 C., the optimum from 37 to 

 39 C., and the maximum about 45 C. Its resistance to chemical 

 and physical agents is about the same as that of the streptococcus. 



Products of Growth. Chemical. The organism exhibits no evidence 

 of proteolysins ; it is relatively inert in protein media. No indol, 

 skatol or volatile sulphur compounds are produced. Acid is produced 

 in dextrose and lactose broths; the action on other sugars is yet to 

 be determined. 



Enzymes. No enzymes are known. 



Toxins. No toxic products have been detected in cultures of 

 Micrococcus ovalis. 



Distribution. The normal habitat of Micrococcus ovalis appears 



to be the intestinal tract of man; it occurs in the meconium frequently, 2 



i 



1 Cent. f. Bakt., 1901, xxix, 635. 



2 Escherich, loc. cit. 



