SYSTEMATIC AND DESCRIPTIVE. 21Q 



Micrococcus violaceus, Schroter. Cocci 

 or elliptical cells, described as uniting into violet 

 blue gelatinous spots, which again unite to form 

 larger patches. They were observed on boiled 

 potatoes exposed to the air. 



Micrococcus luteus, Schroter. Cocci similar 

 in size to the above, elliptical, with highly refrac- 

 tive cell contents. They form yellow drops of 

 i 3 mm. diam. on boiled potato, and a thick, 

 wrinkled, yellow skin on nutrient liquids. The 

 colouring matter is insoluble in water, and un- 

 changed by sulphuric acid or alkalies. 



Micrococcus rosaceus. Cocci forming pink 

 colonies, and a rose-coloured growth on the surface 

 of nutrient agar-agar. Observed contaminating 

 an old cultivation (Plate XXIV., Fig. 2). 



Micrococcus haematodes, Zopf. Cocci, 

 which, cultivated on boiled white of egg in a 

 damp chamber in the incubator, form a red layer. 

 The reaction of the colouring matter is similar to 

 that produced by Bacterium prodigtosum. They have 

 been observed in human sweat, especially from the 

 axilla, colouring the surrounding parts and the 

 linen an intense brick or blood-red colour.* 



Micrococcus candidus, Cohn. Cocci forming 

 snow-white points and spots, upon slices of cooked 

 potato. Possibly identical with the following : 



Micrococcus candicans,Flugge. Cocci which 

 collect in masses. In plate-cultivations they form 



* Babes, " Vom Rothen Schweiss," Biol. CcntrabL, Bd. 2. 1882. 



