128 BACTERIOLOGY. 



violet blue gelatinous spots, which again unite to 

 form larger patches. They occasionally grow on 

 boiled potatoes exposed to the air. 



Micrococcus luteus, Schroter. Cocci some- 

 what larger than M. prodigiosus, elliptical, with 

 highly refractive 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 

 unchanged by sulphuric acid or alkalies. 



Micrococcus fulvus, Cohn. Cocci round 

 i '5 JJL in diam., frequently in pairs. They form rusty- 

 red conical drops of a firm consistency, and about 

 5 mm. diam., on horse dung. 



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 M. prodigiosus. 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.* 



Genus V. Ascococcus. 



Ascococcus Billrothii. Small globular cocci, 

 united into characteristic colonies. They form on 

 the surface of nourishing fluids a cream-like skin, 

 divisible into an enormous number of globular or 

 oval families. Each family is surrounded by a 



* Babes, Vom rothen Schweiss. Biol. Centralbl., Bd. 2, 1882. 



