SARCINA ROSEA 187 



precipitated caseine at the bottom remaining white while 

 between them lies the rose-coloured whey. The formation 

 of pigment takes place in the dark as well as by daylight. 

 According to Hueppe, it appears to result from metabolism, 

 that is, to be a coloured ptomaine, and is seemingly in- 

 dependent of other influences and conditions. 



Ked coloration of milk may also be due to the Bacillus 

 prodigiosus, which, however, causes only a very slow sepa- 

 ration out of the caseine, and does not originate any further 

 changes. 



Sarcina rosea. Menge has found that the agent pro- 

 ducing the red tint may be a sarcina to which he has given 

 the above name. In does not, however, appear to be 

 identical with the micro-organism of the same name de- 

 scribed by Schroter (see p. 109). In two days small 

 translucent, perfectly circular colonies form on the gelatine 

 plate, and soon assume the figure of a rosette having a red 

 nodule in the centre surrounded by concentric rings. In 

 the thrust-culture the surface is covered with a thin rose- 

 red coat with jagged edges, whilst the needle-track remains 

 colourless. Liquefaction takes place very late. On agar a 

 coherent growth develops which is white at first but becomes 

 coloured on the third day ; in the incubator, however, pig- 

 mentation fails altogether. On potato which has been 

 rendered alkaline the sarcina grows excellently. The pig- 

 ment forms in milk independently of light. 



The Micrococcus of bovine mastitis. In different diseases 

 originated in the lacteal glands of animals by the action of 

 micro-organisms the latter can be found in the milk also, 

 and amongst these is the micrococcus of mastitis in the cow 

 described by Kitt, which is met with in the partly milky 

 and partly purulent contents of the udder of cows suffering 

 from this complaint. On the gelatine plate small puncti- 

 forrn colonies of the size of a pin's head develop, and a thrust 



