174 IMPORTANT VARIETIES OF FISSION-FUNGI. 



scription it cannot be differentiated from the Micr. tetra- 

 genus Gaffky and Koch, except that it forms some skatol. 

 It possesses a very lively spontaneous motion, and consti- 

 tutes, until more material is at hand, the motile, presum- 

 ably flagellated, related form of the Micr. tetragenus (see 

 Micrococcus roseus). 



Micrococcus rosettaceus (Zimmermann) (i, p. 72). 



According to the description of Zimmermann it is almost identical 

 with the Micr. candicans, but upon gelatin it is grayish-white and upon 

 potato of a yellowish-gray color ; size from 0. 7 /i to 1.0 M. 



Micrococcus concentricus (Zimmermann) (i, p. 86). 



Upon all nutrient media it forms only a thin, delicate, iridescent 

 growth, resembling somewhat the Bact. typhi. Upon gelatin plates 

 the border is irregular, and concentric zones are almost always seen on 

 gelatin. It never liquefies gelatin. Upon potato thin, yellowish- 

 gray, slimy growth. They are 0. 9 ,« in diameter. Found by Zimmer- 

 mann in Chemnitz hydrant-water. 



Micrococcus viticulosus (Katz). 



This was, so far as we know, isolated only once bvKatzinFliigge's 

 laboratory in Gottingen. In the gelatin stab and in deep colonies in 

 gelatin plates it forms delicate white tendrils. "We kno\\- it only from 

 the description, according to which its cultures evidently have a great 

 similarity to tho.se of the Bact. Zopfii, which we have represented in 

 Plates 29 and 30. Gelatin is not liquefied. The cocci are always oval, 

 being 1.2 /i long and 1 11 broad. 



Micrococcus of Bitter Milk (Conn) (C. B. ix, 653). 



Rather large coccus, non-chromogenic. Gelatin rapidly liquefied, 

 which, as well as bouillon, becomes very mucilajtinous. Milk at first 

 is coagulated, then becomes clear and slimy. It tastes faintly acid, but 

 is very bitter. 



Micrococcus Freudenreichii (Quillebeau). 



Large cocci (2 11 and over in diameter), usually single, rarely (in 

 bouillon) arranged in chains. In milk gelatin, the colonies first appear 

 white, entire, finely granular; after two days rapid liquefaction occurs. 

 Agar culture is white. Potato culture sulphur-yellow to yellowish- 

 brown, at times delicate and at other times luxuriant. Bouillon first 

 becomes cloudy, then clear with a flocculent sediment. In sterile milk 



