198 IMPORTANT VARIETIES OF FISSION-FUNGI. 



(a) Culture pale grayish-orange (cream). Bact. cremoides, 



L. andN., 1 page 267. 

 (/?) Growth lemon-yellow. Bact. luteum (Fl. ), L. and N. , 



page 268. 



2. Gelatin slowly liquefied. 



(a) Luxuriant lemon-yellow layer on gelatin. Agar and 



gelatin colored red. Bact. erythrogenes (Groten- 



felt), L. and N., page 268. 

 (j8) Rather abundant lemon-yellow growth on gelatin. 



Agar and gelatin colorless. Bact. helvolum (Zimm.), 



L. and N., page 268. 

 (y) Growth on gelatin at first white, then yellowish. Milk 



slimy. Soapy smell. Bact. lactis saponacei, Weig- 



mann, page 269. 



3. Gelatin rapidly liquefied. Growth upon gelatin very del- 



icate. Little chromogenesis. Bact. nubilum (Frank- 

 land), L. and N., page 269. 

 (b) Spontaneous motility from polar flagellum. Gelatin lique- 

 fied, pale ocher-yellow sediment. Upon potato and agar, a 

 pale ocher-yellow deposit. Bact. ochraceum (Zimm.), L. 

 and N., page 270. 

 (C) Short rods to long threads. Cultures grayish-orange to pale 

 orange and brick-red. Never branches in the stab. 

 (a) Non-motile. Bact. fulvum (Zimmermann), L. and N., page 



270. 

 (6) Motile. Bact. chrysoglcea Zopf., page 272. 



III. Formation of a rose-red to a brown-red pigment upon agar and 

 gelatin. Especially beautiful chromogenesis upon potato. (For red-brown 

 and brick-red varieties, compare also Bact. fuscum and chrysoglcea. ) 



{A ) Stains by Gram's method. Non-motile. Gelatin not lique- 

 fied. Bact. latericium (Adametz), L. and N., page 272. 



(B) Does not stain by Gram's method. Motile. Gelatin lique- 

 fied. Pigment rose to carmine-red, more rarely reddish- 

 yellow. Bact. prodigiosum (Ehrenberg), L. and N., page 

 272. 



IV. Formation of a non-diffusible, violet or blue pigment in the cultures 

 upon agar, gelatin, and potato. 



(A) Gelatin more or less rapidly liquefied. Forms a deep violet 

 pigment, which is soluble in alcohol. Bact. violaceum, 

 Schroter, page 277. 



(B) Gelatin not liquefied. Pigment pale to deep indigo-blue, 

 insoluble. Bact. indigonaceum (Claessen), L. and N., page 

 280. 



(C) Gelatin slowly liquefied. Bluish-green, insoluble pigment, 

 especially marked on potato. Bact. cseruleum (Voges.), L. 

 and N., page "280. 



V. The growths of the bacteria are colorless or only slightly yellowish, 

 bluish, brownish, or greenish in color ; on the contrary, a yellowish-green to 



1 For relatives and synonyms, see the text. 



