398 GENERAL SYSTEMATIC BACTERIOLOGY 



Putrificoideae that in meat medium produce gas and various color changes; 

 yellowish, pink, grey or mauve, depending on the medium; the particles of meat 

 are gradually suffused with a black pigment, and bleach at the top. The meat 

 is softened but the particles do not greatly diminish in size. Do not attack sugars. 

 Gram-negative (weak methyl violet) rods that form terminal spherical spores. 

 Colonies in deep agar diverse. Common in soil, found in horse feces, may multi- 

 ply in wounds, but do not normally invade tissue. Produce a characteristic 

 neuro-toxin. 



Type-species N. tetani (Bacillus tetani Nicolaier), to be described in a future 

 paper. 



The definite designation by Buchanan (1918, p. 38) of Plectridium 

 tetani (Nicolaer) Fischer as the type of this genus would seem to 

 reduce the genus Nicolaer illus to a synonym of Plectridium. However, 

 the author (Heller) insists that this is not the Plectridium of Fischer. 



Nigrococcus. A name applied by Castellani and Chalmers (1919, 

 p. 925) to a genus of the tribe Micrococceae. The description (1919, 

 p. 932) follows: 



Micrococceae saprophytic, rarely parasitic, producing black or bluish-black 

 pigment. 



Type. Nigrococcus nigrescens (Castellani, 1911). 



Nitribacillus A generic name suggested by Beijerinck (1914, 

 p. 1163) to replace Nitrohacter Winogradsky. Later (1914, p. 110) 

 he states: 



In meiner Mitteilung in der Akademie der Wissenschaften zu Amsterdam, Bd. 

 23, pag. 1163, 28 Miirz (10 April) 1914, habe ich das Nitratferment, wegen seiner 

 Beweglichkeit Nitribacillus genannt. Doch scheint es mit gegenwartig, dass der 

 von Winogradsky eingefiihrte Name Nitrohacter bleiben kann. 



Nitrobacter. A name proposed by Winogradsky (1892a, p. 87) 

 (1892b, p. 127) to include those organisms which transform nitrous 

 into nitric acid. No species name was appended, hence from the 

 standpoint of strict nomenclature perhaps the name is invalid as a 

 generic designation, Winogradsky makes the following statement. 



S'il fallait donner des nous a tons ces organismes, je proposerais de conserver 

 celui de nitrobacterees a tout le group de microbes, transformed I'ammoniaque en 

 salpetre Le ferment nitrique porterait le nom de Nitrobacter. 



The organism described is a small rod, about 0.5/i in diameter, about 

 2 to 3 times as long as broad, non-motile, embedded in delicate gelat- 

 inous masses. It stains poorly. It grows only on media containing 

 nitrites and little or no organic matter. It transforms the nitrites to 

 nitrates. 



