GENERAL SYSTEMATIC BACTERIOLOGY 433 



Buchanan (1918, p. 54) emended the generic description as follows: 



Short rods, showing great variation in morphology, filamentous and bent rods 

 as involution forms frequent. Motile by means of peritrichous flagella. The 

 species commonly produce motile "islands" on the surface of moist solid media. 

 No spores. Gram-negative. Usually producing acid and gas from certain car- 

 bohydrates. In general the species are closely associated with decay and putre- 

 faction, sometimes pathogenic. 



The type species is Proteus vulgaris Hauser. 



Winslow et al. (Committee Soc. Am. Bact., 1920, p. 210) have de- 

 scribed the genus as follows: 



Highly pleomorphic rods, filaments and curved cells being common as involu- 

 tion forms. Gram negative. Actively motile. Characteristic amoeboid 

 colonies on moist media. Liquefy gelatin rapidly and produce vigorous decom- 

 position of proteins. Ferment glucose and sucrose (but usually not lactose), 

 with formation of acid and gas (the latter being CO2 only). 



Type species, P. vulgaris Hauser. 



The genus is also recognized by Castellani and Chalmers (1919, p. 

 943). 



Bergey et al. (1923, p. 209) include Proteus as the third genus of the 

 tribe Bactereae with the following description. 



Highly pleomorphic rods. Filamentous and curved rods are common as invo- 

 lution forms. Gram-negative. Actively motile, possessing peritrichous flagella. 

 Produce characteristic amoeboid colonies on moist media and decompose proteins. 

 Ferment dextrose and sucrose but not lactose. Do not produce acetyl-methyl 

 carbinol. 



Protobacteries. A name used by Maggi (1886, p. 81) as the designa- 

 tion of his first order of bacteria, with one genus Aphaneroglia, but 

 without description. 



Protococcus. A genus of green algae proposed by Agardh. One 

 species Protococcus roseo-persicinus Klitzing (1849) was later described 

 by Schroter as Lamprocystis roseo-persicina and included among the 

 bacteria. Protococcus is a vaUd algal generic name and should not be 

 used for the bacteria. 



Miller (1892, p. 123) makes the following statement: 



Klencke (1850) beschreibt auch einen, von ihm entdeckten Parasiten, eine 

 Protococcus art, Protococcus dentalis, welcher Schmelz und Zahnbeim in ahlicher 

 Weise verfliissigt, wie der Hausschwamm, Merulius lacrymans, das Holz der 

 Hauser oder Mobel erweicht. 



