25G GENERAL SYSTEMATIC BACTERIOLOGY 



It may be noted that the correct designation of the subfamily would 

 be Chromatioideae (q.v.). 



Chromatieae. The fifth tribe of the subfamily Chromatioideae 

 named by Buchanan (1918, p. 470). The diagnosis follows, "Sulphur 

 bacteria in which the cells are not united into families, but free, and 

 capable of swarming at any time." The tribe is the equivalent of 

 Migula's Chromatiaceae q.v. Five genera were included, Chromatium, 

 Rhabdomonas, Thiospirillum, Rhodocapsa and Rhodothece. 



This usage is followed by Bergey et al. (1923, p. 400). 



Chromatioideae. The first subfamily of the family Rhodobacteria- 

 ceae named by Buchanan (1918, p. 464) with the description: "Cells 

 not filamentous, containing both sulphur granules and bacteriopurpurin. 



The subfamily is practically the equivalent of Thiorhodaceae q.v. 



Five tribes are included, Thiocapseae, Lamprocysteae, Thiopedieae, 

 Amoebobaderieae, and Chromatieae. 



Bergey et al. (1923, p. 394) have followed in the use of this term. 



Chromatium. A generic name created by Perty (1852, p. 179) 

 with the following diagnosis: 



Korper iiusserst klein, cylindrisch, roth, braun, violett, griin gefarbt, im aus- 

 gebildeten Zustand mit innem Blaschen (Blastien). Ein Bewegungsfaden am 

 Vorderende? Vermehren sich durch Quertheilung. 



Two species were described, C. Weissii and C. violascens. He states 

 the former to be related to the Manas Okenii of Weiss, but smaller. 

 The genus was recognized and more fully described by Schroeter (1886, 

 p. 156) as containing those organisms with cylindrical-elliptical or 

 relatively thick cylindrical cells multiplying by fission, and with cell 

 contents colored red, and containing black (sulphur) granules. He 

 states that this genus is placed with the bacteria only provisionally, 

 for it has many resemblances to the monads. Winogradsky (1888, 

 p. 86) includes the genus among his sulphur bacteria. He accepts the 

 Schroeter diagnosis of the genus and recognizes the best known species 

 Chromatium Okenii. In this species the cells are very large, averaging 

 15.3iu in length and 6m in maximum width. The ceUs are somewhat 

 variable in shape, straight or more or less bent, short cells ovoid and 

 longer forms more cylindrical. The cells are motile by means of polar 

 flagella. Other species are Chr. weissii, Chr. minus, Chr. vinosum and 

 Chr. minutissimum. 



The genus is included in classifications of sulphur bacteria in the 

 subfamily Chromatiaceae by Migula (1900, 1904), E. F. Smith (1905, 



