236 GENERAL SYSTEMATIC BACTERIOLOGY 



The diagnosis of Winogradsky has been quite generally accepted by 

 subsequent writers on systematic bacteriology, among others by 

 Schroeter (1886, p. 171), Trevisan (1889, p. 10), De Toni and Trevisan 

 (1889, p. 935), Hueppe (1891, p. 30), Ludwig (1892), Clements (1894). 



Migula (1894, p. 238) stated: 



Beggiatoa Trevisan, Zellen mit Schwefelkornchen. Diese letzere Familie und 

 Gattung schliess sich auch in ihrem anatomischen Ban so eng an die Oscillarien 

 an, dass sie besser mit diessen vereinigt und die Schizophyceen zugeweissen wird. 



The definition of Winogradsky is also used by Chester (1889, p. 64), 

 Fischer (1897, p. 32), Migula (1900, p. 1040), Chester (1901, p. 379), 

 Schmidt und Weis (1902), Kendall (1902, p. 484), Fischer (1903, p. 62), 

 E. F. Smith (1905, p. 162), Orla-Jensen (1909, p. 334), Frost (1911, p. 

 60) and Heim (1911, p. 254). 



The following diagnosis of E, F. Smith taken from Migula will give 

 the modern conception of the genus: 



Threads destitute of a sheath, formed of flat discoidal cells, free, i.e., not 

 attached. Multiplication by folding and separation of the threads. Motile by 

 means of an undulating membrane as in Oscillaria. The organism creeps along, 

 but at the same time rotates around the long axis, mostly with a swinging of one or 

 both free ends. Habitat, hot sulphur springs and other fluids in which hydrogen 

 sulphide is developed. No reliable method is yet known for the separation of 

 the species. The number and size of the included sulphur granules are not of 

 specific value. They depend on the amount of hydrogen sulphide in the water. 



Buchanan (1918, p. 464) designated the type species as Beggiatoa alba 

 (Vaucher) Trevisan. 



Bergey et al. (1923, p. 409) include this as the second genus of the fam- 

 ily Beggiatoaceae with the following description : 



Threads sheathless, formed of fiat, discoidal cells, not attached. Multiplica- 

 tion by transverse splitting of the threads. Show undulatory creeping. Cells 

 contain granules of sulphur. 



The type species is Beggiatoa alba (Vaucher) Trevisan. 



Beggiatoaceae. A family of bacteria created by Migula (1894, p. 

 238). It included the single genus Beggiatoa. The diagnosis given 

 in (1895, p. 41) follows: "Fadenbacterien, faden ohne Scheide durch 

 undulierende Membran wie Oscillaria beweglich. Zellinhalt mit 

 Schwefelkornchen. Bildung von Conidien nicht sicher beobachtet." 



In his "System der Bakterien" Migula (1900, p. 1039) includes in the 

 family those genera of sulphur bacteria that have the cells in filaments, 

 destitute of bacteriopurpurin. As thus defined it contains both the 

 genera Beggiatoa and Thiothrix. 



