GENERAL SYSTEMATIC BACTERIOLOGY 481 



subfamily those spiral bacteria in which the cells are flexible. Three 

 genera are recognized: Spirochaeta, Treponema, and Borrelia. As a 

 family name this is used by Schneider (1912, p. 23), coordinate with 

 sLx other families of bacteria. It is defined to include long, unicellular, 

 flexible, spirally twisted threads without flagella. One genus only, 

 Spirochaeta, is recognized. 



Winslow et al. (Com. Soc. Am. Bact., 1917, p. 562) regard this 

 as a group intermediate between the bacteria and the protozoa with 

 the following description: 



Free living or parasitic spirilliform organisms with or without flagella, with 

 undulating or rigid spiral twists. Reproduction by transverse division and by 

 "coccoid bodies," the equivalent of spores. 



Spirochaetales. The name proposed b}^ Buchanan (1918, p. 542) 

 for the SLxth order of the Schizomycetes with the description: 



Protozoan-like in many characters. Cells usually relatively slender flexuous 

 spirals: multiplication of cells apparently by longitudinal division in some 

 types, by transverse division in others, or both. 



One family is recognized, Spirochaetaceae. 



Spirochaete. A variant of the spelling of Spirochaeta Ehrenberg 

 first used by Cohn (1872, p. 180). It was later used by Luerssen 

 (1879, p. 25), Trevisan (1879, p. 148), Van Tieghem (1884), Schroeter 

 (1886, p. 168), De Toni and Trevisan (1889, p. 1006), Billet (1890, p. 

 24), Sternberg (1892, p. 18), Ludwig (1892), Fischer (1897, p. 32), 

 Migula (1897, p. 47), Lehmann and Neumann (1901, p. 126), Kendall 

 (1902, p. 484), Matzuschita (1902), Fischer (1903, p. 61), Migula (1904, 

 p. 145), Thesing (1906, p. 351), EUis (1909, p. 7), Heim (1911, p. 252), 

 and by manj' writers in the modern Hterature of medical bacteriology. 

 Attention has been drawn to the fact that this form is incorrect by 

 Stiles (1905, p. 94) and by Blanchard (1906). 



Spirochaetidae. A familj^ (zoological) name ascribed to Ehren- 

 berg 1833 by Castellani and Chahners (1919, p. 436). They state 

 " Spirochaetacea with an undulating membrane. Body may be ribbon 

 shaped on transverse section." The genera included are Spirochaeta, 

 Cristispira, Saprospira, Pseudospira, and Spiroschaudinnia. 



Spirochaetoidea. A name used for a group of spiral organisms by 

 Dobell (1911, p. 536). Three genera are recognized: Spirochaeta, 

 Treponema and Cristispira. He says: 



The organisms commonly called Spirochaetes may be conveniently collected 

 into a single group, for which I propose the name Spirochaetoidea. This group 



