480 GENERAL SYSTEMATIC BACTERIOLOGY 



for the organism specific for syphilis. The same conclusion was reached 

 by Gleitmann (1913, p. 31), but he stated that there is as yet no uni- 

 formity in the nomenclature of these forms. 



Gonder (1914, p. 674) gives the following diagnosis, agreeing in 

 essential points with Zuelzer: 



Charakterisiert ist demnach die Gattung Spirochaeta wir folgt: (stark aktiv 

 flexibel; ein in echten Spiralen stark gewundener, nackter, einlichen Achsen- 

 stab mit Volutinkornern in den Plasmaspiralen; Fortpflanzung durch echte 

 Querteilung.) 



It would seem that there is sufficient evidence to show the advisa- 

 bility of including only those forms closely related to Spirochaeta plica- 

 tilis in the genus Spirochaeta. 



Winslow et al. (Com. Soc. Am. Bact., 1917, p. 563) give the generic 

 diagnosis : 



Non-parasitic, with flexible undulating body and with or without flagelliform 

 tapering ends. Common in sewage and foul waters. 

 The type species is Spirochaeta plicatilis Ehrenberg. 



Buchanan (1918, p. 543) states: 



Slender, spiral cells, living free, usually in water containing hydrogen sulphide, 

 actively motile, flexuous. Flagella unkno^vn. Anaerobic. Protoplasm is spi- 

 rally wound around a flexible or elastic axis filament. Volutin granules regularly 

 present in the plasma. No differentiation of exterior. Cell circular in cross 

 section. 



The type species is Spirochaeta plicatilis Ehrenberg. 



The genus is also recognized in this limited sense by Castellani and 

 Chahners (1919, p. 436) and by Bergey et al. (1923, p. 419). 



Spirochaetacea. An order of flagellates named by Fantham (1908) 

 according to Castellani and Chalmers (1919, p. 435) who give the 

 following description: 



Plasmodromata, generally parasitic, in form narrow, wavy, and thread-like, 

 with or without an undulating membrane. The cytoplasm is divided into endo- 

 plasm and ectoplasm, and is bounded by a flexible, chitinous periplast. The 

 nucleus consists of a spiral achromatic filament, on which are arranged transverse 

 bars or rodlets of deeply staining chromatin. 



Two famihes are included, Spirochaetidae and Treponemidae. 

 Spirochaetaceae. A subfamily name used by SweUengrebel (1907, 

 p. 581) under the family Spirillaceae. This author includes in the 



