318 GENERAL SYSTEMATIC BACTERIOLOGY 



According to Lohnis (1913, p. 704) this organism was placed in the 

 genus Gloeosphera by Rabenhorst, with the name G. ferruginea. De 

 Toni and Trevisan (1889, p. 1007) give as authority Rabenhorst, Alg. 

 Mitteleur, n. 387. Ktitzing (1865, p. 53) used Gallionella as the second 

 subgenus of Melosira. Later (p. 56) he says "Ganz ausgeschlossen 

 muss werden Gallionella ferruginea Ehr. welch gar keine Diatomee, 

 sondern eine Conferva ist." Kirchner (1878, p. 250) placed this or- 

 ganism in the genus Spirulina with the name Sp. ferruginea. Hansgirg 

 (1888, p, 264) uses the designation Spirochaete ferruginea (Ehr.) Hansg. 

 De Toni and Trevisan (1889, p. 1007) included the species in the genus 

 Spirillum because of its curved form. De Toni (1891, p. 1331) used 

 Gallionella Bory as a valid generic name of a diatom genus. Hansgirg 

 (1873, p. 184) used the designation Leptothrix ochracea to include this 

 organism not recognizing any distinction between Leptothrix and 

 Gallionella. Migula (1897, p. 321) discussed this organism. 



In his "System" Migula named the organism Chlamydothrix ferru- 

 ginea (1900, p. 1031). In this genus was included the Leptothrix 

 ochracea also. 



Ellis (1907, p. 516) returns to the designation "Gallionella ferruginea," 

 He states. 



The structure is like that of a hairpin, spirally wound round itself. The 

 spiral winding produced a number of loops, the number of which may be few or 

 many. The thickness of the threads varies usually from § to fu. The winding 

 may be loose or tight. The structure of the cell is perfectly homogeneous. 

 Migula states that an extremely delicate membrane is present, but I have not been 

 able to confirm this observation. Multiplication takes place freely by the cutting 

 off of small portions, which then elongate to form a new individual. Conidia 

 formation is also quite common, though not universal as in Leptothrix ochracea. 

 The process of formation of conidia is identical with the same in this organism, 

 as is also the size and shape of conidia. The deposit of iron is the same as in other 

 iron bacteria. In no stage of its life history was any motility observable. 



Orla-Jensen (1909, p. 331) says 



Die Schraubenform des Leptothrix sind Gallionella und Spirophyllum. Jedoch 

 kann den mehr oder weniger zufalligen Biegungen und Flechten der Gallionella- 

 Faden nicht dieselbe systematische Bedeutung wie den regelmaszigen Windun- 

 gen der starren Spirillen zugeschrieben werden, und wir tun daher besser, GaL- 

 lionella nur als eine Leptothrix-Art aufzufassen. 



The name Gallionella ferruginea Ehrenberg was also accepted by 

 Molisch (1910, p. 22) who studied the organism at length and has given 

 us the best description. He states: 



