344 GENERAL SYSTEMATIC BACTERIOLOGY 



Three species were described at this time. Later (1849, p. 154-157) 

 thirty species were included, some of them doubtless being mold mycelia, 

 others yeasts and probably some bacteria. 



De Toni and Trevisan (1889, p. 933) regarded one species, L. diver- 

 gens as a bacterial form and named it Leptotrichia rigidula. 



This is not a valid bacterial genus. 



Leptonema. A genus of algae named by Rabenhorst (1857). It is 

 invalid because of prior use in botany for other forms (Jussieu, 1824, 

 Hooker 1844) according to De Toni and Trevisan who (1889, p. 932) 

 give Leptonema nivea Rabenhorst as a synonym of Leptotrichea 

 nivea Trevisan. 



Leptospira. A generic name proposed by Noguchi (1917, p. 755). 

 Enlows (1920, p. 51) summarizes as follows: 



Type species (monotypy). L. icterohaeviorrhagiae (Inada and Ido, 1914). 

 Cause of infectious jaundice. Closely wound, 10 to 12 coils within 5^, slender, 

 cylindrical filaments with gradually tapering ends. Lengths 7 to 14/x; rarely 30 

 to 40m; diam, 0.25 to 0.3^- Spiral amplitude, 0.45 to 0.5ju. Spiral depth, 0.3/x 

 regular. One or more gentle wavy curves throughout the entire length. In a 

 free space one or both ends may be semicircularly hooked, while in semisolid 

 media the organism appears serpentine, waved or bent. Flexible. No axial 

 filament present; no chambered structure; no membrane; no crista; no flagellum; 

 no terminal finely spiral filament; terminal or caudal (last 6 or S spirals) portion 

 highly motile. Division transverse. Stains reddish violet by Giemsa's solution. 

 Also places here Spirochaeta biflexa Wolbach and Binger. Noguchi considers 

 this genus intermediate between the protozoa and bacteria. He later included 

 the cause of yellow fever under this genus : L. icteroides Noguchi. See J. Exp. 

 med. V. 29, 1919. 



Bergey et al. (1923, p. 429) include this as the sixth genus of the 

 family Spirochaetaceae with the following description: 



Parasitic forms. Sharply twisted cylinders with flagelliform tapering ends, 

 one extremity being sharply curved into a "hook." 



The type species is Leptospira ictohemorrhagica (Inado and Ido) Noguchi. 



Leptothrichaceae. See Leptotrichaceae. The third family of the 

 order Desmobacteria proposed by Hansgirg (1888, p. 230). Two sub- 

 families are included, Leptothricheae and Beggiatoeae. No description 

 is given. 



Leptothricheae. A family name first used by Kuetzing (1843, p. 

 197) with the following diagnosis: ''Trichomata tranquilla tenuissima, 

 continua, (pel obsolete articulata). Cellulae propagatoriae propriae 

 nullae." As a subfamily this name was also used by Rabenhorst 

 (1865, p. 73) with the following diagnosis: 



