GENERAL SYSTEMATIC BACTERIOLOGY 347 



Trichomata tenuissima, abbreviata, adhaerentia, segregata vel laxe aggregata, 

 nunquam intricata, saepius oscillantia, indistincte articulata et saepe distincta 

 vaginata; cytioplasma hoinogeneum, aetate provecta granulosum nonnunquam 

 fasciatim contractum. 



Billroth (1874, p. 15) used the term to designate one of the growth 

 forms of his pleomorphic Coccobacteria septica in which the organism 

 occurred as a slender filament without visible articulations. 



Cohn (1875) included this genus in his tribe Nematogenes to include 

 those organisms which produce slender filaments, in which the articu- 

 lations are indistinct, colorless, cylindrical, free and unbranched. 



Trevisan (1879, p. 147) concluded that the genus Leptothrix is 

 strictly algal, and created the new genus Leptotrichia (q.v.) with the 

 single species L. buccalis. 



Luei-ssen (1879, p. 24) accepts both the free hving water forms and 

 the parasitic types as members of this genus. He says: 



Von der Gattung Bacillus nur durch. die sehr langen dunnen undeutlich geglie- 

 derten Faden verschieden. Im Wasser auf anderen Algen und Wasserpflanzen 

 u. s. w. bei gewissen Krankheit prozessen auch am menschlichen Korper beo- 

 bachtet. L. buccalis Rob. Auf dem Epithelium der menschlichen Mundhohle, 

 im Zahnen. 



Magnin (1880, p. 90) emphasized that Leptothrix differs from Bacil- 

 lus in that the filaments are long, adherent, very slender and indis- 

 tinctly articulated. 



Winter (1880, p. 56) includes two species only in his genus, Lepto- 

 thrix buccalis and L. parasitica. His generic description is "Faden 

 sehr lang und dlinn, unverzweigten scheinbar ungegliedert, farblos, 

 ohne Bewegung, ohne Kornchen, frei oder verfilzt." He states that 

 the fungi which have been assigned to the genus Leptothrix are of very 

 questionable specific value, and that the most of the true species of 

 Leptothrix are typical algae containing phycochrome, implying that 

 another designation should be formed for the organisms which are 

 colorless and are grouped with the bacteria. 



Grove's statement (1884, p. 34) is essentially a translation of that 

 of Winter. 



Zopf (1885, p. 95) states "Faden bescheidet oder unbescheidet. 

 Theilungen sehr weit gehend. Zellen schwefellos." 



From this time the term Leptothrix is frequently found used as a 

 morphological designation for slender unbranched long rods. For 

 example, Fliigge states (1886) that "formerly" the bacilli were sub- 

 divided to include the true bacillus and leptothrix or very long rods. 



