346 GENERAL SYSTEMATIC BACTERIOLOGY 



The next reference to Leptothrix is for an entirely distinct type. 

 Robin (1847, p. 345) according to Winter (1884, p. 56), De Toni and 

 Trevisan (1889, p. 930) and Schroeter (1886, p. 171) described an 

 organism from the teeth of a horse, which he termed Leptothrix hue- 

 calls. An examination of this reference shows the organism to be 

 referred to (pp. 42-46) as "Algu fihforme de la bouche," but the name 

 Leptothrix buccalis does not appear. Later Robin (1853, 345) gave 

 the following generic description of Leptothrix and specific description 

 of L. buccalis. 



Genre Leptothrix, Kl'itz, Trichomata tenuissima eramosa, nee concreta 

 Filaments non rameux, ni engaines, ni coherents. Trichomatibus rigidulis' 

 linearibus rectis vel inflexis, non moniliformibus, achromaticus, extremitatibus 

 obtusis, basi in stromate amorpho granuloso adhaerentibus. Long. 0™'",020- 

 Ommmioo, lat. 0'°™,1005. Hab. In superficie linguae, intervallis dentium, 

 cavo dentium corruptorum, et in succis stomachi et intestini. Filaments assez 

 roides, droits ou courbes, quelquefois coudes brusquement, a angle generalement 

 obtus a bords nets, non moniliformes, extremites non effilees, larges de 0'"™,0005 

 et longs de 0™'",020 a 0"'",100, incolores, elastiques, reunis generalement, 

 par la base, a une gengue amorphe granuleuse, et formant des faisceaux plus 

 ou moins serres, a moins qu'ils n'aient ete detaches (pi. I, fig. 1 et 2). Hab., 

 surface de la langue, matieres accumulees dans les interstices des dents, ou la 

 cavite des dents cariees, d'ou lis passent dans les liquides de I'estomac, ou de 

 I'intestin dans les cas de diarrhee. 



Robin also described a Leptothrix insectorum, from the rectums of 

 various insects, particularly those living in water. The generic de- 

 scription given to fit this form by Trevisan (1879, p. 147) is "Somatia 

 cylindrica, plus minus distincte articulata, tenuis, elongata, filiformia, 

 recta, laxe fasciculata." 



Kuetzing in 1847 (p. 220) published nine species of Leptothrix, 

 all of them water and algal forms. Two years later (1849, p. 262) 

 he listed and described a total of thirty-seven species. His generic 

 description reads "Tricho7nata tenuissima eramosa nee vaginata, nee 

 concreta." Eight species are grouped in the first division of the genus 

 under the heading ''Species basi adnatae." All of them are water 

 algae, usually colored, but in some species colorless. Under the head- 

 ing "Species trichomatibus liberis, vel intrqcatis et stratum formatibus" 

 the other twenty-nine species are described. The first of these is 

 L. ochracea. All species are water forms, and most are greenish in 

 color. The L. buccalis is not recognized. 



Rabenhorst (1865, p: 73) includes this genus among the Nemato- 

 genae with the description 



