468 GENERAL SYSTEMATIC BACTERIOLOGY 



Indessen kommt es allerdings auch vor, dass fremdartige kleine Korper, beson- 

 ders Diatomeen sich ansetzen und von den Flocken eingeschlossen werden. So 

 waren unter den Exemplaren, die ich in der Linnaea abgebildet habe, eine Menge 

 kleiner Kalktheilchen, daher die mikroskopische Zeichnung nicht genau und 

 hiernach zu berichtigen ist. 



In 1849 (p. 147) two other species, Sph. ochraceus and Sph. glaucus 

 were named. 



Apparently the same organism was described under the name Clado- 

 thrix dichotoma by Cohn (1875, p. 185). Eidam (1876, p. 133) used the 

 generic name Sphaerotilus. Winter (1880, p. 62) gives the following 

 diagnosis : 



Zellen rundlich-eckig oder langlich, an den Ecken abgerundet, in grosser Zahl 

 reiheniveise in einer farblosen Schleimscheide vereinigt zu langen Faden, die dicht 

 zopfartig verflochten und verwirrt schwimmende. Flocken bilden. Vermehrung 

 durch sich isolirende, vegetative Zellen, die durch fortgestzte Theilung neue 

 Faden erzeugen. Fortpflanzung durch Sporen, die endogen in den vegetativen 

 Zellen sich bilden. 



Grove (1884, p. 53) uses the same description. It was regarded 

 by Fliigge (1886) as a doubtful genus. The generic description was 

 revised by Schroter (1886, p. 173) and included as a vaUd genus in 

 "Die Pilze Schlesiens." 



De Toni and Trevisan (1889, p. 926) recognize both Cladothrix 

 and Sphaerotilus. The description given of the latter follows: 



Filamenta primitus affixa, basi ab apice superiori distincta, mitio simplicia, 

 dein Cladotricis more pseudoramosa a basi ad apicem subaequiliata articulata, 

 vagina gelatinosa obducta, in fascicules crassos floccosus varie divisos consociata. 

 Multiplicatio fragmentis filamentorum secedentibus ,quae filamenta et fascicu- 

 les, novos efficiunt. Arthrosporae niunerosissimae, articulorum divisiones in 

 tres directiones ortae. 



The genus was also recognized by'^Ludwig (1892). Migula (1909, p. 

 1035) redescribed the genus. ThisTdescription as given by Smith 

 (1905, p. 162) is as foUows: 



Cells cylindric, enveloped in sheaths, forming dichtomously branched threads 

 with no differentiation into base and apex. Multiplication by means of conidia 

 which swarm out of the sheath, attach themselves anywhere, and immediately 

 grow out into new threads. The conidia possess a tuft of^flagella inserted sidewise 

 under one pole. 



It should be noted that this same author (Smith 1905) includes 

 Sphaerotilus in a hst of generic names to^be abandoned. Orla-Jensen 



