516 GENERAL SYSTEMATIC BACTERIOLOGY 



The organisms included under this head are filamentous forms and possess 

 many characters relating them to the group of true molds (Hyphomycetes) rather 

 than to the bacteria proper (Schizomycetes) . They may be said perhaps to stand 

 in an intermediate position between the bacteria and the higher fungi. All have 

 a more complicated cycle of development than has been observed in any of the true 

 bacteria. On the other hand, they are distinguished from the higher fungi by 

 the slenderness of their filaments and their more simple life-history. Among the 

 so-called Trichomycetes themselves great confusion has prevailed both in classi- 

 fication and in nomenclature, and there is still far from being any universal agree- 

 ment concerning the subdivision of the group and their designations. 



The genera Leptothrix, Cladothrix, Nocardia, and Actinomyces are 

 included. 



Petruschky (in Kolle and Wasserman, Vol. 5, p. 267) includes Actino- 

 myces and Streptothrix under the heading of Trichomycetes but places 

 Cladothrix and Leptothrix with the Trichobacteria. 



Heim (1911, p. 253) has modified the conception somewhat. He 

 saj's : 



Der Name ist von J. Petruschky fiir eine Gruppe von Microorganismen vorge- 

 schwungen worden, die man bisher entweder under die Hjrphomyzeten eingereiht 

 oder denen man eine besondere Stelle zwischen diesen und den Schizomyceten 

 zuerkannt hat. Es sind fadenformige Gebilde mit echten Verzweigungen, die 

 entweder spitz oder mit einer kolbigen Anschwellung endigen und in ihren Breit- 

 endurchmesser die Bakterien nicht betriichtlich tibertreffen. 



Diese Eigentiimlichkeiten kommen vielen Bakterien unter gewissen Ernah- 

 rungsbedingungen zu, darum ist man geneigt, solche, und zwar insbesondere 

 die Tuberkel-, Rotz-, Diphtheriebazillen und ihre Verwandten hierher zu 

 rechnen. 



Castellani and Chalmers (1919, p. 1040) make this a synonym of 

 Nocardiaceae. 



Trichomyzeten. A variant of Trichomycetes used by Heim (1911, 

 p. 253). 



Tricogene. A variant of Trichogenae used by Trevisan (1889, p. 9) 

 for the first suborder of bacteria. He states: "Tre stati di sviluppo 

 vegetative: 1. Filamenti; 2. Baculi; 3. Cocchi. Filamenti; (state 

 prim.ario, iniziale, archetipo) ora rivestitidi vagina propria ambiente, 

 ora non vaginati, per lo piu forniti di base distinta dalla estremita 

 superiore, affisi o irradianti da un punto centrales, di rado liberi colle 

 due estremita perfettamente eguali. BacuU e cocchi provenienti dai 

 filamenti." 



