272 LABORATORY EXERCISES IN BACTERIOLOGY, 



(b) Cells ordinarily long-branched filaments; 

 non-motile; without endospores, but produce 

 short gonidia-like bodies by multiple seg- 

 mentation of filament ; cultures on solid media 

 raised, dry, rough, crumpled, often mould-like 



from formation of aerial hyphae, Genus : Streptothrix. 



V. Filamentous bacteria, composed of rod-shaped 

 cells ; filaments surrounded by sheath ; cell 

 division into motile or non-motile gonidia, .. Family : Chlamidobacteriaceae. 



(a) Filaments unbranched; non-motile; inclosed 

 in delicate or thick sheaths ; fixed or in slimy 

 masses. Cell contents become segmented into 

 round or oval gonidia by transverse division; 

 gonidia non-motile. (Separation of filaments 

 and presence of sheath shown by iodine stain- 

 ing), Genus : Leptothrix. 



(b) Filaments unbranched; surrounded by very 

 delicate sheath seen only in old filaments; 

 filaments consist at first of rods in one plane, 

 which later divide in three planes to form 

 sarcina-like packets; later the cells become 



spherical and free, Genus : Phragmidiothrix. 



(c) Filaments unbranched, surrounded by defi- 

 nite sheath, fixed, usually thinner at base than 

 at free end ; cell division in three directions to 

 formation of gonidia (micro- and macro- 

 gonidia), which may escape or germinate in 



filament, Genus : Crenothrix. 



(d) Filaments show false branching, due to 

 intercalary growth of a cell through the sheath 

 laterally; filaments generally with delicate 

 sheaths, often fixed and forming tufts; repro- 

 duction by formation of motile gonidia 

 (swarm spores) which bear a bundle of 



flagella laterally to one pole, Genus : Cladothrix. 



LIST OF MORE OR LESS EQUIVALENT TERMS IN GENERIC NOMEN- 

 CLATURE. 



Streptococcus, Billroth (diplococcus; leuconostoc, VanTieghem; ascococcus, Cienkowski). 

 Micrococcus, Hallier-Cohn (coccus; sph&rococcus; tetrad; merismopedia; merista; 



pediococcus; staphylococcus, Ogston; leucocystis, Schrotter; hyalococcus, Schrotter; 



lampropedia, Schrotter; bacteridium, Schrotter; ascococcus, Billroth; monas, 



Ehrenberg) . 

 Sarcina, Goodsir. 



Planococcus, Migula (id. micrococcus). 

 Piano sarcina, Migula. 

 Bacterium, Ehrenberg-Migula (bacillus, Cohn ; bacteridium, Davaine ; Neumann and 



Lehmann and others reserve the name for rods devoid of endospores). 



