370 METHODS USED IN SYSTEMATIC BACTERIOLOGY 



Amorphous (colonies) : without visible differentiation in structure. 



Amphitrichate : having a single flagellum at each pole. 



Anaerobic : growing in the absence of free oxygen ; strictly anaerobic, growing 



only in the absence of free oxygen ; facultatively anaerobic, growing both 



in the presence of and in the absence of oxygen. It must be noted, however, 



that growth of even strict anaerobes will occur in the presence of molecular 



oxygen, provided the medium contains a reducing system capable of bringing 



about a sufficiently low 0-R potential (see Chapters 3 and 36). 

 Beaded (stained bacteria) : deeply staining granules arranged at regular intervals 



along the course of the rod. (In stab or stroke culture) : disjointed or semi 



confluent colonies along the line of inoculation. 

 Beaten-copper : multiple small crateriform depressions on the surface of a growth, 



resembling beaten copper. 

 Bipolar : at both ends or poles of the bacterial cell. 

 Butyrous : growth of butter-like consistency. 

 Chains : four or more bacterial cells attached end-to-end. 

 Chromogenesis : the production of colour. 



Citron : shaped like a lemon, having a small knob at each end. 

 Clavate : club-shaped. 

 Coagulation : formation of a firm clot in milk with the subsequent separation of 



the casein from the whey. 

 Contoured : an irregular, smoothly undulating surface. 

 Convex : the segment of a sphere of short radius ; Low convex, the segment of a 



sphere of long radius. 

 Crateriform : a saucer-shaped liquefaction of the medium. 

 Crenated : small, shallow indentations of the edge, which has a scalloped 



appearance. 

 Cuneate : wedge-shaped. 



Curled : composed of parallel chains in wavy strands, as in anthrax colonies. 

 Effuse : growth thin, hardly raised at all from the medium. 

 Endospores : thick-walled spores formed within the bacterial cell. 

 Entire : with an even margin. 



Equatorial : situated about equidistant from each end. 

 Erose : border showing fine, pointed, tooth-like projections. 

 Filaments : applied to morphology of bacteria, refers to thread-like forms, generally 



unsegmented ; if segmented, to be distinguished from chains (q.v.) by the 



absence of constrictions between the segments. 

 Filamentous : growth composed of long, often interwoven threads. 

 Filiform : in stroke or stab cultures, a uniform growth confined to the line of 



inoculation. 

 Fimbriate : fine, sometimes recurved, processes projecting from the edge of the 



colony or growth. 

 Flocculent : containing small adherent masses of bacteria of various shapes floating 



in the culture fluid, or deposited at the bottom. 

 Fluorescent : having one colour by transmitted light and another by reflected 



light. 

 Friable : growth dry and brittle, when touched with a platinum needle. 

 Granular : composed of granules ; fine, medium or coarse. 



