PLATES 167 



distinguished. The condition of the condensed water in the tubes is 

 also noted, and whether it is clear or cloudy, or whether there is a 

 precipitate, and whether the latter is granular, flocculent, or slimy, or 

 shows any other particular quality. 



Plates. On plates are studied the individual colonies in particular, 

 their size is noted, the following features are distinguished, and the 

 following descriptive terms are used: 



Punctiform denotes the dimensions so small that they cannot be 

 well measured by the naked eye. 



Round, elliptical, fusiform, irregular are self-explanatory terms; 

 cochleate is a colony which is twisted somewhat like the shell of a snail. 

 . Ameboid is a colony irregular in outlines and with processes 

 looking somewhat like the pseudopodia of an ameba. 



Myceloid is a colony of bacteria with radiating slender masses 

 looking more or less like a mould mycelium. 



FIG. 93 FIG. 94 FIG. 95 



I 



Round surface colony, colon Colony of typhoid in rather Colonies of typhoid and 



bacilli grown in stiff gelatin. stiff gelatin. (Park.) colon bacilli in rather soft 



(Park.) gelatin. (Park.) 



Filamentous colonies are composed of an irregular mass of loosely 

 woven filaments. 



Floccose indicates a dense woolly structure. 



Rhizoid denotes an irregularly branched, root-like character. 



Conglomerate is an aggregation of small colonies more or less equal 

 in size and character which present one compound larger colony. 



Toruloid are colonies composed of several small round or oval 

 colonies, arranged like a group of budding torula or yeast cells. 



Rosulate means shaped like a rosette. 



Sometimes terms indicating a fancied resemblance to certain pic- 

 torial objects are used; anthrax colonies, for example, are sometimes 

 spoken of as being like the head of Medusa, because under low power 

 they show tortuous twisted strings and masses of bacilli at the margin 

 which somewhat resembles the mythologic serpent-surrounded head 

 of a Medusa. With reference to their elevation over the surface, 

 colonies are described as flat, raised, convex, pulvinate, hemispheric, 

 or capitate; also umbilicated, having an umbilicus-like impression, 

 and umbonate, having a central nipple-like elevation or knob. 



