GLOSSARY OF TERMS.
AGAR HANGING BLOCK, a small block of nutrient agar cut from a pour plate, and placed on a cover-glass, the surface next the glass having been first touched with a loop from a young fluid culture or with a dilution from the same. It is examined upside down, the same as a hanging drop. AMEBOID, assuming various shapes like an ameba. AMORPHOUS, without visible differentiation in structure. ARBORESCENT, a branched, tree-like growth. BEADED, in stab or stroke, disjointed or semiconfluent colonies along the lines of inoculation. BRIEF, a few days, a week. BRITTLE, growth dry, friable under the platinum needle. BULLATE, growth rising in convex prominences, like a blistered surface. BUTYROUS, growth of a butter-like consistency. CHAINS, Short chains, composed of 2 to 8 elements. Long chains, composed of more than 8 elements. CILIATE, having fine, hair-like extensions, like cilia. CLOUDY, said of fluid cultures which do not contain pseudozoogleæ. COAGULATION,[22] the separation of casein from whey in milk. This may take place quickly or slowly, and as the result either of the formation of an acid or of a lab ferment. CONTOURED, an irregular, smoothly undulating surface, like that of a relief map. CONVEX surface, the segment of a circle, but flattened. COPROPHYL, dung bacteria. CORIACEOUS, growth tough, leathery, not yielding to the platinum needle. CRATERIFORM, round, depressed, due to the liquefaction of the medium. CRETACEOUS, growth opaque and white, chalky. CURLED, composed of parallel chains in wavy strands, as in anthrax colonies. DIASTASIC ACTION, same as DIASTATIC, conversion of starch into water-soluble substances by diastase. ECHINULATE, in agar stroke a growth along line of inoculation, with toothed or pointed margins; in stab cultures growth beset with pointed outgrowths. EFFUSE, growth thin, veily, unusually spreading. ENTIRE, smooth, having a margin destitute of teeth or notches. EROSE, border irregularly toothed. FILAMENTOUS, growth composed of long, irregularly placed or interwoven filaments. FILIFORM, in stroke or stab cultures a uniform growth along line of inoculation. FIMBRIATE, border fringed with slender processes, larger than filaments. FLOCCOSE, growth composed of short curved chains, variously oriented. FLOCCULENT, said of fluids which contain pseudozoogleæ, i.e., small adherent masses of bacteria of various shapes and floating in the culture fluid. FLUORESCENT, having one color by transmitted light and another by reflected light. GRAM’S STAIN, a method of differential bleaching after gentian violet, methyl violet, etc. The + mark is to be given only when the bacteria are deep blue or remain blue after counter-staining with Bismarck brown. GRUMOSE, clotted. INFUNDIBULIFORM, form of a funnel or inverted cone. IRIDESCENT, like mother-of-pearl. The effect of very thin films. LACERATE, having the margin cut into irregular segments as if torn. LOBATE, border deeply undulate, producing lobes (see [Undulate]). LONG, many weeks, or months. MAXIMUM TEMPERATURE, temperature above which growth does not take place. MEDIUM, nutrient substance upon which bacteria are grown. MEMBRANOUS, growth thin, coherent, like a membrane. MINIMUM TEMPERATURE, temperature below which growth does not take place. MYCELIOID, colonies having the radiately filamentous appearance of mold colonies. NAPIFORM, liquefaction with the form of a turnip. NITROGEN REQUIREMENTS, the necessary nitrogenous food. This is determined by adding to nitrogen-free media the nitrogen compound to be tested. OPALESCENT, resembling the color of an opal. OPTIMUM TEMPERATURE, temperature at which growth is most rapid. PELLICLE, in fluid bacterial growth forming either a continuous or an interrupted sheet over the fluid. PEPTONIZED, said of curds dissolved by trypsin. PERSISTENT, many weeks, or months. PLUMOSE, a fleecy or feathery growth. PSEUDOZOOGLEÆ, clumps of bacteria, not dissolving readily in water, arising from imperfect separation, or more or less fusion of the components, but not having the degree of compactness and gelatinization seen in zoogleæ. PULVINATE, in the form of a cushion, decidedly convex. PUNCTIFORM, very minute colonies, at the limit of natural vision. RAPID, developing in twenty-four to forty-eight hours. RAISED, growth thick, with abrupt or terraced edges. RHIZOID, growth of an irregular branched or root-like character, as in B. mycoides. RING, same as RIM, growth at the upper margin of a liquid culture, adhering more or less closely to the glass. REPAND, wrinkled. SACCATE, liquefaction the shape of an elongated sac, tubular, cylindrical. SCUM, floating islands of bacteria, an interrupted pellicle or bacteria membrane. SLOW, requiring five or six days or more for development. SHORT, applied to time, a few days, a week. SPORANGIA, cells containing endospores. SPREADING, growth extending much beyond the line of inoculation, i.e., several millimetres or more. STRATIFORM, liquefying to the walls of the tube at the top and then proceeding downward horizontally. THERMAL DEATH-POINT, the degree of heat required to kill young fluid cultures of an organism exposed for ten minutes (in thin-walled test-tubes of a diameter not exceeding 20 mm.) in the thermal water-bath. The water must be kept agitated so that the temperature shall be uniform during the exposure. TRANSIENT, a few days. TURBID, cloudy with flocculent particles; cloudy plus flocculence. UMBONATE, having a button-like, raised centre. UNDULATE, border wavy, with shallow sinuses. VERRUCOSE, growth wart-like, with wart-like prominences. VERMIFORM-CONTOURED, growth like a mass of worms or intestinal coils. VILLOUS, growth beset with hair-like extensions. VISCID, growth follows the needle when touched and withdrawn, sediment on shaking rises as a coherent swirl. ZOOGLEÆ, firm gelatinous masses of bacteria, one of the most typical examples of which is the Streptococcus mesenterioides of sugar vats. (Leuconostoc mesenterioides), the bacterial chains being surrounded by an enormously thickened, firm covering inside of which there may be one or many groups of the bacteria.