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. NOTES.