GLOSSARY OF TERMS 107 
Radiate, showing ray-structure. 
Raised. growth thick, with abrupt or terraced edges. 
Reduction, removing oxygen from a chemical compound. Refers to the 
conversion of nitrate to nitrite, ammonia, or free nitrogen, and to the de- 
colorization of litmus. 
Rhizoid, growth of an irregular branched or root-like character, as in B. mycoides. 
Ring, growth at the upper margin of a liquid culture, adhering to the glass. 
Repand, wrinkled. 
Rapid, developing in twenty-four to forty-eight. 
Rugose, wrinkled. 
Saccate, liquefaction in form of an elongated sac, tubular, cylindrical. 
Scum, floating islands of bacteria, an interrupted pellicle or bacterial membrane. 
Slow, requiring five or six days for development. 
Short, applied to time, a few days, a week. 
Spindled, larger at the middle than at the ends. Applied to sporangia, refers 
to the forms frequently called clostridea. 
Sporangia, cells containing endospores. 
Spreading, growth extending much beyond the line of inoculation, i.e., several 
mulimeters or more. 
Stratiform, liquefying to the walls of the tube at the top and then proceeding 
downwards 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 diam- 
eter 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, lasting a few days. 
Truncate, ends abrupt, square. 
Turbid, cloudy with flocculent particles, i.c., cloudy plus flocculence. 
Umbonate, having a button-like, raised center. 
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Viscid, growth follows the needle when touched and withdrawn; sediment 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. 
Zoogloes, 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. 
Suggested Procedure for Studying Bacteria According to the 
Descriptive Chart of the Society of American Bacteriologists. The 
following procedures are suggested for use with the Descriptive Chart. 
