Abstract
A method is descr. in which the guinea pig omentum is used to estimate an index of the evaluation of antimicrobial agents. When guinea pigs are inoculated intraperit. with virulent tubercle bacilli, the omentum swells. The ratio of the wt. of the omentum in g. to the wt. of the guinea pig in kg. is called the omental index. A drug which possesses antituberculous activity maintains the omental index near the normal level.