The relationship of biological defense mechanisms to the antibiotic activity of penicillin; the modifying influence of penicillin on the histopathological pattern of pneumococcus infection in normal and debilitated rats and guinea pigs.

In the many recent investigations into the mode of action of the newer antibiotic agents attention has largely been devoted to in vitro studies of their effects on various microorganisms, to biochemical and physiochemical investigations of their effects on the metabolic processes of susceptible organisms, and to extensive clinical studies of their action on various disease processes. Those studies devoted to investigations of their mode of action in the experimental animal have, in the main, been centered about examinations of the toxic effects of the antibiotics, or have been concerned with comparisons of the survival times of treated and untreated