Existing knowledge of immunity is in large part concerned with the production of antibodies in experimental animals and the reactions of antibodies in vitro. Something is known about the way these agents act within the living body to neutralize or destroy invading microörganisms or other injurious substances but defects in our knowledge of the subject are very conspicuous. Many of the books on immunology include infection and immunity in their titles but there can be found in them little consecutive discussion of the fate of microörganisms after entering the body of an animal. Present knowledge of the subject is highly controversial and doubtless authors wisely refrain from discussions that would contain little more than speculation.
Inflammation may be defined as the process by which cells and serum accumulate about an injurious agent and tend to remove or destroy it (1). Phagocytes and other cells are mobilized at the site of invasion and plasma containing opsonins and the normal bactericidal substances of the blood exudes from the blood vessels.