PATHOGENESIS
When tubercle bacilli invade the body by any portal of entry they are ingested by neutrophiles, many of which enter the blood stream and are soon focalized in various places. More focalizations occur in the lungs than in any other organ. Lemon and Montgomery 1 found that when tubercle bacilli are placed into pleural spaces of normal rabbits they are soon phagocytosed and some are deposited in lymph nodes and remote organs. Others have observed that when tubercle bacilli are introduced subcutaneously or directly into the stomach or intestines, many may soon be found in the lungs and elsewhere about the body where they have been focalized. Tubercles are formed at the points of focalization and may harbor bacilli for long periods. At any point of focalization where bacilli remain alive they may at a subsequent time be liberated and disseminated to immediate and remote areas.Inasmuch as many