INTESTINAL PROTOZOA IN THE TROPICS

Of the numerous and varied forms of life that are known to enter and at times inhabit the alimentary tract of man, comparatively few, aside from bacteria, have established a reputation for pathogenicity. Larger organisms like the intestinal worms have, of course, long been regarded as highly detrimental. Their noxiousness has been ascribed primarily to the harm these parasites might do mechanically or locally; and not until more recently has the possibility of the production of soluble poisons by the invading organism been reckoned with. The occurrence of eosinophilia in the leukocytes of the blood is itself a significant indication of response to chemical products rather than to the mere mechanical irritation of the parasite.

Among the smaller forms, the trypanosomes and coccidia are justly the objects of grave suspicion whenever they exhibit their presence in the body. Some of the intestinal amebas, like the Ameba coli, have also given