Some Recent Advances in Our Understanding of Parasitic Protozoa * †

SYNOPSIS. Striking progress in our understanding of parasitic protozoa has been achieved thru the employment of advanced electron‐microscopic, biochemical, immunologic, and cultivation methods. Some recent information gathered by means of these methods on trichomonad and trypanosomatid flagellates as well as on eimeriidian and plasmodiid haemosporiidian Sporozoa is discussed. It is emphasized that the parasitic protozoa when studied by the presently available sophisticated methods in the context of being parasites, not merely cells maintained on refined media, can aid us greatly in illuminating the highly complex functional aspects of host‐parasite interactions.