ABSTRACT
Avian erythrocytes are susceptible to parasitization by certain unicellular eukaryotic organisms. The Genus Haemoproteus is the largest and most commonly encountered group of parasites that invades the erythrocytes of birds. The partial encirclement of the erythrocyte nucleus by Haemoproteus results in a characteristically recognized “halter shaped” parasite. Erythrocytes from an assortment of species of avians demonstrating parasitization by Haemoproteus. A fall in erythrocyte number and hemoglobin concentration is generally noticeable on the day before the parasite peak is reached in infections which do not terminate fatally. Erythrocytes of embryos of the Pekin duck and goose but not those of the white leghorn chicken embryo can be infected by Plasmodium berghei, a species of Plasmodium whose usual hosts are a mammal’s erythrocytes. Parasites belonging to the Genus Leucocytozoon, Family Leucocytozoidae with rare exception are found solely in birds. Erythrocytes from a blood smear of a white Pekin duck infected with Leucocytozoon simondi.
