Fig. 1

Blood stages of Plasmodium (Haemamoeba) matutinum (lineage pLINN1) from a roadkill fieldfare Turdus pilaris: erythrocytic trophozoites (a, b), erythrocytic meronts (c–f), macrogametocyte (g), microgametocyte (h), phanerozoites (i–u, w) and phanerozoic merozoites (v). Multiple infection of same host cell with several parasites was common (a, b, d). Erythrocytic meronts often contained prominent vacuoles (c, e). Mature gametocytes often enucleated infected erythrocytes (g, h). Developing (i, k) and mature (j) phanerozoites in mononuclear leucocytes; note the prominent cytoplasm, nuclei, and vacuoles (i, k) and numerous mature phanerozoic merozoites, each containing a prominent nucleus and cytoplasm (j). Mature phanerozoite in a granulocyte (l); note the numerous nearly mature merozoites. Developing phanerozoites in mononuclear leucocytes (m-o); note the prominent vacuoles, which numbers increase as the parasites increase in size (compare m with n, o). Extracellular phanerozoites in heart blood at different stages of maturation (p-s); note that vacuolization of the cytoplasm decreases in maturing phanerozoites (compare p, q with r, s). Extracellular developing (t) and nearly mature phanerozoite (u), which are normally located in endothelial cells of capillaries (see Fig. 2b) but were washed out from the capillaries and present in the heart blood as free bodies; note numerous developing merozoites and still adjacent host-cell nucleus. Mature phanerozoic merozoites (v); note oval shape of the parasites containing prominent nuclei and cytoplasm. Phanerozoite phagocytized by a mononuclear leucocyte (w) indicating an immune reaction against free phanerozoites intra vitam; note the degenerating nuclei and cytoplasm of the affected parasite. All images taken from cytologic preparations of heart blood in Wright Giemsa stain, except for the images m and o (cytologic imprint of the lung in Wright Giemsa stain). Simple arrows vacuoles, triangle arrowheads parasite nuclei, simple arrowheads pigment granules, simple wide short arrows developing merozoites, triangle wide arrowheads host cell nuclei, simple wide long arrows parasites, simple wide arrowheads mature merozoites. Scale bars 10 μm