Figure 2.

Semithin sections of the spleen stained with toluidine blue. (A,B) The spleen of molly fish illustrates the components of the parenchyma, the red pulp (RP), and the white pulp (WP). Note the macrophages (white arrowheads) and ellipsoids (black arrowheads). (C) The red pulp (RP) consisted mainly of erythroid cells, which comprised the majority of the splenic parenchyma. Splenic cords were a mesh of fibroblast-like cells (black arrowheads) that typically surrounded ellipsoids. Note the mitotic cells (arrow) and macrophages (white arrowheads). (D) The ellipsoids consisted of cuboidal endothelial cells (black arrowheads). (E,F) Melanomacrophage centers (white arrowheads) contained varying amounts of pigment localized in close relation to the ellipsoids (black arrowheads).