Abstract: An open framework enclosure is provided and defines a plurality of laterally spaced side-by-side sets of vertically spaced elongated horizontal cavities open at one set of corresponding ends. At least one open top tray is slidingly removably received in each of the cavities through the open ends thereof and the upper portions of corresponding adjacent cavities of adjacent sets of cavities are horizontally communicated and the upper and lower portions of adjacent vertically spaced cavities are in direct communication with each other. The trays include foraminated bottom, side and end walls and the enclosure defines structure for preventing movement of the trays between corresponding laterally spaced cavities, outwardly of the remote sides of the endmost cavities and outwardly from the ends of the cavities remote from the open ends thereof.