The amoeba starts out on an agar petri dish in which one part of the plate contains a source of food (symbolized by the yellow oval to represent an oat flake, although in the actual experiment the oats were blended with agar and poured into the plate). As shown on the left, the cell was initially placed in a region of the dish separated from the food by a sector of agar containing a noxious chemical such as quinine or caffeine, symbolized by the gray rectangle. Physarum tends not to enter such regions, but eventually will do so, after which it finds the food patch and migrates to that part of the plate. If the cell is then taken off the dish and the entire experiment repeated, it will gradually take less time to move across the noxious patch and find the food.