What was there first: the spores or the fruitbody? The gills, tubes, spines or ridges under the cap of a mushroom contain the spores. Wind and weather (rain) disseminate the spores. Under the right conditions two spores combine and multiply to form a mycelium. The mycelium in turn forms the fruitbody. It pushes the fruitbody out of the forest soil in order to disseminate the spores. The function of the fruitbody, the mushroom you see, is to disseminate the spores. The mycelium is thus not like the roots of a tree. The mycelium is the tree, so to speak, and the mushroom its fruit.