To facilitate its growth, we add soil around the bottom of the stalk.

Once it reaches the surface of the soil, the slug undergoes another transformation: Most of the cells turn into a stiff stalk, while the others crawl to the top and form a sticky ball of spores.

Because of the organic-matter decomposed by the pure stalk have not any soil to keep up, the relative content of organic-matter that can be distilled is the lowest(PS100) .