This section is from the book "Studies of American Fungi: Mushrooms, Edible, Poisonous, Etc.", by George Francis Atkinson. Also available from Amazon: Studies of American Fungi: Mushrooms, Edible, Poisonous, Etc..
These fungi are called the trembling fungi because of their gelatinous consistency. The colors vary from white, yellow, orange, reddish, brownish, etc., and the form is various, often very irregular, leaf-like, or strongly folded and uneven. They are when fresh usually very soft, clammy to the touch, and yielding like a mass of gelatine. They usually grow on wood, but some species grow on the ground, and some are parasitic. The fruit surface usually covers the entire outer surface of the plant, but in some it is confined to one side of the plant. The basidia are peculiar to the order, are deeply seated in the substance of the plant, rounded or globose, and divided into four cells in a cruciate manner. From each one of these cells of the basidium a long, slender process (sterigma) grows out to the surface of the plant and bears the spore. A few species only are treated of here.