The motions of the plastic matter contained within the dust-like spores of the Æthalium septicum exhibit amœban motions of the same character as its mycelium. For when M. de Bary placed ripe spores of that fungus in water, their skin burst open and the plastic granular matter was set free under the form of a coherent globular mass without any exterior membrane. These globular corpuscles exhibited amœba-like changes of form; processes were pushed out, and then drawn in, till at last they assumed an elongated cylindrical shape round at one end, prolonged at the anterior end into a long cilium with which they turned convulsively round their axis. At the same time vacuoles were frequently seen to expand and contract alternately in the round extremity. Ultimately these bodies lost their middle, and at last were divided into two equal parts, each of which went through the same changes as the primary globule, and at length assumed the ciliated active form. Besides these active bodies, there were others which never acquired cilia. The motile bodies were also discovered in other species of these fungi by M. Hoffmann; there can be no doubt that they are either zoospores, or of the same nature as the eel-shaped motile bodies in some of the Algæ; possibly the bodies which never acquire cilia may be germ cells. There is still much obscurity with regard to the Myxogastres, inasmuch as the origin of their mycelium is unknown, whilst in all other fungi mycelium or spawn are produced by the germination of the spores. The spiral vessels found in the threads of the Trichia prove that the members of this singular family are truly vegetables. Professor Fries places the geographical maximum or centre in the temperate zone, but different species are found from New Zealand to high northern latitudes. The Nidulariacei constitute a beautiful order of this family of fungi. The plants are exactly like a bird’s nest with eggs, sometimes with a stem, sometimes without. At first the nest or cup has a cover consisting of several coats, which either burst open with a stellate or irregular figure, or by the separation of a little lid; then the hollow of the cup or nest is exposed, and at the bottom are seen one or more sporangia, that is spore cases, often immersed in jelly and either free or fixed to the nest by an elastic string. The spore-coats at first contain a compact circular mass, but a cavity is afterwards formed in the centre, and the cells which terminate in the walls of the cavity bear spores on their tips. When ripe the spore cases are ejected by elastic power. The force with which the sporangium of the species of Sphærobolus is ejected, far exceeds _in proportion_ the force with which a shell is projected from a large mortar; this fungus sometimes grows in damp hothouses.[54] Many Nidulariæ are widely spread, but they thrive best in warm climates.