In Fig. 4b the _Himantia villosa_ is represented, a rhizomorpha found in the mines of the Upper Harz Mountains, thus showing another form of this vegetable growth. Though it is difficult, as above stated, to recognize by their shape the rhizormorphæ as fungi, the origin of the peculiar _Agaricus myurus_ of Hoffmann (Fig. 4a) will be much easier discovered, though a retrograde development and degeneration has taken place also in this fungus. It still shows, however, the elements of a regular toadstool, only that the stem is much elongated and looks like a thread or a tube, while the cap is small, and this explains how, by gradual degeneration, the cap may disappear entirely, leaving nothing but a stem, as, for instance, in the case of the _Clavaria deflexa_, the club fungus, shown in Fig. 3b. In connection with the above it may be well to speak of the fungi constituting the mould which often covers the roof and the doors in the brown-coal mines of Halle, specimens of which are shown in Fig. 5. [Illustration: FIG. 5.--FORMS OF MOULD FUNGI FOUND IN THE BROWN-COAL MINES NEAR HALLE A. S.] We now come to the animal life in mines and pits. This is mostly represented, of course, by lower organisms, as infusoria and worms. Thus, in the slime on the bottom of the waters in mines, several species of _amoebæ_ are found, which consist of microscopically small animated bodies, continually floating about, nourishing themselves by absorbing organic matter, possessing sensation, propagating, etc., and, in fact, having actually the qualities of real animal nature. Further, we find in those subterraneous waters a species of the sun infusorium (_Actinophrys_), which is especially frequent in the mines of Klausthal. Fig. 6 shows one of these peculiar little beings. Also the _Stylonychia_ (Fig. 7) is a characteristic inhabitant of those places, and always present there. [Illustration: FIG. 6.--THE SUN INFUSORIUM (ACTINOPHRYS).] [Illustration: FIG. 7.--THE RAPACIOUS INFUSORIUM (STYLONYCHIA).] It moves with great rapidity in the water by means of the numerous hairs covering its body, can turn quickly in any direction, and thus is enabled to catch suddenly the little beings on which it lives and which it hunts; for which reason the stylonychia is called the "rapacious infusorium."