1525. As being simply galvanic process, they would require but little light and air; they therefore seek the darkness, like the roots, and thrive also in a corrupt atmosphere, in caves, mines, cellars, and such like situations. They can from the same cause thrive only in moisture, in water, upon marshy meadow lands, after rain, copious dew, and so on. 1526. They are devoid the process of fermentation, as being that which is imparted by the oxydation of air, and they therefore yield neither sugar nor acids. They are simply the organized process of putrefaction; their ultimate product is therefore germinal powder, infusorial matter. Their remaining secretions are alkaline bodies; to which belong the pungent, fetid, and nauseous excretions, as the hydrogen gas and ammonia of the fungi, the mucus of the fuci, the carbonate of lime in the lichens, the cell-threads of the mosses, the fetid principle of ferns. 1527. Very few of these plants require the course of a summer in order to perfect or complete the vital course; a single ray of light of one day's, aye, of one hour's duration, is sufficient with most of them to evoke the feeble difference, to rouse the swell of the sap, and precipitate the infusorial powder. 1528. Automatic movements, as in the leaves and stamina of the higher plants, scarcely occur in them, or at most in the ferns, from their possessing spiral vessels. They divide, according to the tissues, into three classes, into Cell-, Vessel-, and Trachea-plants. _CLASS I._ _Cell-plants--Fungi._ Here belong those plants which consist simply of cellular tissue, having no sap-tubes and tracheæ. Such plants, too, possess no regular or hexagonal cellular tissue. 1529. The cellular tissue, in which there is only a single active process, cannot essentially alter its primary form. It is therefore an accumulation of round or cylindrical mucus-vesicles. 1530. Mucus-vesicles, in which the air-process is not as yet active, cannot be coloured green; but must have the colour of the earth. 1531. Plants, composed of amorphous and earth-coloured cellular tissue, are _Fungi_. The fungi are simply clusters of mucus-vesicles joined together in a more or less regular manner, their union being effected in dark, hollow and wet situations. 1532. They may therefore originate wherever mucous juices are evolved by the potential agency of a higher organization, and thus by putrefaction. The fungi originate by _æquivocal generation_. They are the anal-organizations of the higher plants and animals; the corrupted and luxuriating juices. 1533. Nevertheless the fungus is propagated by division of its vesicles, which again, in accordance with their peculiar laws of polarity, attract mucus-vesicles, and thus obtain the form of the earlier or parent fungus. This is only a more regulated kind of _æquivocal generation_.