[footnote] *On multiplication by spontaneous division of the mother-corpuscle and intercalation of new substance, see Ehrenberg 'Van den jetzt lebenden Thierarten der Kreidebildung', in the 'Abhandl. der Berliner Akad. der Wiss.', 1839, s. 94. The most powerful productive faculty in nature is that manifested in the Vorticellae. Estimations of the greatest possible development of masses will be found in Chrenberg's great work 'Die Infusionsthierchen als volkommne Organismen', 1838, s. xiii., xix., and 244. "The Milky Way of these organisms comprises the genera Monas, Vibrio, Bacterium, and Bodo." The universality of life is so profusely distributed throughout the whole of nature, that the smaller Infusoria live as parasites on the larger, and are themselves inhabited by others, s. 194, 211, and 512.
The minutest of the Infusoria, the Monadidae, have a diameter which does not exceed 1/3000th of a line, and yet these silicious-shelled organisms form in humid districts subterranean strata of many fathoms in depth.
The strong and beneficial influence exercised on the feelings of mankind by the consideration of the diffusion of life, throughout the realms of nature is common to every zone, but the impression thus produced is most powerful in the equatorial regions, in the land of palms, bamboos, and arborescent ferns, where the ground rises from the shore of seas rich in mollusca and corals to the limits of perpetual snow. The local distribution of plants embraces almost all heights and all depths. Organic forms not only descend into the interior of the earth, where the industry of the miner has laid open extensive excavations and sprung deep shafts, but I have also found snow-white stalactiitic columns encircled by the delicate web of an Usnea, in caves where meteoric water could alone penetrate through fissures. Podurellae penetrate into the icy crevices of the glaciers on Mount Rosa, the Grindelwald, and the Upper Aar; the Chionaea nivalis (formerly known as Protococcus), exist in the polar snow as well as in that of our high mountains. The redness assumed by the snow after lying on the ground for soome time was known to Aristotle, and was probably observed by him on the mountains of Macedonia.*
[footnote] *Aristot., 'Hist. Animal.', v. xix., p. 552, Bekk.
p 345 While, on the loftiest summits of the Alps, only Lecideae, Parmeliae, and Umbilicariae cast their colored but scanty covering over the rocks, exposed by the melted snow, beautiful phanerogamic plants, as the Culcitium rufescens, Sida pinchinchensis, and Saxifraga Boussingaulti, are still found to flourish in the tropical region of the chain of the Andes, at an elevation of more than 15,000 feet. Thermal springs contain small insects (Hydroporus thermalis), Gallionellae, Oscillatoria and Confervae, while their waters bathe the root-fibers of phanerogamic plants. As air and water are aniimated at different temperatures by the presence of vital organisms, so likewise is the interior of the different portions of animal bodies. Animalcules have been found in the blood of the frog and the salmon; according to Nordmann, the fluids in the eyes of fishes are often filled with a worm that lives by suction (Diplostomum), while in the gills of the bleak the same observer has discovered a remarkable double aniimalcule (Diplozoon paradoxum), having a cross-shaped form with two heads and two caudal extremities.
Although the existence of meteoric Infusoria is more than doubtful, it can not be denied that, in the same manner as the pollen of the flowers of the pine is observed every year to fall from the atmosphere, minute infusorial animalcules may likewise be retained for a time in the strata of the air, after having been passively borne up by currents of aqueous vapor.*
[footnote] *Ehrenberg, op. cit., s. xiv., p. 122 and 403. The rapid multiplication of microscopic organisms is, in the case of some (as, for instance, in wheat-eels, wheel-animals, and water-bears or tardigrade animalcules), accompanied by a remarkable tenacity of life. They have been seen to come to life from a state of apparent death after being dried for twenty-eight days in a vacuum with chloride of line and sulphuric acid, and after being exposed to a heat of 248 degrees. See the beautiful experiments of Doyere, in 'Mem. sur les Tardigrades et sur leur propriete de revenir a la vie', 1842, p. 119, 129, 131, 133. Compare, also, Ehrenberg, s. 492-496, on the revival of animalcules that had been dried during a space of many years.
This circumstance merits serious attention in reconsidering the old discussion respecting 'spontaneous generation',* and the p 346 more so, as Ehrenberg, as I have already remarked, has discovered that the nebulous dust or sand which mariners often encounter in the vicinity of the Cape Verd Islands, and even at a distance of 380 geographical miles from the African shore, contains the remains of eighteen species of silicious-shelled polygastric animalcules.
[footnote] *On the supposed "primitive transformation" of organized or unorganized matter into plants and animals, see Ehrenberg, in Poggendorf's 'Annalen der Physik', bd. xxiv., s. 1-48, and also his 'Infusionsthierchen', s. 121, 525, and Joh. Muller, 'Physiologie des Menschen' (4te Aufl., 1844), bd. i., s. 8-17. It appears to me worthy of notice that one of the early fathers of the Church, St. Augustine, in treating of the question how islands may have been covered with new animals and plants after the flood, shows himself in no way disinclined to adope the view of the so-called "spontaneous generation" ('generatio aequivoca, spontanea aut primaria'). "If," says he, "animals have not been brought to remote islands by angels, or perhaps by inhabitants of continents addicted to the chase, they must have been spontaneously produced upon the earth; although here the question certainly arises, to what purpose, then, were animals of all kinds assembled in the ark?" "Si e terra exort" sunt (bestiae) secundum originem primam, quando dixit Deus" 'Producat terra animam vivam!' multo clarius apparet, non tam reparandorum animalium causa, quam figurandarum variarum gentium (?) propter ecclesiae sacramentumin arca fuisse omnia genera, si in insulis quo transire non possent, multa animalia terra produxit." Augustinus, 'De Civitate Dei', lib. xvi., cap. 7: 'Opera, ed. Monach. Ordinis S. Benedicti', t. vii., Venet., 1732, p. 422. Two centuries before the tiime of the Bishop of Hippo, we find, by extracts from Trogus Pompeius, that the 'generatio primaria' was brought forward in connection with the earliest drying up of the ancient world, and of the high table-land of Asia, precisely in the same manner as the terraces of Paradise, in the theory of the great Linnaeus, and in the visionary hypotheses entertained in the eighteenth century regarding the fabled Atlantis: "Quod si omnes quondam terrae submersae profundo fuerunt, profecto editissilimam quamque partem decurrentibus aquis primum detectam; humillimo autem solo eandem aquam diutissime immoratam, et quanto prior quaeque pars terrarum siccata sit, tanto prius animalia generare coepisse. Porro Scythiam adeo editiorem omnibus terris esse ut cuncta flumina ibi nata in Maeotium, tum deinde in Ponticum et Aegyptium mare decurrant." — Justinus, lib. ii., cap. 1. The erroneous supposition that the land of Scythia is an elevated table-land, is so ancient that we meet with it most clearly expressed in Hippocrates, 'De Aere et Aquis', cap. 6, 96, Coray. "Scythia," says he, "coonsists of high and naked plains, which, without being crowned with mountains, ascend higher and higher toward the north."
Vital organisms, whose relations in space are comprised under the head of the geography of plants and animals, may be considered either according to the difference and relative numbers of the types (their arrangement into genera and species), or according to the number of individuals of each species on a given area. In the mode of life of plants as in that of animals, an important difference is noticed; they either exist in an isolated state, or live in a social condition. Those species of plants which I have termed 'social'* uniformly cover vast extents of land.