Besides much carbonate of lime and magnesia, Madrepores and Astræas also contain some fluoric and phosphoric acids [75], [76]
Oscillatory state of the bottom of the sea according to Darwin [76]-[79]
Traditions of Samothrace. Irruptions of the sea. Mediterranean. Sluice theory of Strato. Myth of Lyktonia, and the “Atlantis broken into fragments” [78]-[83]
On the causes which prevent the sinking down of clouds and precipitation taking place from them [83]-[84]
Heat disengaged from the crust of the earth while solidifying. Hot currents of air which in the early ages of the earth, from frequent corrugations of the strata and elevations of land, may have been diffused in the atmosphere from temporary fissures [84], [85]
Colossal size and great age of some kinds of trees; Dragon tree of Orotava thirteen, and Adansonia digitata (Baobab) thirty-two English feet in diameter. Characters cut in the bark of the trees in the 15th century. Adanson assigns to some of the Baobab trunks in Senegambia an age of between 5100 and 6000 years [86]-[92]
Judging by the annular rings, there are yew-trees (Taxus baccata) from 2600 to 3000 years old. Is it true that in the northern temperate zone the part of the tree turned towards the north has narrower annular rings, as Michel Montaigne affirmed in 1581? Species of trees in which individuals attain a size of above twenty-one or twenty-two English feet diameter, and an age of several centuries, belong to the most different natural families [92]-[94]
Diameter of the Mexican Schubertia disticha of Santa Maria del Tule 40½ English feet; the sacred Banyan fig-tree of Ceylon almost 30; and the oak at Saintes (Dep. de la Charente Inférieure) 29½ English feet. The age of the oak tree estimated from its annular rings at from 1800 to 2000 years. The root of the rose tree growing against the crypt of the Cathedral of Hildesheim is 800 years old. A kind of sea-weed, Macrocystis pyrifera, attains a length of 630 English feet, exceeding therefore the height of the loftiest Coniferæ, even that of the Sequoia gigantea [94]-[97]
Examination of the probable number of phænogamous plants hitherto described or preserved in herbariums. Relative numbers. Laws discovered in the geographical distribution of plants. Relative numbers of the great divisions of Cryptogamia to Cotyledonous plants, and of Monocotyledonous to Dicotyledonous plants, in the torrid, temperate, and frigid zones. Elements of arithmetical botany. Number of individuals; predominance of social plants. The forms of organic beings are mutually dependent on and limit each other. If we know exactly the number of species of one of the great families of Glumaceæ, Leguminosæ, or Compositæ, at any one part of the globe, we may infer approximatively both the number of species in the remaining families, and the entire number of phænogamous plants in the same district. Application of the numerical ratios to the direction of the isothermal lines. Mysterious original distribution of types. Absence of Roses in the southern, and of Calceolarias in the northern hemisphere. Why has our heather (Calluna vulgaris), and why have our oaks never advanced eastward beyond the Ural Mountains into Asia? The vegetation cycle of each species requires for its successful organic development a certain minimum amount of temperature. [97]-[113]
Analogy between the numerical laws of the distribution of animal and of vegetable forms. If there are now cultivated in Europe above 35000 species of phænogamous plants, and if our herbariums probably contain, described and undescribed, from 160000 to 212000 species of phænogamous plants, it is probable that the number of collected insects and collected phænogamous plants are nearly equal; whilst we know that certain well-explored districts in Europe have more than three times as many insects as phænogamous plants [113]-[119]