of beds of fossils, the prolonged and repeated submersion of continents, the slow growth of animal and vegetable deposits, the vast antiquity of life, the stripping, fracturing and gradual transformation of the terrestrial surface,[4] and, finally the grand picture in which Buffon describes in approximate manner the entire history of our globe, from the moment it formed a mass of glowing lava down to the time when our species, after so many lost or surviving species, was able to inhabit it. — Upon this science of inorganic matter we see arising at the same time the science of organic matter.  Grew, and then Vaillant had just demonstrated the sexual system and described the fecundating of plants; Linnaeus invents botanical nomenclature and the first complete classifications; the Jussieus discover the subordination of characteristics and natural classification.  Digestion is explained by Réaumur and Spallanzani, respiration by Lavoisier ; Prochaska verifies the mechanism of reflex actions ; Haller and Spallanzani experiment on and describe the conditions and phases of generation.  Scientists penetrate to the lowest stages of animal life.  Réaumur publishes his admirable observations on insects and Lyonnet devotes twenty years to portraying the willow-caterpillar; Spallanzani resuscitates his rotifers, Tremblay dissects his fresh-water polyps, and Needham reveals his infusoria.  The experimental conception of life is deduced from these various researches.  Buffon already, and especially Lamarck, in their great and incomplete sketches, outline with penetrating divination the leading features of modern physiology and zoology.  Organic molecules everywhere diffused or everywhere growing, species of globules constantly in course of decay and restoration, which, through the blind and spontaneous development, transform themselves, multiply and combine, and which, without either foreign direction or any preconceived end, solely through the effect of their structure and surroundings, unite together to form those masterly organisms which we call plants and animals :  in the beginning, the simplest forms, and next a slow, gradual, complex and perfected organization ; the organ created through habits, necessity and surrounding medium; heredity transmitting acquired modifications,[5] all denoting in advance, in a state of conjecture and approximation, the cellular theory of later physiologists[6] and the conclusions of Darwin.[7] In the picture which the human mind draws of nature, the general outline is marked by the science of the eighteenth century, the arrangement of its plan and of the principal masses being so correctly marked, that to day the leading lines remain intact.  With the exception of a few partial corrections we have nothing to efface.