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 Reaumur 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. Reaumur 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,[3105]
all denoting in advance, in a state of conjecture and approximation,
the cellular theory of later physiologists[3106] and the conclusions of
Darwin. 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. Wi