After the terrible tempests of the primitive period--after these great
disturbances of the mineral kingdom--Nature would seem to have gathered
herself together, in sublime silence, in order to proceed to the grand
mystery of the creation of living beings.
During the primitive epoch the temperature of the earth was too high to
admit the appearance of life on its surface. The darkness of thickest
night shrouded this cradle of the world; the atmosphere probably was so
charged with vapours of various kinds, that the sun’s rays were
powerless to pierce its opacity. Upon this heated surface, and in this
perpetual night, organic life could not manifest itself. No plant, no
animal, then, could exist upon the silent earth. In the seas of this
epoch, therefore, only unfossiliferous strata were deposited.
Nevertheless, our planet continued to be subjected to a gradual
refrigeration on the one hand, and, on the other, continuous rains were
purifying its atmosphere. From this time, then, the sun’s rays, being
less obscured, could reach its surface, and, under their beneficent
influence, life was not slow in disclosing itself. “Without light,” said
the illustrious Lavoisier, “Nature was without life; it was dead and
inanimate. A benevolent God, in bestowing light, has spread on the
surface of the earth organisation, sentiment, and thought.” We begin,
accordingly, to see upon the earth--the temperature of which was nearly
that of our equatorial zone--a few plants and a few animals make their
appearance. These first generations of life will be replaced by others
of a higher organisation, until at the last stage of the creation, man,
endowed with the supreme attribute which we call intelligence, will
appear upon the earth. “The word _progress_, which we think peculiar to
humanity, and even to modern times,” said Albert Gaudry, in a lecture on
the animals of the ancient world, delivered in 1863, “was pronounced by
the Deity on the day when he created the first living organism.”
Did plants precede animals? We know not; but such would appear to have
been the order of creation. It is certain that in the sediment of the
oldest seas, and in the vestiges which remain to us of the earliest ages
of organic life on the globe, that is to say, in the argillaceous
schists, we find both plants and animals of advanced organisation. But,
on the other hand, during the greater part of the primary
epoch--especially during the Carboniferous age--the plants are
particularly numerous, and terrestrial animals scarcely show themselves;
this would lead us to the conclusion that plants preceded animals. It
may be remarked, besides, that from their cellular nature, and their
looser tissues composed of elements readily affected by the air, the
first plants could be easily destroyed without leaving any material
vestiges; from which it may be concluded, that, in those primitive
times, an immense number of plants existed, no traces of which now
remain to us.
We have stated that, during the earlier ages of our globe, the waters
covered a great part of its surface; and it is in them that we find the
first appearance of life. When the waters had become sufficiently cool
to allow of the existence of organised beings, creation was developed,
and advanced with great energy; for it manifested itself by the
appearance of numerous and very different species of animals and plants.
One of the most ancient groups of organic remains are the Brachiopoda, a
group of Mollusca, particularly typified by the genus Lingula, a species
of which still exist in the present seas; the Trilobites (Fig. 17), a
family of Crustaceans, especially characteristic of this period; then
come Productas, Terebratulæ, and Orthoceratites--other genera of
Mollusca. The Corals, which appeared at an early period, seem to have
lived in all ages, and survive to the present day.
[Illustration: Fig. 17.--Paradoxides Bohemicus--Bohemia.]
Contemporaneously with these animals, plants of inferior organisation
have left their impressions upon the schists; these are Algæ (aquatic
plants, Fig. 28). As the continents enlarged, plants of a higher type
made their appearance--the Equisetaceæ, herbaceous Ferns, and other
plants. These we shall have occasion to specify when noticing the
periods which constitute the Primary Epoch, and which consists of the
following periods: the Carboniferous, the Old Red Sandstone, and
Devonian, the Silurian, and the Cambrian.