Part 25 (2/2)

The _Cupanioides_, among the Sapindaceae; the _Cuc.u.mites_, among the Cucurbitaceae (species a.n.a.logous to our bryony), climb the trunks of great trees, and hang in festoons of aerial garlands from their branches.

The Ferns were still represented by the genera _Pecopteris_, by the _Taeniopteris_, _Asplenium_, _Polypodium_. Of the mosses, some _Hepaticas_ formed a humble but elegant and lively vegetation alongside the terrestrial and frequently ligneous plants which we have noted.

_Equiseta_ and _Charae_ would still grow in marshy places and on the borders of rivers and ponds.

It is not without some surprise that we observe here certain plants of our own epoch, which seem to have had the privilege of ornamenting the greater watercourses. Among these we may mention the Water Caltrop, _Trapa natans_, whose fine rosettes of green and dentated leaves float so gracefully in ornamental ponds, supported by their spindle-shaped petioles, its fruit a hard coriaceous nut, with four h.o.r.n.y spines, known in France as _water-chestnuts_, which enclose a farinaceous grain not unpleasant to the taste; the pond-weed, _Potamogeton_, whose leaves form thick tufts of green, affording food and shelter to the fishes; _Nympheaceae_, which spread beside their large round and hollow leaves, so admirably adapted for floating on the water, now the deep-yellow flowers of the _Nenuphar_ now the pure white flowers of the _Nymphaea_.

Listen to Lecoq, as he describes the vegetation of the period:--”The Lower Tertiary period,” he says, ”constantly reminds us of the tropical landscapes of the present epoch, in localities where water and heat together impress on vegetation a power and majesty unknown in our climates. The Algae, which have already been observed in the marine waters at the close of the Cretaceous period, represented themselves under still more varied forms, in the earlier Tertiary deposits, when they have been formed in the sea. Hepaticas and Mosses grew in the more humid places; many pretty Ferns, as _Pecopteris_, _Taeniopteris_, and the _Equisetum stellare_ (Pomel) vegetated in cool and humid places. The fresh waters are crowded with _Naiades_, _Chara_, _Potamogeton_, _Caulinites_, with _Zosterites_, and with _Halochloris_. Their leaves, floating or submerged, like those of our aquatic plants, concealed legions of Molluscs whose remains have also reached us.

”Great numbers of Conifers lived during this period. M. Brongniart enumerates forty-one different species, which, for the most part, remind us of living forms with which we are familiar--of Pines, Cypresses, Thuyas, Junipers, Firs, Yews, and Ephedra. Palms mingled with these groups of evergreen trees; the _Flabellaria Parisiensis_ of Brongniart, _F. raphifolia_ of Sternberg, _F. maxima_ of Unger; and some _Palmacites_, raised their widely-spreading crowns near the magnificent _Hightea_; Malvaceae, or _Mallows_, doubtless arborescent, as many among them, natives of very hot climates, are in our days.

”Creeping plants, such as the _Cuc.u.mites variabilis_ (Brongn.), and the numerous species of _Cupaniodes_--the one belonging to the Cucurbitaceae, and the other to the Sapindaceae--twined their slender stems round the trunks, doubtless ligneous, of various Leguminaceae.

”The family of Betulaceae of the order Cupuliferae show the form, then new, of _Quercus_, the Oak; the Juglandeae, and Ulmaceae mingle with the Proteaceae, now limited to the southern hemisphere. _Dermatophyllites_, preserved in amber, seem to have belonged to the family of the Ericineae, and _Tropa Arcturae_ of Unger, of the group nothereae, floated on the shallow waters in which grew the _Chara_ and the _Potamogeton_.

”This numerous flora comprises more than 200 known species, of which 143 belonged to the Dicotyledons, thirty-three to the Monocotyledons, and thirty-three to the Cryptogams.

”Trees predominate here as in the preceding period, but the great numbers of aquatic plants of the period are quite in accordance with the geological facts, which show that the continents and islands were intersected by extensive lakes and inland seas, while vast marine bays and arms of the sea penetrated deeply into the land.”

[Ill.u.s.tration: Fig. 149.--Branch of Eucalyptus restored.]

It is moreover a peculiarity of this period that the whole of Europe comprehended a great number of those plants which are now confined to Australasia, and which give so strange an aspect to that country, which seems, in its vegetation, as in its animals, to have preserved in its warm lat.i.tudes the last vestiges of the organic creations peculiar to the primitive world. As a type of dicotyledonous trees of the epoch, we present here a restored branch of _Eucalyptus_ (Fig. 149), with its flowers. All the family of the Proteaceae, which comprehends the _Banksia_, the _Hakea_, the _Gerilea protea_, existed in Europe during the Tertiary period. The family of Mimosas, comprising the _Acacia_ and _Inga_, which in our age are only natives of the southern hemisphere, abounded in Europe during the same geological period. A branch of _Banksia_, with its fructification, taken from impressions discovered in rocks of the period, is represented in Fig. 150--it is different from any species of Banksia living in our days.

[Ill.u.s.tration: Fig. 150.--Fruit-branch of Banksia restored.]

Mammals, Birds, Reptiles, Fishes, Insects, and Molluscs, form the terrestrial fauna of the Eocene period. In the waters of the lakes, whose surfaces are deeply ploughed by the pa.s.sage of large Pelicans, lived Molluscs of varied forms, as _Physa_, _Limnaea_, _Planorbis_; and Turtles swam about, as _Trionyx_ and the _Emides_. Snipes made their retreat among the reeds which grew on the sh.o.r.e; sea-gulls skimmed the surface of the waters or ran upon the sands; owls hid themselves in the cavernous trunks of old trees; gigantic buzzards hovered in the air, watching for their prey; while heavy crocodiles slowly dragged their unwieldy bodies through the high marshy gra.s.ses. All these terrestrial animals have been discovered in England or in France, alongside the overthrown trunks of palm-trees. The temperature of these countries was then much higher than it is now. The Mammals which lived under the lat.i.tudes of Paris and London are only found now in the warmest countries of the globe.

The Pachyderms (from the Greek pa???, _thick_, de?a, _skin_) seem to have been amongst the earliest Mammals which appeared in the Eocene period, and they held the first rank from their importance in number of species as well as in size. Let us pause an instant over these Pachyderms. Their predominance over other fossil Mammals, which exceed considerably the number now living, is a fact much insisted on by Cuvier. Among them were a great number of intermediate forms, which we seek for in vain in existing genera. In fact, the Pachyderms are separated, in our days, by intervals of greater extent than we find in any other mammalian genera; and it is very curious to discover among the animals of the ancient world the broken link which connects the chain of these beings, which have for their great tomb the plaster-quarries of Paris, Montmartre and Pantin being their latest refuge.

Each block taken from those quarries encloses some fragment of a bone of these Mammals; and how many millions of these bones had been destroyed before attention was directed to the subject! The _Palaeotherium_ and the _Anoplotherium_ were the first of these animals which Cuvier restored; and subsequent discoveries of other fragments of the same animals have only served to confirm what the genius of the great naturalist divined.

His studies in the quarries of Montmartre gave the signal, as they became the model, for similar researches and restorations of the animals of the ancient world, all over Europe--researches which, in our age, have drawn geology from the state of infancy in which it languished, in spite of the magnificent and persevering labours of Steno, Werner, Hutton, and Saussure.

[Ill.u.s.tration: Fig. 151.--Palaeotherium magnum restored.]

The _Palaeotherium_, _Anoplotherium_, and _Xiphodon_ were herbivorous animals, which must have lived in great herds. They appear to have been intermediate, according to their organisation, between the Rhinoceros, the Horse, and the Tapir. There seem to have existed many species of them, of very different sizes. After the labours of Cuvier, nothing is easier than to represent the _Palaeotherium_ as it lived: the nose terminating in a muscular fleshy trunk, or rather snout, somewhat like that of the Tapir; the eye small, and displaying little intelligence; the head enormously large; the body squat, thick, and short; the legs short and very stout; the feet supported by three toes, enclosed in a hoof; the size, that of a large horse. Such was the great Palaeotherium, peaceful flocks of which must have inhabited the valleys of the plateau which surrounds the ancient basin of Paris; in the lacustrine formations of Orleans and Argenton; in the Tertiary formations of Issil and Puy-en-Velay, in the department of the Gironde; in the Tertiary formations near Rome; and in the beds of limestone[82] at the quarries of Binsted, in the Isle of Wight. Fig. 151 represents the great Palaeotherium, after the design, in outline, given by Cuvier in his work on _fossil bones_.

[82] This limestone belongs to the Bembridge beds, and forms part of the Fluvio-marine series. See ”Survey Memoir on the Geology of the Isle of Wight,” by H. W. Bristow.

[Ill.u.s.tration: Fig. 152.--Skull of Palaeotherium magnum.]

The discovery and re-arrangement of these and other forms, now swept from the face of the globe, are the n.o.blest triumphs of the great French zoologist, who gathered them, as we have seen, from heaps of confused fragments, huddled together pell-mell, comprising the bones of a great many species of animals of a former age of the world, all unknown within the historic period. The generic characters of Palaeotherium give them forty-four teeth, namely, twelve _molars_, two _canines_, and twenty-eight others, three toes, a short proboscis, for the attachment of which the bones of the nose were shortened, as represented in Fig.

153, leaving a deep notch below them. The molar teeth bear considerable resemblance to those of the Rhinoceros. In the structure of that part of the skull intended to support the short proboscis, and in the feet, the animal seems to have resembled the Tapir.

[Ill.u.s.tration: Fig. 153.--Skeletons of the Palaeotherium magnum (_a_) and minimum (_b_) restored.]

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