30 



NATURAL HISTOKY OF THE PRIMEVAL WORLD. 



announce a contlition of things very cliflcrent from any 

 thai has hithei to prevailed. No indications of central 

 heat now mark the seasons; already zones of latitude 

 show signs of their existence; already the biological 

 relations of living beings are such as man can under- 

 stand, and vegetation assumes a truly peculiar form." 



Prior to this epoch two classes of vegetation have 

 predominated — the cellular cryptogams at first; and 

 secondly, the dicotyledonous gymnosperms. But now, 

 in the transition age of vegetation, these two classes 

 begin to fail, and a third, the dicotyledonous angio- 

 sperms, "timidly take possession of the earth;" con- 

 sisting, primarily, of a small number of species, and 

 occupying only a limited portion of the soil. In later 

 periods, as in our own times, we shall find their sup- 

 remacy firmly established. 



Some arborescent ferns still maintain their position, 

 and the graceful Protoptais Sinrieri and Pivtoj/tcris 

 Buvigneri unfurl their light fronds, like banners, to the 

 breeze. Sorao Pecopteri, differing from the Wealden 

 species, flourish in their company. Zamites, and cycads, 

 and Zamiostrobi prove that the temperature of the Cre- 

 taceous period was still almost tropical. New varieties 

 of Palmucca; reveal themselves, and among others, the 

 Flahdlaria cJiamccropifolia is distinguished by the 

 majestic diadem at its summit. 



The conifers have withstood the lapse of time and 

 the influence of change more successfully than the 

 cycadcre; then, as now, they were gathered together 

 in vast forests, where Damaritcs, Cunninghamias, 

 Araucarias, Eleoxylons, Ahictites, and Pinites remind 

 us of numerous forms still existing, but distributed all 

 over the earth. 



From this epoch, moreover, date the Complonias, a 

 genus of the natural order Myricacem; the Almites 

 Fresii, a member of the Betidaccce; the Carpinites 

 arenaceus, which is one of the Cupidiferce; the Salicites, 

 now represented by the' long, drooping, arborescent 

 willows; the Aceritis crctaccce, belonging to the Ace- 

 rince; and the Juglamlitcs clcgans to the Juglandittv. 



But unquestionably the most interesting botanical 

 event of this period is the advent of the Crednarm, 

 with its triple-veined leaves, of which no less than 

 eight species have been found and described, but 

 whose place in the scientific systems of classification 

 remains undetermined. The Crednarias, like the Sali- 

 cites, were certainly trees, as were most of the species 

 of this remote epoch. 



These details will enable the reader to understand 

 the accompanying illustration (Plate 7), in which 

 our artist has presented a landscape of the Cretaceous 

 period. Through an opening in the dense wood we 

 obtain glimpses of the radiant heavens beyond; and 

 we can imagine the sunlight playing upon the quaint, 

 vigorous foliage of the pillared trees, and lipping with 

 golden hues the feathery fronds of the ferns. Tall 

 palms in the distance wave in the passing wind their 

 fan-shaped leaves, which ever and anon droop like the 

 plumes of a knightly crest in the rush of battle. Rich 

 grasses and exquisite mosses clothe the Uving sward, 

 and the murmur of insects fills the air, their monotonous 

 hum being occasionally interrupted by the crash of an 

 aged tree in a distant forest glade, or the cry of some 



listless,lizard like reptile, or the hoarse roarof ignanodon 

 and megalosaurus, as they engage in furious combat. 

 Leaving these huge monsters to contend for supremacy, 

 we wander far away into a still and shadowy avenue, 

 where the walnut, the maple, and the alder rear their 

 well-known trunks. AVe note with surprise a vegetation 

 at once temperate and tropical, but feel that the tem- 

 perature, if fresh, is also genial, and admirably adapted 

 to the growth of the more vigorous forms of vegetable 

 life. And so we bid adieu to the ideal solitudes of the 

 Cretaceous forest. 



THE TERTIARY SYSTEM. 

 Also called the Cainozoic, or Recent Life Period. 



With the Tertiary series we enter upon the consider- 

 ation of an order of entirely new phenomena, presenting 

 formations in which the remains of animal and vegetaUo 

 life gradually approximate to the species of our own 

 epoch. AVe are in the position of a traveller who, 

 after long wandering through remote and previously 

 unknown landscapes, finds himself rapidly approaching 

 his own home, and everywhere recognizes the features 

 of a familiar scenery. 



For the convenience of comparison the Cainozoic is 

 usually subdivided into Eocene, Miocene, Pliocene, and 

 Pleistocene; words of Greek origin which respectively 

 signify the earliest, less recent, more recent, and most 

 recent life-stages. But the reader must remember that 

 these distinctions are entirely arbitrary, and that no 

 definite line of demarcation has been drawn between 

 them by the hand of nature. There are not vast 

 impassable gulfs separating the one period from the 

 other. The animal and vegetable forms of the Eocene 

 pass into the Jliooene, and are even protracted into the 

 Pliocene ; and no error could be more disastrous than 

 to suppose that either of these divisions represents, as 

 it were, a sole and independent world, with a fauna 

 and a flora entirely its own. To return to a previous 

 image, the paUeontologist, in tracing the growth and 

 development of created life, is like a traveller who 

 passes from the icy regions of the north into the glow- 

 ing and luxuriant climes of the south. In so doing 

 he traverses numerous countries, not separated by any 

 consjiicuous barrier or boundary', but gradually melting 

 into one another, so that the transition is everywhere 

 accomplished without any sudden or violent change. 



As we have said, the term Eocene implies the earliest 

 stage, or dawn of the existing state of the animal crea- 

 tion, and the strata of this series contains but a very 

 small proportion of shells referrible to living species. 



As types of these series we shall take the London 

 clay and the Calcaire grossier, or marls and gypsums 

 of the Paris basin. For a detailed account of their 

 nature and relations we are indebted, primarily, to the 

 exhaustive laboiu's of Cuvier and Bi'ongniart, 



After describing how slowly the cabinets of Paris 

 had been filled with innumerable relics of unknown 

 animals, exhumed from the gypseous beds of Mont- 

 martre, Cuvier graphically describes the manner in which 

 he addressed himself to the task of making these "dry 

 bones" live, of reconstructing from apparently shape- 

 less fragments the complete and perfect skeletons. 



