[CHAPTER XI.
TERTIARY MAN.]
Definition of Periods—Passage from Pliocene to Quaternary—Scarcity of Human Remains in Tertiary—Denudation—Evidence from Caves wanting—Tertiary Man a necessary inference from widespread existence of Quaternary Man—Both equally inconsistent with Genesis—Was the first great Glaciation Pliocene or Quaternary?—Section of Perrier—Confirms Croll's Theory—Elephas Meridionalis—Mammoth—St. Prest—Cut Bones—Instances of Tertiary Man—Halitherium—Balæonotus—Puy Courny—Thenay—Evidence for—Proofs of Human Agency—Latest Conclusions—Gaudry's Theory—Dryopithecus—Type of Tertiary Man—Skeleton of Castelnedolo—- Shows no approach to the Missing Link—Contrary to Theory of Evolution—- Must be sought in the Eocene—Evidence from the New World—Glacial Period in America—Palæolithic Implements—Quaternary Man—Similar to Europe—California—Conditions different—Auriferous Gravels—Volcanic Eruptions—Enormous Denudation—Great Antiquity—Flora and Fauna—Point to Tertiary Age —Discovery of Human Remains—Table Mountain—Latest Finds—Calaveras Skull—Summary of Evidence—Other Evidence—Tuolumne—Brazil—Buenos Ayres—Nampa Images—Take us farther from First Origins and the Missing Link—If Darwin's Theory applies to Man, must go back to the Eocene.
The first difficulty which meets us in this question is that of distinguishing clearly between the different geological periods. No hard-and-fast line separates the Quaternary from the Pliocene, the Pliocene from the Miocene, or the Miocene from the Eocene. They pass from one into the other by insensible gradations, and the names given to them merely imply that such considerable changes have taken place in the fauna as to enable us to distinguish one period from another. And even this only applies when we take the periods as a whole, and see what have been the predominant types, for single types often survive through successive periods. The course of evolution seems to be that types and species, like individuals, have their periods of birth, growth, maturity, decay, and death. Thus fish of the ganoid type appear sparingly in the Silurian, culminate in the Devonian, and gradually die out in the later formations. So also Saurian reptiles appear in the Carboniferous, culminate in the Lias, and die out with the Secondary, or so nearly so that the crocodilia are their sole remaining representatives.
And this applies when we attempt to take our first step backwards in tracing the origin of man, and follow him from the Quaternary into the Pliocene. When did the Pliocene end and the Quaternary begin? Within which of the two did the first great glacial period fall? Does pre-glacial mean Pliocene, or is it included in the Quaternary? and to which do the oldest human remains belong, such as the skeletons of Spy?
The difficulty of answering these questions is increased because, as we go back in time, the human remains which guide us in the Quaternary age necessarily become scarcer. Mankind must have been fewer in number, and their relics to a great extent removed by denudation. Thus the evidence from caves, which affords by far the most information as to Quaternary man, entirely fails us as to the Pliocene and earlier periods. This may be readily accounted for when we consider the great amount of the earth's surface which has been removed by denudation. In fact we have seen that nearly 2000 feet of a mountain range must have disappeared from denudation in the Weald of Kent, since the streams from it rolled down the gravels with human implements, scattered over the North Downs as described by Professor Prestwich. What chance would Tertiary caves have of surviving such an extensive denudation? Moreover, if any of the present caves existed before the glacial period, their original contents must have been swept out, perhaps more than once, before they became filled by the present deposits. There is evidence in many caves that this was the case, from small patches of the older deposit being found adhering to the roof, as at Brixham and Maccaguone in Sicily, in which latter case flakes of chipped stone and pieces of carbon were found by Dr. Falconer in these patches of a hard breccia.
There is another consideration also which must have greatly diminished the chance of finding human remains in Tertiary deposits. Why did men take to living in dark and damp caves? Presumably for protection against cold. But in the Miocene and the greater part of the Pliocene there was no great cold. The climate, as shown by the vegetation, was mild, equable, and ranged from semi-tropical to south-temperate, and the earth was to a certain extent covered by forests sustaining many fruit-bearing trees. Under such conditions men would have every inducement to live in the open air, and in or near forests where they could obtain food and shelter, rather than in caves. And a few scattered savages, thus living, would leave exceedingly few traces of their existence. If the pygmy races of Central Africa, or of the Andaman Islands, became extinct, the chances would be exceedingly small of a future geologist finding any of their stone implements, which alone would have a chance of surviving, dropped under secular accumulations of vegetable mould in a wide forest.
It is the more important therefore where instances of human remains in Tertiary strata, supported by strong primâ facie evidence, and vouched for by competent authorities, do actually occur, to examine them dispassionately, and not, as a good many of our English geologists are disposed to do, dismiss them with a sort of scientific non possumus, like that which was so long opposed to the existence of Quaternary man, and the discoveries of Boucher-de-Perthes. It is perfectly evident from the admitted existence of man throughout the Quaternary period, already spread over a great part of the earth's surface, and divided into distinct types, that if there is any truth in evolution, mankind must have had a long previous existence. The only other possible alternative would be the special miraculous creations of men of several different types, and in many different centres, at the particular period of time when the Tertiary was replaced by the Quaternary. In other words that, while all the rest of the animal creation have come into existence by evolution from ancestral types, man alone, and that not merely as regards his spiritual qualities, but physical man, with every bone and muscle having its counterpart in the other quadrumana, was an exception to this universal law, and sprang into existence spontaneously or by repeated acts of supernatural interference.
As long as the account of the creation in Genesis was held to be a divinely-inspired narrative, and no facts contradicting it had been discovered, it is conceivable that such a theory might be held, but to admit evolution for Quaternary, and refuse to admit it for Tertiary man, is an extreme instance of "straining at a gnat and swallowing a camel," for a duration of even 10,000 or 20,000 years is just as inconsistent with Genesis as one of 100,000 or half a million.
In attacking the question of Tertiary man, the first point is to aim at some clear conception of where the Pliocene ends and the Quaternary begins. These are after all but terms applied to gradual changes through long intervals of time; still they require some definition, or otherwise we should be beating the air, and ticketing in some museums as Tertiary the identical specimens which in others were labelled as Quaternary. This turns very much on whether the first great glaciation was Pliocene or Quaternary, and must be decided partly by the order of superposition and partly by the fauna. If we can find a section where a thick morainic deposit is interposed between two stratified deposits, a lower one characterized by the usual fauna of the Older Pliocene, and an upper one by that of the Newer Pliocene, it is evident that the glacier or ice-cap which left this moraine must have existed in Pliocene times. We know that the climate became colder in the Pliocene, and rapidly colder towards its close, and that in the cliffs of Cromer, the forest bed with a temperate climate had given place to Arctic willows and mosses, before the first and lowest boulder-clay had brought blocks of Scandinavian granite to England. We should be prepared, therefore, for evidence that this first period of greatest cold had occurred within the limits of the Pliocene period.