Popular Science Monthly/Volume 1/June 1872/The Natural History of Man II

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GENTLEMEN: I shall to-day continue the Natural History of Man, which I have undertaken to give you entire. Those of you who were present at our first lecture know that it was devoted to the examination of a fundamental question. We inquired if all the men living upon earth, however they may differ among themselves, are of one and the same species; that is, if they are to be regarded as descended from a single primitive pair.

To answer this question, we appealed to science alone. We started with the principle that, so far as the body is concerned, man is an animal—nothing more, nothing less; that, consequently, all the general laws to which animals are subject bear upon him, and he cannot evade their dominion.

We then asked, not only of animals, but also of plants, What is meant by the word species? and we were led to distinguish species from race.

Without going into the details I then gave, this distinction is easily established. When two individuals of different species unite, the union is almost always infertile, and, if the first union is fertile, the offspring, either immediately or at the end of a few generations, will reproduce no more. So that, between two species, we cannot establish a third series of individuals, starting at first with a father and a mother taken from two distinct species. The examples I gave are known to you all. When we unite a jackass with a mare, an ass with a stallion, we obtain a mule or a hinny, and never a horse or an ass; and, to get mules, it is always necessary to have recourse to a jackass and a mare.

When, on the contrary, we take two individuals of two different races of the same species, whatever their differences of exterior conformation, the resulting individual is fertile, and may give birth to an intermediate series of individuals between the two races.

As examples, I took the different races of dogs, of sheep, of cattle. Whatever the skin, the color, the form, the proportions of the dog, he remains a dog; whatever the proportions, the figure, the color of horses or of oxen, they remain horses and oxen. So, when we cross a water-spaniel with a greyhound, a lap-dog with a Havana dog, the offspring are fertile, and we get what are called fertile mixed races.

Now, when human beings unite with each other, whatever their exterior differences, whether they are white, or black, or yellow, these marriages are fertile. From this fact, verified a thousand times, we ​draw the conclusion that there is but one species of men, and that the differences existing between them are only differences of race. Again I say, in reaching this conclusion, we have never gone beyond science. I repeat this declaration, because, in all that I shall say to you, I wish you distinctly to understand that I never put foot outside the domain of science, where alone the scientific man can speak with. authority.

The unity of the human species once demonstrated, many problems arise before us.

The first is that of the antiquity of man. Have men been always upon the earth? Did they appear at the same time with the other species of animals? Are they very ancient on the globe? Such are the first questions which present themselves to our minds.

Throughout all time have men lived on the earth? Many of you,

doubtless, are already able to answer me. My brother professors of geology and paleontology have probably addressed you on these questions. I shall only recall to you the general facts bearing upon the case.

You all know what is the action of heat upon certain bodies. For example, you all know that water heated to a certain degree vaporizes; that if this vapor loses a certain quantity of heat, it is liquefied; that in losing still more, it forms a solid body ice. This ice may become so solid, that in St. Petersburg they have been able to construct it into palaces, and have made cannons of ice that have been fired. You can understand that a sufficient quantity of heat will reduce all bodies to vapor, and that sufficient cold will solidify them.

Now, the facts of astronomy seem to prove that, of old, our earth, ​with all it contains, and all the materials that compose it, began as a vast, vaporous mass diffused in space. It was a globe of vapor. When the process of cooling set in, this mass became liquid, and, during periods of time which we cannot compute, it was only a vast mass of rocks and of matter melted by fire.

It is needless to insist on the fact that, at this epoch, on the surface of our globe, there were no living beings, and consequently no men.

The cooling progressing, there is formed a pellicle on the surface of the globe, and this pellicle goes on increasing in thickness. This is what we will call the primitive earth. On this primitive earth, during a long period, water could not exist in a liquid state, and consequently there were as yet upon our globe no living beings, for all these beings need water; and, of course, no men.

But the process of cooling continued. The water which was vaporized in the atmosphere fell in torrents on this crust which enveloped the globe; chemical reactions, of a violence of which we can form no idea, were produced. At this moment began the formation of what we call the earth of transport, and the globe entered upon what is called the Secondary epoch.

Strictly we may say that, from the moment the waters rested in a liquid state upon the surface of the earth, life might begin to manifest itself. In certain thermal waters of high temperature, we find confervæ—microscopic vegetables which are already organized and living. But no animal could yet live in this medium, for the heat would coagulate its albumen. Later, the cooling always progressing and the sea enveloping the greater part of the globe, more complex vegetables appeared. Soon animals, chiefly aquatic, made their appearance, and among them I would mention those gigantic reptiles you have sometimes seen represented in certain book announcements on the walls of Paris. Mammals—man—could not yet inhabit our globe.

As the cooling progressed, continents were formed by the upturnings of Nature. The time came when true mammals and birds, analogous to living species, appeared in their turn. This was the commencement of the Tertiary epoch. Then, very probably, man might have lived. We shall presently have to ask if he did not exist, at least in the latter part of this period.

The dislocation of the crust of the globe elevated the mountains, dug the valleys, sank the seas, formed the continents, and, toward the end of the Tertiary period, the globe presented a surface much resembling what we see now. Here commences the Quaternary period. This quaternary period presents to us a very remarkable phenomenon.

Up to this time, putting out of account the slight oscillations that have occurred, the globe seems to have cooled in a nearly uniform manner, from the time when it formed only a mass of vapor, down to the Tertiary epoch. With the Quaternary period came a moment ​wherein a cooling, perhaps sudden, but in any case very marked, showed itself and then disappeared.

At this moment, a part of the globe at least, and Europe in particular, was much colder than it is now. We have proof of this in the glaciers of the Alps. Instead of stopping at the place where they do now, these glaciers filled most of the Swiss valleys, descending even in the valley of the Rhone; and from one end to the other of these valleys enormous blocks of rock were transported by the glaciers, and

Fig. 1.	Fig. 2.
Arrow-shaped Flint Implements.

left on the spot. It is these which now constitute what we call erratic blocks.

During the Quaternary epoch, there lived in France very different animals from those which we find now. Among them I may refer to the great cave-bears, which were remarkable for their size and for their bulging foreheads. I will also mention the hyena. You know that now we have no hyenas, and that they are only found in countries much warmer than France. To the preceding species I will add the rhinoceros. I call attention particularly to an elephant, of which this is the picture (Fig. 1), and which we call the mammoth. This elephant, ​you see, is easily distinguished from species now living; by its size, first, for it is much larger than they; then by the form of its remarkably recurved tusks; finally and chiefly because, in place of the naked skin of the elephants we know, he was covered with a thick wool and very long hairs.

Of all this we are certain; for this elephant has been found preserved whole, with his skin and his hairs. At different times they have discovered in the frozen earth of Siberia the dead bodies of these animals. That country contains in such great numbers the tusks of these antediluvian elephants, to employ a vulgar expression, that the commerce in fossil ivory constitutes a considerable source of revenue, and the state reserves a monopoly of it.

I call special attention to this elephant, and we shall presently see why.

The Quaternary period ended as those that preceded it; and then began the present period. Since the time of its commencement, the continents, the flora, and the faunæ, have not undergone any considerable modifications.

Nobody has ever questioned the existence of man at the beginning of the present period, and some have even considered his appearance as the characteristic feature of this period. But did man exist before? To employ the common expression, were there antediluvian men? In other words, and to return to scientific language, is man the contemporary of those animal species among which appears the mammoth? May he be found, like the mammoth, in a fossil state?

Such is the question that has been often put, and which was long answered in the negative. Down to these later times, the most eminent men in Natural History, in Geology, in Paleontology, were all agreed on this point, and I need only state that Cuvier, in particular, never admitted the existence of fossil man.

To-day we are led by many well-ascertained facts to answer this question very differently. We are forced to admit that fossil man does really exist, and that man was contemporary with those species of animals I have been speaking of, especially with the mammoth.

This is certainly one of the most beautiful discoveries of modern times! The ground for it was laid by the establishment of a certain number of facts observed in England, in Germany, in France. But the honor of having brought decisive proofs, which convince everybody, belongs incontestably to two Frenchmen—to M. Boucher de Perthes, and to M. Edouard Lartet.

M. Boucher de Perthes, the eminent archaeologist of Abbeville, while inspecting the excavations made in the earth around his native village, at Menchecourt, and at Moulin-Quignon, discovered stones fashioned in a peculiar manner, and the same form was constantly reproduced. It was soon evident to him that this circumstance was not accidental, but that these stones owed their form to human industry. ​Now, these polished flints (Figs. 2 and 3), these stone hatchets (Figs. 4 and 5), were found in the earth associated with the bones of elephants; whence he concluded that the men who had fashioned them lived at the same epoch with those great mammifers long since extinct.

This conclusion, drawn by M. Boucher de Perthes, was at first vigorously contested. In particular, some of the men whose decisions have justly the highest authority on questions relating to the history of the earth, thought that the chipped flints and the bones of elephants

Fig. 4.	Fig. 5.
Flint Hatchets.

were found together in the same bed because this bed had been altered. They said: A first bed was formed which enclosed the bones of elephants. On this bed, during the present period, men lived and have left these chipped flints as a trace of their presence. Then came a mighty tempest, which rolled and confounded together the hatchets and the elephants' bones. Hence we now find them side by side, although the bed to which they belong contains the remains of two perfectly distinct epochs.

It will be apparent to you that, if, in our day, men were buried in this bed of Menchecourt and of Moulin-Quignon, and, if a great storm should come and mingle these modern bones with the hatchets and bones of elephants, our grandchildren would find them all mixed together, and yet the men of to-day are not contemporaneous with the hatchets you see before you.

The objection was all the stronger for having been advanced, as I have said, by the highest authorities in Geology. This is why I attach ​such importance to the facts, for which we are indebted to M. Lartet, and which entirely refute these conjectures.

M. Lartet studied at Aurignac, in the south of France, a burial-place of these remote times. It is a grotto excavated in the side of a hill, at a height which is not attained by water-courses analogous to those of which we find the trace in the neighborhood of Abbeville. This sepulchral grotto at the time of discovery was closed by a slab taken from a bed of rocks at some distance from this point. In the interior were found the bones of seventeen persons, men, women, and children; and before the entrance were found the well-attested remains of a fireplace. There were traces of funeral repasts that the first inhabitants of our country were in the habit of making, and such as we sometimes find in our own day among certain European peoples. In the ashes of this fireplace were found bones bearing the trace of fire, and excrements of wild animals. These bones, scorched by the fire, bearing traces of the hand of man, were the bones of the bear and of the rhinoceros. The excrements were those of a species of hyena contemporaneous with the preceding animals. Here, consequently, man appears as eating the animals in question; as making his repast of those very animals whose contemporaneousness with him had been disputed.

M. Lartet crowned these beautiful researches by discovering in a cave, in the centre of France, a piece of ivory on which was unmistakably represented the very mammoth (Fig. 6) to which I have just called your attention. It is very evident that this picture could only be made by a man who lived at the same time with this elephant.

In view of M. Lartet's discoveries, we must admit the existence of fossil man, that is to say, the coexistence of our species with the lost species of animals of which I have spoken.

Since this epoch, besides, we have not only found traces of these primitive industries, but débris of jawbones, and entire crania. Hence we can judge of the characters which distinguished our first ancestors. Strange to tell, we find that these men who, even in France, warred with stone weapons such as I have shown you, against the elephant and the rhinoceros, have still at the present day in Europe descendants presenting the same characters.

So man lived in the Quaternary epoch. May we go further, and admit that he also existed during the Tertiary epoch? Was he contemporaneous, not only with the rhinoceros and mammoth, of which I have spoken, but also with earlier mammals?

The question is perhaps still premature. Some facts seem to indicate that it is so; but in such matters it is better to adjourn conviction than to admit opinions that are yet in doubt. Consequently, we shall regard the debate as remaining open.

After demonstrating that man goes back in geologic time to an epoch much anterior to that in which we formerly believed, we are ​naturally led to ask if it is possible to estimate in figures this antiquity of our species. We are obliged up to the present time to answer, No.

We can perfectly establish relative epochs; but we cannot judge of the number of years that each of these epochs represents.

​This, however, has been attempted. From calculations of the time required to form a bed of peat, some have attempted to compute the duration of certain periods of the age of stone, of the age of bronze, and of the age of iron.

But the results have been so discordant as to throw doubt upon the method. Then the accumulations of débris thrown up by torrents of the Alps have been studied, and, in particular, an accumulation of this kind known under the name of the cone of Tinnière. A railroad has cut through these materials, which have probably been accumulating ever since the commencement of the present epoch, and in the cut there have been found débris reaching back in one case to the Gallo-Roman epoch, in others to the Roman epoch—these to the epoch of iron, those to that of bronze, and, finally, to the epoch of stone.

As we know the duration of some of these periods, it has been thought possible by a simple proportion, taking account of the thickness of the beds, to go back to the epoch of the first formation of the cone. But here again, I repeat, the results are so uncertain that we cannot give them any serious confidence.

We cannot, then, give precise figures. Yet, from all these researches, and from archæologic facts not less demonstrated, it results that it is necessary to go back much farther than we have been accustomed to, to look for the advent of man upon the earth. Let me cite you just one of these proofs.

You were at the Universal Exposition—probably you entered the Egyptian Temple. At the bottom of the hall, facing the entrance, you saw a statue—that of King Cephren. This statue goes back something like four thousand years before our era. Consequently, it was sculptured about six thousand years ago. Now, you may know that the work was very difficult, for the stone of which it is made is very hard. The statue is remarkably perfect. From this, as well as from other data, we learn that in Egypt, six thousand years ago, civilization was already much advanced. We must, therefore, date back the origin of the Egyptians more than six thousand years. But we shall presently see that Egypt was not the first inhabited country. Man must have come there from his original home. Consequently, his first appearance on the globe will be found much more remote in time.

So we are now certain of the existence of Quaternary man; we already suspect the existence of Tertiary man, and it is precisely in our country that the discoveries which led to these conclusions were made.