TREPANNED SKULLS.

87

trepanned human skulls, found by Dr. Prunières in the cave of Homme-mort in Lozère and in several dolmens in the same department. Discs of bone, equal in size to the holes in the skulls have been found, sometimes within them, sometimes separately, lying beside them or at some distance. Many of these are pierced by one or two holes, so as to allow them to be strung upon a cord. Their diameter varies from that of a shilling to that of a crownpiece (see fig. 22). Some of them, more or less elliptical in shape, measure seven inches in length and five in their greatest width. M. Broca has made an exhaustive study of the subject,2 which is, thanks to his labours, now very well known.

The trepanning was effected sometimes on the living subject, sometimes after death. An incision in the form of a T was first made on the skin under the hair, then the bone was scraped with a flint knife, until sooner or later the disc or discs of bone were detached from the skull; for sometimes two or three were taken from one individual even while living. It is a remarkable fact that the cases in which the operation, which is especially dangerous when we consider the poverty of the surgical apparatus of our ancestors of the stone age, proved fatal, are so rare that out of twenty skulls in the possession of Dr. Prunières, he has only observed one instance. All the others present unmistakeable traces of a complete recovery.

The motive of this operation has of course been sought, and the use of these discs found in the interior of the cranium or in the soil where the corpses had been buried. We shall return to this subject in the chapter on Religion. We shall see that the practice of trepanning persisted throughout the neolithic period, and that the use of these discs is the earliest proof of a belief in a future life.

The instances of human bones in the caves which were

• Artificially perforated skulls have also been found in the burial caves of la Marne, of Sordes, in the neighbourhood of Pau, in the ancient tombs of the Canary Isles, in the dolmens of Algeria, and even in Mexico and Peru.

2 See the Revue d'Anthropologie, t. ii. p. 18, 1873, and t. vi. pp 1 and 193, 1877.

undoubtedly contemporary with extinct species are rare; we purposely repeat this fact, and the greatest circumspection is required before pronouncing on this kind of synchronism. Nothing is easier than to make the greatest mistakes on this point; the cautious M. Ed. Lartet himself assumed that the human bones of Aurignac were contemporary with those of Ursus spelaus and of the mammoth which he had himself found in the true archæolithic stratum of this cave, whereas, imbedded in a far more recent layer, overlying the former, they dated in reality from the neolithic age.

VII. PROOFS FURNISHED BY THE CONDITION OF THE BONES, AND THEIR CHEMICAL COMPOSITION.

When human bones are found buried in the same strata with those of extinct species, and when it is certain that the bed which contains them both is virgin and undisturbed soil, we may logically conclude, as we have said, that these remains of men and animals date from the same epoch. The similarity of appearance, and especially the equal quantity of animal matter which they still contain, duly considering, of course, the age and nature of the animal, give new weight to this conclusion. Now the quantity of ossein is easily deduced from that of the nitrogen discovered by chemical analysis. In this manner M. Delesse found that the proportion of nitrogen contained in the human bones found at Aurignac was very nearly the same as that in the bones of the bear, reindeer, and rhinoceros with which the remains of our own species were found associated in this burial cave. The numerous analyses of M. Scheurer-Kestner produced similar results, and led their author to believe with M. Delesse in the co-existence of man and the extinct species whose remains were under examination.

The nature of the bones, that of the soil, its dryness or humidity, its permeability by air and water, the more or less ancient date of burial, the depth at which they lie, &c., have a considerable effect on the condition of the bones, so that those most recently buried are not always

CHEMICAL COMPOSITION OF FOSSIL BONES.

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the best preserved. Hence M. Frémy has had no difficulty in proving that nothing is more variable' than the quantity of organic matter contained in fossil bones; some of them no longer contain any at all, others have a proportion of 8, 10, and even 20 per cent. Some strata have such a preserving power that M. Gimbernat was able to make an edible jelly from some bones of Elephas primigenius, and M. Bibra made a strong paste from the bones of Ursus spelaus. Mr. A. Milne-Edwards has seen a tooth of the last-named fossil species, found in the diluvium of the neighbourhood of Compiègne, which still contained sufficient ossein to retain its shape, after its calcareous substance had been expelled by the action of hydrochloric acid. Lastly, some bones of the mastodon found at New York, in 1845, still contained 27 to 30 per cent. of animal matter. With bones so well preserved it would then be possible to prepare an antediluvian broth, a real soup of pre-adamite gelatine. Who knows if this strange notion may not one day be realised by the unceasing progress of chemistry, which every day displays wonders far more surprising and of greater interest.2

The impossibility of determining by analysis the precise age of any bone, ancient or recent, will be easily seen from the foregoing statements. On the other hand, if the bones under examination, belonging partly to the human race, partly to extinct species, occupy the same bed and contain the same proportion of nitrogenous matter, we may admit with some degree of certainty the synchronism of the analysed remains. In this way M. ScheurerKestner satisfied himself that the skull of Eguisheim, for example, was of the same date as the bones of the mammoth and of the cave bear found along with it.3

Marcel de Serres had long since observed that the chemical composition of the bones of the caves and that of the remains contained in the tertiary beds are sometimes absolutely identical.

6

2 This strange idea, of which we have just spoken, was put in execution by German naturalists at the congress of Tübingen. They had the pleasure,' M. Babinet tells us, of eating, not a beefsteak, but a soup of mammoth gelatine.' See Revue Scientifique, 1866. Conference by M. Babinet on the Glacial Period.

• Scheurer-Kestner, Recherches Chimiques sur les Ossements trouvés

From all these facts we must conclude that if the chemical analysis of bones can, in certain cases, and by comparison, furnish useful data with respect to their relative ages, it cannot tell us anything about their absolute age. Hence again it results that if the doubts recently put forward with regard to the human bones of Aurignac have a real foundation, that is, if these bones are much less ancient than those of the cave bear, mammoth, and rhinoceros, considered as contemporaneous by M. Ed. Lartet, we must also conclude that the analysis of these bones made by M. Delesse does not prove all that which he wished it to show.

dans le lehm d'Eguisheim. Annales des Sciences Naturelles, t. vii. p. 165, 1867

CHAPTER IV.

THE PEAT MOSSES AND THE KITCHEN MIDDENS.

I. THE DANISH PEAT MOSSES.

It is well known that in certain regions (chiefly at the bottom of gently sloping valleys), and under the influence of certain conditions, aquatic plants, the hypnum, the sphagnum, &c., herbaceous land plants, heaths, and even forest trees, heaped up in shallow waters, become interlaced and partly decomposed, and produce a combustible of no great value. This combustible is peat. Denmark is especially rich in various kinds of peat beds, known in that country as engmose (meadow marshes), lyngmose (heath marshes), and skovmose (forest marshes).

The last alone deserve a few moments' attention, since they show that very different vegetations succeeded each other at different epochs in the soil of Denmark. Professor Steenstrup, who has made a special study of the subject, tells us that a layer of peat, composed of perfectly recognisable aquatic plants (hypnum), is placed above the amorphous, almost felt-like peat, which occupies the centre and bottom of the funnel-shaped basins in which it was formed. Stunted pines, heaped one over the other, still occupy the place in the marsh where they grew in the remote past. Then the sphagnum takes the place of the hypnum, and the heath appears, along with whortleberries, birches, hazels, and alders. Lastly, the Scotch fir, which once grew along the borders of the moss, but which has long since disappeared from the land, appears in great abundance, and principally on the outer belt. These trees now lie overturned in such a way that their roots are turned towards the edge of the basin and their tops towards the