rather, if he and the present apes are derived from a common ancestor, then we must expect to find the early remains of man closely drawing near, in his characters, to that hypothetical form which is looked for in "the missing link." Thus far all the characters of the early remains of man point distinctly in that way, though many a long gap must yet be filled before the sharp lines of demarkation between the higher groups break down. From the exceeding rarity of the remains of the order of primates, the different groups stand quite as isolated as man from them. Not to speak of the gaps yet to fill between the different genera of the higher apes, a great gap separates the true apes from the half-apes or lemurs, and these in turn have affinities with the most aberrant and puzzling forms, like the aye-aye and tarsier, with its extraordinary long tarsal segment, so that we have the affinities of man brought by a quick passage, as it were, to the lower levels of the mammalia; and in this connection it is interesting to observe that in the lower eocene, both in Europe and America, lemuroid forms have been discovered.

In recalling the low characters of ancient man, it is not necessary to mention here the oft-repeated examples of the Neanderthal and Engis skulls, the skulls of Perigord, the jaws of La Naulette, Moulin Quignon, and a host of other examples now classic in the literature of the subject, and the equally remarkable remains in this country, such as the platycnemic tibiæ of Michigan, and the remarkable skull from that region, with the temporal ridges nearly approximating. Suffice it to say that, just as we find the remains of man at lower levels, so do we find his characters in the main departing not only from the higher races of to-day, but in the same proportion approaching a type which is ape-like. If we examine the races to-day we find the savage groups presenting a number of low characters, such as a deficiency of the sharp ridge at the base of the nostrils, differences in the proportion of the pelvis, in some the foramen magnum farther back; a certain percentage of perforated humeri, prognathism, and other characters, all of which are an approach to the apes, and a departure from higher man. No one savage race possesses all these characters, but each race has some of them. If we look for these characters among the higher races, we meet with them rarely. Thus, the percentage of perforated humeri in the white race is very low. Of fifty.

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two humeri examined by Wyman, only two were perforated. In the present Indian and Negro, this peculiarity occurs more frequently, and in the prehistoric races of America it is very common. Wyman found in a Florida mound thirty-one per cent. perforated, while Gillman estimated the percentage of perforated humeri in a Michigan mound as at least fifty per cent. He has furthermore pointed out the interesting fact that these low humeri are associated with excessively flattened tibiæ.

If now we note successively the percentage of low characters revealed in the higher races of to-day, in existing savages, in the races, both savage and civilized, at the dawn of history, and finally, in those savage races which alone existed in neolithic and down through to paleolithic times, we find this percentage becoming greater as we descend. So marked is the increase that one may almost predict that, when still more remote horizons yield their human remains, an enormous percentage, if not all, will be found with low, receding foreheads; heavy frontal crests; rounding of the base of the nostrils; a nearer approximation of the temporal ridges; a greater posterior position of the foramen magnum; the absence of a projecting chin; ape-like proportions of the molar teeth; perforated humeri; quadrumanous proportions of the pelvis; flattened and saber-like tibia; conspicuous roughness and ridges for the attachments of muscles, and other low osteological characters, all pointing in one direction. Of the soft parts, the amount of hairiness and the racial character of the hair, the persistence of ape-like muscles, which at the present time occur but rarely, or of their habits and mental attributes, nothing, of course, can be known.

These characters, when found, will have become merged so completely with those of the ancestors on another line that new genera will have to be erected to embrace them. This conclusion brings no strain upon the accepted methods of logical deduction. For these remains we are still seeking.

There are many species of mammals whose early progenitors are not known, and, though many wide and important gaps in conspicuous groups of mammals have been filled up, thanks to the labors of our American paleontologists, there are many "missing links" in other groups as well as in that group to which we belong. The intense impatience to fill this gap in man's genealogy arises from the special interest that man naturally feels in his own species. How long we have patiently waited

for those links which Geoffroy St. Hilaire so earnestly looked for-the closing up of wide gaps between the paleotherium, hipparion, and the horse; and who could have foretold in his day that, in the wild regions far beyond the Mississippi, amid hostile savages, these precious remains would be brought to light!

Many other intermediate forms, of equal importance in forming connected series, though not so well known to the public, have been discovered by Leidy, Marsh, and Cope. Indeed, such intermediate and generalized forms have been added to the mammalia that we have creatures combining the characters of the pigs and ruminants, animals possessing the characters of the hoofed beasts, carnivora, and rodents! Professor Flower, the distinguished English osteologist, confesses that the modern classification of mammals completely breaks down in the light of these revelations. Cuvier's law of the "Correlation of Structures," although applicable within certain limits, would have led him into the gravest errors as applied to the fossils known at present. Professor Marsh, in his address on the "History and Methods of Paleontological Discovery,” says that if Cuvier "had had before him the disconnected fragments of an eocene tillodont, he would undoubtedly have referred a molar tooth to one of his pachyderms, an incisor tooth to a rodent, and a claw-bone to a carnivore."

The sharp lines of demarkation which discriminate the various groups of mammals in Cuvier's day have been, in many cases, rounded off or completely obliterated. Man, who is still seeking his own phylum with those of many other species of mammals, must patiently wait.

Huxley, in his courageous little book on "Man's Place in Nature," published nearly twenty years ago, closes by asking the question: "Where, then, must we look for primitive man? Was the oldest Homo sapiens pliocene or miocene, or yet more ancient? In still older strata do the fossilized bones of an ape more anthropoid, or a man more pithecoid, than any yet known, await the researches of some unborn paleontologist? Time will show; but, in the meanwhile, if any form of the doctrine of progressive development is correct, we must extend, by long epochs, the most liberal estimate that has yet been made of the antiquity of man."

EDWARD S. MORSE.

INDEX

TO THE

HUNDRED AND THIRTY-SECOND VOLUME

OF THE

North American Review.