The Cambridge Natural History Part 49

The Orang seems to be usually of a fairly mild disposition; it will rarely attack a man unprovoked. But Dr. Wallace, who has acc.u.mulated a large number of observations upon these animals, describes a female Orang who "on a durian tree kept up for at least ten minutes a continuous shower of branches, and of the heavy-spined fruits as large as 32-pounders, which most effectually kept us clear of the tree she was on. She could be seen breaking them off and throwing them down with every appearance of rage, uttering at intervals a loud pumping grunt, and evidently meaning mischief." The name given by the Dyaks to the Orang is Mias Pappan.[446]

FOSSIL ANTHROPOID APES.--Undoubtedly the most interesting of fossil Anthropoids is the now famous _Pithecanthropus erectus_. Our knowledge of it is due in the first place to Dubois.[447] But there is hardly an anatomist or an anthropologist who has not had his say upon this regrettably very incomplete remnant. The creature is only known by a calvarium, two separate teeth, and a femur. And the femur, moreover, is diseased. M. Dubois discovered these remains in the island of Java in andesite tufa of Pliocene or at least early Pleistocene age. The remains were found in company with _SteG.o.don_, which is now extinct, and _Hippopotamus_, which is no longer found in that part of the world. The name _Pithecanthropus_ was given to it by the discoverer in order to furnish with a definite habitation and a name the theoretical _Pithecanthropus_ of Haeckel. Even the most particular of students of mammalian nomenclature will hardly object to the utilisation of a name for a second time which is with some clearness a _nomen nudum_! The animal when erect must have stood 5 feet 6 inches high. The contents of the cranium must have been 1000 cm., that is to say 400 cm. more than the cranial capacity of any Anthropoid {585} Ape, and quite as great as or even a trifle greater than the cranial capacity of some female Australians and Veddahs. But as these latter are not 5 feet in height, the Ape-like man had really a less capacious cerebral cavity. The skull in its profile outline stands roughly midway between that of a young Chimpanzee (young in order to do away with the secondary modifications caused by the crest) and the lowest human skull, that of Neanderthal Man. This creature is truly, as Professor Haeckel put it, "the long searched for 'missing link,'" in other words represents "the commencement of humanity."

The remains of Apes, more distinctly Apes than _Pithecanthropus_, are known from Miocene strata of France. Two genera, _Pliopithecus_ and _Dryopithecus_, are known. The former appears to be close to _Hylobates_.

_Dryopithecus_ is more Man-like than any other, and seems to have been as large as a Chimpanzee. The incisors are human in their relatively small size. But it has been pointed out that the long and narrow symphysis of the lower jaw is a point of likeness to the Cercopithecidae.

FAM. 3. HOMINIDAE.--Apart from _Pithecanthropus_, which perhaps is a member of this family, but whose remains permit us to leave it among the Simiidae, at least for the present, the family Hominidae contains but one genus, _h.o.m.o_, and probably but one species, _H. sapiens_. The characters of the family may therefore be merged in those of the genus.[448]

Though it is easy enough to distinguish a Man from an Ape, it is by no means easy to find absolutely distinctive characters which are other than "relative." As Professor Haeckel has pointed out, there are really only four characters which differentiate Man: these are the erect walk, and the consequent modification of the fore- and hind-limbs to that position; the existence of articulate speech; the faculty of reason. Whether one body of psychologists are right who argue that reason is a distinctive human attribute, not to be confused with the apparent reasoning powers of lower animals, or whether others are justified in separating Man only in degree from the lower animals, it is clear that this very diversity of opinion prevents us for the present from utilising such characters as absolute differences. In any case the discussion of these matters is beyond the scope of the present book. {586}

[Ill.u.s.tration]

FIG. 281.--Skull of Immanuel Kant. (After C. von Kupffer.) The great size of the cranium is a noteworthy feature. (From Wiedersheim's _Structure of Man_.)

Anatomically there are a number of small points which distinguish Man; but they are mainly due to the erect gait. It is sometimes attempted to divide Man as a naked animal. But this is an apparent difference only; the hair is not so much developed upon the body as in the Apes, save in occasional abnormalities, such as the various hairy men and women who can be seen in travelling shows, and to a less extent the j.a.panese Ainos, but it is present everywhere, as is shown by microscopical investigation of the skin.

The skull in Man "is a smooth and imposing, rounded or oval bony case,"

which contrasts with the smaller and deeply ridged skull of the Anthropoid Apes. The shape of the skull is largely in accord with the large brain. The face does not project so much as in the Anthropoid Apes, though this character must not {587} be insisted upon too strongly, as in some American Monkeys the face is as little projecting. Still we are now comparing Man with his undoubtedly nearest relatives the Simiidae. In the lower jaw the anterior line at the symphysis is an approximately straight one, that is at right angles to the long axis of the jaw, while Apes have a more retreating chin. The "beautiful sigmoid curve formed by the lumbar and dorsal vertebrae" is more p.r.o.nounced in Man, but exists not only in the Anthropoids, but in other Apes.[449]

[Ill.u.s.tration]

FIG. 282.--Foot of Man, Gorilla, and Orang of the same absolute length, to show the difference in proportions. The line _a'a'_ indicates the boundary between the tarsus and metatarsus; _b'b'_, that between the latter and the proximal phalanges; and _c'c'_ bounds the ends of the distal phalanges.

_as_, Astragalus; _ca_, calcaneum; _sc_, scaphoid. (After Huxley.)

[Ill.u.s.tration]

FIG. 283.--Skeleton of the left pes of a Chimpanzee. (Dorsal aspect.) _as_, Astragalus; _cb_, cuboid; _cl_, calcaneum; _ec_, ectocuneiform; _en_, endocuneiform; _ms_, mesocuneiform; _nv_, navicular; _I-V_, digits. (From Wiedersheim's _Structure of Man_.)

The fore-limbs are relatively short, the extreme length of the arm being such that the outstretched hand does not reach the knee. The thumb is a large and useful digit in Man, much more so than in the Anthropoids. On the other hand the hallux is not opposable. This is, of course, correlated with the upright att.i.tude, as is also the greater relative thickness of that digit, upon which {588} the greatest stress is laid in walking. As to muscles, the glutaeus maximus is more developed in Man--the Ape which most nearly approaches him being the Gorilla, in which animal the life is less thoroughly arboreal than in some others. The so-called "scansorius" is only present in Man as an occasional occurrence. The rudimentary character of the ear muscles for the movement of the external ear in Man has often been insisted upon, as also their occasional functional activity. But here and elsewhere, so numerous are the abnormalities, that "the gap which usually separates the muscular system of Man from that of the Anthropoids appears to be completely bridged over." These are words of Professor Wiedersheim quoted from Testut, and express a final summary of the matter of muscles in Man and the Apes. {589}

[Ill.u.s.tration]

FIG. 284.--The hard palate, A, of a Caucasian; B, of a Negro; C, of an adult Orang-Utan, showing the differences in shape of the bones. The palate of the Negro represents a type transitional between that of the Caucasian and that of the Orang. _mx_, Maxilla; _pl_, palatine; _p.mx_, premaxilla.

(From Wiedersheim's _Structure of Man_.)

In his teeth Man differs by the small exaggeration of the canines, which hardly, if at all, differ in the two s.e.xes. There is also a complete absence of a diastema. The teeth are also on the whole weaker than in the Anthropoids, though _Hylobates_ is very human in this particular.

[Ill.u.s.tration]

FIG. 285.--Human Larynx in frontal section. _cr_, Cricoid cartilage; _sn_, sinus of Morgagni; _t.c_, first tracheal cartilage; _th_, thyroid cartilage. (From Wiedersheim's _Structure of Man_.)

There is a tendency in Man towards the disappearance of the upper outer incisors, and more markedly still of the wisdom teeth, which appear very late, and are often imperfect. In a large number of cases the tooth does not appear at all. In the larynx there is no great development of the great throat pouches of the Anthropoids. The minute diverticula of that organ, known to human anatomists as the ventricles of Morgagni, alone remain to testify to a former howling apparatus in the ancestors of Man.