unsupported, that part, abandoned to the force of gravity, immediately nods forwards.

The greatest number, and by far the most powerful muscles are placed at the back of the head, and pass between the posterior surface of the vertebral column and the occipit. The recti postici, obliqui superiores, trachelomastoidei, complexi, splenii capitis and trapezii are balanced by few and inconsiderable muscles in front; by the recti antici, recti laterales, and longi colli.

Let a line be drawn according to the plane of the occipital foramen; it will pass from the posterior edge along the surface of the condyles, and, if continued anteriorly, will come out just under the orbits. It forms, in short, almost a horizontal line, which intersects, nearly at right angles, the vertical line of the body and neck, when the head is held straight, without being inclined backwards or forwards.

In this attitude, the face is in a vertical line, parallel to that of the body and neck; and consequently the jaws hardly extend in front beyond the forehead. They are very short in comparison with those of most animals: for the length of the lower maxillary bone of man, measured from the chin to the posterior edge of the condyle, is only half the length of the whole head, as taken from the chin to the occipu and scarcely the ninth part of the height of the body from the anus to the vertex: and about the eighteenth part of the whole length of the body from the top of the head to the feet. This latter point of comparison is, however, scarcely applicable to the subject; inasmuch as there is hardly any animal but man, which has the hind legs as long as the trunk, neck, and head taken together, and measured from the vertex to the pubes.

The horizontal plane of the foramen magnum, its nearly central position in the basis of the skull, the support of the head by the spine, and the direction of the face forwards, are admirably suited to the erect attitude of man, and correspond to the absence of the ligamentum nucha. If the human spine were placed horizontally, how could the weight of the head be sustained? there is no adequate muscular power to support and elevate the heavy mass; not to mention that it could not be carried sufficiently backwards on the spine, for the eyes to be directed forwards; and that, if lowered, the jaws would not come to the ground, as they do in animals, in consequence of their shortness, but the forehead or vertex would touch it.*

The absence of the rete mirabile, and of all analogous provision for mo derating the influx of the blood into the brain, accords, with the other circum

In most animals, the great occipital foramen is placed at the back of the head; the jaws are considerably elongated; the occiput forms no projection beyond this opening, the plane of which is vertical, or at least very slightly inclined. Hence, the head is connected to the neck by its back part, instead of being articulated, as in man, by the middle of its basis; and, instead of being in equilibrium on a perpendicular column placed under it, it hangs to the front of the neck, where its weight is sustained by the powerful cervical ligament.* This arrangement bestows on quadrupeds the power of using their jaws for seizing what is before them; of elevating them to reach what may be above the head, although the body be placed horizontally; and of touching the ground with the mouth, by depressing the head and neck as low as the feet. In several animals there is some distance between the foramen magnum and the posterior extremity of the occiput; but this interval is no where so considerable as in the human subject; and in proportion as it is increased, does the direction of the occipital foramen approach more to the horizontal one.

Animals of the monkey kind exhibit a closer resemblance of the human structure, in the position and direction of the occipital foramen, than any others. In the orang-outang it is twice as far from the jaws, as from the back of the head ;† and it is considerably inclined downwards, so that a line drawn in its level passes below the lower jaw, instead of going just under the orbit, as in man.

The difference in the direction of the foramen may be estimated, by noting the angle formed by the union of a line drawn in the manner above-mentioned, according to the direction of

stances enumerated above, in showing that man is entirely unfit for the attitude on all fours.

The ligamentum nuchæ or suspensorium colli, which is confounded in the Physiological Lectures (p. 116), with the yellow ligaments connecting the plates of the spinous processes, is affixed at one end of the spines of the cervical and dorsal vertebræ, and at the other to the middle of the occiput, between the two fossæ cerebelli. This thick and powerful ligament affords a steady and constant support to the head of quadrupeds, which would have otherwise needed an immense mass of muscles to sustain it. Such a structure is not required in man, where, if this ligament can be said to exist at all, it is only as a weak and insignificant rudiment. I do not know how the orang-outang and other monkeys are circumstanced in this respect. Camper, however, states, that the spinous processes of the cervical vertebræ are very long in the orangoutang (Œuvres, 1. p. 126). And the same circumstance is still more remarkable in the skeleton of the pongo of Batavia, whose enormous jaws and face must require the support of a suspensory ligament, probably attached in both animals to the cervical spines. Audebert, Hist. Nat. des Singes; pl. anat. 2.

The effect of this structure in throwing the centre of gravity forwards, and thus increasing the difficulty of maintaining the erect position, is particularly pointed out by Mr. Abel; Journey in China, p. 322.

the opening, with another line passing from the postertor edge of the foramen to the inferior margin of the orbit. This angle is of 30 in man, and of 37° in the orang-outang; 47° in the Lemur. It is still greater in the dog; and in the horse it is of 90° or a right angle, the plane of the opening being completely vertical.

The distance of the foramen magnum from the front of the jaws and the posterior surface of the occiput may be in man respectively, as and, or even more nearly equal: the former is twice as great as the latter in the orang-outang; while, in almost all other mammalia, the opening is at the very posterior aspect of the skull.

The teeth of man are distinguished by being all of one length, and by the circumstance of their being arranged in an uniform unbroken series. The cuspidati are a little longer than the others at first; but their sharp points are soon worn down to a level with the rest. In all animals the teeth of different classes differ in size and length, often very considerably; and they are separated by more or less wide intervals: this is particularly the case with the teeth called canine, or cuspidati, which are long, prominent, and distinct from the neighbouring teeth: their not projecting beyond the rest, nor being separated from them by any interval, is, therefore, a very characteristic circumstance in the human structure. Even in the simiæ, whose masticatory apparatus most nearly resembles that of man, the cuspidati are longer, often very considerably longer than the other teeth; and there are intervals in the series of each jaw to receive the cuspidati of the other.

The inferior incisors are perpendicular; the teeth, indeed, and the front of the jaw are placed in the same vertical line. In animals, these teeth slant backwards, and the jaw slopes backwards directly from the alveoli; so that the full prominent chin, so remarkable a feature in the face of our species, is found in no animal, not even in the orang-outang: it appears as if the part were cut off.

The obtuse tubercles of the grinders are again very peculiar and characteristic: they are worthy of particular remark, because, being the great instruments of dividing the food, they correspond to the kind of nourishment which the animal naturally takes. Their surface does not resemble the flat crowns with rising ridges of intermixed enamel belonging to our common herbivorous animals: nor are they like the cutting and

tearing grinders of the carnivora. But they are well adapted to that mixed diet prepared by the arts of cookery, which man has always resorted to, when he could get it, and when his natural inclinations have not been thwarted by the interference of religious scruples or prohibitions, nor opposed by his own whims and fancies.

The lower jaw of man is distinguished by the prominence of the chin, a necessary consequence of the inferior incisors being perpendicular; by its shortness,* and by the oblong convexity and obliquity of the condyles.

CHAPTER V.

Differences between Man and Animals in Stature, Proportions, and some

other Points.

THE height of the whole body, and the proportion of its several parts, afford important points of comparison in examining the specific differences between man and the most anthropomorphous simiæ.

The difference of stature is remarkable: of the orang-outangs or chimpansés hitherto brought into Europe, none has been more than three feet high; and most have been several inches under that height. The individual brought to England by Mr. ABEL, and now at Exeter Change, is thirty-one inches. † Of eight seen by CAMPER none exceeded two feet and a half (Rhynland measure): from observing the state of the teeth, and progress of ossification, and estimating, according to the human subject, the additions which the stature might be expected to receive, he thinks that their adult height may be set down at four feet of the same measure. F. CUVIER§ makes it considerably less. Yet they are spoken of, on the faith of travellers, as being five or six feet high, or even more: what is said of their erect gait, and many other particulars, is probably of equal accuracy. TYSON'S chimpansé, measured twenty-six inches from the vertex to the heel. ||

The great length of the upper limbs, the predominance of the

• The length of the inferior maxilla is of that of the trunk from the vertex to the anus, in the simia satyrus; it is in man.

The elephant is equally remarkable with man for the shortness of the lower jaw, of which a considerable portion projects in front of the teeth. This cannot properly be deemed a chin. The incisors and cuspidati do not exist in the lower jaw of this animal; the projection in question is the part, which in other cases is occupied by those teeth.

Journey in China; 322.
Annales du Muséum; xvi. 51.

Euvres; I. 51.
Anat. of a Pygmie, 15.

fore-arm over the upper arm, the shortness of the lower limbs, and the great length of the hands and feet, are other striking characters of the monkey kind.

The span of the extended arms in man equals the height of the body; it is nearly double that measure in the anthropomorphous monkeys. Our upper arm is longer than the forearm by two or three inches; in the last-mentioned animals the fore-arm is the longest. In us the hip-joint divides the body equally; the lower extremity is less than half the height of the body in monkeys. The proportion of the hand and foot to the body is much greater in them than in us; the excess arising from increase in the length of the phalanges. That all these circumstances are very suitable to the climbing habits of the monkey race, is too obvious to require particular elucidation.

In the following table, I have arranged in parallel lines, the dimensions of some parts of a male skeleton, of the orang-outang measured by CAMPER, of that described by Mr. ABEL, and of TYSON's chimpansé.

Man.
Inches.

Simia Satyrus. Camper. Abel. 30 31

25 13

9

10 {

Simia Troglodytes.

Ulna
Radius

6 7-10ths

32

39

13

97

81

7

44

41

3

In a monkey of two feet two inches the humerus measured four and a quarter, the ulna five inches.

The upper extremities of the pongo* of Borneo reach to the ankles, when the animal is erect: its ulna, in the College Museum, is 15 inches long; the whole height certainly not exceeding five feet. The man, whose gigantic skeleton is preserved in the same place, was eight feet four inches; the ulna, however, is only 132 inches.

The upper limbs of the gibbon touch the ground when the animal is erect.

Audebert, Hist. Nat. des Singes; Planche anat. 2, fig. 6. The short description of this animal, which, from the enormous size and strength of his jaws, must be extremely formidable, given by Wurmb in the second vol. of the Memoirs of the Batavian Society in Dutch, is translated in the work of Audebert, pp. 22, 23. It is the first and only description we have of the animal. Buffon, who had never seen this creature, nor any Part of it, gives the name of pongo to the orang-outang.