upon the legs, and reciprocally to move these upon the trunk. The great breadth and anterior concavity of the ilium, 62, are characteristic modifications of this bone in man. The pelvis is more capacious, the tuberosity of the ischium is less prominent, and the symphysis pubis shorter, than in apes. The tail is reduced to three or four stunted vertebræ, anchylosed to form the bone called "os coccygis." The five vertebra which coalesce to form the sacrum are of unusual breadth, and the free or "true" vertebræ, that rest on the base of the sacral wedge, gradually decrease in size to the upper part of the chest; all the free vertebræ, divided into five lumbar, twelve dorsal, and seven cervical, are so articulated as to describe three slight and graceful curves, the bend being forward in the loins, backward in the chest, and forward again in the neck. A soft elastic cushion, of "intervertebral" substance, rests between the bodies of the vertebra. The distribution and libration of the trunk, with the superadded weight of the head and arms, are favoured by these gentle curves, and the shock in leaping is broken and diffused by the numerous elastic intervertebral joints. The expansion of the cranium behind, and the shortening of the face in front, give a globe-like form to the skull, which is poised by a pair of condyles, advanced to near the middle of its base upon the cups of the atlas; so that there is but a slight tendency to incline forwards when the balancing action of the muscles ceases, as when the head nods during sleep in an upright posture.

The framework of the upper extremity shows all the perfections that have been superinduced upon it in the mammalian series, viz., a complete clavicle, 58, antibrachial bones, 54, 55, with rotatory movements as well as those of flexion and extension, and the five digits, 57, free and endowed with great extent and variety of movements: of these, the innermost, which is the first to shrink and disappear in the lower mammalia, is in man the strongest, and is modified to form an opposable thumb more powerful and effective than in any of the quadrumana. The scapula, 51, presents an expanded surface of attachment for the muscles which work the arm in its free socket. the humerus, 53, exceeds in length the bones of the fore-arm. The carpal bones, 56, are eight in number, called scaphoides, lunare, cuneiforme, pisiforme, trapezium, trapezoides, magnum, and unciforme; of these the scaphoid and unciforme are compound bones; i.e. they consist each of two of the bones of the type-carpus, connate.

In the human skull, viewed in relation to the archetype, as exemplified in the fish and the crocodile, the following extreme modifications have been established. In the occipital segment the hamal arch is detached and displaced, as in all vertebrates above fish; its pleurapophysis (scapula, 51) has exchanged the long and slender for the broad and flat form; the hamapophysis (coracoid, 52) is rudimental, and coalesces with 51. The neurapophyses (exoccipitals, 2) coalesce with the neural spine (superoccipital), and next with the centrum (basioccipital). This afterwards coalesces with the centrum (basisphenoid) of the parietal segment. With this centrum also the neurapophyses, called "alisphenoids," and the centrum of the frontal vertebra, called "presphenoid," become anchylosed. The neural spine (parietal) retains its primitive distinctness, but is enormously expanded, and is bifid, in relation to the vast expansion of the brain in The parapophysis (mastoid) becomes confluent with the tympanic, petrosal, and squamosal, and with the pleurapophysis, called "stylohyal," of the hæmal (hyoidian) arch. The hæmapophysis is ligamentous, save at its junction with the hæmal spine when it forms the ossicle called "lesser cornu of the hyoid bone," the spine itself being the basihyal or body of the hyoid bone. The whole of this inverted arch is much reduced in size, its functions being limited to those of the tongue and larynx, in regard |

man.

IN RELATION TO THE ARCHETYPE.

259

to taste, speech, and deglutition. The neurapophyses (orbitospenoids) becoming confluent with the centrum (presphenoid) of the frontal vertebra, and the latter coalescing with that of the parietal vertebra, the compound bone called "sphenoid” in anthropotomy results, which combines the centrums and neurapophyses of two cranial vertebræ, together with a diverging appendage (pterygoid) of the maxillary arch.

The knowledge of the essential nature of such a compound bone gives a clue to the phenomena of its development from so many separate points, which final causes could never have satisfactorily afforded. As the centrum, 5, becomes confluent with No. 1, a still more complex whole results, which has accordingly been described as a single bone, under the name of "os spheno-occipital" in some anthropotomies. Such a bone has not fewer than twelve distinct centres of ossification, corresponding with as many distinct bones in the cold-blooded animals that depart less from the vertebrate archetype. The spine of the frontal vertebra (frontal bone) is much expanded and bifid, like the parietal bone; but the two halves more frequently coalesce into a single bone, with which the parapophysis (postfrontal) is connate. The pleurapophysis of the hæmal arch (tympanic bone) is reduced to its function in relation to the organ of hearing, and becomes anchylosed to the petrosal, the squamosal, and the mastoid. The hamapophysis is modified to form the dentigerous lower jaw, but articulates, as in other mammals, with a diverging appendage (squamosal) of the antecedent hæmal arch, now interposed between it and its proper pleurapophysis; the two hamapophyses, moreover, become confluent at their distal ends, forming the symphysis mandibulæ.

The centrum of the first or nasal vertebra, like that of the last vertebra in birds, is shaped like a ploughshare, and is called "vomer:" the neurapophyses have been subject to similar compression, and are reduced to a pair of vertical plates, which coalesce together, and with parts of the olfactory capsules (upper and middle turbinals), forming the compound bone called "æthmoid;" of which the neurapophyses (prefrontals) form the "lamina perpendicularis" in human anatomy. The prefrontals assume this confluence and concealed position even in some fishes-xiphias, e.g.—and repeat the character in all mammalia and in most birds; but they become partially exposed in the ostrich and the batrachia. The spine of the nasal vertebra (nasal bones) is usually bifid, like those of the two succeeding segments; but it is much less expanded. The hamal, called "maxillary" arch, is formed by the pleurapophyses (palatines) and by the hæmapophyses (maxillaries), with which the halves of the bifid hæmal spine (premaxillaries) are partly connate, and become completely confluent. Each moiety, or premaxillary, is reduced to the size required for the lodgment of two vertical incisors: as the canines in man do not exceed the adjoining teeth in length, and the premolars are reduced to two in number, the alveolar extent of the maxillary is short, and the whole upper jaw is very slightly prominent.

Of the diverging appendages of the maxillary arch, the more constant one, called "pterygoid," articulates with the palatine, but coalesces with the sphenoid; the second pair, formed by the malar, 26, and squamosal, 27, has been subject to a greater degree of modification; it still performs the function assigned to it in lizards and birds, where it has its typical ray-like figure, of connecting the maxillary with the tympanic; but the second division of the appendage (squamosal) which began to expand in the lower mammalia, and to strengthen, without actually forming part, of the walls of the braincase, now attains its maximum of development, and forms an integral constituent of the cranial parietes, filling up a large cavity between the neural arches of the occipital and

260

GENERAL AND SPECIAL TERMS IN OSTEOLOGY.

parietal segments. It coalesces, moreover, with the tympanic, mastoid, and petrosal, and forms, with the subsequently anchylosed stylohyal, a compound bone called "temporal" in human anatomy. The key to the complex beginning of this "cranial " bone is again given by the discovery of the general pattern on which the skulls of the vertebrate animals have been constructed. In relation to that pattern, or to the archetype vertebrate skeleton, the human temporal bone includes two pleurapophyses, 38 and 28, a parapophysis, 8, part of a diverging appendage, 27, and a sense-capsule, 16.

The departure from the archetype, which we observe in the human skull, is most conspicuous in the neural spines of the three chief segments, which, archetypally, may be regarded as deformities by excess of growth to fulfil a particular use, dependent on the maximization of the brain; the deviation is again marked by arrest of growth or suppression of parts, as e. g. in certain parapophyses, and in the hæmal arch of the parietal segment; it is most frequently exemplified in the coalescence of parts primarily and archetypally distinct; and it is finally manifested by the dislocation of a part— viz., the hæmal arch of the occipital segment—the diverging rays of which have become the seat of that marvellous development which has resulted in the formation of the osseous basis of the human hand and arm. With the above explanation the structure of the human skull can be intelligibly comprehended, and not merely empirically understood, as through the absolute descriptions penned in reference to material and utilitarian requirements, and without reference to the great scale of vertebrate structures, of which man is the summit.

The fruit of a series of comparisons, extended over all the vertebrate kingdom, being the recognition of the archetype governing the structure of the vertebrate skeleton, the expression of such knowledge has necessitated the use of general terms, such as "vertebra," for the segments of the skeleton, "neurapophyses," for a constant element of such segment, and the like "general names" for other elements. When any of these elements are modified for special functions, then also a special name for it becomes a convenience, as when a "pleurapophysis" becomes a jaw or blade-bone, &c., a 66 diverging appendage" an arm or a leg. Deep thinking anatomists have heretofore caught glimpses of these higher, or more general, relations of the vertebral elements, when much modified or specialized, as e.g. in the head, and have tried to give expression to the inchoate notion, as when Spix called the "maxillary arch" the "arm of the head." These glimpses of a great truth were, however, ill received; and Cuvier alluded to them, with ill-disguised contempt, as being unintelligible and mystical jargon, in his great work on Fossil Animals (1825). But the error or obscurity lay rather in the mode of stating the relationship of certain bones of the head to those of the trunk, than in the relationship itself: in the endeavour, e. g., to express the relation by special instead of general terms. Even in 1845 the learned and liberal-minded editor of Baron Cuvier's last course of lectures, M. de Saint Agy, commenting upon the osteological essays of Spix and Oken, remarks: "For my part, an 'upper jaw' is an 'upper jaw,' and an 'arm' is an 'arm.' One must not seek to originate an osteology out of a system of metaphysics."* But a jaw is not the less a jaw because it is a "hæmapophysis," nor is an arm the less an arm because it is a “diverging appendage." In the same spirit a critic might write: “Newton calls this earth a 'planet,' and the moon a 'satellite;' for me the carth is an earth, and "Pour moi, une mâchoire superieure est une mâchoire superieure, et un bras est un bras. Il ne faut pas chercher à faire sortir l'osteologie d'un systeme de metaphysique."

FACIAL ANGLE-PROGRESSIVE EXPANSION OF CRANIUM.

261

the moon is a moon. One must not strive to make an ouranology out of a system of metaphysics." After the first recognition of a thing, one may seek to penetrate, and succeed in knowing, its essential nature, and yet keep within the bounds of nature.

Fig. 47.

In no class of vertebrate animals is the progressive superiority of the cranium over the face marked by such distinct stages as in the mammalia. Various methods of determining these proportions have been proposed; but the only satisfactory one is by comparing vertical sections of the skull, as in the series figured in the cuts 47-52.

CROCODILE.

In the cold-blooded ferocious crocodile (Fig. 47), the cavity for the brain, in a skull three feet long, will scarcely contain a man's thumb. Almost all the skull is

made up of the instruments for gra

tifying an insatiable propensity to slay and devour; it is the material symbol of the lowest animal passion.

In the bird (Fig. 48), the brain-case has expanded vertically and laterally, but is confined to the back part of the

Fig. 48.

ALBATROSS.

skull. In the small singing birds, with shorter beaks, the proportion of the cranial

cavity becomes much greater. In the dog (Fig. 49), the brain-case, with more capacity, begins to advance further forward. In the chimpanzee (Fig 50), the capacities or area of the cranium and face are about equal. In man the cranial area vastly surpasses that of the face.

A difference in this respect is noticeable

between the savage (Fig. 51) and civi

lized (Fig. 52) races of mankind; but it is immaterial as compared with the contrast in

this respect presented by the lowest form

of the human head (Fig. 51) and the highest of the brute species (Fig. 50). Such as it is, however, the more contracted cranium is commonly accompanied by more produced premaxillarics and thicker walls of the cranial cavity, as is exemplified in the negro or Papuan skull.

If a line be drawn from the occipital condyle along the floor of the nostrils, and be intersected by a second touching the most prominent parts of the forehead and upper jaw, the intercepted angle gives, in a general way, the proportions of the cranial cavity and the grade of intelligence; it is called the facial angle. In the dog this

Fig. 50.

CHIMPANZEE.

angle is 20°; in the great chimpanzee, or gorilla, it is 40°, but the prominent super

orbital ridge occasions some exaggeration; in the Australian it is 85°; in the European it is 95°. The ancient Greek artists adopted, in their beau ideal of the beautiful and intellectual, an angle of 100.

A retrospect of the varied forms and proportions of the skeletons of animals, whether modified for aquatic, aerial, or terrestrial life, will show that whilst they were perfectly and beautifully adapted to the sphere of life and exigences of the species, they adhered with remarkable constancy to that general pattern or archetype which was first manifested on this planet, as Geology teaches, in the class of fishes, and which has not been departed from even in the most extremely modified skeleton of the last and highest form which Creative Wisdom has been pleased to place upon this earth.

It is no mere transcendental dream, but true knowledge and legitimate fruit of inductive research, that clear insight into the essential nature of each element of the bony framework, which is acquired by tracing them step by step, as, e. g., from the unbranched pectoral ray of the lepidosiren to the equally small and slender but bifid pectoral ray of the amphiume, thence to the similar but trifid ray of the proteus, and through the progressively superadded structures and perfections of the limbs in higher reptiles and in mammals. If the special homology of each part of the diverging appendage and its supporting arch are recognisable from man to the fish, we cannot close the mind's eye to the evidences of that higher law of archetypal conformity on which the very power of tracing the lower and more special correspondences depend.

Buffon has well remarked, in the Introduction to his great work on Natural History, "It is only by comparing that we can judge, and our knowledge turns entirely on the relations that things bear to those which resemble them and to those which differ from them; so, if there were no animals, the nature of man would be far more incomprehensible than it is."

And if this be true, as to man's general nature and powers, it is equally so with regard to his anatomical structure.

In the same spirit our philosophic poet felt that

""Tis the sublime of man,

Our noontide majesty, to know ourselves

Part and proportions of a wondrous whole."-COLERIDGE.