changes, and multiplied combinations of movement, according to the probable direction of the expected impulse, in boxing, wrestling, and other similar feats of activity, in pushing, pulling, &c. &c. In all the particulars just described, we see a strong contrast between man, and the nearest or most anthropomorphous animals, even the monkey and orang-utang. In the latter, the cervix femoris is short, the thigh-bone straight, and its two condyles of equal length *. The foot rests on its outer edge, the heel not touching the ground; the tarsus is contracted, and the digital phalanges lengthened, so that in these respects it resembles a hand +. The peculiarities of the human pelvis coincide with those of the lower limbs. The form of this part is very characteristic in man, and distinguishes him from the simiæ, and indeed from all other mammalia. It might be asserted, that the human skeleton alone has a proper pelvis: that is, such an incurvation of the sacrum and coccyx, and such an union of them with the ossa innominata, as forms a basin-like cavity; from which, the space included between the elongated ilia, and the straight sacrum and coccyx of monkeys, differs toto cælo. In the orang-utang, and the elephant, we find the nearest approach to the human formation. In the former ‡, however, the upper part of the ilium is narrow and elongated, stretching upwards in the direction of the spine, and its length exceeds its breadth; so that the relations of these two dimensions are very different * TYSON, fig. 5. ↑ Euvres de CAMPER, pl. II. fig. 5 & 6. · TYsón fig, eit. in man and this animal. In the latter, the symphysis pubis is very deep; and in both, there is neither that incurvation of the sacrum, from the promontory downwards, nor that direction of the coccyx forwards, which, with the broad horizontal expansion of the ilia, and the shallowness of the symphysis pubis, are peculiar to the human frame, and make it a broad and firm basis for the trunk, on which the weight of the abdominal contents, and particularly of the pregnant uterus, is supported. The lower part of the sacrum and the os coccygis are turned forwards in man, and form the only firm bony resistance, in the inferior aperture of the pelvis, to the abdominal viscera, forced downwards by the diaphragm and abdominal muscles. These bones are straight in all other animals, because the weight of the viscera is differently supported. Even in the orang-utang, the sacrum is flat and contracted, and continued, together with the os coccygis, in a straight line with the vertebral column. If the human sacrum and coccyx had been continued in a straight line with the spine, as those of the orang-utang and monkeys are, the ossa innominata remaining as at present, they would have projected beyond those bones, so as to disable us from sitting. The curve which they describe, in man only, obviates this inconvenience; and allows the pelvis to rest securely in the sitting attitude on the broad and strong ischiatic tuberosities. The influence of this structure on the direction and functions of the vagina will be considered afterwards, The height of the whole pelvis, from the tuber ischii to the crista of the ilium is : 7 in. 3 li. in man. The distribution, size, and offices of the muscular masses correspond to the organic arrangements of the skeleton. The lateral and posterior surfaces of the pelvis give origin to the powerful glutei, of which the exterior (glutei magni), exceeding in size all other muscles in the body, and covered by a remarkable stratum of fat, form the buttocks, which, by their ample, fleshy, and convex protuberances, conceal the anus; and are accounted both by the classical authors in natural history, as ARISTOTLE and BUFFON, and by the greatest physiologists, as GALEN and HALleb, as the chief character by which man is distinguished from the buttockless simiæ. "Les fesses," says the great historian of nature, "n'appartiennent qu'à l'espèce humaine." The final cause of this prerogative has been assigned by an anatomist. "Solus homo ex omnibus animalibus commode sedet, cui carnosæ et magnæ nates contigere, et pro substernaculo pulvinarique, tomento repleto, inserviunt, ut citra molestiam sedendo, cogitationibus rerum divinarum animum rectius applicare possit." The use of the glutei, however, is not confined solely to what the pious SPIGELIUS has imagined; viz. the forming a cushion on which the body may be softly supported, for the purposes of divine cogitation; but they are very important agents in extending the pelvis on the thighs, and maintaining it in that state in the erect position of the trunk. In standing on both feet, the glutei magni fix the pelvis firmly behind, and counteract the natural tendency to fall forwards, which the weight of the head, the usual position of the upper limbs in front of the body, and the prominence of the abdominal viscera, impress upon the trunk. Hence, the bulk and power of these very muscles * SPIGELIUS de hum. Corp. Fab. p. 9. in the human subject afford a clear proof that man was designed for the attitude on two feet. The other two glutei are not essentially concerned in the attitude of standing on both feet; but they are the principal agents in supporting and balancing the trunk on one foot, by inclining the pelvis over the head of that thigh-bone, on which the body rests, so that the centre of gravity of the trunk may be in a line drawn through that lower extremity. In this case, their exertion counteracts the tendency of the trunk to fall on that side which is not supported. These muscles are employed in a similar manner in progression: the gluteus magnus balances the pelvis, while one leg is carried before the other, and brought to the ground; and the two others support the trunk laterally, while the limb of the opposite side is in the air. The gluteus magnus, which is the largest muscle of the human body, is so small and insignificant in animals, that it may be almost said not to exist. F. CUVIER observes of the orang-utang, "les fesses étoient presque nulles, ainsi que les mollets *." TYSON indeed asserts, of the chimpansé, that"our pygmie had buttocks or nates, as we shall see in the myology, but not so much as in man+." However, in his apparently accurate figure there is no trace of them. The extensors of the knee are much stronger in the human subject than in other mammalia; as their twofold operation of extending the leg on the thigh, and of bringing the thigh forwards on the leg, forms a very essential part in the human mode of progression. The flexors of the knee are, on the contrary, stronger in animals; and are Annales du Muséum, v. 16, p. 47. The correctness of this remark is fully verified by the orang-utang belonging to Mr. ABEL. It has neither buttocks nor calves. + F. 2, Anatomy of a Pygmie, p. 14. inserted so much lower down in the tibia, even in the monkeys, than in the human subject, that the cord which they form, keeps the knee habitually bent, and almost prevents the perfect extension of the leg on the thigh. Where the thigh and leg thus form an angle, instead of being continued in a straight line, the support of the body on the hind legs must be very insecure. The extensor muscles of the ankle joint, and chiefly those which form the calf of the leg, are the principal agents in progression. Hence man is particularly characterised by the largeness of his calves; and no animal equals him in this respect. By elevating the os calcis, they raise the whole body in the act of progression; and, by extending the leg on the foot, they counteract that tendency, which the weight of the body has to bend the leg in standing. The muscles of the calves lift the heels, and thereby elevate the whole body, which is supported on the astragalus: the weight is thus maintained on the anterior part of the feet, and the individual is said to stand on tiptoes. If the foot of one side be lifted from the ground, and the opposite heel be raised by the calf of its own side, the whole body is then elevated by the muscles of one calf. When a person stands on tiptoe with a burden on the shoulders, or any other part of the trunk, the weight of this, as well as of the body, must be raised and supported by the muscles of the calf. In running, leaping, jumping in the air, dancing, &c. the projection of the body is accomplished by the same power. ARISTOTLE, and others after him, have justly observed that calves of the legs can be ascribed to man only. The whole arrangement of the thorax corresponds to the erect attitude of man. It is flattened anteriorly, possesses a very broad sternum, is wide transversely, but shallow from before backwards. Its lateral width and inconsiderable depth from sternum to spine, not only throw the arms far |