ON THE FABRIC OF THE HUMAN BODY, BOOK I

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Regarding the joints of bones.

...derived from the types of joints, unless the joints are accurately explained, cannot be easily understood. That there are very many of them, and not at all easy to know, the fourth chapter will attest. Likewise, any differences that may depend on cartilage could not be readily grasped by anyone until the nature of cartilage has been explained.
Regarding cartilage.

For if cartilage is unknown, it is difficult to understand which bones are entirely devoid of cartilage, such as the bones of the crown of the head the parietal bones; which are almost entirely covered by it, like certain bones of the wrist original: "brachialis ossa", the carpal bones; or which are encrusted only in part, like the thigh bone the femur; and also which turn into cartilage, like the nasal bones, the ribs, and the breastbone the sternum. Having reserved these differences for their proper place, let us add here those that are gathered from the substance and constitution of the bones.
Regarding the substance and constitution of bones.

Contradicting Colombo, Chapter 1 on bones.

For there are some bones that are completely solid, and if broken in any way, do not appear to be occupied by internal small hollows or boundaries. Such are, among others, the two bones of the nose, and the smallest bone in the socket of the eyes likely the lacrimal bone, and the one numbered second among the bones of the upper jaw; and those compared to sesame seeds sesamoid bones; and the two tiny bones proper to the organ of hearing the ossicles of the ear, the malleus and incus. All of these, unless dried out excessively over time, show no internal cavity at all. Some, however, appear solid on the outside as if covered by a continuous crust or layer, but when broken, they are seen to be filled inside with certain small boundaries and hollows very much like the holes of a very compact sponge or a very light pumice stone, resembling the appearance of a dried fungus. Among the smaller bones, these include the bones of the wrist carpals and the bones of the ankle tarsals; and among the larger ones, the sacred bone the sacrum, the bodies of the vertebrae, the breastbone sternum, the heel bone calcaneus, the ankle bone talus, and then the bones of the crown of the head parietals. Some bones, however, in addition to these small hollows placed without order or number, show a certain large and remarkably hollow space a marrow cavity or sinus which, surrounded by the most solid and strong substance of the bone, is marked at its extreme corners by bone-like lines. Almost every single bone that possesses such a space has only one. Among the smaller bones of this class are those of the instep metatarsals, the back of the hand metacarpals, and the bones of the fingers; and most especially the first and second ranks of the fingers the proximal and middle phalanges, however much it seemed otherwise to Galen Galen of Pergamon, the ancient authority whose anatomy Vesalius often updated through dissection, the chief of the professors of anatomy, who established that the bones of the digits were solid.
In Book 1 of On the Use of the Parts, and Book 2 of the Commentary on Hippocrates' On Fractures.

The larger bones endowed with such a space are the thigh bone femur, the shin bone tibia, the arm bone humerus, the lower jaw, the fourth bone of the upper jaw, the forehead bone frontal bone, the bones of the temples, and frequently the wedge-shaped bone itself the sphenoid bone. The teeth, which are easily the hardest of all bones, also possess a space of this kind; but meanwhile they are entirely devoid of the aforementioned small hollows and the tiny holes formed in the manner of pumice. These larger spaces, and that construction not unlike pumice or fungus, were granted to the bones so that when they necessarily had to be thick or otherwise large for some important use, they might be rendered lighter for the sake of movement. They were also made this way to contain the marrow, which is their proper nourishment, or to encompass air or some specific matter (as in the forehead bone and the bones of the temples) instead of marrow. Nor is marrow stored only in those larger cavities of the bones, as someone might perhaps think;
In which part of the bones the marrow is stored.

but those small hollows constructed like a sponge are no less stuffed with marrow than those more notable spaces.
Regarding the holes in the bones.

In addition to the small hollows and spaces with which the bones abound inside, some are also pierced by wide holes foramina, such as the bone of the back of the head occipital bone and the vertebrae, where they transmit the spinal marrow the spinal cord. The bones of the pubes the pubis also have a hole larger than all others, so that they may be burdened with less weight. Others are pierced by small little holes, such as most of the bones of the head and the jaws, providing a path for veins, nerves, and arteries. And the bone which is numbered eighth among the bones of the head the ethmoid bone is seen to be pierced with fine little holes for the sake of smells, in the manner of a sieve or, as some have preferred, a sponge. Others show no hole on the outside or on the surface that can be distinguished by the senses, such as the bones of the wrist...

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