Book One -- The things that sustain and support the entire body, and what braces and attaches them all. [the bones and the ligaments that interconnect them] | Chapter 28 On the Ossicles Which Resemble a Sesame Seed

Appendix The 1555 version of Chapter XXVIII

In addition to the bones explained in the three preceding chapters, certain other small bones [ossa sesamoidea] (T, V, X, X in fig. 1, ch. 25) occur in the hand, compared by anatomists to sesame seeds. Of what sort they are, where they are situated, and what their number is in man or even in monkey, no one I know has either observed or described, and still less has the use of those bones been systematically set forth precisely and truly. It is therefore timely for me here to describe how many ossicles of this sort I have so far discovered in the careful examination of muscles and tendons. In the inspection of muscles rather than bones, I have found no unsatisfying number of these ossicles, as much in the foot as in the hand, since most and in fact nearly all are attached to tendons. Coated on only one surface with smooth, slippery cartilage, 14 they come into contact with the smooth, slippery surface of a bone. They are never attached to the bone by special ligaments.

The construction of the patella demonstrates the nature of sesamoids

In just this way we see the bone (fig. for ch 32; see also * in the 6th table of muscles and k in the 8th) in front of the knee joint, which we call the patella, attached to tendons 15 which extend the tibia. Indeed, in no other way will you more readily discover the makeup of the sesamoid bones than from the structure of the patella; for these ossicles are seen immersed in tendons and attached to them so that with their hardness they may sustain and absorb the impact in certain motions of the bone on which the tendon so augmented and protected is stretched. And while they check the impact of the bone, one would justifiably think that they also prevent the bone against which they are placed from becoming easily dislocated from its joint. The patella, as by far the largest sesamoid, nicely demonstrates their nature. They are larger and, in a manner of speaking, more numerous the older the person and the more you dissect the human body to study the bones. In children they are still cartilaginous and not very conspicuous in the // p. 153 // tendons where they are contained. They also present themselves in dogs and monkeys, and generally in other quadrupeds more than in man, a moister 16 animal and one possessed of less hard bones.

How many sesamoids occur in the hand

A man who has achieved his full growth has two ossicles [ossa sesamoidea] (T in fig. 1, ch. 25 and T in fig. 2, ch. 25) in the anterior side of the second joint of the thumb, placed in front of the head of the first bone [caput ossis metacarpalis I] of the thumb which enters the depression of the second bone [phalanx proximalis], attached to tendons of the muscles (1, 2, 3 in the 7th table of muscles) [m. adductor pollicis] that originate from the palm and flex the second joint of the thumb. These ossicles, scarcely larger than a fenugreek seed, are situated at the sides of the anterior part of the joint and permit the tendon [m. flexor pollicis longus, tendo] (q of muscle h in the 6th table of muscles) to ascend between them which will be thought to cause flexion of the thumb’s third joint. Just as these ossicles are seen at the second joint of the thumb, two others (V, V in fig.1, ch. 25) are seen at the first joints of the four fingers, smaller than the ones just mentioned, but like them contained in the short tendons of muscles [mm. interossei] that originate from the metacarpals and flex the first joints of the four fingers. On the anterior surface of the third joint of the thumb a single ossicle is discovered situated in front of the middle of the joint, its smooth surface matching the depression that is seen between the two capitula of the second bone of the thumb which go up into the depressions of the third bone for articulation. This ossicle is attached to the tendon [m. flexor pollicis longus, tendo] that flexes the third bone of the thumb and widens here for the joint. Another (X, X in fig. 1, ch. 25), much smaller than this and almost wholly cartilaginous, occurs in the second and third joint of the four fingers, matching the ossicle in the thumb joint in location and embedded in the tendon from which the joint to which the ossicle belongs obtains its flexion.

How many sesamoids are observed in the foot

All the sesamoids in the foot are identical with those of the hand, except that in the four toes they are much smaller and less easily seen to the degree that the fingers are larger than the toes. But as the big toe is formed of larger bones than the thumb, it has much larger ossicles [ossa sesamoidea] than the thumb. Two quite large sesamoids (y, w in fig. 2, ch. 33 and in the figure at the head of the present chapter) are placed beneath the first joint of the big toe next to the head of the metatarsal which is articulated to it. The inner [medial] of these is nearly half again as large as the outer nearer the second toe, more or less equal in size to half of a rather large pea cleaned of its skin, and even in its form it is not very unlike it. These two ossicles of the toe are attached to the sinewy part of the muscles [m. flexor hallucis brevis] (b in the 14th table of muscles) that flex the first bone of the toe, near their insertion. The ossicle (* in fig. 2, ch. 33) beneath the second joint of the toe is embedded in the tendon [m. flexor hallucis longus, tendo] (d, d of muscle L in the 14th table of muscles) that flexes the second bone of the toe, and is much smaller still than the outer of those that belong to the first joint of the toe.

Additional sesamoid ossicles

To the class of ossicles that we are treating in this chapter, someone will perhaps add the ossicle (N in figs. 1 and 2, ch. 25) that we see occasionally in the hand next to the connection of the metacarpal bone supporting the little finger at the eighth carpal bone [os hamatum], which nearly faces the tendon [m. extensor carpi ulnaris, tendo?] (d of muscle L in the 9th table of muscles) inserted here in the metacarpal, causing extension of the wrist. He will count two ossicles occurring in the back of the knee which are embedded in the heads (p, r, p, r, of muscles F, Y in the 12th table of muscles) of the first two muscles [m. gastrocnemius: caput mediale, caput laterale] that move the foot, early in their beginning from the femur. On their smooth and slippery surface where they project beyond the tissue of the muscles, these ossicles face the higher surface of the posterior region of the lower heads [condylus medialis, c. lateralis] (E, F in fig. 1, ch. 30) of the femur, whose movement they facilitate and support. Their special feature is that they are embedded at the beginning of muscles rather than in tendons, as are nearly all the other sesamoid ossicles. To these will perhaps be added the bony part occurring in the tendon of old people which by a unique stratagem of Nature bends back to the bone resembling a cube (X of muscle V in the 15th table of muscles) and belongs to the seventh of the muscles [m. fibularis longus, tendo] that move the foot. To these belongs the ossicle (near to k 17 in fig. 2, ch. 33) found more than once at the outer side of the articulation of the metatarsal bone supporting the little toe and the tarsus, at the insertion // p. 154 // of the tendon (b of muscle a in the 15th table of muscles) of the eighth of the muscles [m. fibularis brevis] moving the foot. But of all these, none is as large and hard as the inner of the two ossicles which are seen on the first joint of the toe. I therefore suspect that the magi and devotees of occult philosophy are thinking of this bone when they say there is a certain hard ossicle in man, subject to no corruption and resembling a chickpea; they aver that it lies in the earth after death like a seed, destined to bring a man forth on the final day of judgement. For this bone is situated in the lowest part of man and is especially hard. But even teeth lose their hardness, and this ossicle is no less subject to corruption than the teeth themselves. Moreover, the eighth carpal bone [os hamatum] (N in figs. 1, and 2, ch. 25) bears a better resemblance to a chickpea than this ossicle of the foot.

The Albadaran ossicle 18

But whether the Arabs and the truly occult and shadowy philosophers believe rightly that man will be made again from this ossicle that they call the Albdaran, I leave theologians to dispute who claim free disputation and opinion about resurrection and the immortality and destiny of the soul.

Book One -- The things that sustain and support the entire body, and what braces and attaches them all. [the bones and the ligaments that interconnect them] | Chapter 28 On the Ossicles Which Resemble a Sesame Seed