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 18 On the Sacral Bone and the Coccyx

The 1555 Version of Chapter XVIII

The ten bones to be described in this chapter

Beneath the lumbar vertebrae (E, F in the fig. for ch. 14) are situated ten bones [os sacrum, os coccygis] (G-K in the same fig., M, N in the skeletons, and all of figs. 1, 2 in this chapter), of which the remaining part of the backbone, extending from the loins to the anus, is made up. The upper six of these [vertebrae sacrales] (nos. 25-30 in the fig. for ch. 14, A-F in fig. 1 of this chapter) are so attached to each other that when they are unearthed from graves they are usually all together, almost like a single bone. 49

The sacrum or wide bone

We see this called platu/ by the Greeks and latum or amplum by the Latins because its width, especially in man, in whom it is proportionally wider than in other animals (as is the backbone as a whole) easily surpasses the breadth of the other vertebrae on its upper side, being placed beneath them like a foundation and an extremely sound fulcrum. 50 I do not believe the ancients compared this in breadth with all the bones of the body, since the iliac bones (the widest portions of the figures in ch. 29; o in the skeletons) are far wider. Why they called this the i(ero/n or sacrum is unclear to me, unless it happened as a result of its uncommon look and shape, or because it so resembles a strange bulwark, in various ways fending off anything that faces it even in a cursory way as it rests upon its base; or because it was believed (wrongly) by many that during childbirth its connections [ligg. sacro-iliaca] with the iliac bones are relaxed, open up, and then come together miraculously, without the aid of muscles; 51 or perhaps because it appears large and great, in the same way as in the poets, I believe, Troy, the sea, hunger, and other things are called “sacred.” 52 But even so (once its breadth has been mentioned) the sacral bone should be compared only to the vertebrae, since the bones attached to it on each side, the femora (L in the skeletons), and the inner bones of the tibiae (F in the skeletons) are greater than it is, though composed of a single bone while the sacrum is a combination of six. Others, carefully investigating the reason for this name, contrive something or another about the sacrifices of the ancients. Many apply other names to this bone, which will be added to the end of this book along with all the nomenclature of other bones to avoid confusing the text unnecessarily here and elsewhere with inept and barbaric words.

The coccyx

The four ossicles [vertebrae coccygeae] 53 (31-34 in the fig. for ch. 14, G-K in figs. 1, 3 of this chapter) which come after the sacrum are named after the shape of a cuckoo bird’s beak and (as it were) its color, 54 just as if they were a single bone, chiefly called ko/kkuc by the Greeks and the Latins as well, as it will now be known more intelligibly in our entire account of these ten bones.

Description of the sacrum; the connection of its bones

The six upper bones, forming the sacrum, are so mutually constructed that they show the same connection (A-F in the middle of fig. 1) in the middle of their anterior surface [facies pelvica] as the vertebral bodies would have put forth had they so far fused that nothing more of the cartilaginous ligament [discus intervertebralis] (R in the fig. for ch. 14) were seen between them. In children, however, where these bones have not yet fully or as strongly grown together as in persons of advanced years, some cartilage occurs in this union just as it does in their epiphyseal unions. In the sides of the anterior surface, where the so-called transverse processes [pars lateralis] of these six bones (they are no less wide than the bodies of the bones) are fused to each other, the type of connection 55 is still more obscure than in the middle. But in the posterior side (fig. 2) the union is altogether missing, and it looks like a single bone formed from the six. No line of union presents itself here, except sometimes in the meeting of the first bone with the second, for the first bone is occasionally joined with the second [articulatio zygapophysialis] (Y in fig. 2) by the kind of joint by which the ascending and descending processes [proc. articularis superior et inferior] of the lumbar vertebrae (the lowest O and N in the fig. for ch. 14) are articulated. But although those processes of the sacrum are joined in that way, the transverse processes of the first bone fuse everywhere (Z in fig. 2) with those of the second bone; all these connections are so strong that the first bone cannot be moved even the least bit on the second. I do not once recall finding a sacrum in the cemeteries where the first bone had been broken off and which was discovered apart almost as if it were a lumbar vertebra (figs. in ch. 17). Were that first bone not equipped with thick, wide processes, its form could scarcely be distinguished from that of lumbar vertebrae. In children, the meeting of these six bones is visible even on the posterior side, just as we have said it is clearly manifest on the anterior of their sacrum as well. As in no persons is the type and place of fusion 56 altogether and completely erased in the middle of the anterior side, so also in the posterior side of the sacrum an image forever presents itself of the fusion which happened to the bodies of the bones.

The foramen made for the dorsal medulla

For if you pay attention to the foramen [canalis sacralis] (e-k in fig. 2) incised for the dorsal medulla [m. spinalis] in all the bones of the sacrum, you will perceive through the course of the foramen as clearly as on the anterior side that the bodies of the bones are joined there. The entire series of bones (figs. 1, 2) running downward from a broad base [basis ossis sacri] to a point [apex ossis sacri] is of such a kind that each bone becomes smaller the lower its position in the sacrum and in the series itself. This notwithstanding, the second bone [vertebra sacralis II] (B in fig. 1) is constructed with wider, thicker, and more forward and backwardly prominent transverse processes [partes laterales] (L, L in figs. 1, 2) than the other bones of the sacrum.

The upper surface of the sacrum

The upper part [basis ossis sacri] (top of figs. 1, 2) of the first or highest bone corresponds in shape to the upper surface [corpus vertebrae, facies intervertebralis] of any lumbar vertebra (upper surface in figs. 1 & 2, ch. 17). In its middle it protrudes with a round body [promontorium] (above A, fig. 1) having an epiphysis, in amplitude matching the lower side of the body of the fifth lumbar vertebra. It is attached to that vertebra (F is joined to G in the fig. for ch. 14) in the same way that we see the bodies of the lumbar vertebrae are attached to each other by a thick cartilaginous ligament [discus intervertebralis]. // p. 101 // The posterior side of the first bone puts forth two ascending processes [pp. articulares superiores] (S, T, V, X in figs. 1, 2) carved out in the same way as the ascending processes of the vertebrae in the loins [pp. articulares superiores] (K in figs. 2, 3, ch. 17). These processes of the sacrum admit the descending processes [pp. articulares inferiores] of the five lumbar vertebrae in quite the same way as the lumbar vertebrae are joined to each other by the same such processes.

The lower surface

The lower part of the sixth bone [apex ossis sacri] (a in figs. 1, 2), rather slender as the bone itself is slight, has no descending processes with which to articulate with the bone beneath it. Instead, it ends only in a round but slightly widened tubercle or body which is connected to the first ossicle of the coccyx [vertebra coccygea I] (G in figs. 1, 3) by no other means than the vertebral bodies are bound to each other, by a wide and cartilaginous ligament [discus intervertebralis].

The sides

A depression [pars lateralis, facies auricularis et tuberositas sacralis] (N, O, O, P, Q, F in fig. 2) is carved in the transverse processes of the sacral bones in their outer side somewhat toward the posterior, to which the iliac bone (what is above S, N, C in fig. 3, ch. 29) is very strongly fitted on either side. This depression is quite rough and irregular. First, it has a line [crista sacralis lateralis] (O, O in fig. 2), or a tubercle that stands out like a rather wide line, projecting through its length in the middle. This divides the depression in turn into an anterior depression [facies auricularis] (N, N in fig. 2) and a posterior depression (P, F, Q in fig. 2). The anterior is quite simple but rough, and is quite irregularly incised. The posterior is more deeply hollowed, but in the middle it shows a process [tuberositas sacralis] (F in fig. 2) projecting transversely, which divides this posterior depression into an upper (P in fig. 2) and a lower (Q in fig. 2) depression. The iliac bones fit these depressions and projections, having corresponding projections and depressions [facies sacropelvica] (A-G in fig. 3, ch. 29). But these high and low places are not covered with smooth, slippery cartilage like other sockets and heads made for articulation: they put forth nothing but cartilaginous ligaments which bind the sacrum in the most robust way to the iliac bones without a slippery, smooth juncture almost as the epiphyses are attached to their bones. 57 These depressions, carved in the transverse processes of the sacrum and made rough by blind foramina so as to put forth ligaments, 58 are most particularly typical of the three upper bones of the sacrum. The lower bones have thin but wide processes that run together, from which a muscle originates (F in the 11th table of muscles) [m. piriformis] which we shall establish as the fourth of the muscles that move the femur. But at the point where it is joined to the transverse process of the sixth, the transverse process of the fifth bone puts forth a quite thick, prominent tubercle (R in figs. 1, 2) so that two ligaments (g and d in the 10th table of muscles) 59 may be implanted here in the sacrum. One of these, it will be explained, originates from the sharp process of the hipbone [spina ischiadica] (d in fig. 2, ch. 29), the other from the upper posterior surface (l in the same figure) [tuber ischiadicum] of the epiphysis which you will learn belongs to the hipbone [os ischii].

The posterior side

The spines or posterior processes [crista sacralis mediana] (d, d, d in fig. 2) also occur in the bones of the sacrum, the higher on each bone as the bone itself from which it grows is larger and higher. But the sixth bone and generally the fifth, at the place (i, k in fig. 2) where the others put forth the spine and to which the end [filum terminale] of the dorsal medulla extends, develop a gap [canalis sacralis], are open in various ways — not the same way for all — and lack spines. Whatever the case, no spine of the sacrum, if I understand anything correctly, angles in the least degree upward: rather, all face downward, just as in the other vertebrae when they establish an interval for the transverse processes and a place into which several muscles that move the back (G in the 13th table of muscles, T in the 14th) [m. erector spinae] are fitly situated and from which they most properly originate along with other muscles (T of muscle Q in the 10th table of muscles, K of muscle D in the 12th) 60 taking their origin from here. That is why this posterior surface of the sacrum is remarkably rough and as if decayed, clearly so that the beginnings of muscles may be more conveniently brought from them along with ligaments. The whole area is convex and curved so as more safely to serve as a bulwark for the parts which the sacrum contains.

The anterior

On the anterior side it is smooth and wider but not rough; it is depressed and concave so as to form a more fitting surface for those organs which together with the other bones attached to it (Q [os ilii] joined to M [sacrum] in the skeletons) // p. 102 // it surrounds like a kind of basin [Lat. pelvis]. The lowest region of the back, being almost semicircular, does not make a straight line with the coccyx beneath it. 61 Sometimes, not infrequently, the sacrum is made of only five bones, showing in almost all its construction nothing peculiar except in the series of foramina that transmit its nerves, as I shall state presently.

Foramina provided for the transmittal of nerves

From the portion of the dorsal medulla situated in the sacrum 62 (F, G, 24, 30 in fig. 1, ch. 11, bk. 4) six pairs of nerves [cauda equina] generally sprout; the first of them (25 in fig. 2, ch. 11, bk. 4) 63 comes out between the fifth lumbar vertebra and the first bone of the sacrum in the same way as the nerves come out from the sides of vertebrae in the thorax and the loins. From the back of the body of the first bone and before the anterior surface of this bone’s ascending process [p. articularis superior], a cavity [foramen intervertebrale] (1 in figs. 1, 2) is hollowed out on each side which makes a common foramen with the cavity of the fifth lumbar vertebra, by which a nerve 64 escapes on each side; a vein and an artery 65 also enter here to the dorsal medulla. Foramina are not provided for the remaining pairs of nerves in the sides of the sacrum occupied by the attachment of the iliac bones above, and below where they are transversely so thin that they could not be pierced by too long a lateral course. Therefore when the sacrum is made of six bones (as in all our figures) ten round foramina will be seen in its anterior and posterior surfaces, five on each side (2-6 in figs. 1, 2) [foramina sacralia anteriora et posteriora]; these are carved out between the bones where they come together, and become narrower the lower their position on the sacrum. The nerves (in figs. 2-3, ch. 11, bk. 4) [nervi sacrales] for which they provide a path are therefore not of an equal size above and below. For the same reason, the foramina carved in the posterior side are smaller than those which are seen in the anterior, for on the latter side the nerves are thicker than those which exit on the former and because more and larger veins and arteries enter the sacrum through the anterior foramina than through the posterior. The foramina being as they are, the second pair of nerves [nervus sacralis I] of the sacrum puts forth two branches forward and the same number to the rear [nervi sacrales, rami anteriores et rami posteriores] through the four foramina provided for them between the first bone and the second. The other pairs come forth in such a way that the exiting pair is numbered according to the bone beneath it, as in the vertebrae. Besides these foramina cut for the nerves, others (f, g, h in fig. 2) occur at intervals between the spines of the bones in the posterior side of the sacrum, reaching into the path [hiatus sacralis] where the dorsal medulla is carried and filled with ligaments, just like the intervals and foramina seen between the spines of the other vertebrae.

What happens when the sacrum is made of only five bones

Whenever the sacrum is made of only five bones, 66 two foramina are missing in its anterior side and a path is carved for the sixth pair only in the posterior surface (but more towards the sides); there is also a different type of joint between the lower part of the sacrum and the coccyx. The topmost ossicle of the coccyx has a depression carved in its top surface and it not only receives the body of the fifth sacral bone, but it puts forth two small processes [cornu coccygeum] besides which are brought upward and fuse with small processes [cornu sacrale] of the fifth sacral bone which face downward.

Description of the coccyx

A quite small portion of cartilaginous ligament [discus intervertebralis] has a role in what remains of this attachment, more or less corresponding to the common structure of the sacral bones. But when there are six of them [vertebrae sacrales], the highest ossicle [vertebra coccygea I] (G in figs. 1, 3) of the coccyx raises no little processes [cornu coccygeum] in its posterior side and is only loosely joined to the body of the sixth sacral bone (a in figs. 1, 2) [apex ossis sacri] by means of a cartilaginous ligament [discus intervertebralis] (b in figs. 1, 2). This ossicle is transversely and upwardly convex at both sides 67 of its depression and gradually narrows from here downward. It is supported (b in fig. 3) [discus intervertebralis] by the second ossicle of the coccyx [vertebra coccygea II] (H in figs. 1, 3)in the same way as it is by the sixth sacral bone. The third and fourth ossicles follow the second, joined together in exactly the same way, and narrower and shorter as each occupies the lower position in the series. The fourth ossicle (K in figs. 1, 3) ends with a cartilage (c in fig. 3) where its point touches the final and lowest part [m. sphincter ani externus] (M in fig. 1, ch. 49, bk. 2) of the straight intestine, // p. 103 // for the same purpose that we have said cartilages grow on the spines of the vertebrae and the extremities of other bones. No foramen is cut into these four ossicles for the dorsal medulla to enter or for any nerves to make their exit. The substance of these ossicles resembles that of epiphyses: spongy, porous, and rather cartilaginous in children. Their common structure ends in a point from a broad base and is markedly bent inward in a slanting curve. Because of its loose attachment, it is movable in childbirth and sometimes when the anus is opened widely. Since this structure of the four bones gradually narrows to a point from a kind of base, is curved, and is reddish 68 before it dries, somewhat like the pectoral bone, it is likely that the ancients, who taught boys the art of dissecting bodies, compared its appearance to a cuckoo’s beak, and for this reason called it chiefly ko/kkuc as we stated earlier, and o)rropu/gion 69 because the structure to a great extent resembles the movable ossicles in the tail of birds, but unlike the beginning of the tail of quadrupeds.

How Galen described the sacrum and coccyx

You will readily judge how our account of the sacrum and coccyx agrees with Galen’s descriptions if you compare them first with each other (since they are not consistent) and then with ours. In the books On the Use of the Parts the sacrum is mentioned more than once; 70 it is explained there that it is constructed of four bones, without the least word added about the coccyx. Besides the fact that Galen paid no attention to the coccyx in those books, there can be little doubt that it was unknown to him while he was writing those books and giving a quite inaccurate count of the nerves. For when he states that the bones of the sacrum are four, he adds that a cartilage 71 is attached to their end [apex ossis sacri] like the one that we stated is on the point of the coccyx, and into which the ends of bones not attached to another bone almost always revert. Moreover, in the twelfth book On the Use of the Parts he states that the transverse processes [pars lateralis] of the sacrum are thin and delicate, while in his book On the Bones he explains that they are thick and wide (as indeed they are). 72 In this book he says that the sacrum is formed from only three bones, 73 writing that three other are situated beneath them, to which he gave the name coccyx. Also in his books On Anatomical Procedures he now and again mentions the sacrum and coccyx, as he does sometimes in his Commentary on Hippocrates’ Book ‘On the Joints,’ but he does so (as far as I can understand his opinion) according to exactly the same system that he describes more fully than elsewhere in On the Bones. 74 So that you may the better judge whether the construction of bones described there is simian rather than human, I shall now be glad to explain how the bones situated beneath the lumbar vertebrae occur in monkeys and dogs. This must be done the more attentively, as the impudence of those who maintain that Galen described humans rather than simians is altogether damnable. Such persons daily pervert his books in the most disgraceful way and attribute all sorts of things to copyists and scribes, more and more bringing it about that finally the writings of Galen can be applied to some Chimaera, but not to monkeys or the animals that Galen most dissected, nor to humans. 75

The bone formed from three bones in the ape and the dog, which we call the sacrum

In the ape and the dog, a certain bone (nos. 1-3 in fig. 4; fig. 5 shows the posterior side) is located beneath the lowest lumbar vertebra; it is composed of three bones 76 so joined together that in their anterior side near the middle they display the kind of connection that the bodies of the vertebrae would show if they ever fused in such a way they could not be moved in the slightest way, and all the cartilage between them had disappeared with the passage of time — though in puppies the union of those three bones is still filled with some cartilage, 77 as in the attachment of epiphyses. In the sides of the anterior surface just mentioned, these bones in advanced age show hardly any appearance of fusion; likewise, their posterior surface (except perhaps in quite young puppies) // p. 104 // looks altogether continuous. The first bone has a round body on its upper side no different from that of any lumbar vertebra, 78 joined to the lowest lumbar vertebra in the same way as the lumbar vertebrae are joined to each other. This first bone puts forth ascending processes [p. articularis superior] by which the descending processes of the lowest lumbar vertebra are received [articulatio zygapophysialis]. The lower side of the third bone corresponds to the lower side of any lumbar vertebra in that like them it has a round body and descending processes by which it is articulated to the ossicle beneath it (4 in fig. 4) [os coccygis I] no differently than the lumbar vertebrae are put together. The sides of these three bones, which have quite broad and wide transverse processes continuous with each other, also have a depression [pars lateralis, facies auricularis] carved toward their posterior side, which is rough and uneven and serves for the connection of the iliac bone to these bones on each side. This depression is proportionally shorter than the one in the human sacrum, to the degree that the iliac bone in man is much broader than in quadrupeds. 79 The transverse processes in the second of these bones do not exceed those of the first in size, and the second bone is in every way lesser than the first, as the third is also lesser than the second. In these three bones is carved a continuous foramen [canalis sacralis] through which the dorsal medulla runs, and from their posterior surface they each put forth a spine or posterior process facing upward rather than downward, though not conspicuously so, and as much smaller as is the bone from which it rises in the series. In the intervals between the spines there are no foramina, not do the bones separate at all there; rather, the spines protrude like a single line, more or less continuously with each other. Four foramina provided for the exit of nerves show themselves on the anterior [foramina sacralia anteriora] and posterior [for. sac. posteriora] sides, two on each side, by which a route is supplied to the front and the rear for the branches of the second and third nerve pairs 80 belonging to these bones. The foramen is prepared for the first pair 81 in the same way as in the lumbar vertebrae, at the back of the body of the first bone [vertebra sacralis I] and the lowest lumbar vertebra [vert. lumbalis V].

The ossicles beneath the sacrum in the ape and the dog, and their coccyx

In these animals, the dorsal medulla does not end at the end of the third bone, but proceeds downward through other ossicles [os coccygis] (4-6 in fig. 4; they are also seen in fig. 5) besides, which like the lumbar vertebrae offer a path [foramen intervertebrale] for the nerves to the posterior part of their bodies but not the anterior [ff. sacralia anteriora] where the second and third pairs 82 belonging to the bones of the sacrum put forth their principal branches. The nerves [n. sacralis III ?] coming out beneath the third bone, constituting the first pair of the nerves of the dorsal medulla contained in the ossicles beneath the third bone, have foramina between the third bone [n. sacralis III] and the first ossicle (between 3 and 5 in fig. 4) just as do the nerves exiting from the lumbar vertebrae, from the back of the vertebral bodies. Thus, beneath the third bone of the sacrum three other ossicles follow [vertebrae coccygeae I-III] (4-6 in fig. 4), and sometimes more in caudate apes and some dogs, 83 extremely similar in shape to lumbar vertebrae. In no appearance do they differ, except they have wider transverse processes [pares laterales] than lumbar vertebrae and they slope more downward than upward; they also put forth no spine or a very small one. In the shape of their body they closely resemble those vertebrae, though someone looking at the smallest might add that they are wider in proportion to their size. In the ascending and descending processes, however, they are not at all different. The highest of them 84 is connected to the lowest part of the sacrum, and they are with each other, by the same articulation or attachment as the lumbar vertebrae. Thus in the connection of their bodies as well there occurs a noteworthy portion of cartilage or rather of cartilaginous ligament [discus intervertebralis] No differently than in the lumbar vertebrae, a path [canalis vertebralis] is provided in these ossicles for the dorsal medulla, and like the lumbar vertebrae they accommodate a way for three pairs of nerves 85 behind the back of their bodies (as we previously stated), and before their ascending // p. 105 // and descending processes. The lowest ossicle [vert. coccygea III] (6 in fig. 4), from which the dorsal medulla exits more or less unconnected and simple, ends randomly in cartilage like the ends of other bones in the non-caudate apes. But in dogs and caudate apes where these ossicles [vertebrae] are quite loose and mobile, a great many other ossicles are added to the lowest in a continuous series.

The sacrum and the coccyx are described in Galen as they are in the ape

These are not perforated for the dorsal medulla, but are long and solid; above and below, where they are interconnected like the vertebral bodies by cartilagimous ligament [discus intervertebralis], they are a little thicker; but in the middle they are thin. These, in a word, make up the tail. Since, therefore, in the ape and the dog a single bone [os sacrum] occurs immediately below the lumbar vertebrae combined from three bones (1-3 in fig. 4) as if from vertebrae in such a way that their connection differs from that of vertebrae chiefly because there is no cartilaginous ligament 86 as there is between the vertebral bodies (R, R in the fig. for ch. 14); and since this bone puts forth spines [crista sacralis mediana] that angle upward more than downward, and has foramina [ff. sacralia anteriora et posteriora] carved out before and behind for the second and third pairs of its own nerves [nervi sacrales I, II] (to grant Galen something here), 87 I judge the bone was described by him in place of the sacrum in his book On the Bones. Likewise, because in apes and dogs at least three bones (4-6 in fig. 4; cf. 1-3 in the same fig.) succeed after it, which also transmit the dorsal medulla and unlike the three bones of the sacrum in those animals have a cartilaginous ligament in their connection; and since even without long or extensive boiling or other great effort they can readily be torn apart no differently than lumbar vertebrae, and since these bones put forth nerves only from the back [facies dorsalis] of their bodies and not also toward the front, I am convinced that Galen had given them the name of the coccyx. I believe also that he had established special differences between his sacrum and the coccyx: in the connection between them, the emission of nerves, and the foramina. Indeed, because he attributed more cartilage to the bones of the coccyx than to the sacrum, I take it he meant that cartilage [discus intervertebralis] (R, R in the figure for ch. 14 and 3 of the figure inserted in ch. 40, bk. 2) which the ancients affirmed is the principal bond of the vertebral bodies, unlike Galen 88 — though I regularly call it cartilaginous ligament (as in fact it is). I do not at all agree with many self-described experts, corrupters of the works of Galen, who say that he was speaking here of the cartilage that attaches to the sides of the bones, since more of the cartilage, and indeed cartilaginous ligament, 89 exists in the depressions [pars lateralis, facies auricularis et tuberositas sacralis] (N, N, O, O, P Q in fig. 2) that receive the iliac bones, particularly in their posterior area, where the iliac bones separate a little from the sacrum, than in the bones which lie close beneath the connection of the iliac bones with the sacrum [art. sacro-iliaca], whether in ape (4-6 in fig. 4) or in man (D, E, F in fig. 1). Those corrupters, lest Galen seem to have passed over or ignored the six foramina [ff. sacralia anteriora] (the foramina of one side are marked 4, 5, 6 in fig. 1) add in his chapter on the coccyx that the nerves [n. coccygeus, plexus coccygeus] of that bone are also brought out anteriorly as well, 90 boldly arguing that this had been omitted by the copyists. This is more to be condemned because, as before in the connection and meeting of the bones, now in the course and exit of the nerves they set aside every difference by which Galen learnedly and in true anatomical fashion distinguished the bones of his coccyx from those of the sacrum in the structure of apes and dogs, to which Galen’s descriptions will not afterward be able to be reconciled. Moreover, I am unable to conjecture how descriptions so augmented, or rather distorted and corrupted, are applied to the ten bones [os sacrum et os coccygis] of man lying beneath the lumbar vertebrae. To make no mention of the mutual attachment of the first six bones which I shall describe in the section on the sacrum, as well as the structure in a single series from a more or less wide base [basis ossis sacri] to a point [apex ossis sacri], the equal distribution of nerves forward and backward, and the fact that the spines [crista sacralis mediana] do not incline upward, I do not know why Galen neglected the four bones [vertebrae coccygeae I-IV] (G-K in figs. 1, 3) about which I have written in the section on the coccyx and which provide no path for the dorsal medulla, when the upper two of these are so conspicuous and have a position in that // p. 106 // structure, and with the others perform such a useful function that they ought not be lightly passed over by anyone dissecting the human body. But the perverters of Galen’s books say that our coccyx was passed over purposefully by him because its bones are not unearthed from graves with the sacrum, or because Galen was unwilling to present them — like the hyoid bone, the bone of the heart, 91 and the sesamoid ossicles — to beginners in his book On the Bones; or because he considered all four bones equivalent to a single cartilage. Finally, they consider it of the greatest importance that Galen should not be inconsistent in his books On the Use of the Parts with his other writings; so that the three bones of his sacrum should be counted as three, and the three bones of his coccyx as only a single bone, and so that our coccyx should be the cartilage that the said in this work attaches to the extremity of the fourth bone of the sacrum. 92 When these things are recalled and I find them cited in opposition to my views, I seem to hear those who quite absurdly and with great pomposity try to show that Galen, Avicenna, and who knows what physicians and philosophers or conflicting works of the same author do not disagree with each other. They read things into the writings which their authors did not think even in a dream, and which are altogether foreign to their views. If Galen omitted our coccyx in the eleventh and twelfth chapter of his book On the Bones because its discussion was not relevant for those who were being introduced to the subject, he indubitably mentioned our coccyx at the end of his book On the Bones as he did the other ossicles which he described more fully elsewhere — though no mention of this coccyx of ours occurs in any book of Galen. 93 The fact that it occurs separated from the sacrum in graves and sepulchers, and its ossicles are seen scattered like vertebrae, is ground for argument that Galen adapted descriptions of the ancients for his apes, supposedly because as their ligaments shrivel the simian bones succeeding the sacrum separate from each other, unlike the three lower bones of our sacrum. It is necessary with these people to base discussion only on a human sacrum made from the bones of an elderly person. For when five or only four bones making up our sacrum are found in man, they can in no way whatever be reconciled with Galen’s six bones, since not even the number of bones providing a path for the dorsal medulla matches. If bones that have separated from each other in cemeteries must be taken into consideration, what account is to be made of vertebrae, ribs, bones of the hand, foot, chest, and of nearly every part, since these present themselves parted and separated unlike the bones of our sacrum? When they imagine that Galen justifiably considered our coccyx bone a cartilage because its bones appear soft and cartilaginous in children, and, as they say, seem to be only four cartilages, it is as if Galen had constructed an account about children rather than persons of middle age, or about animals. But they too casually consider that in the makeup of many bones, in the entire system of epiphyses — particularly in their number — in the cartilages of the ribs [cart. costalis], and nearly a hundred other ways, this account of Galen more exactly fits apes and dogs, which are quite dry and extremely bony animals, so to speak, than man, who is nearly the dampest of all animals, and soft. 94 So far as I can tell, it would be possible to invent anything from these people, and impose it on one’s hearers with an opinion of Galen that they have perverted, did I not for my part show the true structure of man to those who are eager to learn. I do not think it altogether incumbent on me to alter the books of Galen as if they were sacred, when in the great and infinite difference between man and the apes and other beasts upon which Galen especially worked, Galen’s account is more in conformity with them than with man — particularly whenever that difference, however manifest, does not appear to have been noticed by Galen or otherwise expressed. Indeed, he himself should be heeded in the beginning of the third book // p. 107 // of his Commentary on Hippocrates’ book On the Joints, when he says that he wrote his book On the Joints after carefully inspecting the peculiar character of each bone especially in the actual dried-up cadavers of humans, and if not these then certainly in apes. 95 In this way he clearly indicates at least that he has spared no effort to explain apes, and that they are extremely similar to man in the construction of their bones.

More than Galen’s other anatomical works, his work On the Bones should be attributed to him

For this reason, none of all Galen’s anatomical works seems more attributable to him than this one On the Bones. This is certainly the one which he so often recommends and seriously considers worthy of repeated reading and being committed to memory because it is so concise. Though it more exactly fits apes 96 than humans, it contains fewer false descriptions and errors than all the others, and I am accustomed in the schools to mention it openly, altogether dispassionately (may the gods prosper me) and with approval in the midst of demonstrations. But no matter what, I am unable to escape the calumnies and false detractions of certain vicious old men who are withering with envy because they themselves are ignorant of these things.

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 18 On the Sacral Bone and the Coccyx