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]

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Chapter 6 On the Eight Bones of the Head and the Sutures Connecting Them


figure of the sixth chapter illustrates two portions of the bones [os parietale] of the vertex slightly separated from each other so that the extremely ingenious construction of the suture [sutura sagittalis] can be more readily inspected.

THE SECOND figure.

This shows part [os parietale] of the skull cut away from the rest of the head with a saw to show the construction of the bone from two dense, solid scales or layers marked ei [lamina externa] and oi [lamina interna], between which lies a porous or spongy bone structure [substantia spongiosa] marked ai [diploë]. Such scales are commonly called the tables of the head; the upper or outer scale, marked ei, is called the first table. The inner, which is nearest the hard membrane [dura mater] clothing the brain and is marked oi, serves as a second table; some people also call this the diploë. 1 There are those who consider the spongy or porous bony substance marked ai to be a table, calling it the middle or second table; thus they establish three tables of the skull. In all humans they are unequal in thickness and hardness. 2

THE THIRD figure of the sixth Chapter.

The third figure represents the entire skull of the natural shape 3 (which resembles an elongated sphere slightly compressed on both sides towards the front), shown from the left side without the lower maxilla, fairly exposing to view sutures on the outside of the head. 4

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THE FOURTH figure of the sixth Chapter.

This figure represents the skull lying more on its left side so that some of its base can be viewed. For the sake of some of the sutures, we have removed the jugal bone with a saw. You will readily learn about these sutures in the figure legend which follows, as well as from the text of this and some subsequent chapters. This figure will also serve well for recognizing the bones of the upper maxilla and showing certain foramina in the bones.

This figure legend is common to the third and the fourth figures, since nearly the same characters appear in both; where one appears only in the third or the fourth, I shall add a subscript 3 or 4 to the character listed.

A, B[ 3 , 4 ] Coronal or anterior suture [sutura coronalis] of those which run transversely. In Figure 3, B and A mark the middle [and extremity] of the coronal suture on the left side; in Figure 4, the right side is shown. 5
C, D[ 3 , 4 ] Posterior suture of the transverse sutures [sutura lambdoidea], resembling the Greek capital lambda (L). The left portion of this suture is seen in the third figure, the right in the fourth. The third of the figures representing the entire structure of the bones shows at B the full area in which this is altogether like a true suture. Its extensions running through the base of the head, to be illustrated in the fifth and sixth figures below, are another matter. 6
E 3 Suture [sutura sagittalis] running from the middle of the lambda-shaped suture to the middle of the coronal suture, from D [lambda] to B [bregma].
F[ 3 , 4 ] Squamous adhesion [sutura squamosa] or agglutination; 7 the left is shown in the third figure, the right one in the fourth.
G[ 3 , 4 ] 8 In both figures an interval of adhesion [sutura parietomastoidea] is marked from C to G, extending from the lambdoid suture to the true squamous adhesion, which shows a construction not of plates lying upon each other, but a genuine suture.
H[ 3 , 4 ] The part that extends from G to H through F is a squamous adhesion common to the vertex [os parietale] and the temporal bone. A squamous adhesion is also shown from H to A, common to the vertex and the frontal bone.
I 3 Left bone of the vertex [os parietale sinister].
K[ 3 , 4 ] Right bone of the vertex [os parietale dexter].
L[ 3 , 4 ] Frontal bone [os frontale], which is a single bone.
M[ 3 , 4 ] Occiput [os occipitale], likewise a single bone.
N[ 3 , 4 ] The left temporal bone [os temporale, pars squamosa] is shown in the third figure, the right in the fourth.
O[ 3 , 4 ] Bone compared by professors of dissection to a wedge [ala major ossis sphenoidalis], which we more often call by the briefer name (with apologies to those who care only about names) cuneiform. This is single, without a mate. 9
P[ 3 , 4 ] This specifically identifies the processes [processus pterygoidei] of this bone [os sphenoidale], which we shall compare to the wings of bats. There are two [lamina lateralis, lamina medialis] on each side, visible in the fourth figure and marked, besides P, with the numbers 2 , 3 , 4 , and 5 . The fifth figure of this chapter will show them more clearly.

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QQQ[ 3 , 4 ] This will be the first [os zygomaticum] of the bones of the upper maxilla, here designated with several Q’s to avoid confusion with d [ 3 , 4 ] [ala major ossis sphenoidalis, facies temporalis], which is nearby. The line between the two Q’s, marked with an asterisk [ 3 , 4 ], marks the process [margo temporalis] of this bone which greatly increases the cavity carved in the temple.
RRR[ 3 , 4 ] Slight roughness [linea temporalis superior] in the frontal bone and the vertex, from which the temporal muscle takes its semicircular origin.
SS[ 3 , 4 ] Fourth bone [maxilla] of the upper maxilla: the left in the third figure, the right in the fourth. T was left out by accident.
V, X 3 Part of the skull which we call the jugal bone and will describe in the next chapter. Here V [sic: X] marks the process [processus zygomaticus] of the temporal bone (N) brought out to form the jugal bone. X [sic: V] is the process [processus temporalis] of the first bone of the upper maxilla (Q).
Z 3 Suture [sutura zygomatiotemporalis] joining the processes just named from which the jugal bone is constructed.
V, X 4 The points in the fourth figure from which we have cut those processes with a saw. 10
a a[ 3 , 4 ] Portion of the suture [sutura sphenosquamosa] surrounding the cuneiform bone [os sphenoidale], common to this bone and the temporal bone.
b[ 3 , 4 ] Portion of the suture [sutura sphenofrontalis] around the cuneiform bone, common to this bone and the frontal bone.
c 4 This part of the cuneiform bone sometimes appears as a separate ossicle, 11 thin like a scale and separated from the cuneiform bone by a line which we have marked q3[ 4 ], but it does not appear very often.
e[ 3 , 4 ] Portion [fissura pterygomaxillaris] of the suture around the cuneiform bone [os sphenoidale, processus pterygoideus], common to this bone and the largest bone [maxilla] of the upper maxilla (S).
f f 4 In the fourth figure you see f, serving no purpose for the present chapter; it marks the suture [sutura zygomaticomaxillaris] common to the bones marked Q and S; we shall deal with it together with the other sutures of the upper maxilla. I mention it here in passing because I have cut away the jugal bone in the fourth figure so it can be seen. 12
gg[ 3 , 4 ] Suture [sutura frontozygomatica] separating the frontal bone from the cuneiform and the upper maxilla.
h 4 Socket [fossa mandibularis] in which the head of the lower maxilla is articulated.
i[ 3 , 4 ] Process of the temporal bone, jutting out like a writer’s stylus [processus styloideus].
k[ 3 , 4 ] Mammillary process [processus mastoideus] extending from the temporal bone. In the fourth figure, k marks the process on each side.
l l 4 Heads [condyli occipitales] of the occipital bone, which are articulated to the sockets of the first cervical vertebra. A foramen [foramen magnum] stands between them, hollowed out for the dorsal medulla. But since we have not set out to discuss the foramina of the bones in the present chapter, we have decided they need not be marked with letters.
F 4 The letter F [fissura pterygomaxillaris et fossa pterygopalatina], however, is placed only in Figure 4, to which you may refer from the twelfth chapter on the foramina.


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IN THE FIFTH figure we have assigned many of the same letters to the same parts as in figures 3 and 4, as follows:

A : End of the coronal suture, visible in the hollow of the temple.
CC : Lambdoid suture; these letters mark the lower part of the legs of this suture, where this figure no longer shows the exact shape of the suture. The sagittal suture is not shown here. 14
F : The squamous adhesion [sutura squamosa] is not seen in its entirety here; for this reason we have not put in the other characters of the third and fourth figures. It was possible, though, for K to mark here too the same thing it identified in the third and fourth figures. 15
K : The left bone of the vertex [os parietale sinister], a small part of which is seen.
L : The frontal bone [os frontale, processus zygomaticus] a slight portion of which is also visible.
MMM : Here can be seen the greatest part of the occipital bone, which is to say the entire part situated in the base of the skull.
NN : One temporal bone is marked on each side.
OO : The cuneiform bone [ala major ossis sphenoidalis]. 16
PP : Processes [processus pterygoidei] of the cuneiform bone resembling bats’ wings; they are four in number, marked 2 , 3 , 4 , 5 . 17
QG : The first bone of the upper maxilla, which I have also marked G here [os zygomaticum].
SL : The largest or fourth bone of the upper maxilla [maxilla, facies infratemporalis], here also specially marked with a number of L’s.
VX : Jugal bone [arcus zygomaticus]. 18
Y : Suture [sutura zygomaticotemporale] of the jugal bone [os zygomaticum].
aa Section of the suture around the cuneiform bone [os sphenoidale], between it and the temporal bone.
b Section of the suture around the cuneiform bone, between it and the frontal bone [sutura sphenofrontalis].
d At this point the section of the suture around the cuneiform bone [sutura sphenozygomatica], between it and the bone constituting the outer angle of the eye socket, marked Q, is hidden.
e Part of the suture [sutura sphenomaxillaris] around the cuneiform bone, between it and the fourth bone of the upper maxilla. 19
f This suture [sutura zygomaticomaxillaris] is considered peculiar to the upper maxilla, and therefore need not be explained here.
g Suture [sutura frontozygomatica] common to the frontal bone and the upper maxilla [os zygomaticum].
h Socket [fossa mandibularis] into which the head [processus condylaris mandibulae] of the lower maxilla [mandibula] is articulated.
i Process not unlike a writing stylus [processus styloideus].
k Mammillary process [processus mastoideus].
l l Heads [condylus occipitalis] of the occipital bone, which are joined to the first cervical vertebra [atlas].
m m m These letters, which like those that follow belong to the fifth figure only, mark additions 20 [sutura petro-occipitalis] to the lambdoid suture [m. sinister] which descend anteriorally through the base of the skull and go back upon each other at n.
n n Line [synchondrosis spheno-occipitalis] joining the additions [mm] just mentioned, common to the cuneiform bone [os sphenoidale] and the occipital bone.
o p Suture moving to the right side of the skull from the line marked n, between the cuneiform and the left 21 occipital bone [synchondrosis spheno-occipitalis]; n to o is not, however, properly a suture, nor by the same token is the anterior m to n, but a crack (synchondrosis) with a notable distance from bone from bone, distinct from what occurs in other sutures or harmoniae [suturae planae].
q q Section of the suture 22 around the cuneiform bone [os sphenoidale], common to it and the sixth bones of the upper maxilla marked P [lamina horizontalis ossis palatini]. To follow the line of sutures surrounding the cuneiform bone [os sphenoidale], examine this fifth figure together with the third and fourth with attention to the characters of each figure. Follow them from n to o, and thence to p, a, H, b, d, e, and q, and imagine that the cuneiform bone [os sphenoidale] is delimited by sutures in this way on each side 23 —but not without holding up a human skull for inspection in such a way that it can be easily turned in every direction. Since these three tables must be consulted simultaneously, to make it easier to follow the outline of the bone at least on the outside of the skull I have drawn here the lambdoid suture [CDC, sutura lambdoidea] and its additions [sutura occipitomastoidea], and the line (n) [synchondrosis spheno-occipitalis] between the occipital and the cuneiform bone [os sphenoidale] with the suture surrounding the latter, adding the same letters as in the third, fourth, and fifth figures.

r In this figure and in the fourth is marked the line [fissura petrotympanica] of the temporal bone, where the bone containing the beginning of the auditory meatus [meatus acousticus externus] is carved as by a suture, holding it and as it were separating it from the bone.
s 24 Roughness and process [apex partis petrosae] of the temporal bone where it faces back toward the transverse line, marked n, common to the cuneiform and the occipital bone.
S [facing backwards] Process of the eighth bone 25 of the head, or septum dividing the space of the nostrils. The other letters pertain separately to the bones [processus palatinus maxillae] [lamina horizontalis ossis palatinae] of the upper maxilla.

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This figure 26 presents the inner surface of the base of the skull [basis cranii interna]. Here we have drawn a skull whose upper part [calvaria] is shown in the next figure, removed in the manner by which we regularly divide the head with a saw to show the fabric of the brain.


The seventh figure 27 [calvaria] shows the remaining part of the inner surface of the skull [cavitas cranii, lamina interna], not shown in the sixth figure. 28

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The two immediately preceding figures are marked with several letters; here Greek capitals serve best to mark sutures of the bones of the head, which can be observed even on the inner surface of the skull where the brain is contained. The remaining characters visible in these figures will show the foramina of the skull. 29

G G In the seventh figure the coronal suture [sutura coronalis] is illustrated, not presenting its structure as precisely as on the outer surface.
D D [ 6 , 7 ] The lambdoid suture [sutura lambdoidea], shown in the seventh figure; there is also a D in the sixth, marking the same suture.
Q Q The sagittal suture [sutura sagittalis] in Figure Seven. The letters which follow refer only to the sixth. 30
L L Squamous adhesion [sutura parietomastoidea et squamosa] of the left temple.
C C Extension 31 of the lambdoid suture of the left side, which runs through the base of the skull.
P Line [synchondrosis spheno-occipitalis] common to the cuneiform and occipital bones, joining the two sides or extensions of the lambdoid suture.
S S Section of the suture [sutura sphenosquamosa] around the cuneiform bone, common to this bone, the frontal bone, 32 and the eighth bone [os ethmoidale, crista galli] of the head, to be marked A, B in the eighth figure. If you follow from P to S [sutura sphenosquamosa], and hence to the other S, then to the first Y [sutura sphenofrontalis] and the second Y, you will have made a line around the cuneiform bone on the inner surface of the left side. And if you imagined the same letters placed on the appropriate sutures of the right side as on the left, and followed them around, you would have included the entire cuneiform bone described here.


Although I should like to be as little trouble to the reader as possible in the number of figures and will therefore avoid separately illustrating individual bones of the head wherever possible, yet because the circumference of the cuneiform bone [os sphenoidale] and the eighth bone [os ethmoidale] of the head, which is as full of holes [lamina et foramina cribrosa] as a seive, 34 is not as readily understood as the other bones of the head, the cuneiform bone is represented in this figure with the eighth bone free from all the others on the side where it faces the inside of the skull [basis cranii interna], the seat of the brain. 35 We have presented it so that the hollows that generally occur in the cuneiform bone will be as conspicuous as possible.

A B A : The eighth bone 36 of the head; B specifically identifies the septum [crista galli] separating the areas provided for the processes [tracti] of the cerebrum which come out of the brain like nerves [tractus et bulbus olfactorius] and are considered to be the organs of smell. 37
C D : The two principal hollows [sinus sphenoidales] of the cuneiform bone.
E : Septum [septum intersinuale sphenoidale] dividing the hollows just indicated.
F : Foramen [apertura sinus sphenoidalis] of one hollow or antrum, extending into the space of the nostrils.
G : Cavity located in the lower area of the septum dividing the two principal antra. The remaining foramina visible everywhere in this figure will be explained in the twelfth Chapter, together with the other foramina of the skull. 38
H : Processes [laminae mediales et lateralis processus pterygoidei] of the cuneiform bone that resemble bats’ wings, 39 visible here on each side.
It is now time to begin the text of the Chapter, to discuss all these parts in order, and judge the diligent craft of our Maker in building the skull. I believe it will be permitted, with apologies to those preoccupied with words alone, to include the entire construction represented in the third, fourth, fifth, sixth, and seventh figures under the name “skull”, though others would wish only the part adorned with hair to be so called. For teaching purposes, we are dividing this mass into the head [cranium] and the upper maxilla [maxilla]. 40

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What kind of dwelling Nature prepared for the brain.
It is extremely advantageous that the brain, the seat of reason (which like a queen rules in the highest part of the body and holds sway over two desirous spirits), 41 is kept under safe protection. For this purpose, the provident Maker of things imparted protection to the brain, made not just of skin and fleshy parts, as in the abdomen, or of bones separated from each other at intervals as in the thorax, but he surrounded it on all sides with a helmetlike bone.

Why the skull is not made of solid bone. 42
But because the head resembles the roof of a warm house, receiving whatever smoky and vaporous wastes of the parts below that ascend upwards, 43 and consequently the head itself needs a more plentiful means of evacuation, the wise Parent of things shaped a helmet for the brain that is not solid everywhere but full of hollows 44 and laced with sutures (figs. 1 and 2), not piercing the face everywhere like a sponge with small and uneven foramina like little cavities: rather, he wished the little cavities to end on each side, inside and out (ai, ei, oi in fig. 2 and the character & in fig. 6), in a smooth, dense scale of bone, because they would meet on one side the hard membrane of the brain [dura mater] and on the other the membrane surrounding the skull which is called perikra/nioj. 45 For if the entire substance of the skull remained porous, and the pores were covered by no cortex, the bone’s roughness would abrade and damage things near it. Moreover, if it were entirely porous and spongy, it would have no strength, and would be weak and fragile, like pumice. Perhaps someone will think there is no reason why the bone of the skull between the two scales is porous and full of cavities, 46 since the abundance and size of its sutures require no further assistance in transpiration. So if as this person judged preferable the entire skull were at once thin, dense, and solid, the construction of the organs lying beneath would be rendered no safer by this means, since things that injure bones would be able to penetrate inside quickly because the distance to be traveled would be so short. But if the skull were created at once thick and dense without any kind of pores, the resulting weight would be no different than if a person were compelled constantly to carry a knapsack on his head. The third recourse therefore was for the bone of the skull to be constructed neither thin nor dense or solid, but thick, loose-knit, and porous. 47 Thus it would not be too heavy, nor would there be a short path into the brain for things striking through it.

The use of sutures.
The skull did not need sutures so much for the transpiration of wastes, but it was fitting that it be made of many bones so that if it should be struck and break, its fractures should not proceed through the whole skull as through a clay pot, but be checked and cease in those places where the bone itself ends at the sutures. In addition, it was proper that the ventricles of the brain and several other bodies therein be swollen and elevated, so as not to collapse; this also is very well accomplished by the sutures. We shall demonstrate in the seventh Book that the fibers (G, H, I, and F in fig. 1, Bk. 7) of the hard membrane [dura mater cranialis] sheathing the brain, going through the sutures together with the ends of certain vessels, 48 spread out into the membrane [periosteum] covering the outside of the skull, and thus sustain the brain so that it does not collapse upon itself. It is particularly this usefulness, causing the parts in the brain requiring support to be correctly held up, that makes the distribution of skull sutures seem most just. For something that is oblong and rotund like the brain is no more fittingly raised than by transverse supports and by others that run lengthwise. 49

Sutures of the naturally shaped head.
First, the natural shape 50 of the head has three sutures: two transverse, of which one is in the sinciput, the other in the occiput (C, D in figures 3 and 4, D, D in figures 6 and 7) [sutura lambdoidea]; the third (in figure 3, from D through E to B; Q Q in figure 7) [sutura sagittalis] extends from the middle of the posterior suture, or that which is in the occiput, through the longitude of the head to the middle of the anterior suture [sutura coronalis].

The coronal, lambdoid, and sagittal sutures
They call the anterior the coronal suture, because crowns are most often put on that part of the head; they name the posterior lambdoeidh/j [sutura lambdoidea] after the Greek letter L; the third, running through the vertex [sutura sagittalis] and the longitude of the head, is called o)belai=a by the Greeks 51 because it runs straight like a spit or arrow, whence it also came to be called abdoeidh/j from the shape of a rod. This one sometimes 52 runs forward through the middle of the forehead (figs. 2 and 4 in ch. 5 show something of the sort) to the top of the nose, without the same complexity as on the vertex itself, or as elaborate a sutural structure.

The heads of men do not always differ from those of women.
Some falsely contend that it is peculiar to all men, others to women, but we have taken care to observe that it occurs very rarely in men and still more rarely or hardly ever in women. 53 You may infer from this that out of twenty skulls that one finds in cemeteries you will find scarcely one 54 whose forehead is seamed; and not any difference (though Aristotle 55 has said otherwise, clearly erring in his account of the sutures) is seen in this respect between men and women. In quadrupeds, the sagittal suture extends from the lambdoid at the back of the head to the middle of the brows [glabella] (canine skull in Chapter 9, figure 1), as the skulls of dogs, horses, cattle, and such animals 56 clearly attest. Aristotle is not to be believed when he ascribes to dogs a continuous skull unmarked by sutures; 57 the skulls of dogs clearly show the sutures we have already mentioned and nearly all that will be enumerated in this entire chapter. Some also claim that in infants this suture descends through the middle of the occipital bone and continues to the foramen [foramen magnum] of the dorsal medulla (e in figure 6), dividing the entire occipital bone.

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We have certainly observed the same ourselves, but this division has more to do with a su/mfusij joint 58 than with a type of suture, since in children it is closed by cartilage and in older people no trace of this division occurs. Therefore no account of such a division appears in this text on the sutures, but will be explained in the description of the occipital bone.

Sutureless heads
I am not at all suprised that Herodotus and many others besides write that skulls are found in Persia that are divided by no sutures at all, 59 and that Aristotle himself reports a man’s skull was found in his own time without sutures. 60 This is because the skulls of very old people show us only the site of the sutures, and quite obscurely at that, with no clear image of a suture. 61 Nor indeed is it strange that sutures grow together in the elderly, since we see that their vertebrae unite and fuse, 62 and we observe also that the brows and processes of their bones so grow out that they are unable to perform their accustomed motions.

Differences in bones of old, young, and juvenile persons. 63
Even if I had never recognized that the bones of old persons differ from those of young, or of children from young people, I should certainly have learned this in my last Anatomy at Bologna when in addition to a large number of bones, those of a newborn infant child, a nonagenarian, and persons of middle age were eagerly brought in by medical students when I was lecturing there on Galen’s book De ossibus, before dissecting muscles. While a large number were preparing bones for inspection which they had gotten from broken tombs and corpses gotten out of hospices it naturally occurred that one had found an old man’s bones, another a child’s, another the bones of people of this or that age, and brought them to lectures. 64 That was when (to return to what I was saying) I came to the conclusion that in infant bones everything is smooth, unjoined, soft, and mostly cartilaginous, that processes are least prominent, and that a great many parts that are held in adults to be made of a single bone are in infants made of several. I shall not hesitate to add to my account features in individual bones caused by fractures, dislocations, distortions, and plications. Any student of true medicine who reads the books of Hippocrates fully understands how important it is to know these things; so will those who have learned from daily experience that epiphyses are dislocated from children’s bones more often than joints, and who have at one time or another prepared for dissection persons where there has been a dislocation or some other bone damage early in life.

Sutures in unnatural heads
We have now enumerated three sutures that more frequently occur in the naturally shaped head. When a skull is lying on its side, these describe the letter H, or rather h. 65 In the heads that vary from the natural structure, the sutures are as follows. 66 Where the anterior eminence of the head is missing (Chapter 5, figure 2), the coronal suture is absent and the lambdoid remains together with the sagittal, which then runs to the middle of the brows [sutura metopica]. Where the posterior eminence is missing (Chapter 5, figure 3), the lambdoid suture is lost and the coronal remains, while the sagittal is extended through the middle of the occiput to the base of the skull. If you imagine this one resting on its occiput, each of the remaining sutures will resemble the letter T; similarly, the sutures of the first unnatural type will resemble a T 67 when it is rested on its forehead. When the anterior and posterior eminences are both missing (Chapter 5, figure 4), the two sutures that are then seen intersecting each other at right angles make the letter X. One transverse suture [s. coronalis] runs from the area of one ear to that of the other across the middle of the head; another suture extends from the foramen (e in fig. 6) [f. magnum] incised for the dorsal medulla in the occipital bone along the length of the head to the top of the nose, like the one that we commonly call the sagittal suture. Indeed, this suture [s. sagittalis] is always preserved in the first three shapes of head that differ from what is natural. The other two 68 sutures [lambdoidea et coronalis] are missing in various ways according to the shape of the head as a whole. The fifth variant (Chapter 5, figure 5), as it is completely unlike the natural, also contains sutures entirely at odds with it. The transverse or coronal suture and the lambdoid run along the length of the head, while the straight or sagittal suture is carried transversely.

The scaly seams of the temples
Now we direct our account to the remaining seams of the head. First, there are two lines (F in figures 3 and 4, [sutura squamosa] L L [sutura occipitomastoidea] in figure 6) more or less equidistant from the sagittal suture, extending lengthwise on each side above the ears. They begin (C to G in figures 3 and 4) [sutura parietomastoidea] from the lowest point of the lambdoid suture where it is near the lower parts of the occiput and no longer looks very much like a suture. From this point the lines run more or less straight and soon after move upwards (from G through F [sutura squamosa] and H to A [sutura sphenoparietalis] in figures 3 and 4) and extend in something like a semicircle to the end of the coronal suture. They consist mostly of two bones resting upon each other, and connected; not by a suture, but the vertex [os parietale] (I in figure 3, K in figure 4) 69 as it descends gradually becomes narrow like a scale and goes in under the bone ascending from the ears below (N in figures 1 and 4) 70 which is likewise thinned like a scale. Both bones assume a similar roughness at the point where they meet. For this reason neither Hippocrates nor any of those who have carefully studied the fabric of the body has deigned to name these sutures, but from their resemblance to a scale anatomists have called them lepidoeidh= proskollh/mata, that is, squamous agglutinations [sutura squamosa, sutura spheno- parietalis]. 71

The sutures are visible also inside the skull
It should not be thought because of the false doctrines of certain people 72 that these agglutinations are less visible in the hollow of the skull where the brain lies than the three sutures previously described, and for this reason are never called sutures.

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Their outline (L L in figure 6) [sutura parietomastoidea et squamosa] can be seen inside the skull exactly as that of the sutures, which do not look as much like sutures inside the skull; but because they are less convoluted, especially the coronal suture, they look more like a line [sutura plana] or a harmonia. These squamous agglutinations are not joined along their entire course like scales resting on top of each other. For at the point where they first leave the lambdoid suture, they take on the look of a suture outside and inside the skull for some distance (C to G in figs. 3, 4). Moreover, the portion of these agglutinations that is closest to the coronal suture (H to A in figures 3 and 4) must also be considered common to the vertex [os parietale] and the cuneiform bone (O in figs. 3, 4) [os sphenoidale].

Why squamous agglutinations do not resemble the other sutures.
The reason why these joints are not constructed everywhere with a serrated bond like the skull sutures we have described, or with a connection like a fingernail, we believe is chiefly because it was necessary for the entire part of the skull 74 surrounding the thick cerebral membrane [dura mater] from the vertex [os parietale] and the sides of be lightly constructed, porous, and full of holes, but for the rest to be hard and solid, particularly in the temporal bones, which are thin [os temporale, pars squamosa] because of an indentation carved out for the temporal muscle (G in the 4th table of muscles), and perhaps also for the sake of sound (since the organ of hearing is inside); this is easily the hardest [os temporale, pars petrosa] of all the bones of the body. This is why the edges of the bones are thinned to a scaly edge, with the bone of the vertex placed inside to approach and meet the hard membrane over a longer space, while the other bone [os temporale, pars squamosa] goes up from the ears like a shield made for the vertex itself. We also believe the bones of the vertex could not have been joined to the hard, dense bones of the temple because a firm and harmonious union between a loosely constructed material and a hard one is not so easy to achieve.

Sutures already accounted for.
So far we have explained five sutures peculiar to the head and joining no bones other than those of the head: the coronal, the lambdoid, and the one that runs straight through the vertex [sutura sagittalis], as well as the two equidistant from the vertex, which we have called the squamous agglutinations [suturae squamosae].

The suture surrounding the eighth bone [os ethmoidale] of the head.
There is also another (near h, L, and Y in figure 6) [sutura frontoethmoidalis] common to the head inside the skull, appearing mainly where the brain is contained, between the frontal bone and the bone (A, B, A in fig. 8) [os ethmoidale] where the organs of smell (L and D in fig. 13, Bk. 7) are located and which looks as full of holes as a seive [lamina et foramina cribrosa]. This bone, as if inserted into the base of the frontal bone, is obscurely surrounded by this suture, which skirts it in the head cavity; it has another suture as well between it and the bones of the upper maxilla. This bone extends a bony septum (S in fig. 5, O in fig. 1, ch. 9) [lamina perpendicularis] separating the foramina [cavitates nasi] of the nostrils; it is divided by a suture (g in figure 1, Ch. 9) [sutura vomeromaxilla] along the lower part of the septum, extending its length from the largest bones of the upper maxilla which hold the teeth, just as it is also separated from the cuneiform bone [os sphenoidale] in the place (ϖ, m,n, c in fig. 2, ch. 12) where the foramina of the nostrils reach the throat. 75 I shall explain in what manner this bone is perforated like a seive in my account of other bones of the head, after I have gone over the other sutures common to the head and other bones.

Sutures between the head and other bones.
There are other sutures common to the head and other bones such as the upper maxilla, and the bone they call the sphenoid (O, P in figs. 3, 4, 5 and nearly all of fig. 8) from its resemblance to a wedge—it is likewise the only one of its kind and, like several bones of the body, without a mate. Some count it among the bones of the head, others among those of the upper maxilla, since it is in between the two of them. But it is much more correctly ascribed to the bones of the head than to those of the upper maxilla, since it makes up an area that is not the smallest in the space of the skull where the brain is located, along with other bones that all anatomists associate with the skull. But we shall now endeavor to explain its shape and size, and the sutures by which it is surrounded.

Extensions of the lambdoid suture [synchondrosis petro-occipitalis].
The ends of the lambdoid suture (C, C in figure 5, then m, m on each side; see especially the illustration in the figure legend), which no longer present the exact structure of sutures near the lower part of the occiput, extend to the bottom or base of the head and run forward through the middle of the base (which in hardness and appearance is like a rock outcropping) and the place where the head is articulated 76 to the first vertebra [atlas] of the neck, gradually approaching each other.

The edge of the cuneiform bone
When these ends reach a point near the foramina [choanae] of the nostrils that open into the mouth cavity, they are joined together by a transverse line [synchondrosis spheno-occipitalis] (n, n, in figure 5, P in figure 6) which can properly be called neither a suture nor a harmonia but should by all means be considered a symphysis 77 or fusion. In children it is filled with cartilage in the same way as a union of bone and epiphysis is seen in them, while in older persons the line is entirely hidden just as in those of advanced age. 78 In whatever form, this line is common to the occiput and the cuneiform bone. From here, a suture [sutura sphenosquamosa] runs laterally on both sides (in figure 5, from n through o and p on the right side, on the left through a and a to A; in figures 3 and 4, through a, a to H) through the hollows [fossae temporalis et infratemporalis] of the temples upward in an oblique curve towards the anterior part (from H to A in figs. 3, 4) of the squamous agglutinations. When the suture reaches that point (because it is at a notable distance from the end of the coronal suture in the hollow of the temple), it [sutura sphenoparietalis] runs forward and slightly downward to the ends of the coronal suture. From here it [sutura sphenofrontalis] moves downward again for a while (from A to b in figs. 3, 4) until it reaches the bone [os zygomaticum] of the upper maxilla, which will be explained to be the outer angle [margo supraorbitalis] of the eye socket [cavitas orbitale]. From here it proceeds down through the hollows of the temples to the posterior side of the innermost teeth [dentes molares], and goes transversely through the entire nasal cavity (q, q in fig. 5). 79 This suture, extending in this way from the transverse line [synchondrosis spheno-occipitalis] which we have said joins the ends of the lambdoid suture [synchondrosis sphenopetrosa] upward to the hollows of the temples, and downward again as far as

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the palate [os palatinum, lamina horizontalis] on either side as described, surrounds the cuneiform bone on the outside. On the inside, in the skull cavity (following P, S, S, Y, and Y in fig. 6) the cuneiform bone also ends at this suture; 80 the circumference of this bone is easier to find here than on the outside if one only keeps careful track of the suture’s course, since it presents itself here and there in many places.

In what places the suture around the cuneiform bone occurs
First, the line [synchondrosis spheno-occipitalis] common to the occiput and the cuneiform bone is visible both on the outside (n, n in figure 5) and the inside (P in figure 6). Likewise the portion of the suture extending from this line obliquely upward to the hollows of the temples as far as the anterior part of the squamous agglutinations is visible on the inside (from P through S, 81 S in figure 6) [sutura occipito-mastoidea] and the outside (from n through a, a to A in figure 5, from a, a to H in figures 3 and 4); it [sutura sphenosquamosa?] is common to the temporal bones and the cuneiform [os sphenoidale, ala major], and resembles a true suture. 82 The part that travels forward from here to the ends of the coronal suture resembles the squamous agglutination [sutura coronalis] common to the vertex [os parietale] and the cuneiform bone. The portion running from the ends of the coronal suture to the bones [os zygomaticum] that make up the outer angles of the eye sockets also resembles a squamous agglutination [sutura sphenofrontalis] and is common to the frontal bone and the cuneiform bone [ala major]. The interval and course of this suture that resembles a squamous agglutination is higher on the outside than inside the skull (compare figs. 3 and 4 with 6) to the same degree as the cuneiform bone is beveled like a scale where it is joined to the frontal and vertex bones. The same thing happens in the connection of the temporal bones with the vertex [os parietale]; the squamous agglutinations of these bones seem to run up much higher on the outside than on the inside, where the brain is. 83 Also, the part (from b through d to e in figs. 3 and 4) of the suture [sutura sphenosquamosa] around the cuneiform bone which is carried downward through the hollows [fossae infratemporales et temporales] of the temples is not seen inside the skull but only in the hollows of the temples and the eye sockets (Q in fig. 1, ch. 9) in their external angles. 84 This interval of suture [fissura pterygomaxillaris et fossa pterygopalatina] separates the cuneiform bone from the bones in the external angles of the eyes. The section of the suture which we are now discussing (e in figures 3, 4, 5), running forward near the back [tuber maxillae] of the innermost tooth [dens molaris III], is visible on the outside and in the nasal cavity [choana]; it is common to the cuneiform bone [os sphenoidale, processus pterygoideus, lamina lateralis] and the largest bones of the upper maxilla on either side. The portion of this suture visible in the upper part of the nasal cavity is seen better on the inside (Y on the left [right] side of L in figure 6) than on the outside (q, q in figure 5) of the skull, joining the cuneiform bone [jugum sphenoidale] with that which we said was perforated like a seive [lamina cribrosa ossis ethmoidalis]. Inside the skull, not only is the section of the present suture common to that bone and the cuneiform bone [synchondrosis spheno-ethmoidalis] obvious, but to this section another portion of the same suture [sutura sphenofrontalis] (Y on the right [left] side of L in figure 6) presents itself on both sides; this is believed to lie between the cuneiform and the frontal bone; it is clearly seen in the root of the eye socket (S, T of figure 1, chapter 9) near its more prominent region. If you closely examine the eye sockets (which the Greeks call ko/gxoi 85 ) you will observe that their root (N in figure 1, chapter 9) 86 and a large portion of their outer side near the inside is made up of the cuneiform bone. So you will learn if you consider such things in the fabric of man worth looking into and are taken with things that have little to do with applied skill but show the marvellous industry of the great Creator, and without doubt were closely studied by the ancient professors of anatomy.

On a passage in Galen’s De ossibus; the suture between the frontal bone, the bones of the maxilla, and others.
Further, this portion of suture which I said lies between the frontal bone and the cuneiform bone is a large part of one of two sutures which Galen says are common to the head [calvaria] and other bones. He counts as one of them the suture that surrounds the cuneiform bone where we said it borders on the occiput, the temporal bones, and the vertex. 87 After describing the suture surrounding the cuneiform bone, 88 he says that the other of the two (from b to g [sutura sphenofrontalis], g in figures 3 and 4 [sutura frontozygomatica, sutura sphenozygomatica]; 89 then see R [sutura frontozygomatica], S, T, V, X, Z and the interval of this suture in figure 1, chapter 9) extends from the hollows of the temples through the middle of the eye sockets to the top of the nose or halfway between the brows. 90 It does in fact so extend, beginning where the suture surrounding the cuneiform bone descends through the hollow of the temples towards the innermost tooth [dens molaris]. In its first segment this suture separates the frontal bone from the bone of the upper maxilla [os zygomaticum] that makes up the outer angle of the eye socket; then, for some distance, it separates the cuneiform [alae major et minor ossis sphenoidalis] from the frontal bone along the entire course where these adjoin in the eye sockets and the inner surface of the skull. That is why this portion is considered to be part of the suture around the cuneiform bone, not part of the separation of the frontal bone from the other bones of the maxilla. So it is that the next part of the suture leading transversely through the eye sockets separates the frontal bone from the second, third, fourth, and fifth bones of the upper maxilla 91 on one side and is common to the frontal bone and these bones of the maxilla along the entire surface where this suture occupies the inner angle of the eye socket and the top of the nose [nasion] 92 or midway between the brows [glabella]. We shall talk about the bones and sutures of the upper maxilla in the ninth Chapter, where we shall need to resume discussion of this suture. Now we must separately enumerate the eight bones of the head which are surrounded by the sutures so far counted, 93 together forming the space [basis cranii interna] of the head wherein the brain is contained. There are two bones of the vertex [ossa parietalia], one on each side; two below, one near each ear, which I have been calling the temporal bones;

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the fifth is the frontal bone, usually a single one; sixth is the occiput , likewise single; seventh is the cuneiform, also single; the eighth shall be considered that bone [os ethmoidale] constituting the place wherein lie the two processes of the brain not unlike nerves, which we generally call the olfactory organs. 94

The borders of the vertex bones [ossa parietalia].
The vertex bones (I in fig. 3, K in fig. 4; in both the bone is circumscribed by B, D; A, B; C, D; C, G, F, H, A) have in their upper portion a suture [sutura sagittalis] peculiar to them, which runs in a straight course along the length of the head and divides them from each other. In front they are distinguished from others by the coronal suture, behind by the lambdoid. In the lower portions they are bounded by the squamous agglutinations [sutura squamosa]: whence it happens that they appear four-sided and uniform throughout, except where they are thinned like scales and go beneath the temporal bones. Here they are quite thin but solid and not at all porous, while on the remainder of their surface (above R, R in figs. 3, 4), where they are not covered by temporal muscles, they appear porous [foramen parietale] and full of cavities [canales diploïci] between their scales, having almost the same thickness throughout this area. Then, where they meet the frontal bone, they look thinner than they are next the occiput. I will run through whatever hollows or foramina they have in the twelfth chapter, which will be dedicated to them.

The borders of the frontal bone
The frontal bone (L in figs. 3, 4; circumscribed by B, A, b, g, g; in fig. 6, following h, L, Y and beyond) is surrounded by the coronal suture, by the suture [sutura fronto-ethmoidalis] that bounds the eighth bone [os ethmoidale] of the head where the organs of smell [organum olfactorium] are located, 95 and by the suture [sutura frontozygomatica] that begins from the hollow of the temples, runs [sutura sphenofrontalis] through the middle of the eye sockets to the place where the brows meet [nasion], and separates [sutura frontomaxillaris] the frontal bone from the bones of the upper maxilla [processus frontalis maxillae]. This one has taken the last place in the number of sutures. Thus the frontal bone is somewhat circular, and nowhere thinner than where (at the side of h, L in fig. 6) it constitutes the upper region of the eye sockets and is joined to the eighth bone [os ethmoidale] of the head. Here is it formed as it were of two thin scales with an empty space between filled with air, like the cavity [sinus frontalis] (K in figures 6 and 7) which you will hear it has between its scales [laminae externa et interna] at the brows beginning at the top. This bone is much thicker than elsewhere because of this cavity, and seems to bulge out. One of its scales, which faces the eye socket and is exterior, seems smooth. The one that faces the inside of the head bulges with irregular, cloudlike swellings (figs. 12 and 13 in Bk. 7 show something of the kind) [impressiones gyrorum] which match the convolutions of the brain. In the temples where the temporal muscles are located it is thin, solid, and not at all porous, except at the point (“&” in fig. 6) where it joins the vertex bone [os parietale]. For Nature made each individual bone thicker there toward the inside, lest an excessive thinness of the bones should make the skull too weak at that point. Moreover, the frontal bone shows no noticeable cavity in the forehead a little above the brows and the remaining part which is unfleshed, 96 and it feels much stouter and thicker than the bones of the vertex. Yet at the point where it is joined to them, and the sagittal suture meets the coronal, the os frontis is thinner and weaker than in the forehead itself.

The softest and least dense part of the skull
This area [bregma] where the sutures just mentioned join is thought to be the softest and least dense part of the entire skull: this is the part [fonticulus anterior] 97 that in newborn infants is still membranous, and feels like fresh cheese; it moves visibly when babies chew and breathe. Because this spot, called Zeudech by the Arabs, is the thinnest among the unfleshed parts of the head, and the sutures nowhere hold more loosely, doctors apply to this point what is commonly called cautery, either with glowing gold, or iron, or whatever caustic medication they think appropriate to the condition (unsafe though this is). 98 In ourselves, the place is readily guessed with the tip of the middle finger if one places the beginning of the wrist between the brows or the top of the nose 99 and presses the middle finger straight down upon the top of the head.

The borders of the occipital bone
The occipital bone (M, M in figures 3, 4, 5. It is circumscribed in figure 3 by C, D, then in figure 5 by m, m, m, m, and n, n) ends at the lambdoid suture, its extensions, and the line joining them. It therefore consists more or less of five sides: the two made by the legs of the lambdoid suture, two others [suturae occipitomastoideae] which are defined by the extensions of that suture, and finally a fifth marked by the line 100 that is considered common to the occipital and cuneiform bones. This bone is quite uneven in thickness, nor is it everywhere consistent with itself. Whatever is unfleshed in the occiput and free of the origins and insertions of muscles, is quite thick, 101 as much thicker than the frontal bone as that bone is thicker than the bones of the vertex.

The thickest point of the occiput
Nor is the bone of the occiput of equal thickness throughout its unfleshed surface; at its root it looks much the thickest in the middle [protuberantia occipitalis interna] (k in figure 6), in the region (R in figure 7, Book 7) where — as you will hear in the account of the vessels of the brain — the two greatest sinuses [sinus sagittalis superior et sinus rectus] of the hard membrane [dura mater] of the skull, containing blood and vital spirit in the manner of veins and arteries, are joined [confluens sinum], and put forth two other sinuses [sinus transversus]. For Nature seems to have provided for this meeting of sinuses [confluens sinum] by the thickness of the bone, both because a wound here could be extremely dangerous to a person, and also because she was not unaware that this part of the occiput, having no eyes, would be constantly exposed to blows, and likely frequently to be dashed against the ground in various falls. This thickest part of the occipital bone, like all the unfleshed part of this bone, is made of little cavities [diploë] inside that are covered on both sides with a strong plate [lamina externa et interna], just as we have reported the vertex and the frontal bone are constructed in their unfleshed portions (these are found in fig. 6 but more clearly shown in fig. 9, Bk. 7). The remaining surface of the occipital bone, where some of the muscles 102 occupying the back of the neck are inserted, and from which some take their origin,

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is seen to be solid and rather dense but exceedingly thin, and without pores. This is the place that the cerebellum fills. To avoid negligenge of the bone’s strength because of its unusual thinness, a long, linear tubercule [crista occipitalis interna] (from k to the foramen [foramen magnum] marked e in fig. 6) projects in the middle, greatly increasing the bone’s strength in that area. Further, because this tubercule projects into the inner space of the skull, it forms two depressions [fossae cerebellares], one on each side, which the cerebellum fills. This tubercule, like the thin part of the occipital bone, extends from the base [protuberantia occipitalis interna] of the unfleshed part of the occipital bone to the posterior region of the foramen [foramen magnum] made for the dorsal medulla. From the anterior part [clivus] (from e to P in figure 6) of the foramen transmitting the dorsal medulla, and where the occiput is narrowst, it thickens gradually so that it appears quite thick where it joins the cuneiform bone.

Capitula of the occipital bone
On the outer surface, at the sides of the foramen carved out for the dorsal medulla, the occipital bone puts out two capitula (l, l in figures 4 and 5) [condyli occipitales] which are articulated to the first cervical vertebra [atlas], by means of which the head is tilted and extended by its own motion. In young children, these capitula [condyli] are epiphyses; in old persons they are hidden, like the other epiphyses. Also in young children, the bone is constructed of three parts [partes laterales, pars basilaris] separated by three lines [sutura] filled with cartilage [synchondroses]. One of these runs from the end of the sagittal suture to the posterior part of the foramen [foramen magnum] of the dorsal medulla; the other two [fonticuli mastoidei] extend transversely from the sides of the foramen to the extensions of the lambdoid suture. Consequently, the very young have two bones [partes laterales] in the occiput, and one [pars basilaris] attached to the cuneiform bone in the base of the skull. The occipital bone is smooth inside and not at all rough, just as on its entire unfleshed outer surface it also appears smooth. Beneath it, where the occipital bone makes up no small portion of the head’s base, it is very rough and uneven to provide a better point of origin for ligaments and certain muscles, and so that others might be more safely and firmly inserted therein.

The circumference of the temporal bones
The temporal bones (one marked N in figs. 3, 4, 5; in figs. 3, 4 its circumference is from C through G, F to H, and in fig. 5 from C through m, m to n, and then through a, a to H in figs. 3, 4) are surrounded by squamous agglutinations and extensions of the lambdoid suture; also by a portion of the suture that terminates the cuneiform bone and runs obliquely on both sides from the transverse line [synchondrosis spheno-occipitalis] common to the occiput and the cuneiform bone upward through [sutura sphenosquamosa] the hollows of the temples [fossa temporalis] to the squamous agglutinations [sutura squamosa].

Mammillary processes
These bones would not wrongly be called circular, did not a part of them project beyond the circle. This part is closest to the lambdoid suture and puts forth the mammillary process [processus mastoideus] of the head (k in figures 3, 4, 5), one on each of the temporal bones. It protrudes not only to offer an opportune insertion for muscles [m. sternocleidomastoideus] from the pectoral bone and the clavicles that move the head; it is also an apt seat for the organ of hearing, which requires a great cavity.

The cavity of the temporal bone
The temporal bones protrude here not only for the mammillary processes [processus mastoideus] but also into the inner space [fossa cranalis media] (between T and i in fig. 6, or Z in fig. 8, Bk. 7) of the head to make a large empty place [cavitas tympanica] where the organ of hearing might have a sufficient space to dilate its nerve, form its sinuses, and locate its special ossicles [ossicula auditoria]. In the second chapter after this I will explain what sort of ossicles these are. Now I shall complete my account of the temporal bone, one of whose processes I have now described: from the shape of the teat of a cow’s udder the Greeks call it mastoeidh/j, mastoid; we call it mammillary [processus mastoideus]. It is larger than could fitly be compared to the delicate nipples of women. 103

The process resembling a writer’s stylus
The temporal bone has another process (i in figure 3, 4, 5) [processus styloideus], taking its beginning not far from the inner side of the mammillary process. This is long, thin, and quite solid, whence, from its resemblance to a needle, the Greeks call it belonoeidh/j, “needle-shaped,” from its resemblance to a writer’s stylus grafoei/dhj and stuloei/dhj, and from its resemblance to a rooster’s spur plh=ktron. 104 Though it appears solid, since it is also thin, projects considerably, and is easily broken off, it is rarely found in skulls dug from the earth. From this process muscles extend to the hyoid bone and tongue as well as to the lower maxilla 105 —those muscles that draw it downward. 106 The hyoid bone is joined to this process either by long, thin ossicles 107 or by a strong, rounded ligament [ligamentum stylohyoideum].

The jugal process of the temporal bone
In addition to these, still another process (X in figs. 3, 4, 5) in the temporal bone, by no means the lowest, forms half of the jugal bone. In the next chapter you will hear that it is nothing other than processes [os temporalis, processus zygomaticus] [os zygomaticum, processus temporalis] of two bones joined by an oblique suture [sutura temporozygomatica] (Z in figure 3, Y in figure 5). At the base of this process, in front of the auditory passage, a depression (h in figures 4 and 5) [fossa mandibularis] is carved in the bone, 108 into which the capitulum [processus condylaris, caput mandibulae] of the lower maxilla [mandibula] is articulated. Here too [the bone at] the beginning of the auditory passage [meatus acusticus externus], which is very thick, is separated from the rest of the temporal bone by a kind of small, obscure suture (r in figures 4 and 5) [fissura petrotympanica] at some point, chiefly in the lower anterior area. The remaining expanse of bone [os temporale, pars squamosa] can be seen facing the vertex, broad and quite thin but solid and free of pores, smooth on the outside but swelling unevenly on the inside like the convolutions of the brain which resemble the twists of the intestines. Near the base of the head it [os temporale, pars petrosa] is rough and quite uneven, particularly where like a process [apex partis petrosae] it faces the transverse line [synchondrosis sphenopetrosa] common to the occiput and the cuneiform bone (∫[s] in figure 5). At this point it projects unevenly, is rough like pumice, and pierced by a transverse foramen [canalis caroticus] by which you will hear the principal branch of the sleep artery [arteria carotis interna] is carried into the skull.

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The cuneiform bone [os sphenoidale]
We have fully explained the sutures that surround the cuneiform bone (O, P in figs. 3, 4, 5 and separately in fig. 8). This is a remarkably complicated bone, if any is: whence without violence to the truth the ancients called it polu/morfon, 109 from its complex form. 110 At its sides [ala major ossis sphenoidalis], and in the hollows of the temples [fossa temporale], it is thin and quite solid; in the middle and at the base of the head [basis cranii externa], it appears by far the thickest of all the bones of the skull, and mostly hollow inside. In the hollow space (C, D, E, F, G in fig. 8) it shows two large cavities [sinus sphenoidalis] separated by a thin, bony septum [septum intersinuale sphenoidale], in whose lower area is seen a small cavity. These are closed off on all sides by a plate of bone, or should I say they are hedged on every side by bone, never accessible except into the space of the nostrils [cavitas nasi]. The two chief cavities [choanae] extend into it with one foramen each; 111 they take in air from the nostrils during respiration, and they surround the nasal cavity together with a kind of soft medulla. I would like you to break open the cuneiform bone and closely scrutinize these cavities hidden inside, especially as they are shaped with astonishing skill and are little known by experts at dissection. They should also be carefully observed because Galen wrongly left it written that this bone is perforated like a seive or sponge and transmits cerebral phlegm. 112

The cuneiform bone is not perforated like a sponge
For it is by no means perforated by little holes of that sort, but appears continuous and solid throughout its surface; and if it ever lacks closed cavities, it is not at all different from the makeup and configuration of the talus, the calcaneus, or other such bone that is wrapped and covered on the outside by a continuous scale and is filled only on the inside with small cavities, as in the finest pumice. Where the cuneiform bone is so thick and faces the inside of the skull, it has a certain cavity [sella turcica, fossa hypophysialis] (M in figure 6) in which Nature has placed a small gland [hypophysis (glandula pituitaria)] (A in Book 7, figure 16) that receives the runoff of phlegm. 113 From this cavity, smooth passages then run on each side that carry off the phlegm. For it would be impossible, even if we should grant that this bone is perforated like a sponge on its surface, that phlegm would be carried by such foramina. But it will be more suitable to explain the passages or cavities hollowed out for the phlegm together with our presentation of the foramina of the head bones in the twelfth chapter, and to postpone the drainage of phlegm until the seventh Book, which will be dedicated to the brain. Here, our concern is with basic knowledge of the bones. The processes of the cuneiform bone which it shows inside the skull at the sides of the cavity mentioned will in the end be better understood when we have explained that cavity and the foramina of the bone.

The winglike processes
Besides those processes, the cuneiform bone puts out four others (P, P and 2, 3, 4, 5 in figs. 4, 5) on the outside near the base of the skull, two on each side, sticking out like the wings of bats, whence they are called pterugoeidei=j [processus pterygoideus, lamina lateralis et medialis]. 114 Between the wings, a hollow or cavity [fossa pterygoidea] is seen from which a powerful muscle ([D in the] 6th table of muscles) [m. pterygoideus medialis] originates which disappears in the mouth and draws the lower maxilla upwards. The processes protrude for the sake of this muscle’s origin, so that it may have a suitable beginning, and so that its beginning will be protected by them.

The eighth bone of the head
The eighth bone of the head (A, B, A in fig. 8; along h, L, Y in fig. 6) [lamina cribrosa ossis ethmoidalis], contained in the base of the frontal bone, is surrounded by that suture [sutura fronto-ethmoidalis] which separates it from the frontal bone and the cuneiform bone, as well as by that (g in fig. 1, ch. 9) which we have previously said runs in the lower part [vomer] of the nasal septum and separates this bone from those of the upper maxilla. Besides the nasal septum [lamina perpendicularis] 115 produced out of it, this bone is the seat of the organs of smell (C, D, E in figure 12, Book 7) and is pierced by many small foramina [foramina cribrosa] for the sake of smells, 116 yet upon inspection it looks thin and solid in substance. 117 It puts forth a long process [crista galli] (h in figure 6) into the skull cavity, dividing like a septum the places where the organs of smell are located. Indeed, to this process 118 is very tightly attached that part (H in fig. 12, Bk. 7) [falx cerebri] of the hard membrane [dura mater cranialis] of the brain which divides the brain’s right part from the left.

A bone inside the canine skull 119
This is how the bones of the head are arranged, forming a place where the brain is contained. Someone might think from Galen’s book De ossibus that another bone should be added to them which will be judged to be located in the brain; for at the end of his book, among the bones not described to medical students, Galen seems to have counted another in the brain. 120 It is perhaps a process 121 of the occipital bone that is quite evident in dogs, but it is never less apparent than in humans. In dogs, a broad, thin bone 122 comes between the cerebellum and the cerebrum where in humans we observe only the hard membrane of the brain (O, O in figure 7, Book 7). Since there is no other mention of this bone in Galen, it must be asked whether that canine process is what he had in mind, or whether someone prior to him mentioned it (as I believe Marinus had done) 123 and Galen never afterwards saw it in his cattle, whose brains he most often dissected, and was willing consequently to mention this bone only in a perfunctory way lest in his tractate on anatomy he seem to have omitted anything that other experts in dissection had mentioned in any way. As will be clearly shown in what follows, this was the case with the acromion or upper process of the scapula, when because of a few words of Hippocrates he reported that a certain third bone 124 is observed in addition to the clavicle and the acromion at the joint of those bones (Q to l in the skeletons).

Appendix A: Why the entire brain is surrounded by bones, and why these vary and are connected chiefly by sutures (1555 edition, pp. 31-32)
But although this helmet 125 [neurocranium et chondrocranium], making up the entire cavity in which the brain is contained, did not for any reason need to be constructed of various bones articulated together and capable of voluntary movement, nevertheless it consists of eight distinct bones 126 which are bound together by a structure of sutures [suturae cranii] or other strong and quite immovable, tenacious fabric [synchondroses cranii]; they are attached besides to the twelve bones 127 of the upper maxilla [viscerocranium], and together with them make up the skull [cranium] as occurs in cemeteries. Because that helmet is necessarily quite [differently] formed in different places, and since it was fitting that its osseous substance and nature vary significantly in hardness and thickness, in its depressions and processes, and in the fashioning of its great internal cavities, it could not be fashioned all of a single bone — not to mention that we commonly believe it is less exposed to injuries if constructed of several parts, since fractures and several other kinds of damage end with the bones themselves and do not go through the whole helmet like cracks in clay vases. Moreover, this crowded structure // 1555 p. 32 // of bones is conducive to the purgation of vaporous and smoky wastes; especially because the head resembles the roof of a warm house, 128 receiving wastes which rise upward and accordingly requiring greater ventilation, it was necessary that a hard and solid substance of bones, not full of holes inside and out, having no little foramina like sponge or pumice and consequently quite weak and excessively rough and harsh to neighboring parts, that such a substance provide an exit somewhere for this waste. This is provided by the various sutures of the bones. But this helmet or calvarium possesed sutures not only for the reasons mentioned but also particularly for the transit of those membranous fibers which attach the hard membrane [dura mater cranialis] of the brain to the skull itself 129 outside the ambit of certain vessels; and by the presence and benefit of the skull the fibers quite nicely (as we shall explain in the seventh book) support and, as if suspending it, preserve the cerebrum, which would otherwise collapse because of its softness and crush its own ventricles and cavities. Consequently we believe that the sutures are provided chiefly because of the hard membrane of the brain, and for the fibers that pass through the sutures and when widened and unfolded make up the membrane 130 that covers the skull on the outside, and that the sutures are distributed in accordance with the shape of the brain, which imitates the cavity of the bones of the head. Because, therefore, the oblong body is appropriately sustained along its length by fastenings and attachments 131 as well as by transverse tensions, and is held as if in suspension, the shape of the head that is called natural has in the first place three sutures. 132

Appendix B: On the occurrence of cohesive squamous joints instead of sutures (1555 edition, pp. 33-34)
But at the same time three sutures, most particularly the coronal, produce for me the likeness not so much of a suture as of a harmonia [sutura plana]. 133 Of the cohesive squamous joints with which this account is concerned, the part nearest to the coronal suture (from H to A in figures 3, 4) [s. sphenoparietalis], to the vertex (I 134 in figure 3), and to the bone that we compare to a wedge [os sphenoidale] (O in figures 3, 4) // 1555 p. 34 // must be considered a mutual attachment; likewise the most anterior region [sutura sphenofrontalis] (b under A in figures 3, 4) of the cohesive joints will be referred to the bone of the forehead [os frontale] (to L and O in figures 3, 4) and the cuneiform bone [os sphenoidale], exactly as if Nature had established them here rather than sutures because the part of the skull that is covered by the temporal muscle [pars squamosa ossis temporalis] (G in the 4th table of muscles) as by a kind of quilt or coverlet, did not need to be as thick (lest it be unnecessarily heavy), and the unfleshed 135 regions of the skull as well as its base, which had to be notably thick and irregular because of many cavities and foramina (which the accounts of the temporal and sphenoid bone will identify), so they, lest they come to harm or other damage too directly, are thick. Yet they are not entirely hard and solid, but porous (in figure 2, ai between ei and oi) between two dense plates, primarily to avoid weight. 136 Since, therefore, the entire area of the skull where these cohesive joints occur could be made thin, the sutural structure that requires larger, thicker bone surfaces would have been weak here. Besides, the bones coming up from the base [os temporale et os sphenoidale] (N, O in figure 3) are harder than those descending [os frontale et os parietale] (L, l in figure 3), and for this reason also the cohesive joints [sutura squamosa] are so fashioned that the plates of the harder bones rightly come up on the outside while those of the softer are placed inside, and are as it were covered by the more solid plates in an otherwise level surface. Because the temporal muscle is the principal cause of these cohesive joints, it shows their location [sutura parietomastoidea] (from C to G in figures 3, 4), coterminous with the lambdoid suture, which looks like a suture over the same distance as the unfleshed portion of the skull extends and the bones themselves are thick. Indeed, at the anterior end of the cohesive joints [sutura sphenofrontalis] (from b towards g in figures 3, 4) we see a type of suture where the bones constituting the upper maxilla [os zygomaticum, sutura frontozygomatica] (Q, Q to L in figures 3, 4) turn out thick like the bones of the head, so that over their entire course these cohesive joints are not altogether squamous.

Appendix C: The cuneiform or sphenoid bone (1555 pp. 39-41)
Toward the sides and in the temporal hollows [fossa temporalis] it is thin, extremely solid, and dense. But in its middle [os sphenoidale, corpus], and still more at the base of the head, it is by far the thickest of all the bones of the entire head, though by no means at the same time the densest and most hard. For in the middle of its thick part [corpus], between the surface coterminous with the brain or the hard membrane [dura mater] of the brain, and the surface which faces the cavity of the mouth, rather like the hollow images which we see poured from wax, it is empty and hollow [sinus sphenoidalis] almost in the same way as the frontal bone [sinus frontalis] near the brows is empty, or the fourth bone of the upper maxilla [sinus maxillaris] where the sides of the nostrils are located. This is partly for the sake of the voice and partly to avoid weighing a person down with too much weight as they would if they were solid all the way through, though their thickness is necessary for the common use of the bones. 137

The nature of the middle region of the cuneiform bone
The region [corpus] of the cuneiform bone that is hollow in this way thus shows two distinct chambers [sinus sphenoidalis] (C, D in figure 8) separated by a thin, bony septum [septum intersinuale sphenoidale] (E in figure 8) in whose lower portion, where it is split as it were into two, there is a small chamber (G in figure 8) just as if the septum in this hollow place were promoting the strength of the bone as a whole like a wall in the middle of a house. This cavity is covered by a continuous plate and is never perforated except into the cavity of the nostrils, to which it extends via two foramina [apertura sinus sphenoidalis] (one of them marked F in figure 8) that admit air. Nothing but air is contained in this cavity, along with some soft medulla 138 not proportional in size to the spaces in which it is contained. If these chambers [sinus] are ever not present in certain skulls, Nature has provided for the thickness of this bone in the same way (this is in the figure inserted in chapter 1 at A, B and L, L, m) as the ankle, the heel, or the appendices of these bones are formed. For in such a case it is made porous inside like more solid and compact pumice or sponge [osseus spongiosus], and on the surfaces of its structure continuous but not thick plates [osseus compactus] are drawn over it. Whether the thick part of the cuneiform bone is composed in this fashion or contains the chambers, its inner surface [sella turcica, fossa hypophysialis] (where M is located in figure 3, chapter 12) which faces the brain, I never see it rough, porous, or full of little foramina when the bones are healthy and undamaged by decay, 139 but smooth like the neighboring surface of the head. This interior surface // 1555 p. 40 // of the cuneiform bone (M in figure 3 chapter 12) has a broad depression containing a gland [glandula pituitaria] (A in figures 16 and 18, book 7) by which phlegm is dripped into the brain. The most prominent parts [sella turcica, processus clinoideus anterior, et p. clinoideus posterior] (the four angles around M in figure 3, chapter 12) of this depression are like four processes to which the hard membrane [dura mater] of the brain is strongly attached and which somehow or other resemble the lower part of a litter or table and are therefore called klinoeidei=j (clinoid). From this depression, two oblong depressions [sulcus caroticus] (O, P in figure 3, chapter 12) run off in both directions in which the sleep arteries [a. carotis interna] (c, c in figure 16, book 7) lie, and through which phlegm is seen to run down to the foramina (G, H, Q, R, S, Y in figure 3, 140 chapter 12) which are carved out chiefly to transmit separate veins, arteries, or nerves, and to certain fissures 141 (N in figures 2 and 3, chapter 12) common to the cuneiform bone and temporal bones. I shall deal with the foramina and depressions on the entire skull in the twelfth chapter; here, however, passing mention is necessarily made of some of these for an account of the cuneiform bone, to make it clear that this bone does not seem to me full of pores on the surface near the brain or without a covering of a plate or smooth bone [osseus compactus], or that it resembles pumice or sponge [osseus spongiosus]in the way that a broken-off epiphysis does (A in the figure inserted in chapter 1), or the bone of the vertex between its plates (like ai between ei and oi). 142 Now many people, more given to the opinions of writers than to the truth, quibble that I am unwilling to see such small foramina, thinking that phlegm must percolate through the pores and small foramina resembling spongy fabric (as Galen taught); 143 and some, while considering my view about the purging of phlegm, believe Galen thought otherwise because they have persuaded themselves that in the ninth book of De usu partium the word h)qmw=, i.e., seive or colander, was written there by copyists and scribes instead of sfhni/ or wedge when Galen, while explaining the exit of phlegm to the palate, says that the gland [glandula pituitaria] into which the phlegm of the brain is dripped is received from the cribriform bone [os ethmoidale, lamina et foramina cribrosa]. It is just as if Galen had “not even in a dream” (as they put it) thought that the phlegm in the cuneiform bone percolated through the pores and torturous foramina that do not pass directly through it, that is, if it had been read that the gland was received from the wedge-shaped bone [os sphenoidale]. But at this point in the description of the cuneiform bone, as nowhere else on the occasion of some term or another which may be wrong-headed, I do not disagree with Galen. For however much a recently used term may change, the meaning of an entire book could not be so vitiated that we would not be able somehow or other to follow Galen’s meaning. When Galen in the eighth book of De usu partium stated (inaccurately) that the organs of smell [tractus olfactorius] (C, D in figure 12, book 7, L, L in figure 13; but they are not hollow like channels) put forth processes like nerves from the anterior parts of the front ventricles of the brain [ventriculus lateralis] (LM, LM in figure 4, book 7), and of two channels like phlegm when it comes out a little more profusely than it should, diffuses it to the small foramina [lamina et foramina cribrosa] (I over L in figure 3, chapter 12 and D, D, G, G in figure 13 book 7) carved out to transmit odors, and saying that phlegm percolates through them, he has distinguished the time of painstaking percolation from the time of passage when something is poured through a seive that is perforated straight through. 144 In the ninth book of De usu partium when he is about to complete his entire account of the purgation of cerebral wastes, he examines in detail the first reason why the bones of the vertex, forehead, occiput, and temples needed to be porous and full of foramina for the purgation of smoky and quite minute wastes. 145 Then, when he reasons that such a rough construction could not be made there, he finds that sutures assist this elimination, and gradually he constructs reasons why there needed to be porous bones full of small foramina in the base of the head for the purgation of phlegm rather than a continuous plate coated inside and out. And so when he discovers the necessity of its composition (quite cleverly, as he himself thinks), in order to bring the phlegm to that composition he soon adds that he has described two passages in the eighth book (themselves presumably organs of smell) by which phlegm is taken to the nostrils, and here two others to be explained besides which are carved in the material of the brain, meet [hypophysis, infundibulum] (D in figure 14, book 7) in their own depressions, and carry phlegm into a wine ladle (cyathum) (C, C [glandula pituitaria] in the same figure, and from E [infundibulum] to F [foramina durae matris] in figure 15) and funnel formed from this membrane of the brain, through which it // 1555 p. 41 // flows in turn into a gland [glandula pituitaria] (A in figures 16, 18, book 7). While mentioning this, Galen brings the phlegm to the bony construction [os ethmoidale, lamina] that he inferred in his conclusions must be porous and full of holes [foramina cribrosa] for the sake of phlegm. 146 Then again concerning the way it percolates, he so proceeds that he gives the same account in the eighth and ninth books, and describes no other way for the descent of the phlegm to the palate but through the small foramina [ff. cribrosa] hollowed out for odors. So since the substance of the little chambers which Galen propounds throughout this structure resembles sponge and pumice, and since he so painstakingly distinguishes the way of percolating through a spongy body (which we see happen in the so-called cisterns of the Venetians 147 ) from what happens through a colander, and confutes the ancients as if they had been ignorant of its function, it must have been clear to anyone what Galen’s view is, anyone who did not believe that phlegm runs down through large, straight foramina that are open on both ends as we see in the cuneiform bone, without a ridiculous and quite incompetent delay, no matter how the language which I have been discussing is interpreted. But what Galen [said] in the eleventh book of De usu partium, where he everywhere called the bone “cuneiform” and elsewhere in that work he named the palatal bone (though it scarcely touches the palate), and what in accordance with his own view ordinary physicians call it the colander bone, 148 and likening it to a wedge, they have passed on the tradition that it is dense and hard but nonetheless have not forgotten the little foramina in it that purge phlegm, they judge the same as they do many things that occur in Galen. I will not mention how beautifully it harmonizes; the vacant or empty area [sinus sphenoidales] (C, D, G in figure 8) of the cuneiform bone, the chambers, and the construction of the entire bone here attest how consistent with their own true nature they are; how on account of a strength made for itself and meant to be established in the material of the brain, the infundibulum, the thin membrane, the gland receiving the phlegm, and in countless other parts rather than in the bone, it produces here a rare and special appearance: not considering that the occipital bone where it meets the cuneiform bone [synchondrosis spheno-occipitalis] (n in figure 5, P in in figure 6) is nowhere less dense and hard than here, and is therefore constructed of a kind of epiphysial material because it needed to be thick at that point but not so hard and dense. But since this account is not concerned with refuting objections that people throw in my path or with seriously expounding of the purgation of phlegm, we shall simply complete what remains of our account of the cuneiform bone. On its lower surface, where it is rough primarily for the tunic that surrounds the cavity of the nostrils and is attached to the bony nasal septum [vomer] (S in figure 5), it puts forth four conspicuous processes [processus pterygoidei, lamina medialis et lateralis] (P, P in figures 4 and 5, and numbers 1, 2, 3, 4), two on each side, thin and prominent like the wings of butterflies: from their appearance they are called pterugoeidei=j, pterygoid.

Appendix D: A cartilage or bone in the brain
But since Galen elsewhere 149 mentions a cartilaginous or osseous substance located next to the gland in the brain (L in figure 7, book 7) that is compared by anatomists to the look of a pine cone [corpus pineale], and for this reason one might find lacking something apparently omitted in my account of the bones of the head, I would like to advise those concerned that in the skull of a dog, unlike that of man, a wide and quite thin bone is seen originating from the occipital bone, laid over the entire upper surface of the cerebellum in the same way as we see the process [tentorium cerebelli] (O, O, O in figure 7, book 7 and V, V in figure 8, book 7) of the hard membrane [dura mater cranialis] of the brain covering the cerebellum in humans, parting and separating it from the cerebrum where the latter presses upon the cerebellum; this process is extremely hard and thick at the point (next to V [venae internae cerebri] in figure 7, book 7) where it brings vessels [vena magna cerebri] (H in figure 6, book 7) in its own pocket into the anterior ventricles [ventriculus tertius] of the brain next to the recently mentioned gland 150 (T in figure 7, book 7). The hardness of this part or area has seemed to some so great in certain animals that they have called it cartilaginous or even osseous — unless perhaps people disputing about the cartilage or bone of the cerebrum knowingly referred to that thin, wide canine bone, even though it never occurs in man. But no one should fail to realize that most of the ancients presented as confused an anatomy of many animals as Galen did.

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]