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

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.



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