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

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



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