_What are the Bastard Sutures?_ They are those that are call'd _Squamous_ or scaly. _What is the disposition of natural situation of these false Sutures?_ They are plac'd at the two sides of the Head, and make a Semi-Circle of the bigness of the Ears, round the same Ears. _What difference is there between the true and spurious Sutures._ The true Sutures are made in form of the Teeth of a Saw, which enter one into the other; and the false or Bastard ones are those that resemble the Scales of Fishes, which {82} are join'd together by passing one over the other. _What is the Use of the Sutures?_ The Ancients were of Opinion, that they were made to hinder the Fracture of one Skull-Bone from passing thro' the whole Head; but there is more reason to believe that they have the three following Uses, that is to say, 1. To promote the transpiration of the Brain. 2. To give Passage to the Vessels that go to the _Diploe_. 3. To retain the _Meninges_, and to support the Mass of the Brain, which is cover'd by them. _What are the Names of the Bones that compose the Skull?_ The Bone of the fore-part of the Head is call'd _Sinciput_, or the Fore-head-Bone, as also the _Frontal_ or _Coronal_ Bone. The Bone of the hinder-part, enclos'd within the _Lambdoidal_ Suture, is term'd the _Occipital._ The two Bones that form the upper-part, and are distinguish'd by the Sagittal Suture, bear the Name of _Parietals_, one being on the Right side, and the other on the Left. And those behind the Ears are call'd _Temporal_, _Squamosa_, or _Petrosa_. These also are distinguish'd into the Right and Left Temporals, and are join'd to the bottom of the Parietal by a bastard squamous Suture. _What is most remarkable in the thickness of the Skull-Bones?_ The _Diploe_, which is nothing else but a _Plexus_ or Contexture of small Vessels, that nourish the Bones, and in the middle of their thickness make the distinction of the first and second Tablature of the Bones; whence it sometimes {83} happens that an exfoliative Trepan, or Semi-Trepan, is sufficient, when the first of these two Tables is only broken, the other remaining entire. _Is the Brain which is preserv'd in the Skull all of one Piece, or one equal Mass?_ No, it is distinguish'd by the means of the _Meninges_ into the Brain it self, and the _Cerebellum_ or little Brain; the Brain, properly so called, takes up almost the whole Cavity of the Skull, and the _Cerebellum_ is lodg'd altogether in the hinder-part, where it constitutes only one entire Body; whereas the former is divided into the Right and Left Parts by the _Meninges_, which cut it even to the bottom; whence these Foldings are call'd _Falx_; i. e. a _Scythe_ or _Sickle_. _What is chiefly remarkable in the Substance of the Brain?_ The Ventricles or Cavities which are found therein, together with the great Number of Veins, Arteries, Lymphatic Vessels, and Nerves, that carry Sense to all the Parts of the Body, and Spirits for their Motion.