It hath two Pair, _viz._ the _Erectores_ or _Directores_, and the _Dilatantes_: The _Erectores_ arise from the internal part of the _Os Ischion_, under the beginning of the _Corpora Cavernosa_, where they are inserted, and retake their Fibres in their Membranes. The _Dilatantes_ or _Acceleratores_ have their Source in the _Sphincter_ of the _Anus_ and slipping from thence obliquely under the _Ureter_, are join'd to the Membrane of the Nervous Bodies. _How many Muscles are there in the _Clitoris_?_ {37} It hath two Erectors which spring forth from the Protuberance of the _Os Ischion_, and are inserted in the Nervous Bodies of the _Clitoris_. There are also two others suppos'd to be its Elevators, which proceed from the _Sphincter_ of the _Anus_, and are terminated in the _Clitoris_. _How many Muscles are there in the _Anus_?_ There are three, _viz._ the _Sphincter_, and two _Levatores_. The _Sphincter_ is two Fingers broad, to open and close the _Rectum_. This Muscle being double, is fasten'd in the fore-part to the _Penis_ in Men, and to the Neck of the _Matrix_ in Women, as also behind to the _Coccyx_, and laterally to the Ligaments of the _Os Sacrum_, and the Hips. The two _Levatores_ arise from the inner and lateral part of the _Os Ischion_, and are fasten'd to the _Sphincter_ of the _Anus_, to lift it up after the expulsion of the Excrements. The _Bladder_ hath also a _Sphincter_ Muscle to open and shut its Orifice. * * * * * CHAP. X. _Of the Muscles of the _Omoplatæ_, or Shoulder-Blades, Arms, and Hands._ _How many ways doth the _Omoplata_ or Shoulder-Blade move, and what are its Muscles?_ The _Omoplata_ moves upward, downward, forward, and backward, by the means of four proper Muscles, which are the _Trapezius_, the {38} _Rhomboides_, the proper _Levator_, and the lesser _Pectoral_, or _Serratus Minor Anticus_. The _Trapezius_ or _Cucullaris_ hath its beginning in the back part of the _Occiput_, or hinder part of the Head, in the Spines of the six lower _Vertebra's_ of the Neck, and of the nine upper of the Back, in passing from whence it is implanted in the Spine of the _Omoplata_ or Shoulder-Blade, and the external part of the _Clavicula_, as far as the _Acromion_. This Muscle produceth many Motions by reason of its different Fibres, drawing the Shoulder-Blade obliquely upward, downward, and forward. The _Rhomboides_ is situated over the _Trapezius_, its rise being in the _Apophyses_ of the three lower _Vertebra's_ of the Neck, and of the three upper of the Back, but it is afterward join'd to the whole _Basis_ or Root of the _Omoplata_, which it draws backward. The proper _Levator_ commenceth in the _Transverse Apophyses_ of the four first _Vertebra's_ of the Neck, by different Progressions, but is afterward re-united, and inserted in the upper Corner of the _Omoplata_, which it draws upward.