( *05 ) 
and other Functions of the Probofcii ?. Tho’ it be very obfervable r . 
and of fgnal life, yet ’tis fo Ctuated, that I was not capable to 
give fuch a View, as might afford a true Idea of it, in any of the 
Figures of the Head : However, 1 have mark'd it Cr.r. Fig. i.) 
and ( m. m. Fig. 2) f S . S. pig. ;.J. Freni this flole the Os Max- 
tlU inclines 6 inches, toward the Root of the Teeth (». ) where 
we leave it, and return to 
The Os Zygomatic um {s ) (b.) ( i .) which, as in all other A- yj, e Os Zy- 
nimals, ferves for a Guard to the Mufcles which move the or , nm icuivu. 
Low r er Jaw. In Men, and feveral other Animals, ’tis form’d of 'fig. 1. 
a Production of the Os Tempora.'e, articulated with another from Fig. 2. 
the Os Malx t by a particular Suture, call’d Sutura tranfverfa ; but F‘g- i* 
here ’t s the molt diftinguilb’d Hone of all the Head ^ for being 
12 Inches long and two Inc: es broad, ’tis articulated with the 
Os Maxilla before, and running backward 6 Inches, it meets at 
ks upper part with a Production of the Os Calvaria (f.) as w e F/f. 2. 
may cull it, which accompanies its lower part other 6 Inches, and 
then terminates in an obtnfe Angle. ’Tis loofely join’d with this 
Production, and ; tis probable, that ’tis capable of confiderable 
Motion, upon the following Accounts. 1 . The Sinn* in the back- 
part of the Scull, as fhall be fliewn, for receiving the Condyles 
of the Lower Jaw, are larger than the Condyles themfelves, by 
which they have a pretty good fpace to move from the Right to 
the Left-, and the extremity of the Os Zygomaticum being their 
Guard on each fide at the outer part, which way they move, thefe. 
may befuppos’dto yield. 2. The Lower Jaw is of fuch weight,- 
that its Mufcles muffc require a great fpace to aft. in, and that may 
be conciliated by the Motion and Yeildingof this Bone. *. The 
Grinders of the Lower Jaw are much longer than thofe of the 
Upper, and therefore they require a greater fpace to move in, 
for the better Performance of Maftication, (becaufe the Up* 
per Jaw in this, as in raoft other Animals, is immovable) to 
which the Motion of this Bone mult very much aflift. Add to 
thefe, the manner of its Articulation ; for it refts upon the Pro- 
duction of the Os MaxilUbefote ; and behind it moves, as it were, 
to and fro, upon the Production of the Os Calvaria, which refts 
upon it 
The back-part of the Scull is next to be confider’d: At its ^ 
upper part the two Eminences formerly mention’d now appear J f ^ 
more confiderable, becaufe of the intervening Sinus, which from 
two Inches deep, and 10 Inches from the Right to the Left, be- 
comes. 
