Chap. VI. The Anatmy of aHOKSY.. 97 



by removing not only their Inlertions, but likewife their 

 Dircvftions from the Centre ,ot Motion. 



The Thigh-bone below its Middle becomes thicker, Irs 

 lower End terminating in an ample and broad Head : This 

 Head is form'd into two Procefles, betwixt which there 

 is a large Space that receiv-es a Protuberance of the Head of 

 the Leg- bone. The Ouifide of ihefe tv/o Proceiies is rough,, 

 but their Infide is fmooth, being covered with a Cartilage, 

 for the more eafy Motion of the Joiat. From them pro- 

 ceed fome of the Mufcles that move the Leg, and into, 

 them are inferied fome of thofe that move ihe Thigb, 

 Their Sides are full of fmall Holes, from whence arife the 

 Ligaments that ftrengthen the Patella or Stifle. 



In the Middle, between the two Heads, there are two 

 Cavities, the foremoft of which receives the Protuberation 

 of the Stifle bone, being covered with a Griftle for that 

 Purpofe. The other, which is deeper, is alfo rough and 

 unequal, receives the Protuberation of the Leg- bone. Be- 

 fides thefe, there is a Cavity on the Outfide of the outer 

 Head, and another on the Infide of the inner Head, thro* 

 both which the Tendons of the feveral Mufcles of the Leg 

 defcend. 



Where the lower End of the Thigh-bone ^^^ Patella 

 is joined to the upper End of the Leg bone, Stifle-par, ' 

 on the Forefide is placed a fmall Bone, 

 fomewhat round, called the Patella^ or Stifle-pan ; it is 

 plain without, but on its Infide it is a little convex, having 

 a Ridge which falls between the Jun6ture of the two 

 Bones 5 its Iniide is covered with a GriUle, and its Out- 

 fide with the broad Tendons of fome of thofe Mufcles 

 that extend the Leg, which keeps it firm in its Place, by 

 adhering clofely to it. This Bone not only ftrengthens the 

 Articulation of the Thigh and Leg, but alfo ferves as a 

 Pully for the Tendons of the Mufcles which pafs over it ; 

 and facilitate their Adion, by removing their Direction 

 from the Centre of Motion. 



The Tibia, or Leg- bone, to which the <rheTi\>iSL or 

 Thigh-bone is articulated, comes the next i,eg,hone. ' ' 

 to be defcrib'd. In a Horfe it is very diffe- 

 rent from what it is in Men, being long and round, and not 

 triangular, as in the latter, its upper Part is much broad- 

 er and thicker than its lower, and both receives and is 

 received by the Thigh*bpne, having two Cavities, and be- 

 twixt them a Prominence, which i§ alfo cover 'd with aCar- 

 H tilagej 



