CHAPTER V. 
BONES OF THE LOWER LIMB. 
S fcmoris (Tab. xxvii.) at its upper end has a round 
head, which is received into the focket of the os inno- 
minatum. In moft quadrupeds this head is oblong, and 
makes a firmer articulation; but that fhape will not al¬ 
low of fo much motion as a rounder head. The two 
procefles near the head are called the greater and lefi 
fer trochanters, which are evidently formed for the infertion of mufcles, 
as the neck which lies between thefe and the head, is formed to make 
room for that neceflary quantity of mufcles which are feated on the in- 
fide of the thigh, and alfo by proje&ing outwards to make long levers 
for the mufcles, which are inferted into its upper and external parts. 
Between the great trochanter and the neck is a large finus, into which 
mufcles are inferted; between the two trochanters is a remarkable rough- 
nefs for the fame ufe, from which begins the linea afpera: The middle 
of this bone for the conveniency of the mufcles is bent forwards, which 
would make it fubje£t to break backwards, if there was not a ftrong ridge 
on the back fide, which ftrengthens it fufficiently, and ferves alfo for ad¬ 
vantageous inlertions for feveral mufcles; this ridge is called the linea a- 
lpera. At the lower end of this bone are two large heads called the outer 
