IjECTURES on horses. 
551 
The Knee. 
The knee of the quadruped is the part which corresponds, anato- 
mically regarded, with the carpus or wrist of man : differently cir- 
cumstanced, and differently used as the two parts are, yet is there 
considerable analogy between them in structure. Each of them 
is composed of eight bones, though in the knee only six out of 
the number are placed so as to sustain pressure ; the remaining 
two being situated behind the others, out of the line of the superin- 
cumbent weight. One of these supplementary bones — called, from 
its shape, trapezium — is affixed edgeways to the outer part of the 
back of the knee-joint, and there answers the most important pur- 
pose of furnishing a lever for those muscles whose office it is to flex 
the leg : both celerity and force were required in this flexion or 
catching-up of the leg off the ground in action; and these are at- 
tained through the advantages the muscles derive in their action 
from the projection of the trapezium. When we see, therefore, 
great breadth of the outer side of the knee, and that its hinder part 
is very prominent, throwing the muscles attached to the point back 
and so increasing the breadth of the arm, we may pronounce such a 
horse to possess great power in flexing his legs, and commensurate 
strength and quickness in action. 
There are six small bones, then, sorts of irregular or mis-shapen 
cubes, placed between the two main straight shafts of support of the 
fore limb, viz. the radius above, the cannon-bone below. Upon the 
summit of the latter the three lower of these bones, ranged in two 
rows, rest ; while upon the three constituting the upper row rests 
the lower end of the radius. Why was the knee-joint constituted 
in this manner ] Why were these bones interposed ] Why was 
not the end of the radius connected by joint at once with the end 
of the cannon-bone 1 Because Nature had more objects to fulfil 
than could have been accomplished by any simple or single form- 
ation of joint. By a joint between the radius and cannon-bone 
the weight would have been quite as well sustained as it is at 
present ; but the concussion must have been greater : nay, the 
motion might have been as great even as it is now between these 
two bones ; but then, at the time that the leg was flexed on the 
arm to the utmost, how would the knee-joint in front have become 
exposed, and what must have been the consequences of a broken 
knee 1 or how could the animal with impunity have gone down 
upon his knees, in the act of lying down or kneeling, as he can 
now ] Suppose a sort of patella or knee-pan had been placed 
and fastened in front of the knee, would that have answered the 
purpose 1 Perhaps, as far as standing and motion are concerned, 
it would ; and, perhaps, some such contrivances as exist in the 
knee-joint of a man — 'the semilunar cartilages — might have been 
