THE BONY SKELETON. 49 
_ bones are very closely packed and tightly bound together with ligaments, 
so that the wrist is as. strong as if it consisted of 
but a single bone ; while, at the same time, the ei it vy 
elasticity obtained by having so many bones mov- ; ate I fie 
able on each other, neutralises, to a great extent, 4 no [i hs 
a shock occasioned. by falling on the hands. Next ,\\ [le y, 
to the carpal bones come the 5 metacarpal} (11— (> [\ [ | [| [|x ap Mh hy 
11), which form the comparatively long bones of CBM tw 
the back of the hand. Last of all, come the 14 IR © 
phalanges? or bones of the fingers (12—14), a name j [| Lm urls 
also applied to the corresponding bones of the foot. 
(2) Tae Lowrer ExTREMITIES—THE Lecs.—The 
plan of the bony framework of the legs is very 
similar to that of the arms. The principal point of difference is, that 
the structure of the former is stronger, in order to support the weight 
of the body; strength and solidity being in the lower limbs of even 
more importance than freedom of action, which we saw to be so 
well provided for in the arms. The whole framework to which the 
lower extremities are attached, and which also forms a basin-like cavity 
for supporting the contents of the abdomen, is called the pelvis? (6 in 
fig. 43). In a full-grown person, the pelvis consists of a single bone, called 
the os innominatum or ‘nameless bone.’ On the under side of the 
spreading part of the pelvis is a cup-like socket, to receive the rounded 
head of the thigh-bone. The deepness of the socket here, while it does 
not allow so much freedom of action to the leg, makes the joint a very 
secure one (compare what is said on the shoulder-joint, page 48). In the 
thigh there is only one bone, the femur# (7 in fig. 43), which is jointed at 
the knee to the two bones of the leg proper. These are the tibia,® or 
shin-bone (8 in fig. 43), the larger of the two, and the fibula® (9 in 
fig. 43). It is the tibia alone which supports the thigh-bone, so that the 
fibula, as its name indicates, forms merely a sort of connection between 
the knee-joint and the ankle, and serves for the attachment of muscles. 
On the knee-joint, which is a pure hinge-joint, is a small separate bone, 
the patella,” or knee-pan (10 in fig. 43), the object of which is to change 
the direction of the tendons of the muscles that come down from the front 
of the thigh to be inserted in the tibia, so as to enable them to act more 
advantageously, according to the principle afterwards explained (sce p. 52). 
THE Foor consists of 26 bones, which are arranged on a plan very 
similar to, if not identical with, that of the hand. In the hand, we had 
ee 
pon 
i 
1 From Greek meta, after, or coming after. 
2 From Greek phalangz, the lines of an army drawn up in battle array. 
3 Latin, ‘a basin,’ 4 Latin, ‘ the thigh.’ 5 Latin, the ‘shin-bone.’ 
6 Latin, ‘ that which fastens two things together.’ 
7 Latin, diminutive of patina, a pan or dish. 
D 
