THE BONES. 
39 
parts arising from the prevailing opinion that the part c d 
in the bird’s limb is the part which corresponds with what 
we usually term the leg, namely, B to c, that is, from our 
knee to our ankle; whereas, the hone b c in the limb of the 
bird is, in fact, its real leg-hone. For its thigh we must 
look still higher, hidden as it usually is, amongst the 
feathers, and, probably, by many, scarcely known to exist. 
The great difference between the limbs of birds and human 
beings consists in this, that what we are apt to term the leg 
of a bird is, in fact, the part which answers to our ancle. 
This will he easily seen by a little closer examination. Let 
us look, then, at the joint b in the two figures: in the 
human figure it is at once seen to be the knee, and on 
referring to the same letter in the leg of the bird, we shall 
find that it is the true knee also; for supposing it to kneel, 
that is, to bend its leg, so that the fore part of the joint 
should touch the ground, it can only do so at the joint B, 
it being as obviously impossible from the structure of the 
joint c, that it could bend the part c d forwards, so as to 
