AS TO SOUNDNESS. 59 
structure, take place simultaneously, and spread over a 
‘considerable time. I have before shown that the dine of 
direction of weight is through the long axis of the pha- 
langeal bones, and we find that this comes out at the 
‘point of the frog. For purposes of illustration to-day 
we take two sections of the foot—both vertical sections, 
but one from before backwards, exactly through the 
centre (see Fig. 3'), and the second from side to side, 
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Fic. 3. 
through the long axis of the phalangeal bones, coming 
‘out at the point of the frog using the anterior section 
(see diag. 2, fig. 3). In the first section we get sym- 
metrical halves; but the section of the.coffin bone will 
mislead you if you do not remember its wings, which you 
do not see, but which extend much further back than 
the surface of the same bone which is open to view. 
The anterior part of the second section of the foot 
shows the coffin bone resting upon an arch. This arch 
is formed of the bottom part of the wall of the foot, on 
