ATROPHY OF THE PLANTAR CUSHION. 
415 
On what basis does the admission rest? Upon a pretended 
immobilization of the wall by the nails which secure the shoe. 
For the nails being an obstacle to the expansion of the regions in 
which they are implanted, viz, the anterior parts of the wall, these 
must be expansible. But w r e know that the os pedis receives no 
real displacement; it is then impossible to admit that at every 
step of rest, an expansion of the regions of the wall which 
adhere to it, would take place, without having a stretching of the 
laminae, of the podopliyllous and keraphyllous tissues. 
-Though we were well satisfied of the iiiexpansibility of the 
anterior regions of the wall, we have experimentally proved it. 
To that effect we took a double impression of the contour of the 
wall in two different conditions. In a first operation the foot, 
being properly pared, rested upon a board covered with a sheet of 
white paper, the board being raised a little from the ground, so 
that the foot supported only the weight of the extremity. In 
this position the outlines of the inferior border of the wall was 
taken. The second operation was made with the foot at rest, an 
assistant on the back of the animal to increase the pressure at 
rest, and the opposite foot raised. We have repeated these ex¬ 
periments a number of times upon animals four or five years old; 
and so as to make them more rigorous, we sometimes placed upon 
the inferior border of the wall a thin metallic plate ; and always 
we have obtained two drawings which corresponded exactly to 
each other, at least as far as the anterior regions were concerned, 
those in which the nails are implanted. (In these experiments 
we took no notice of the posterior regions.) 
Therefore the nails which fix the shoe cannot immobilize 
regions which are already immovable ; they cannot prevent the 
motion of the expansion of the posterior regions, if this motion 
exists, as this question is yet doubtful. We must even acknow¬ 
ledge that if this one existed, it would be favored by the pres¬ 
ence of the shoe—as the motion of laterality would be easier 
upon a Hat and smooth surface, as the shoe, than upon the 
ground. 
It is only in young subjects, when the foot is still developing, 
that shoeing might produce a stop in the growth of the anterior 
