well-known organization, it is said that this organization has
forced it to adopt the habits and the miserable condition it is in.

"I am far from thinking so; because I am convinced that the habits
which the individuals of the race of the _ai_ were originally
compelled to contract have necessarily brought their organization
into its actual state.

"Since continual exposure to dangers has at some time compelled the
individuals of this species to take refuge in trees and to live in
them permanently, and then feed on their leaves, it is evident that
then they would give up making a multitude of movements that animals
which live on the ground perform.

"All the needs of the _ai_ would then be reduced to seizing hold of
the branches, to creeping along them or to drawing them in so as to
reach the leaves, and then to remain on the tree in a kind of
inaction, so as to prevent falling. Besides, this kind of
sluggishness would be steadily provoked by the heat of the climate;
for in warm-blooded animals the heat urges them rather to repose
than to activity.

"Moreover, during a long period of time the individuals of the race
of the _ai_ having preserved the habit of clinging to trees and of
making only slow and slightly varied movements, just sufficient for
their needs, their organization has gradually become adapted to
their new habits, and from this it will result:

"1. That the arms of these animals making continual efforts readily
to embrace the branches of trees, would become elongated;

"2. That the nails of their digits would acquire much length and a
hooked shape, by the continued efforts of the animal to retain its
hold;

"3. That their digits never having been trained to make special
movements, would lose all mobility among themselves, would become
united, and would only preserve the power of bending or of
straightening out all together;

"4. That their thighs, continually embracing both the trunks and the
larger branches of trees, would contract a condition of habitual
separation which would tend to widen the pelvis and to cause the
cotyloid cavities to be directed backward;

"5. Finally, that a great number of their bones would become fused,
and hence several parts of their skeleton would assume an
arrangement and a figure conformed to the habits of these animals,
and contrary to what would be necessary for them to have for oth