used for creeping in salamanders, lizards, turtles, crocodiles; the long
and thin legs of good runners, as the hoofed animals; the mobile legs of
the apes used for climbing; and the parachute legs of some squirrels
used for soaring. Even more striking is the great variety of hands and
feet, as seen in the flat, hairy foot of the bear; the fore-foot of the
armadillos, carrying long, sickle-shaped claws; the digging foot of the
mole; the plump foot of the elephant, ending in a broad, flat pad with
nails around the border, and without division into fingers; the hand of
man and of the apes ending with fine and delicate fingers for grasping.
To have discovered a general plan of structure running through such a
great variety of forms was proclaimed a triumph of anatomical study.[3]
Footnote 3:
This paragraph is a free translation of Fleischmann’s text.
A study of the bony structure of the limb shows that typically it
consists of a single proximal bone (the humerus in the upper arm, the
femur in the thigh), followed by two bones running parallel to each
other (the radius and ulna in the arm and the tibia and fibula in the
shank); these are succeeded in the arm by the two series of carpal
bones, and in the leg by the two series of tarsal bones, and these are
followed in each by five longer bones (the metacarpals and metatarsals),
and these again by the series of long bones that lie in the fingers and
toes. Despite the manifold variety of forms, Fleischmann admits that
both the hind- and the fore-limbs are constructed on the same plan
throughout the vertebrates. Even forms like the camel, in which there
are fewer terminal bones, may be brought into the same category by
supposing a reduction of the bones to have taken place, so that three of
the digits have been lost. In the leg of the pig and of the reindeer,
even a greater reduction may be supposed to have taken place.
Fleischmann points out that these facts were supposed to be in full
harmony with the theory of descent.
Public-domain text, read in full here on John Shaqi.
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