Northern Wisconsin advertiser. [volume] (Wabeno, Wis.) 1898-1925, 1901-01-17

the same SITUATION as the upper
part of the little toes of the hippothe-
rum, as these three-toed horses are
called, long slender bone, termed by
veterinarians the splint bone; and it
requires no anatomical training to see
that the bones in the two animals are
the same. The horse lacks the lower
part of his side toes. that is all, just
as man will very probably some day
lack the last bones of his little toe.
We find an approach to this condition
in some of the hippotheres even,
known as Protohippus, in which the
side toes are quite small, foreshadow-
ing the time when they shall have dis
appeared entirely. 1t may also be
noted here that the splint bones of the
horses of the bronze age are little
longer than those of existing horses,
and that they are never united with
the large central toe, while nowadays
there is something of tendency for
the three bones to fuse into one, al
though part of this tendency the writ
er believes to be due to Inflammation
set up by the strain of the pulling
and hauling the animal is now called
upon to do. Some of these three-toed
hippotheres are not in the direct line
of ancestry of the horse, but are side
branches on the family tree, having
become so highly specialized in GER
tain directions that no further pro-
gress horseward was possible.
Backward still, and the bones we
find in the Miocene strata of the west,
belonging to those ancestors of the
horse of the past and present, tell us
that then all horses were small and
that all had three toes on foot, while
the forefeet bore even the suggestion
of fourth toe. From this to our
Eocene hyracother with four toes is
only another longtime step. We may
go even beyond this in time and struc-
ture and carry back the line of the
horse to animals which only remotely
resembled him and had five good toes
to foot; but while these contained
the possibility of a horse, they made
no show of it.
Direct Evidence of GeneaIogy.
We have, then, this direct evidence
as to the genealogy of the horse, that
between the little Eocene hyracothere
and the modern horse we can pass by
gradual stages from one to the other,
and that as we come upward there is
an Increase in stature, in the COM
plexity of the teeth and in the size of
the brain. At the same time the num-
Der of toes decreases, which tells that
the animals were developing more
and more speed; for it is a rule that
the fewer the toes the faster the ami
NAL; the fastest of birds, the ostrich,
has but two toes, and one of these is
mostly ornamental; and the fastest
of mammals, the horse, has but one.
The collateral evidence, though
scanty, bears but the circumstantial
proof, derived from fossil bones, that
the horse has developed from a many
toed ancestor; and the evidence points
toward the little hyracothere as being
that ancestor. II remains only to
show some good reason why this de-
velopment should have taken place or
to indicate the forces by which it was
brought about. We have heard much
about the survival of the fittest,"
phrase which simply means that those
animals best adapted to their sur
roundings will survive, while those i'll
adapted will perish. But it shoule be
added that it means also that the ami
mails must be able to adapt them
selves to changes in their environ.
ment, or to change with it. Living be-
ings cannot stand still indefinitely:
they must progress or perish. And
this seems to have been the cause for
the extinction of the huge quadrupeds
that flourished at the time of the
three-toed Miocene horse. They were
adapted to their environment as il
was; but when the western mountains
were thrust upward, cutting off the
moist winds from the Pacific, making
great changes in the rainfall and
climate to the eastward of the Rocky
mountains, these big beasts, slow of
foot and dull of brain, could not keep
pace with the change and their
race vanished from the face of the
earth. The day of the little hyraco-
there was at the beginning of the
great series of changes by which the
lake country of the west, with its
marshy flats and rank vegetation, be-
came transformed into dry uplands
sparsely clad with fine grasses. On
these dry plains the more nimble-
footed animals would have the advan-
tage in the struggle for existence: and
while the four-toed foot would keep
its owner from sinking in soft ground,
he was handicapped when it became a
question of speed, for not only is a
fleet animal better able to flee from
danger than his slower fellows, but in
time of drouth he can cover the great
er extent of territory in search of
food or water. So. too, as the rank
PUSHES gave place to fine grasses.
often Drowned and withered beneath
the summers sun, the complex tooth
had an advantage over that of simpler
structure, while the cutting-teeth, so
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