The morning call. [volume] (San Francisco [Calif.]) 1878-1895, 1893-01-29
How the Horse Travelled
in the MioCene Age.
THE EVOLUTION OF THE HOOP.
A Short Study i'm Race-Making-A
Freak of Nature That Was Only
Reversion of Type.
Written for THE MORNING. CALL

tinct supeEnumerAIy teet on tach lOIeIeg'
Tie secondary feet were described as more
like toes than horses feet. while the feet
on which the animal walked were ike
those of any horse. veterinary had DIS
sected off the supeTfiuous appendices and
the colt was apparently as sound as any
of his kind. The country editor dis
eoursed wisely. in this connection, upon
freaks of nature, and searched the whole
animal kingdom for some probably handy
creature after whom the mare could have
marked" that foal.
He might have been spared that trouble
could he have known the readily ascertain
able fact that what he took for departure
from type. on the part of Mother Nature.
was in reality a reyersi0n Of type, going
back 10 the prehistoric day when the Great
ure we now know as the horse was
cushion footed toed animal, picking up his
living on the plains OF the early mloeene.
The toes were merely development Of
the "splint bones" on either side OF the
colts leg. All horses have the splint bones,
and few hundred thousand years ago they
used always to develop as toes. but EquuS
has had no use for them for ages. and So
like all unused organs and faculties in every
living thing, they have gradually dlsaD-
peared. Dame Nature is far too thrifty an
old lady TO waste energy and material in
the production of useless organs or tissues.
What we will TO do without she takes away
from us. like wise mother.
But why. when and how did eduus first
dispense with his toesp
These are questions calculated TO open M
whole realms OF interesting study. When
we see an animal for the first time we can
form some idea, even if we are not natural
ISIS, Of the mode Of life of the creature and
the sort of place in which be naturally
ba fvar hau al "a II A
creature from which the horse sprang are
found in the middle e0cene. He was q
traveller even then, but be had to travel
upon sand and the soft, yielding clay Of
that period. and with his first cousin, the
taplr and his big brother, the rhinocer0s,
he padded IN the mud and waded deep in
the soft muck of the half-made world. For
this sort of travel be needed broad. spread
ing toes. and be had them, armed with
stout nails with which to defend himself.
TIE seft sand and clay changed in the
early mocene to harder clays, limeStOnes
and sandst0nes; the bed of the eocene sea
was elevated and great plains were brought
10 the surface of lacnstrIne ana terrestrial
formation. and over these plains miohippus
r0amed in search Of pasturage. He had &c
travel long distances for il and 10 travel
rapidly; and gradually he began to find his
toes in the way on the hard ground. So he
took TO travelling on tptOe, so that the
hindermost toe of each foot was lifted from
the ground. From that time the doom OF
that toe was sealed. 1t sank first into
innocuOus desuetude. aud as time passed
aHophied, and finally disappeared alto
getheT, SO that the creature had but three
toes in front and four behind when the later
miocrne dawned
When, in the pliecene age. the fierce car
niv0ra, who had already arriyt d, began TO
camp on the trail Of little pliolippus he
was obliged TO hustle, not merely for his
living, but TO keep out OF tine reach OF his
enemies, and so lie Travelled so high upon
his tiptoes as to lift ali but the middle digit
of each foot entirely from the ground and
the two useless members began TO follow
in the way of their brothers who had gone
before. For ages they fingered like little
"dew-cia@s" on either side the middle toe,
which had grown hard and solid.
Now, II You want TO get a good idea
OF this process, spread out your fin
gers Oh the table before you, with the
palm, wrist ana arm perpendicular.
Then raise the fingers gradually until
the thumb and little finger are off the
table Imagine that from disuse they have
disappeared Raise the fingers stlll higher,
until only the TIP OF Tie middle finger rests
on the table. Now imagine your middle
finger nail transformed into a boof. The
joints OF the finger become those Of the foot
and pastern of The horse; the long metacar-
pal bone of the middle of the palm becomes
the cannonboue Of the horses leg. and the
wrist is his knee The same change took
place in the horses hind feet, so that what
we call the hoek corresponds to the human
heel
We are so accustomed to the sight Of
horse that we do net consider how wonder
full it is that creature of his size and weight
should be travelling absolutely aud literally
upon a single toe of each foot. This fact
explains in a great measure what to the I'M
initiated mind seems the astonishing fraiity
of equine legs. When old Applause, the
veteran raeeh0rse, fell while exercising on
the Bay District track and broke both hind
ankles some one asked me "wny n horses
leg breaks if he does but stub his toe" 1t
is not quite so bad as that. although their
limbs are very easily injured and require
careful and prompt attention when any
thing goes wrong with them. INC feet no
horse is common saying among horse
men, and the greatest care Is taken Of the
feet and legs of valuable horses. There is
no other creature among the .verte brates
whose organs of locomotiOn are constructed
like those of The horse. lie alone goes
on tiptoe. literally, as we'll as In the pie
turesqne language of the racing reporter
Had he been content to remain on his
native heath, the marshy and yielding
places along the borders of streams
ana lakes. where his relatives, the
tapir and rhinoceTos, sill linger. he would
doubtless have remained as he was, short
legged. broad-fo0ted, ive-tOed member of
the tapir family, but like bad little
eohippus he ran away from his home and
kith and kin, and took to the hard plains
so Nature did the best she could for HIM.
and fitted him out to survive under his
chosen conditions. He is pre-eminentiy
calculated to do so. His long, flexible neck,
turning readily to give his prominent eye
view OF the " hole landscape, his keen, we'll
set ears, and his marvellous sense Of smell.
all serve to warn him of an enepy's az
pToach, while the length of his limbs, the
peculiar angles at which they are set, the
frmResS. lightness aud stability resultant
from the concentration Of all muscular &c
ton upon a single toe of each foot. render
him able to run away from any creature
that pursues him, while IL taken at close
quarters his formidable heels are no mean
weapons OF defense.
The toed horse disappears altogether after
the pliocene age. and the true monodactyl
is the only one Of his species found in the
pleistocene period. The horse as we know
him has existed since then. the fossil re-
mains of that period differing but slightly
from those of the inferior specimens of the
modern horse.
just why eohippus cut loose from his
ponderous family and struck out for him.
self is purely matter of conjecture. There
may have been a family jar. he may not
have married TO please the old folks, he
may lot have liked the table spread for him
in the haunis OF his kind, or. most probable
reason, being smaller and more active than
the others. he wandered up from the
marshes and, finding the plains more
to the taste OF an enterprising
fellow like himself, remained there.
There was a general splitting up OF the
family in that early day. the result being
several different groups, some of which
have become extinct, and only the three
notifications mentioned, the horse, tapir
and rhln0cerOS remain TODAY Greatly dif-
ferentialed as these three now are, their
history. traced back step by step in the
geologic record. goes back If not to com-
mon ancestor at least to ancestors so nearly
alike as 10 leave no doubt of their common
origin. In an old work on these animals |
once came across the statement that the
horse differs from the tapir and rhinoceros
in having callosity on the inner side of
each leg. This Is d useful thing to know.
LII any render Of Lille CALL has any nnna