New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1876-09-23
EVIDENCES OF EVOLUTION.
Continued from first Page.

one ON each side. Aud those bones are obviously
md paply aud can be readily shown to be tine rudl-
ments of the bone which ! am now touching IN my
own hand-the metacarpal' bones OF the sec
ond and of the fourth hnger-so tnat we may
saw that In the horses fore limb the radius and ulna
aTe fused together, that the middle part OF the ulna
ia excessively narrow and that the loot is feduceu
to the single middle finger, with rudlments OF the
two other fingers, one on eaeh SIDE OF IL. 1hose
facts are represented in the diagram now snow
ven of the recent horse Here is the lore limD poht
ing to the diagraml, with the metaearpal DGnes ana
tile little splint bones, one on each SIDE ~ solhe-
times happens that by way Of a monstrosity you
may have an existing horse MIN q. oS IL io
Let me now point out to you what are the ehaIac-
teristcs of the hindlimb. This pointing 10 the ma
raml is the shin bone of the horse, and u appears
at first to constitute the whole of the leg But there
Is little splint this point lllustratlngl when is
fhe rudiment Of the small bone OF the leg-What Is
called the fbnlaand then there IS connected Win
this great bone little nOdue which represents Ihe
lover end of the fbula in just the same way as that
little nOdule in the fore limb represents tine loWer
end of the nina So that in the leg we have modl-
fication of the same character as that when exists
An the fore mbthO suppression OF the greater part
of its lower end with the lbla. SO, again,
We find the same thing II we turn, 10
the remainder of the leg. This lshowlngJ ls
the heel of the horse and here is the great medlan
toe answering to the third toe IN our own toot ana
here we have upon each side two lltue spnnt BONES
Just as in the fore limb, which represent the rual
ments of the second aud the fourth toes-rudunehts
that is 10 say, of the metatalsal bones, the re-
manning bones having altogether Va ansIfoI
d,et me beg your attention to these peculiar,
tiles because shall have to refer to them py anu
by Tho result Of this Modification is that the lore
and hind limbs are converted into long sOll0
spriney. elastic levers which tie great lnstru-
ments of lOcomotiOn OF the horse
THE TEETH OF THE HORSE.
As might be expected, and as have already SAID
the apparatus for providing this machine with the
fuel which it requires is also OF very highly diner
entiated character horse has. or rather may
have A teeth but 1T rarely happens that IN our
Al NI,nnA n for n
which will communicate drectly-and i'll mare 1t
commonly happens that you find no more than 80,
because the " tushesD or canine teeth Oh Uhe lnalc
are rarely developed Then thete are some curious
neculiarities about these teeth. rs every one VINO
has had TO do with horses knows, the cutting teeth
the IncsoTs-are six above and SIX peI9Ws
and those ncisors present what Is called nIh p
a certain age. Ii is sort of dark patch across Ihe
middle of the tooth. The presence OF that DARK
patch arises from great pecullarlty IN the stIuc-
fnre of tbe horses incsOr TOOTH 1t is in TACT III Sec
tjops shaped in this fashion llllusratlng considers
ably curved, and with deep PIT IN the middle anu
then long fang In the young fOal tS plt Is Nelg
deem AS the animal feeds, this space becomes hlleu
M with its fodder, that fodder becomes more
or less carbOnzed, and then you nave tle ILL., ia
aud the reason the dark mark serves a<sn lhuIcSt1
ton OF age, for the horse feeds this IS more anu
more worn down, until at last IN an ageu n4se T
tooth is worn beyond the bottom OIL lnS PIn' aio
the mark disappears. Then, as 1 sad, the maze
horse generally has canine teeth. We need not no
tice their structure particularly IN tl1 Ielnalo,
these are rarely present. Following that, yOn
NAV notice very small and rudimeDtaTy
tooth, but that is very often ~ Soself' the
grinding SERIES Then there are usually TO be ionhd
Six great teeth, with exceedingly long crowns Inc
crowns i'm fact, are SO long that the teeth take
very long time to wear down, whence ARISES the
possibility OF the great age TO winch hOrses eOlno-
times attain. This Is shown IN the slde olagrat,
Then the pattern and structure of a horses tOOth
are very curious The crown of the horses tooth
presents very complicated pattern that IS 10 say,
supposing this to be of the grinders OF the St
S;da Iinstrafinpl above there is kind OF wall like
a double crescent Then Ihere are TWO otucI
crescents which fall in that drectlon anu tleso arc
complicated by folds, and all the spaces ,between
these erescentic ridges hlled up by klnd OF poy
matter which is called cement. Consequently the
surface of the tooth is composed OF very uneven
materials-Of the hard mass OF the tooih, wmch Is
called dentine, then very much harder eHaInels
and softer cement between, the practlcal eIecI Vi
which is the as the Elimination Oh hliistoIe.
In consequence Of the laminatiOn of the nllistone
the ridges wear less swiftly than the intermediate
substance and consequently the surface always
Teens rouob and eNerts a crushing effect upon the
grain The same is true OF the horses tOotn, anu
consequently the grinding of the teeth one aganst
the other instead of hattenlng the surface OF the
teeth tends to keep them always irregular, ana thaI
has a very great influence upon the RAPID maStlca-
ton of the hard gTiSp or the nay upon winch Vle
i think that will suffice as brief indication
OF some of the most important pecqhaIlties ana
characteristics of the horse. 1t the hypothesis OF
Evolution is true, what ought to happen when we
inyestigate the history of this animal We know
that Che mammalian type, as whOle-that mamma
Gan animas-are characterized by the possession Oh
perfectly distinct radius aud ulra, Two separate
and distinct movable bones. we know IuIt tt1I
that mammals in general possess hye Toes, ElDed
nneoual but gtll as completely developed
as the five digits of my hand. We know
further that the general type OF mammal possesses IN
the leg, not only complete u9la' DuI Go aaIS
fibula The small bone OF the leg Is almost always
smaller than the tba. The small bone OF the leg IS
as a general rule perfectly complete, dlSlEct,
movable bone Moreover "a tne d OOt we we n do
in. the fore foot. Hence IT follows that we nave
differentiated animal like the horse when mas pro
ceeded by way of evolution OF grad9al m9alnG i
fiOn from a similar form possessing all the
characteristics we find in mammals IN general; II
that be true it follows that If there be anywhere
preserved in the series of rocks complete history
Of the horse, that is to say OF the various Stages
Through which he has passed, those stages ought
gradually to lead us back to some sort OF animal
which possessed radius, and an ulna and distinct
complete tiba and fibula and In which there were
five toes upOn the fore limb, less than upon the
hind limb. Moreover, in the average general mann
malian type, the higher mammalian, we ma as
constant rule an approximation 10 the nuiilDtt VI
teeth. two are canine, and the others of which
are grinders. In unmodihed mammals we
find the incisors have no P r1le ann increase ease
In size from that which lies in front toward those
which lie in the middle or at the hinder part OF the
series. Consequently, II the theory oi evoI f I
things have q foundation, we ought 10 ma ~ Ilo
series the forms which have preceded the Morse
animals in which the mark upon the lnclsor g graz
ually more and more disappears, animals IN when
the canine teeth present IN both sexes ana am
mails In which the teeth gradually lose the eOmpI,
cations of their crowns ana nave simpler anu
ehorter crown while at the same time they gradual
increase in size from the anterior end OF the series
toward the posterOr Let us turn 70 the Iaccs ana
see how they bear upon the requirements OF thls
doctrine of evolution
poas Ioor. ru4s 'ooL Solls. tS~rs
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