posterior margins are round._ Much of the original coating of the crusta
petrosa is retained, but in colour it may not at this time be dark. At
those places where it has been recently worn down, it is often of a
yellow tint, which is but a little deeper than the enamel, which last,
however, is nevertheless easily distinguished by its greater
transparency and more pearly appearance. This peculiarity in the crusta
petrosa not unseldom gives to the six year old mouth a darker aspect
than is presented by the teeth of the younger animal; and the author, to
convey to the reader some idea of this fact, has purposely rendered the
incisors of the next representation of the mouth, as they frequently are
seen. Such a circumstance, however, will not confuse the judgment. The
corner nippers still look young to him who is acquainted with those
signs which denote youth in the horse's teeth, and the coloured
engraving will convey a fair idea of the aspect they now put on. The
corner nipper, in fact, after the fourth year, leads, in a great
measure, if it does not entirely sway, the judgment. This tooth is
sometimes called the shell tooth, on account of its infundibulum being,
for the most part, better exhibited and longer retained than in the
other incisors. The tables, however, of the other teeth should also
receive some attention: those of the centre nippers may exhibit the
infundibula shallow, or, in certain instances, when the crusta petrosa
which lines these cavities is very thick, no infundibula may be
distinguishable: even then, however, on close inspection, the form of
the cavity will be discovered, marked out by a line of enamel, and the
space that is usually vacant filled up with a substance, which in
appearance differs little from the ivory. The tables of the lateral
incisors will be fully formed, and the infundibulum is rarely
obliterated, while its margin is always circumscribed and well defined,
as the previous wood-cuts will indicate.
[Illustration: _FIVE YEARS OFF._
_The Corner Teeth only show slight wear, and the posterior Margins are
round._]
[Illustration: _SIX YEARS OFF._
_The Corner Teeth look more firmly set, and their edges begin to be
uneven._]
49. _At six years of age, the corner teeth look more firmly set, and
their edges begin to be uneven_; they have become more square in the
figure of the external surface; the edges of the teeth, when the mouth
is closed, fairly meet; the round appearance of the posterior border is
nearly lost, and the teeth are altogether of a most prominent character.
The table of the corner teeth, nevertheless, is still confined to the
part anterior to the infundibulum, which cavity is not yet fairly
circumscribed or surrounded by a level margin. The infundibula may be
lost in the central incisors, and those of the lateral teeth may begin
to look shallow; but more generally these cavities are retained at six
years old. The tables, likewise, have somewhat changed their positions,
and the semi-circle which they formed at the fifth year, now is hardly
so perfect, though still well marked. The above description will be the
better understood by reference to the coloured engraving, which has been
compared with the mouths of numerous animals, viz., Skeleton Sorella,
and a brown horse, the property of Mr. T. Brown, &c., &c. The reader,
however, will at once recognise the general truth of the drawing, the
purpose of which the accompanying wood-cut will serve to explain. The
alteration in the semi-circular arrangement will be better perceived by
contrasting the present diagram with the one which preceded it, and
though the change may not seem very great, nevertheless, sufficient is
indicated to instruct the eye accustomed to observe it. The corner teeth
have now acquired a degree of surface which will fairly represent a
table, though it is still imperfect. The more darkly shaded portion of
the separated table denotes the part which has yet received no
attrition, but notwithstanding it is readily discerned that the nipper
has come into active use.
[Illustration]
50. _At seven years off, the corner teeth, without showing age, exhibit
further evidence of wear._ The coloured engraving to which the reader
must refer, exhibits those alterations which have now taken place. The
original sketch was made from the mouth of a horse in the possession of
the author's father, and having been corroborated by the inspection of
numerous others, it is confidently put forward as characteristic of the
age. I cannot here forbear from acknowledging the personal kindness and
professional attention bestowed upon me by Mr. Percival, who, on being
made aware that I was engaged upon a work illustrative of the horse's
teeth, not only allowed me to inspect the mouths of the animals under
his charge, but honoured me by accompanying me and assisted my
endeavours to arrive at a just conclusion by his remarks. I have also to
express my thanks to Mr. Braby for the liberty to inspect the large stud
of heavy dray horses in the stables of Messrs. Barclay and Perkins, the
eminent brewers. The advantages I derived from comparing so many mouths
of the same age at the same time, and the facilities which were given of
minutely examining each, enable me with more certainty to speak upon a
subject which otherwise it would have been prudent to mention only in
the most qualified terms. However, after such ample investigation, I
can, with confidence, refer to the plate depicting the mouth at seven
years off. Looking at it, the reader will see the teeth have become more
white, in consequence of the crusta petrosa having, by the natural wear,
been to a greater extent removed. The tushes are exhibited as fully up,
in which condition they are generally seen. Where the corner teeth meet,
they close in such a manner as denotes considerable use. The way in
which the gums encircle the necks of the shell teeth has also changed.
By referring back to the engraving of the five-year off mouth, the
difference will be more readily understood, the round arrangement of
the gums at the earlier age being very significant. The tables of the
teeth, however, at this period ought never to be overlooked; they
afford, perhaps, the best indications on which the judgment can be
based. The infundibula may or may not be gone in the lateral teeth; but
those of the corner teeth have at this age become defined. Where the
corner teeth meet, in consequence of those of the lower jaw being, in
many horses, a little the most forward, the upper shell teeth may
present posteriorly a small projection, which is seldom seen prior to
the seventh year. When this is present, it is so obvious as not to
escape observation, therefore, it has not been depicted in the coloured
engraving, which has purposely been made to represent the less marked
indication that is more difficult to judge by. The reader will see the
projection alluded to slightly indicated in the previous coloured
engraving, portraying the mouth at six years off. Where the two shell
teeth meet, he will observe that the most backward portion of the upper,
not being opposed by the lower tooth, and consequently suffering no
wear, bulges slightly downwards. It is this particular part, which often
at the seventh year, by the wearing down of the upper tooth, becomes so
apparent as to be significant of the age. It is, however, not constantly
present, and the tables consequently become of the greater importance,
as they are always to be found. Those of the lateral incisors begin to
depart from their oval figure, and those of the central nippers are
growing decidedly angular: the tushes may have the edges slightly
rounded, and the semi-circle which the tables of the incisors formed
when the animal was five years old, may exhibit some inclination to
change in favour of the lineal arrangement that is in many horses so
prominently marked in old age. This semi-circular arrangement of the
incisors is most conspicuous when the colt is rising five; and from that
period gradually alters, till in very old subjects the tables will
occasionally be ranged almost in a straight line. The alteration which
takes place in this respect is, however, by no means uniform, and
though, consequently, no rule can be absolutely laid down concerning it,
yet, from the known inclination of the teeth to assume a certain figure,
an inference can be drawn which, connected with other signs, enables a
pretty close opinion to be formed. At the seventh year, however, the
corner teeth, their external figure, and the form of their tables, taken
in conjunction with the wear exhibited by the central and lateral
incisors, and considered with the narrowed but not yet sharp edge of the
lower jaw, enable the judge to arrive, with tolerable certainty, at a
conclusion. The following representation of the tables, taken in
conjunction with the coloured engraving of the seven-year old mouth,
will convey an idea of its appearance at that age. The reader will
remark the infundibulum of the corner tooth has become circumscribed,
being now encircled by a flattened surface, which posteriorly is of some
width.
[Illustration]
[Illustration: _SEVEN YEARS OFF._
_The Corner Teeth without showing age, exhibit further evidence of
wear._]
[Illustration: _EIGHT YEARS OFF._
_The Gum of the lower Corner Teeth has become Square, and the lower Tush
blunt._]
51. _At eight years off, the gum of the lower corner tooth has become
square, and the lower tush blunt._ The original drawing was made from
the teeth of that noted horse, Oakley; and in order to render it as
perfect as possible, the mouths of mares (Meal, Edgworth, Bess, &c.)
have been compared. The departure from the circular form of the gum, as
depicted in the coloured engraving, is even more marked than it was at
the seventh year. Added to this change of figure, the gums appear more
hard and less delicate; the mouth looks more firm, and seems to have
attained the perfection of its strength. The margin of the lower jaw is
now comparatively sharp, and the cheeks are flat. The crusta petrosa on
the upper teeth is in a great degree removed; the enamel not yet,
however, having a marked yellow tinge. On the lower corner incisors the
crusta petrosa may still continue, but it no longer has a dull brown
aspect: it is never prominent at this age, but rather speckled over the
outer surface, than regularly enveloping any portion of it. It has a
somewhat rough and worm-eaten aspect, and in colour is nearer to a dirty
yellow than a dull brown. If the posterior angle of the upper corner
incisor is pendant, or exhibits that species of notch, which was alluded
to in the previous paragraph, it is at the eighth year well shown, and
the table has undergone considerable alteration. There is now on the
shell tooth, a full table, the infundibulum of which, if not
obliterated, is always of lessened size, well marked out, and on all
sides surrounded by a broad and a flattened surface. The other teeth
have also changed their figures. The tables of the centre nippers have
taken on a decided angular shape, and those of the lateral display no
dubious tendency to assume that form. The infundibula may be
obliterated, but more generally those in the lateral and corner teeth
are retained, or if now absent, the circle of enamel will, on
inspection, show that the cavity is only filled up by crusta petrosa,
not absolutely worn out. The following wood-cuts exhibit the changes
which the tables undergo; and as the eighth year is an important one,
inasmuch as the horse which has attained it is called "aged," a double
set is here introduced, to show the difference of figure which these
parts may present. In those tables, it will be seen the infundibulum has
gone from a central nipper only; but even in that instance, a white
mark indicates that the cavity is merely filled up by crusta petrosa,
the enamelled lining not being yet worn out. The alteration in the form
and magnitude of the infundibula cannot, if the accompanying wood-cut be
compared with those which have preceded it, fail to strike the reader;
indeed these changes, aided by the worn appearance of tables of the
shell teeth, are now the principal guides when judging of the age by the
mouth.
[Illustration]
52. _After the eighth year_, there is no certainty in any opinion drawn
from the teeth. A guess may be hazarded, and very often that guess will
prove correct, but at the same time it should be received only as a
conjecture. The chance of naming the age decreases as the number of
years increase. After the twelfth, the probability of hitting the exact
year is very small. After the sixteenth year, all is confusion, and
there remains no sign which could warrant any person in pretending he
could pronounce the age by the teeth. It is true that certain tokens may
induce a conviction that an animal is much older than sixteen, and this
conviction may be so justified as to amount almost to a certainty; but
no man, I imagine, could form any opinion with regard to the number of
years by which a horse exceeded sixteen, or pronounce a decision that
should have any appearance of exactitude. They who pretend to an ability
of this kind, may, in a few solitary instances, strike the point; but
repeated failures will show that there is no positive principle in
operation to guide the judgment. Indeed the age is most correctly told
during the periods of dentition, and up to the sixth year. After the
sixth year, the certainty is not so great, but a very fair, if not a
positive judgment can be pronounced until the eighth year is
accomplished. After the eighth year, no man should give an unqualified
opinion concerning the age of a horse. After the twelfth, whatever may
be pronounced should be offered only as a conjecture; and, after the
sixteenth, the practitioner had better be silent. When stating this the
author must be understood as expressing the conviction at which almost
exclusive attention to the subject, and much necessary consideration,
has enabled him to arrive. It must not, however, be thought that he is
arrogating a power of measuring the capabilities of genius; his wish is
only to declare the truth as he perceives it. The intention to publish a
work upon the teeth has not been concealed; opinions have been solicited
and information sought; the author has many obligations to acknowledge;
all to whom he has made application have been liberal in their
communications; but from no one has he been able to obtain anything
opposed to the conclusions he has here promulgated. It may be that
hereafter the power of judging of the age shall be extended. Pessina and
the Girards thought it could be done with exactitude up to an extreme
point, and saw a principle in the latest changes which the teeth
undergo. The general experience in this country, however, seems to have
decided that, after the eighth year, there is no certainty. With that
decision the author is reluctantly obliged to acquiesce, and even to add
that certainty is not to be obtained after the sixth year. This
limitation, coupled as it is with a confession of inability, may seem to
be a backward movement; but truth cannot retrograde. By ascertaining how
far our present knowledge leads us, a motive is given to genius by the
opportunity created for its exercise. No pains have been spared to
investigate the hypotheses which have been made known; they have been
candidly put to the test, and on the proof of their inefficiency
discarded. That the reader may judge for himself, the tables of teeth,
and mouths of various ages are presented. The altered aspect of the
tables at the ninth year is indicated in the following wood-cut, which
exhibits these surfaces as gaining depth and narrowing from side to
side. This appearance they generally assume, and at the same time the
infundibula are either lost or much contracted.
[Illustration]
The next wood-cut, which depicts the form of the tables at the tenth
year, though true in its general character, will serve to show how far
dependence may be placed in ordinary signs, since the infundibulum of
the lateral nipper shows a well-marked cavity, while from the other
teeth it seems to be upon the eve of disappearing. On inspection,
however, it will be seen that in figures the tables approach more
towards the square, which is the last form these surfaces assume.
[Illustration]
53. _At twelve years old, there may be tartar on the lower tush. The
teeth are longer, narrower, and the enamel darker._ The coloured
engraving, which was, on the last occasion justified by a comparison
with the mouth of that famous horse, Charles the Twelfth, will convey a
general idea of the prevailing characteristics of this age. The teeth
have lost the white and firm set aspect they bore at the eighth year.
Often, at this period, they have, by wear, become irregular generally,
as exhibited in the plate; the grooves, extending down the length of the
upper incisors, contain the remnants of the crusta petrosa, which is
almost black. The upper tush is usually much diminished, while the lower
is long, especially in stallions kept for service. The teeth project
more outward and begin to arrange themselves more in a line, no longer
showing the crescentic order which they assumed at five years old. Also,
by the twelfth year, the tongue, when the jaws are closed, protrudes
from the open space between the incisors and molars. The degree in which
these alterations have taken place, together with the protrusion of the
incisors, is all that is present to guide the judgment; and practical
experience is needed, to give him, who attempts to decide upon such weak
evidence, any chance of success. As in cases of this description every
thing that can help the judgment is eagerly seized upon, the general
appearance of the animal is always to be considered; and that may warn
the practitioner to modify his opinion. The lower jaw is sharp, the
cheeks flat, and around the tushes there may be an accumulation of
tartar. It is true the tables, consequent on the wear of the teeth, will
have undergone some change, but that alteration is now so slightly
marked as not to enforce itself upon the observation. It is easily
overlooked, and by no means easily recognised. The annexed wood-cut
will suggest the nature of the change. In it will be seen a further
remove from the oval form of these parts in the young mouth. The
surfaces have become square or angular, and the corners are only
sufficiently rounded to indicate what once was the shape which they
exhibited.
[Illustration]
The following wood-cut depicts the tables at the completion of the
fourteenth year, and only by careful comparison could the increase of
age which they denote be detected. On inspection, however, it will be
seen that the irregularities of outline are less prominent even than at
the twelfth year.
[Illustration]
[Illustration: _TWELVE YEARS OLD._
_Tartar on the lower Tush. The teeth longer, narrower, and the enamel
darker._]
[Illustration: _TWENTY YEARS OLD._
_The Form of the Mouth changed, and the lower Teeth imperfectly seen
from the front._]
54. _At sixteen years old, when the teeth are viewed from the side, only
two incisors can be seen in the lower jaw_, as depicted in the
coloured engraving, which was last authenticated by the mouth of Muley
Moloch, which favourite stallion I was, by the kindness of Mr. Theobald,
permitted to examine at his well-known establishment, where I also saw
many other horses of the purest blood and highest promise. Of the
excellence of the arrangements and the value of the animals, which give
character to that gentleman's establishment, it would be presumption of
me to speak. I have only to express my admiration of what I beheld, and
tender my thanks for the attention I received. The engraving, however,
was fortunately corroborated, and its general indications may therefore
be accepted. The enamel has entirely lost its white and pearly tone. The
tushes, perhaps, loaded with tartar in both jaws, are blunt, and
generally either very short or long, inclining somewhat outward. The
extension of the crescentic arrangement of the lower teeth enables only
two to be seen when the parts are viewed from the side. The tongue
protrudes to an obvious degree, and the saliva runs from the mouth when
the jaws are separated. The edge of the lower jaw is very sharp and
somewhat retracted, while the incisors have taken a horizontal
direction. No sign, however, save the protrusion of the tongue, is
positive. The general character is that of advanced age, and this
general character, at once recognised by the eye of experience, is more
to be depended upon than the teeth themselves. The teeth have now
assumed the permanent character of old age; and in the figure of the
tables will undergo no further alteration upon which any dependence can
be placed. Up to the sixteenth year, however, the tables deserve to be
consulted. Below is exhibited such evidence as they present, which the
reader will perceive is so nice and delicately marked as to be easily
misinterpreted. In the tables which belonged to the fourteenth year, it
will be seen the infundibula are almost gone, a speck alone denotes
their latest trace; nevertheless, the next wood-cut, which exhibits the
tables at the sixteenth year, will show that the absence of the
infundibula is not to be relied upon. Still the advance in age is,
though feebly, indicated. The central incisor has assumed a form which
is peculiarly characteristic of age in the horse. It is seldom that at
sixteen years all the tables take so marked a shape, but some of them,
and generally those in the centre, will, at this period, be symbolical
of the truth.
[Illustration]
Had it not been for the very conspicuous indication of the central
tables, the others in the former wood-cut might have been reasonably
decided to be more juvenile in their aspect.
55. _At twenty years old, the form of the mouth has changed, and the
lower teeth are imperfectly seen from the front._ This circumstance
springs from the more horizontal direction which the teeth have now
assumed, and the acuteness of the angle which they consequently form
when closed. The engraving also depicts that alteration in position
which disables a person, standing in front, from well seeing both rows
of incisors when the lips are separated. When the upper incisors are
fairly presented to the sight, a partial view only of the lower teeth is
obtained, and as the age advances even that is lost. Further inspection
also shows additional changes in position, shape, and tint. The grooves
are broad, deep, and well marked by their dark colour. Between the upper
incisors there are interspaces in which the food has accumulated and
become black, giving to the mouth the appearance represented in the
coloured plate. The upper tush, which is now of a brownish hue, may be
worn to the gum, and the lower continue long and surrounded by tartar,
or both may be reduced to mere stumps. The tongue protrudes greatly; the
membrane of the mouth seems hard; and no longer vascular, it is thrown
into wrinkles. The edge of the lower jaw is sensibly retracted, and its
sides are flattened or narrowed. The general appearance indicates the
decay of nature. Here again, however, nothing is positive, save the
yellowness of the teeth and the protrusion of the tongue. The general
character of the animal is of more value than the indications of the
mouth; and, persons familiar with horses can, sometimes by this, guess
the age of an animal with the same approach to accuracy, which most
people exhibit, when pronouncing the extent of an individual's life, by
simply looking at a man's face. In neither instance, perhaps, could the
basis of the opinion, which possibly shall approach very close to
correctness, be accurately stated. Proof, as to the evidence upon which
a conclusion is in such cases based, cannot be anticipated, and to the
inquiry how they were able to tell the age, each would probably answer,
by the "looks," but neither would be capable of precisely defining in
what these "looks" consisted.