With regard to the difference of form which we have just pointed out, we have sometimes heard the following comparison made: the contour of the hoofs of the fore-limbs, viewed from below, recalls that of an apple; that of the hoofs of the hind-limbs recalls the outline of a pear.
As a mnemonic this comparison is insufficient, for nothing connects either of the forms indicated with the region to which the hoofs belong.
We much prefer one made for us this very year by one of the students of our course at the School of Fine Arts, after the lecture in which we had just pointed out the differences in question. Giving the idea of a semicircle and an ogive, which we described above, he remarked to us that the idea would perhaps be more easily fixed in the memory if we a.s.sociated with it the idea of the chronological order in which the Roman and ogival art succeeded. Indeed, as the Roman art preceded the ogival art, so the hoofs which have the semicircular form precede those which have the form of an ogive.
This interpretation appeared to us ingenious; this is why we wished to give it here a place which seems to us to be merited.
[Ill.u.s.tration: FIG. 104.--LEFT POSTERIOR FOOT OF A HORSE: EXTERNAL ASPECT.]
The wall of the hoof of a fore-limb, viewed on one of its lateral surfaces (see Fig. 98), is more oblique than that of one of the hind-hoofs looked at in the same way (Fig. 104). This difference, very marked especially at the region of the toe, is correlated with that of the direction of the pastern. In fact, in the anterior limbs this is a little more oblique than in the opposite ones.
We have still to describe, in connection with the horse, some epidermic tissues, which are known as _chestnuts_.
The chestnut is a small, h.o.r.n.y plate which is found on the internal surface of each of the limbs, at a level differing on the anterior from that of the posterior ones.
On the anterior limbs the chestnut is situated on the internal surface of the forearm, towards the middle part, or the inferior third of this region. On the posterior limbs it is developed on the back of the superior extremity of the internal surface of the canon, towards the inferior part of the ham--that is, the tarsus.
[Ill.u.s.tration: FIG. 105.--FOOT OF THE OX: LEFT SIDE, ANTERO-EXTERNAL VIEW.
1, Internal hoof; 2, external hoof; 3, internal surface of this latter; 4, internal spur.]
Inasmuch as some authors consider the chestnuts as being vestiges of the thumb and the great-toe, we propose giving a mnemonic which will enable us to remember their situation, or, rather, their difference of level.
If we consider that the thumb, in the human species, is longer than the first toe, we may easily remember that the chestnut is placed higher in the anterior limbs than in the posterior ones. Indeed, if we suppose a digit taking its origin at these points, it will be longer in front (the thumb) than behind (the first toe).
=Hoofs of the Ox and the Pig.=--The ox has four hoofs on each foot--two which contain the third phalanges, and two others, rudimentary, situated at the posterior aspect of the limb, at the level of the inferior part of the canon; these latter bear the name of _spurs_. We will occupy ourselves especially with the former (Fig. 105).
Each of the hoofs presents three faces which, if we consider them in relation to the median axis of the limb to which they belong, are: external, internal, and inferior. The external surface resembles the wall of the hoof of the horse. The internal surface is slightly concave from before backwards, so that the external and internal hoofs of the same foot are not in contact with each other, except by the extremities of this surface, and that an interval separates them between these two points. The inferior surface, slightly depressed, ends behind in a swelling produced by the plantar cushion, which covers a thin lamina of horn.
At the anterior part of the hoof these three surfaces unite in forming a well-marked angle which, on account of the concavity of the internal surface, is slightly curved towards the axis of the foot.
The pig has also four hoofs--two for the great digits and two for the lateral digits. They recall those of the ox.
CHAPTER IV
PROPORTIONS
Inasmuch as we have taken for granted, in connection with the present volume, that before entering on the study of the anatomy of quadrupeds the reader was prepared for it by a sufficient knowledge of human anatomy, it is quite natural that we should extend the same supposition to the study of proportions.
For this reason, the definition of proportions, considered from a general point of view, their signification, their function and their utility, are questions which it would be superfluous to enter upon here.
We will content ourselves by calling to mind that the common measure chosen by preference is the length of the head, and that, ordinarily, it is with it that we compare the dimensions of other parts.
Among the animals whose structure we have examined, there is one of which the proportions deserve to be marked in preference to every other: this is the horse.
Wherefore this preference? In the first place, it is because of the overwhelming position which this animal occupies in the artistic representation of quadrupeds; that it is more frequently a.s.sociated with man; that, notwithstanding its division into different races, its general proportions may be referred to a special type.
It is also because the indications relative to these proportions will suffice to show the way which the artist must follow in order to find for himself, at the time when the necessity for it arises, the proportions which characterize the other animals.
Our intention is not, in connection with the subject which now occupies us, to enter into a deep discussion on the various opinions which have been set forth. We desire, above all, to give some indications which, from the practical point of view, can be utilized in the representation of the horse, and at the beginning to demonstrate the advantages of these indications. Now, there is a fact which we have had occasion to note; it is the following: almost invariably, when a person who is little accustomed to represent the horse, or not previously informed of certain proportions of lengths, begins to draw from nature, the error generally committed is that of making the head too small and the body too long. Is it a preconceived idea which is the cause that one regards them in this manner? Perhaps. At all events, certain artists who have made the representation of horses their special study have even had this habit. It is therefore necessary to be informed of the proportions; this is the object of the study which we are now undertaking.
Bourgelat,[37] in the eighteenth century, fixed for the first time and in complete fashion the proportions of the horse; it is he, consequently, who created the aesthetics of the horse. It is but justice to recall the fact. His system has a point of a.n.a.logy with that which is employed to determine the human proportions. Indeed, Bourgelat chose the length of the head as a standard of measurement, and the subdivisions of the head for measures of less extent. "Since beauty," said he,[38]
"resides in the congruity and proportion of the parts, it is absolutely necessary to observe the dimensions, individual and relative, and in order to acquire a knowledge of the proportions, to a.s.sume a kind of measure which can be indiscriminately common for all horses. The part which can serve as a standard of proportion for all the others is the head. Take a measurement between two parallel lines--one tangent to the nape of the neck or the summit of the forelock, the other tangent to the extremity of the anterior lip--a line perpendicular to these two tangents will give you its geometrical length. Divide this length into three portions, and give to these three parts a special name, which may be applied indefinitely to all heads--as, for example, that of _prime_.
Any head whatsoever will, accordingly, in its geometrical length, always have three _primes_; but all the parts which you will have to consider, whether in their length, in their height, or in their width, cannot constantly have either one prime, or a prime and a half, or three primes; subdivide, then, each _prime_ into three equal parts, which you will name _seconds_, and as this subdivision will not suffice to give you a just measure of all the parts, subdivide anew each _second_ into twenty-four _points_, so that a head divided into three _primes_ will have, by the second division, nine _seconds_, and two hundred and sixteen _points_ by the last."
[37] Claude Bourgelat, founder of the veterinary schools in France. He was born at Lyons in 1712, and died at Paris in 1779.
[38] Bourgelat, "elements de l"art veterinaire. Traite de la conformation exterieure du cheval," Paris, edition of 1785, p.
133.
But where this system appears to us to have lost somewhat of its unity is when the author transforms it, in pointing out the following mode of procedure: "But the head itself may err by default of proportion. This part is not, indeed, considered as either too short or too long, too thin or too thick, but by comparison with the body of the animal. Now, the body, being required to have--whether in length, reckoning from the point of the arm to the prominence of the b.u.t.tock, or in height, reckoning from the summit of the withers to the ground--two heads and a half; whenever the head, by its geometrical length, shall give, in length or in height, to the body measured more than two and a half times its own length, it will be too short; and if it gives less, it will be too long.
"In the case in which one of these faults exists there would be no further question of establishing by its geometrical length the proportions of the other parts. Give up this common measure, and measure the height or the length of the body; divide the length or the height into five equal portions; take, then, two of these divisions, divide them into _primes_, _seconds_, and _points_, corresponding to the divisions and subdivisions which you would have made of the head, and you will have a common measure, such as the head would have given you if it had been proportionate."[39]
[39] Bourgelat, _loc. cit._, p. 135.
[Ill.u.s.tration: FIG. 106.--THE PROPORTIONS OF THE HORSE (AFTER BOURGELAT).
_To face p. 265._]
We understand, up to a certain point, that Bourgelat may have been able to give this advice which, generally speaking, is sufficiently practical, since, in certain cases, he was able to p.r.o.nounce that such a head was too small or too large. But it is always mischievous, with regard to the effect produced on the reader, to propose to him, in the application of a rule, to suppress the foundation on which this rule is established. Besides, even if all the measurements compared with the two-fifths of the length of the body are proportionate with regard to one another, the animal, in spite of this, since the head must be taken into consideration, will, in a strict sense, be none the less disproportioned.
The proportions given by Bourgelat are as follows[40] (Fig. 106):
[40] _Ibid._, p. 136, and onward.
1. =Three geometrical lengths of the head= give:
_The full height_ of the horse, reckoned from the forelock to the ground on which he rests, provided that the head be well placed.[41]
[41] By "the head being well placed," Bourgelat means "vertically posed," the outline of the forehead then coinciding with a vertical line, which at the other end touches the anterior portion of the nose.
2. =Two heads and a half= (B)[42] equals:
[42] The letters in parentheses relate to the corresponding measures marked by the same letters on the third diagram of Fig. 106.
_The height of the body_ from the summit of the withers to the ground.
_The length of the same body_, those of the forehand and of the hind-quarter taken as a whole from the point of the arm to the point of the b.u.t.tock inclusive.
3. =An entire head= (A) gives:
_The length of the forepart_ from the summit of the withers to the termination of the neck.
_The height of the shoulders_ from the summit of the elbow to the top of the withers.