THE CAT FAMILY.[6]
This is the chief of the families of Carnivora, containing as it does all the great beasts of prey. Its members are the most perfectly constructed of animals for a life of rapine; their weapons—teeth and claws—attain the utmost degree of perfection, and their elegant form, silent movements, and often beautiful colouring, make them in every respect the culminating forms of the flesh-eating group, and one of the chief of the upper branches of the great Mammalian tree.
Both the Old and New World are well stocked with Cats. Everywhere they are the correlates, geographically speaking, of the beautiful forms of the Herbivora, and are their natural checkmates in the earth-peopling process. Their terrible office is to cull out the surplus number of Goats, Antelopes, Deer, Oxen, and Sheep; they also are not good neighbours to the Monkey tribes, nor to Rats, Cavies, Hares, Squirrels, and other gnawing animals. The smaller Cats also add feathered game to their diet. Everywhere they are the terror of woodland and of field, of plain and of forest. All are of the kindred of the Lion, and, like him, all “go about, seeking whom they may devour.”
Man has half tamed one of the smallest—we sayhalf tamed, for does not the demon that possesses all Cats still only slumber in the heart of the tamest domestic variety? As for the Hunting Leopard, he is deceived in the services he renders, and, in his own mind, is hunting for himself, and not for his master.
It is only necessary to mention the animals belonging to this noble family of “gentlemen caterers” to assure oneself that in it are contained the best known, the most skilled, the most perfectly armed of all the Carnivorous order. We have the Wild Cats existing under many forms nearly all over the world, the Lion the great tyrant of Africa, the Tiger the despot of India, the Puma and Jaguar taking their place in America, the Leopard helping the work of the Lion and Tiger in Africa and Asia, the Lynxes found in both Old and New Worlds, and the Cheetah, or Hunting Leopard of Asia and Africa. To these need only be added the Wolf, Hyæna, and Bear, to exhaust the list of “beasts of prey” in the ordinary acceptation of the term, that is, of beasts which are dangerous to man, for we “lords of creation” are not sufficiently generous to include under the term beasts of equal cruelty which prey on the lower animals.
By most naturalists all these animals are grouped together under the single genusFelis, which is thus said to include a great number of species, asFelis leo(the Lion),Felis tigris(the Tiger),Felis catus(the wild Cat), &c. It is very usual to separate from the rest the Hunting Leopard, and make it constitute by itself a distinct genus,Cynælurus, orGueparda, distinguished from its cousins by its great length of leg, and a slight difference in the form of its teeth. Some naturalists separate, in addition, the Lynxes, making of them the genusLyncus, and others, again, prefer to make separate genera of all the chief kinds, calling the LionLeo nobilis, the TigerTigris regalis, and so forth. This separation or union is, however, a mere conventional matter, and we prefer to consider allFelidæas belonging to the one genusFelis, as the simplest and most comprehensible plan.
TheFelidæare found over almost the whole world, being absent only in Australia, New Zealand, the south-eastern part of the Malay Archipelago, the Polynesian Islands, Madagascar, and the Antilles. In all other parts of the world Cats—using the word in a wide sense—are found, and, wherever they are found they are feared, for such a compact assemblage of bloodthirsty tyrants and ruthless destroyers has no parallel in the whole animal kingdom.
Remains of fossil Felidæ have been found as far back as the Miocene or even the Eocene epoch, in the South of England, and Central and South Europe, in North-west India, in Nebraska, in North America, and in the caves of Brazil. Of these the best known is the great cave Lion or Tiger, theFelis spelæa.
Every part of these animals is so altered and specialised from the usual type of Mammalian structure as to assist in the best possible way the capturing, killing, and devouring of living prey. Looking merely at the outside, we are struck with the lithe, agile form, the small head, the total absence of anything like a “pot-belly,” the well-proportioned limbs, the usually close fur, the stealthy, silent movements, and the eager, restless glance: all characters suited to an animal to which powers of quiet rapid movement through jungle or long grass, of quick observation, and of great strength and agility, are of the utmost importance.
In the skeleton there are two points of importance, as relating both to the habits of the Cat tribe and to the determining of their systematic position in zoology. These are the character of the skull, and the structure and arrangement of the bones of the toes. Both these points furnish characters by which the Cats may be separated from all other families. To these two points, therefore, we will proceed at once, as, without going into lesser details, there is nothing of special importance in thevertebral column, large limb bones, &c. All the points mentioned in the introduction to the group as being characteristic of the Carnivorous type of skull are here carried to their extreme. The bony ridges for the attachment of the jaw-muscles are immense; the jaws attain their utmost limit of structure and strength, and the lower jaw being perfectly incapable of motion from side to side, the teeth, as we shall see by-and-by, act like scissors and not like mill-stones.
If the skull of a Cat be examined, there will be seen on its under surface, near the hinder end, a pair of rounded swellings, directed somewhat obliquely. On looking at the skull from the side, there is seen to be a roundish aperture, the auditory meatus, leading into each of these swellings, which are found to be thin-walled half globes, stuck on, as it were, to the under surface of the skull. Round the aperture is fixed, in the living state, the Cat’s prominent external ear, and stretched across it, like the parchment of a drum, is a thin membrane, which vibrates with every sound. The rounded cavity is called the “drum of the ear,” the membrane stretched across it the “drum membrane,” or “tympanic membrane,” and the bony half-globe, which forms the floor of the drum cavity, is the “bulb of the drum,” orbulla tympani.
SIDE VIEW OF LION’S SKULL.a.m, auditory meatus;b.ty, bulla tympani;j, jugal arch or zygoma;o.c, occipital condyle for the articulation of the skull with the first vertebra;c, condyle of the lower jaw;g, glenoid cavity with which the condyle of the lower jaw articulates;p, the bony clamp, or paroccipital process.
SIDE VIEW OF LION’S SKULL.
a.m, auditory meatus;b.ty, bulla tympani;j, jugal arch or zygoma;o.c, occipital condyle for the articulation of the skull with the first vertebra;c, condyle of the lower jaw;g, glenoid cavity with which the condyle of the lower jaw articulates;p, the bony clamp, or paroccipital process.
Closely pressed against the hinder wall of this bulla is a sort of bony clamp, which seems to keep the bulla in its place, and running obliquely along the surface of the swelling is an indistinct groove, corresponding to which, in the interior of the drum, is a bony wall, dividing the drum cavity into an inner and an outer compartment, these two divisions being formed from separate bones, as an examination of a very young skull will show.
The almost globular form and great relative size of thebulla tympani; the absence of any distinct bony passage leading from its cavity to the interior, the opening being quite flush with the wall of the drum; and the division of the cavity into two parts by a bony partition, are all very important as distinctive characters of the Cat family, and also, with lesser modifications, of the whole Æluroid group.
UNDER VIEW OF LION’S SKULL.The letters have the same significance as in the side view.
UNDER VIEW OF LION’S SKULL.
The letters have the same significance as in the side view.
The power of retracting the claws, so characteristic a feature of all the true Cats (which are, without exception, digitigrade), is brought about by certain peculiarities of structure of the last two joints of the toes. Of the threephalanges, or bones which make up the skeleton of the toe, the first, or that nearest to the wrist or ankle, is of the ordinary shape: about three times as long as broad, with a regular cylindrical shaft, and pulley-like ends, for articulation with the bone to which it is joined. The second, or middle phalanx, is pretty much like the first, except that its shaft is scooped out on one side, so as to make a greater distance between it and the corresponding bone of the next toe than there would otherwise be. The third and last joint, calledtheungual phalanx, from the fact of its supporting the claw, has the regular pulley-surface to articulate with the preceding joint, but its farther end is strongly curved downwards and pointed at the end; it has, in fact, the shape of the horny talon of which it forms the supporting core. Further support is afforded to the claw by an outgrowth of the phalanx, which commences near its articular end, and grows over the end of the claw like a sort of hood, thus giving the ungual phalanx of the Cat a most peculiar and unmistakable shape. Between the upper surfaces of the last phalanx and the last but one passes a strong and very elastic ligament, which so pulls upon the ungual phalanx as to bend it on its predecessor, and so cause the two to be almost parallel, the hood of the claw-bearing bone being received between the preceding joint of its own toe and that of the next; hence the scooping out of the middle phalanges. Thus, by the action of this ligament, the claw under ordinary circumstances is pulled back within its covering of skin, which forms for it a sort of protecting pouch, and effectually prevents its being worn down by rubbing against the ground. But when the Cat strikes its prey, it bends the paw upon the wrist by means of the strongflexor(or bending) muscles, which are placed along the under surface of the fore-arm and hand. The end of the string-like tendons of one of these muscles divides into four slips, one for each toe, and, running along the under surface of the first two phalanges, is inserted into the corresponding surface of the third, and, this under surface being bent upwards by the elastic ligament, the tendon is, when the claw is retracted, put upon the stretch. But when the flexors come into play, they pull upon the ungual phalanx, causing it to turn through a quarter-circle upon its articulation, and thus protruding the claw from its pouch. Immediately the flexors relax the elastic ligament is again allowed to act, and the claw springs back into its place of repose.
TENDONS AND LIGAMENTS OF A CAT’S TOE.(Twice Natural Size. From a Sketch by T. J. Parker.)A, with the claw retracted;B, with the claw exserted;mtc, the metacarpal;ph. 1, the first;ph. 2, the second;ph. 3, the third phalanx;h, the bony “hood;”c, the claw;l, the elastic ligament;t, the flexor tendon;a, a ligamentous loop, through which the tendon passes.
TENDONS AND LIGAMENTS OF A CAT’S TOE.(Twice Natural Size. From a Sketch by T. J. Parker.)
A, with the claw retracted;B, with the claw exserted;mtc, the metacarpal;ph. 1, the first;ph. 2, the second;ph. 3, the third phalanx;h, the bony “hood;”c, the claw;l, the elastic ligament;t, the flexor tendon;a, a ligamentous loop, through which the tendon passes.
This arrangement is of great importance, as the Cat family always attack their prey in the first instance by a stroke of the powerful fore-paw, and not, as do the Dogs, by a grip of the teeth.
Not less characteristic of the Cat family than the points we have just considered are the number and form of the teeth, which here attain the most perfectly carnivorous character, being so constructed as to be wholly incapable of grinding, thus making it impossible for their possessor to live upon any but highly nourishing animal food.
In the front part of the Cat’s upper jaw are six small teeth with chisel-like edges—three on each side of the middle line. These teeth are, in shape, not unlike our own front teeth, and, like them, are single-fanged, but their small size, when compared with those that follow, is remarkable. They are borne by a bone quite distinct in young skulls from that which carries the other teeth—the premaxillary bone—and are, therefore, classed asincisorteeth. Corresponding with them in the lower jaw are six similar teeth—the lower incisors; so that the incisors of the Cat are said to be(3–3)(3–3), that is, three on each side above and below.
LION’S CLAW, SHEATHED AND UNSHEATHED.
LION’S CLAW, SHEATHED AND UNSHEATHED.
Following the last incisor, and separated from it by a short interval, comes on each side in both jaws a long, pointed fang, the chief means by which the Cats seize and hold on to their prey. These are thecanines, or dog-teeth, and correspond to the “eye-teeth” in ourselves, those adze-like teeth immediately following and slightly projecting beyond the last incisor. When the mouth is closedthe lower canines are seen to bite in front of the upper, and to fit into the space between the latter and the incisors. The canines of the Cat are written thus,(1–1)(1–1).
Following the canines, but separated from them by a slight interval ordiastema, are, in the upper jaw four, in the lower three teeth, which correspond to our “grinders,” or molars and premolars. In the upper jaw the foremost tooth of this set is as small as one of the incisors, and its crown is simple, or nearly so. The next two teeth are larger and have sharp, cutting edges, divided into three points, orcusps. The second of these two teeth is much the larger, its edge is more blade-like, and the front part of its inner edge sends off a strong blunt process, which is supported by a distinct root, so that this tooth has three roots instead of two like its predecessor; it is also of much greater size than any of those in front, and, biting like a scissor-blade against the corresponding tooth of the lower jaw, is called thesectorial, orcarnassialtooth. Behind it comes the last of the set, a small tooth with a transversely-set, almost flat crown.
PERMANENT TEETH OF LION.i. 3, the third incisor;c, the canine;p. 1,p. 2,p. 3, the premolars;m, the molars.
PERMANENT TEETH OF LION.
i. 3, the third incisor;c, the canine;p. 1,p. 2,p. 3, the premolars;m, the molars.
In the lower jaw, the grinding series is represented by only three teeth, all more or less resembling the second of the series in the upper jaw. Of these the third is the largest, and is called the lower carnassial, biting, as it does, against the upper tooth of that name. In every case the teeth of the lower jaw bitewithinthose of the upper, and, the jaws being so articulated as to allow only of up and down motion, and being incapable of play from side to side, the molars and premolars entirely lose their character of grinders, and become trenchant, cutting up the food, in fact, in precisely the same manner as a pair of scissors.
Now comes the question, which of these teeth are premolars, and which molars? This is decided by finding which of them have their place occupied in the young kitten by its first set of back-teeth, thedeciduousormilk molars, and which, on the other hand, have no predecessors: those which replace the milk molars being the premolars of the adult, those which arise as altogether new teeth, and have no representatives in the young animal, molars. The examination of a young Cat shows that there are, behind the canines, in the upper jaw three, and in the lower two teeth; that is to say, one less on each side of each jaw than in the adult. As age advances these deciduous or milk molars all drop out, and are replaced by the permanent premolars, while behind the last milk molar of each jaw an entirely new tooth makes its appearance—the true or permanent molar. Thus it is seen that only the last tooth in each jaw is a molar, and that the carnassials are of different natures in the two jaws, the upper being the last (third) premolar, the lower the single molar.
MILK TEETH OF LION, EXPOSED BY CUTTING AWAY THE OUTER PORTIONS OF BOTH JAWS.(Natural size. From Owen, after Rousseau.)d.i, deciduous incisors;d.c, deciduous canines;d.m.1,d.m.2,d.m.3, deciduous molars. The remaining letters have the same significance as in thepreceding figure.
MILK TEETH OF LION, EXPOSED BY CUTTING AWAY THE OUTER PORTIONS OF BOTH JAWS.(Natural size. From Owen, after Rousseau.)
d.i, deciduous incisors;d.c, deciduous canines;d.m.1,d.m.2,d.m.3, deciduous molars. The remaining letters have the same significance as in thepreceding figure.
We therefore write the premolars of the Cat(3–3)(2–2), and the molars(1–1)(1–1), so that the whole “dental formula” is as follows:—i.,(3–3)(3–3),c.,(1–1)(1–1),p.,(3–3)(2–2),m.,(1–1)(1–1)= 30. In the milk dentition, the number of incisors and canines is the same as in the adult, and, as we have just stated, the molars are absent, so that the formula isdi.,(3–3)(3–3),dc.,(1–1)(1–1),dm.,(3–3)(2–2)= 26,di,dc,dm, standing for deciduous incisors, canines, and molars.
The tongue in this family becomes an important adjunct to the teeth, almost losing its character as a delicate organ of taste. The little elevations or papillæ which beset the tongue in all animals—in ourselves for instance—are formed into strong horny spines set closely together like the teeth of a file, and, as may be seen any day at feeding-time at the Zoological Gardens, used to rasp the flesh from the bones as effectively as any file would do it. Most people must have noticed the differenttexture of a Cat’s and a Dog’s tongue. In the latter it is as smooth as in ourselves, in the former it has more of the texture of a piece of coarse sandpaper.
In someFelidæ, such as the Domestic Cats, the pupil, or small aperture in front of the eye which lets in light to the sensitive retina beyond, has the round shape it possesses in man, only in the dark, when it is dilated to receive every ray of light available. In the day, on the other hand, when more light is to be had than the animal requires, the pupil contracts to an ellipse, or in the strongest light to a mere line. This is not the case in the larger Cats, such as the Lion, Tiger, and Leopard, in which also the eyes themselves and the cavities in the skull for their reception are smaller, proportionally, than in the Domestic Cat.
Taking the structure of the Cat tribe, all in all, there is nothing whatever to make it the least difficult to suppose that they all sprang from one stock, and that size and colour, and every other point in which they now differ from each other, may have been brought about, through long periods of time, as the result of the influence of their surroundings. It is necessary to presume this, for classifiers from necessity lay hold on the most minute differences, for the sake of making proper specific distinctions, although these differences may be merely the outcome of some change of locality, warmer, or colder, drier, or moister, higher upon the hills, or lower down on the plains. Once developed, however, it becomes hereditary, and then avarietybecomes arace, and a race solidifies into aspecies. Yet, the result once obtained, however it arose, the profit is great to us who are careful observers and enthusiastic admirers of the infinite fecundity of Nature.