Whale tooth

“ I could understand how it might be broken, but to be bent as this was, or to be curled around in a spiral, as was the case in our later specimen, it seemed to me that it would have had to be done while the whale was young, and the bone soft and cartilaginous. I could not imagine whales of that tender age fighting fiercely enough to bend a jaw or put out an eye, and I should be convinced—as to the bending of the jaw—only by actually seeing the jaw of a whale bent in a fight with another whale. ”

“ Teeth are wanting in the true whales, but in all other cetaceans they are present, at least in the lower jaw, and in the embryos of true whales they are found well formed about the middle of fœtal life, but they are gradually absorbed and no trace of them exists at birth. The teeth are always simple, with conical or compressed crowns and single roots, and there is only one set, milk teeth not being developed. ”

“ We know that the Mystacoceti at one time had teeth, for in fœtal whales two sets of minute teeth are present under the skin, corresponding to the “milk” and “permanent” dentition of ordinary mammals, but these disappear before the baleen begins to develop.
Another interesting feeding adaptation is present in the throat of the whale. The nostrils, instead of opening into the back of the mouth, as in land mammals, are directly connected with the lungs by a prolongation of the “windpipe” called the epiglottis, which entirely shuts off the whale’s breathing passage from the mouth. ”

“ The ascent to the quadrupeds brings in review before us still more striking illustrations of the apparently incomplete rendering of the structures of animal life. No better instance of the "rudimentary organs" of the naturalist can be found than in the group of the whales, and more especially in the species from which we obtain the commercial whalebone and oil—the Greenland or right whale. This whale possesses no teeth in its adult state, but before birth teeth are found in the gum. ”

“ Whalebone is a horny product of the epithelium lining the mouth, and is comparable to an exaggeration of the transverse ridges which are found in the mouths of all mammals upon the palate. In non-Cetacean mammals these ridges vary in depth, and are arranged as a rule transversely, but with an oblique inclination. This is precisely how the plates of baleen are disposed in the mouth of a Whale. Each piece of "bone" is triangular in shape, the broader end being that of attachment while it narrows gradually ”

“ These ears are close behind the eyes, but the nostrils are usually placed on top of the head. In nearly all varieties of whales we find teeth inside the large mouth. In one very important species there are no teeth, but instead, we find a large number of horny plates. The whale’s mouth opens very wide, and the lips are stiff and immovable, not soft and flexible like our own. ”

“ Then we have a clue, for each blade of whalebone grows from a horny white gum, being fed by a fleshy substance below much in the same way as our nails are, so that these blades are, as it were, a series of hardened ridges, which grow out from the soft palate, till they become frayed at the edges, and form that dense fringe which is the whale’s strainer, upon which he depends entirely for his food. ”

“ The jaw opened very far back, and was nearly sixteen feet in length, the most curious part of its structure being the remarkable substance known as whalebone, masses of which appeared all along the jaws, solid at the base, and splitting into a sort of fringe at the extremity. This arrangement is for the purpose of aiding the whale in procuring its food, and separating it from the water.
The tongue was remarkably large, soft, and full of oil; the opening of the throat wonderfully small, scarcely two inches in diameter.
"Why, what can the monster eat?" exclaimed Fritz ”

“ This asymmetry affects particularly the premaxillae, the maxillae, and the nasals. The base of the skull is symmetrical. The Whale's skull has very long premaxillae which, however, do not, except in the extinct Zeuglodonts, bear any teeth. The nasal bones, whether symmetrical or the reverse, are very small in existing Whales, which arrangement, together with the long and broad maxillary bones, removes the anterior nostrils, the blow-hole, far backwards. The roof of the skull is not at all formed by the parietals externally. ”

“ In the Greenland right whale of the circumpolar seas, the Bowhead of the American whalers (Balæna mysticetus) , all the peculiarities which distinguish the head and mouth of the whales from other mammals have attained their greatest development. The head is of enormous size, exceeding one third of the whole length of the creature. The cavity of the mouth is actually larger than that of the body, thorax, and abdomen together. The upper jaw is very narrow, but greatly arched from before backward, to increase the height of the cavity and allow for the great length of the baleen ”

“ The mouth is very large and wide; and the throat, unlike that of the Greenland whale, is very wide, sufficiently so to admit the body of a man. The upper jaw projects some feet beyond the lower, and is destitute of teeth ”

“ Instead, an elongation of the arytenoid cartilages 44and the epiglottis fits into the soft palate, thereby forming a continuous passage between the nostrils and the trachea, or windpipe, and entirely shutting off the nasal passages from the mouth. In this way a whale can swim with its mouth open, when feeding, without danger of being strangled by getting water into the breathing organs.
The blowholes, or nostrils, have been pushed backward and upward to open on the top of the head instead of at the end of the snout. ”

“ As many as twenty molar teeth have been counted in one half of the jaw, and there is no reason to forbid the assumption that they {336}may get still more numerous. This large number of grinding teeth is obviously suggestive of the Whales, with which the Sirenia are believed by some to be allied. It is at least a remarkable coincidence that these two aquatic groups of mammals should both have assumed the same indefinite tooth formula. It is correct to say assumed, since extinct forms of Manatees, such as Halitherium and Prorastoma, have not a continuous succession of molars. ”

“ Yet, with these exceptions, the position of the limbs is constant from the lower fishes up to man, there being always an anterior pectoral pair placed in front of a posterior or pelvic pair when both are present, and in no single instance are there more than these two pairs.
MOUTH OF A WHALE. The development of whalebone (baleen) in the mouth of the whale is another difficulty. A whale's mouth is furnished with very numerous horny plates, which hang down from the palate along each side of the mouth. ”

“ But there are many examples in animal life which indicate that particular parts of structure remain, in certain species, for ever in an undeveloped state. In respect to teeth, for instance, the Greenland whale may be regarded as a permanent suckling; for that huge creature having no occasion for these organs, they never pierce the gums, although in early life they are distinctly traceable in the dental groove of the jaws. ”

“ As the huge mass is turned round and round by the kent-tackle, the harpooners continue cutting off the slips, till the whole coat of fat is removed. The fins and tail are also cut off; and, lastly, the whale-bone is cut out of the mouth. The whale-bone is placed in two rows in the mouth, and is used instead of teeth, to masticate the food, and to catch the minute animals floating in the water on which it feeds. Each side of bone consists of upwards of three hundred laminae, the interior edges of which are covered with a fringe of hair. ”

“ Mammal teeth pass, in evolution, from the simple types found in that oviparous edentate, the spiny ant-eater of Australia, to those of the indeciduous ancestors of the sloths and armadilloes, and their descendants, inclusive of the dolphins and whales, whose teeth, both in the fetal Greenland and adult sperm whale, preserve this old type. (The whales have degenerated from the hoofed mammals to suit their environment.) ”

“ A whale is a warm-blooded, air-breathing, milk-giving animal. Its fins are hands with finger-bones, having a large number of joints; its tail is a piece of cartilage, and not a fish's fin with bones and rays; it has teeth in its gums, even if it never cuts them; and it gives suck to its little one just as much as a cow does to her calf. Nay, the whalebone whales have even the traces of hind legs entirely buried under the skin, and in the Greenland whale the hip-joint and knee-joint can be distinguished with some of their muscles, though the bones are quite hidden and useless. ”

“ Cetacean bones are easily affected by weather, and if exposed to the sun, rain and wind for a comparatively short time the hard exterior becomes white and chalk-like.
The whale’s skeleton is highly modified in adaptation to an aquatic existence and is very distinctive of the cetacean order. In a general view it is seen to be greatly elongated, the skull is pointed, the fore-limbs are short and flat and the hind-limbs are represented by nodules of bone; all these accompany a fish-like body which offers little resistance to its passage through the water. ”

“ The interior edges are covered with a fringe of hair, and the exterior edge of every blade, excepting a few at each extremity of the series, is curved and flattened down, so as to present a smooth surface to the lips. In some whales, a curious hollow on one side, and ridge on the other, occurs in many of the central blades of whalebone, at regular intervals of 6 or 7 inches.—May not this irregularity, like the rings in the horns of the ox, which they resemble, afford an intimation of the age of the whale? ”

“ The throat is four feet, and is mainly blubber, interpenetrated by fibrous, muscular flesh. The lips and throat of a two-hundred-and-fifty-barrel whale should yield sixty barrels of oil, and, with the supporting jaw-bones, will weigh as much as twenty-five oxen of one thousand pounds each. Attached to the throat by a broad base is the enormous tongue, the size of which can be better conceived by the fact that twenty-five barrels of oil have been taken from one. ”

“ Some whales have all the cerebral vertebrae free NOW, and every one of them has the full number, seven, whether they are free or fixed. No doubt whales had hind legs once upon a time. If when you come up to town you go to the College of Surgeons, my friend Flower the Conservator (a good man whom you should know) , will show you the whalebone whale's thigh bones in the grand skeleton they have recently set up. The legs, to be sure, and the feet are gone, the battle of life having left private Cetacea in the condition of a Chelsea pensioner.
Ever yours faithfully,
T.H. Huxley. ”

“ PROFILE VIEW OF HEAD OF PITHECANTHROPUS, THE JAVA APE MAN, RECONSTRUCTED FROM THE SKULL-CAP.
THE FLIPPER OF A WHALE AND THE HAND OF A MAN
In the bones and in their arrangement there is a close resemblance in the two cases, yet the outcome is very different. The multiplication of finger joints in the whale is a striking feature.
Some men, oftener than women, show on the inturned margin of the ear-trumpet or pinna, a little conical projection of great interest. It is a vestige of the tip of the pointed ear of lower mammals, and it is well named Darwin's point. ”

“ Its motions are rapid and universal; its strength immense. The eyes are situated in the sides of the head, about a foot obliquely above and behind the angle of the mouth. They are remarkably small in proportion to the bulk of the animal's body, being little larger than those of an ox. The whale has no external ear; not can any orifice for the admission of sound be discovered until the skin is removed.
On the most elevated part of the head, about 16 feet from the anterior extremity of the jaw, are situated the blow-holes, or spiracles ”

“ It should rather be said that in general those creatures which present an abnormal development in the covering of their skin, whether in the way of redundancy or deficiency, present, generally, perhaps always, an abnormal dental development, as we see in sloths and armadilloes on the one hand, which have the front teeth deficient, and in some branches of the whale family on the other, in which the teeth are redundant either in number or in size. ”

“ The enamel is derived from the outer layer of the embryonic dog-fish, the epiblast, which also gives rise to the epidermis; while the dentine and bony base arise in the underlying mesoblast, the dermis. A mammalian tooth has essentially the same structure: an outer coat of enamel, derived from epiblast, overlies a mass of dentine, resting on bone, but the dentine is excavated internally, to form a pulpcavity containing blood-vessels and nerves. Most land animals, however, have teeth only in their mouths, and have lost altogether the external teeth which constitute the armour of the dog-fish. ”

“ It may here be mentioned that the modification of the mouth-structure of the right whale is entirely in relation to its food. It is by this apparatus that it is enabled to avail itself of the minute but highly nutritious crustaceans and pteropods which swarm in immense shoals in the seas it frequents. The large mouth enables it to take in at one time a sufficient quantity of water filled with these small organisms, and the length and delicate structure of the baleen make it an efficient strainer or hair sieve by which the water can be drained off. ”