Page:Encyclopædia Britannica, Ninth Edition, v. 24.djvu/559

Rh WHALE 523 WHALE, 1 a name applied rather loosely to various animals of the order Cetacea, the general characters and classification of -which have been described in the article MAMMALIA (vol. xv. p. 391). All the members of the sub-order Jlystacocdi, or Cetacea with whalebone, are called &quot; whales.&quot; But of the Odontoceti, or Cetacea with teeth, only certain of the larger ones are so termed, the smaller species being popularly spoken of as &quot; bottlenoses,&quot; &quot;dolphins,&quot; and &quot;porpoises&quot;; yet so indefinitely has the word been applied that a true dolphin (Delphinus tursio), not exceeding 8 feet in length, is described in some works as the &quot; smaller bottlenosed whale.&quot; Although by their mode of life so far removed from close observation that it is impossible to become as fami liar with them in their natural condition as with many other animals, whales are in many respects the most interesting and wonderful of all creatures; and there is much in their structure and habits which is well worthy of study, much that is difficult to understand, and much that leads to great generalizations and throws light upon far-reaching philosophical speculations. One of the first lessons which a study of these animals affords is that, in the endeavour to discover what a creature really is, from what others it is descended, and to what it is related, the general outward appearance affords little clue, and we must go deep below the surface to find out the es sential characteristics of its nature. There was once, and may be still in many places, a common idea that a whale is a fish. To realize the fallacy of this notion we have only to consider what a fish really is, what under all the diversities of form, size, and colour known among fishes there is common to them all, and we see that in everything which characterizes a true fish and separates it from other classes, as reptiles, birds, and mammals, the whale resembles the last-named and differs from the fish. It is as essentially a mammal as a cow or a horse, and simply resembles a fish externally because it is adapted to inhabit the same element ; but it is no more on that account a fish than is a bat, because adapted to pass a great part of its existence on the wing in the air, nearly related to a bird. The whole structure of a whale is a most instructive in stance of a type of organization which is common to and characteristic of the class Mammalia, only specially modi fied or adapted to a peculiar mode of life. We see in every part the result of two great principles acting and re acting upon each other, on the one hand, adherence to type, or rather to fundamental inherited structural condi tions, and, on the other, adaptation to the peculiar circum stances under which it lives, and to which in all probability it has become gradually more and more fitted. The external fish-like form is perfectly suited for swimming through the water ; the tail, however, is not placed vertically as in fishes, but horizontally, a position which accords better with the constant necessity for rising to the surface for the pur pose of breathing. The hairy covering characteristic of all mammals, which if present might interfere with rapidity of movement through the water, is reduced to the merest rudiments, a few short bristles about the chin or upper lip, Avhich are often only present in very young animals. The function of keeping the body warm is supplied by a thick layer of non-conducting material, the &quot; blubber,&quot; a peculiarly dense kind of fat placed immediately beneath the skin. The fore-limbs, though functionally reduced to mere paddles, with no power of motion except at the shoulder-joint, have beneath their smooth and continuous 1 Icel., hvalr ; Dan. and Swed., hval ; Anglo-Saxon, hwicl ; Germ., wal, walfisch. The meaning apparently is &quot;roller,&quot; the word being closely allied to &quot;wheel&quot; (Skeat). external covering all the bones, joints, and even most of the muscles, nerves, and arteries, of the human arm and hand ; and rudiments even of hind legs are found buried deep in the interior of the animal, apparently subserving no useful purpose, but pointing an instructive lesson to those who are able to read it. In what follows a more detailed account is given of the best known of those species of Cetacea to which the name &quot; whale &quot; is popularly applied, especially those frequenting British waters, than could be given under MAMMALIA. I. Sub-order MYSTACOCETI or Whalebone Whales. Genus Balsena. The Greenland, or more whale (Balcena mysticctus] attains, from 45 to 50 feet. Its external form is shown in fig. 1, from a right careful drawing by Mr Robert Gray. In this species all the peculi- whale. arities which distinguish the head and mouth of the whales from those of 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 bod}, thorax, and abdomen together. The upper jaw is very narrow, but greatly arched from before backwards, to increase the height of the cavity and allow for the great length of the baleen or &quot;whalebone&quot; blades; the enormous rami of the mandible are widely separated posteriorly, and have a still further outward sweep before they meet at the symphysis in front, giving the floor of the mouth the shape of an immense spoon. The baleen blades attain the number of 380 or more on each side, and those in the middle of the series have a length of 10 or sometimes 12 , or more properly Arctic, right Gree s, when full-grown, a length of land FIG. 1. Greenland or Arctic right whale (Balxna mysticctus). feet. They are black in colour, fine and highly elastic in texture, and fray out at the inner edge and ends into long, delicate, soft, almost silky, but very tough, hairs. The remarkable development of the mouth and of the structures in connexion with it, which dis tinguishes the right whale among all its allies, is entirely in relation to the nature of 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 provide an efficient strainer or hair-sieve by which the water can be drained off. If the baleen were rigid, and only as long as is the aperture between the upper and lower jaws when the mouth is shut, a space would be left beneath it when the jaws were separated, through which the water and the minute particles of food would escape together. But instead of this the long, slender, brush-like, elastic ends of the whalebone blades fold back when the mouth is closed, the front ones passing below the hinder ones in a channel lying between the tongue and the lower jaw. When the mouth is opened, their elasticity causes them to straighten out like a bow unbent, so that at whatever distance the jaws are separated the strainer remains in perfect action, filling the whole of the interval. The mechanical perfection of the arrangement is completed by the great develop ment of the lower lip, which rises stiffly above the jaw-bone and prevents the long, slender, flexible ends of the baleen from being carried outwards by the rush of water from the mouth, when its cavity is being diminished by the closure of the jaws and raising of the tongue. If, as appears highly probable, the &quot;bowhead&quot; of the Okhotsk Sea and Heluing Strait belongs to this species, its range is circum- polar. Though found in the seas on both sides of Greenland, and passing freely from one to the other, it is never seen so far south as Cape Farewell ; but on the Labrador coast, where a cold stream sets down from the north, its range is somewhat farther. In the liuhring Sea, according to Scammon, &quot;it is seldom seen south of the fifty-fifth parallel, which is about the farthest southern extent of the winter ice, while in the Sea of Okhotsk its southern limit is about the latitude of 54.&quot; As has been abundantly shown by Eschricht and Keinhardt in the case of the Greenland seas, &quot; every thing tends to prove,&quot; Scammon says, &quot;that the Balsena myslicctus is truly an ice whale, for among the scattered floes, or about the