WHALE (AS. hzecri, OTIG. wal-fisc, Ger. II u1Ji.,rh, whale). Any large marine mammal of the order Cetacea (q.v.), the only essential difference between a whale and a dolphin or por poise being the size, although the name is more particularly applicable to the toothless or whale bone whales. One of the most widely current popular errors in zoijogy is the that a whale is some kind of a fish. The warm blood, the• well-developed brain, the double circulation, the lungs, and the mammary glands and repro ductive organs, all combine, however. to show clearly the far higher organization of a whale as compared with ()yen the highest fishes. The young of whales are born alive, well developed after a long pregnancy, and are suckled and cared for by the mother as in the case of land nmininals. Nevertheless, in their extreme adapta tion to an exclusively aquatic life, whales have certain superficial resemblances to fishes, es pec•ially in the elongated, tapering body, the like limbs, and the termination of the body in a caudal fin, the prineipal organ of locomotion. The skin of a whale is, however, smooth and without scales, although there are frequently barnacles and parasitic crustaceans attached to it in considerable numbers. The only outgrowths of the skin are hair-like bristles near the mouth, and these are not always present, being rather a characteristic of the young. The fore limbs of whales are supported by the same bones as in other mammals, but are very much flattened, and the digits, which have an unusual number of phalanges, are all united in a common skin. The clavicle is wanting, the scapula is very large, and the humerus and forearm bones are very short. The hind limbs are entirely want ing. the only evidence of their ancestral occur rence being a pair of small, slender bones. com pletely imbedded in the body wall and not con nected with the backbone, supposed to represent vestigial ischia. The caudal fin, unlike that of a fish, is flattened horizontally, and the two halves, known as 'flukes,' are therefore right and left, not dorsal and ventral as in a fish; this fin is connected with the body by a narrow but extremely muscular part, known as the 'small.'
Not only does the tail serve as the organ of loco motion, but it is also the most effective weapon of both offense and defense which the true whales possess. Most whales have more or less of a dorsal fin on the median line of the hack, but it is simply an outgrowth of the integument, and even in those forms where it is most highly veloped it has no bony supports. The head of a whale is very large proportionately, in some species as much as one-third of the total length. The eyes are small, as is the ear-opening; there are no external ears. The nostrils or nostril (there is often only one) are situated far back from the nose, on the vertex of the head, and are closed by a plug-like valve, which can only be opened by pressure from the inside. The so-called 'blowing' of a whale takes place through the nostrils, and is merely the release of the long-confined moisture-laden breath. which condenses in the cooler air and gives the ap pearance of a column of water being blown from the nostrils. The old idea that a whale takes water in at the mouth and blows it out through the nostrils is entirely baseless, although water may he blown into the air if the breath is re leased before the animal has quite reached the surface. The mouth of a whale is always large, though the esophagus may he quite narrow. Teeth are wanting in the true whales. hut 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 fictal 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 sat, milk teeth not being developed. The num ber of teeth shows a wide range of variation.