MAMMALS OF THE SEA
Whale is a general name for the extensive and varied order of marine
mammals termed in science Cetacea. Their origin is obscure, but it is
certain that their very ancient ancestors were land animals, evidence
of which is afforded by their anatomy, especially in embryonic and very
young specimens. Here are classified not only the great true whales
but their smaller relatives, the sportive dolphins and porpoises, the
grampuses or blackfish, the white whales often seen in the lower St.
Lawrence River, the killers, and such out-of-the-way forms as the
narwhal, from whose snout projects a long twisted "tusk," which is a
strangely overgrown incisor tooth. In all these animals the shape is
fishlike, as is required by the fishlike habits; the skin is smooth
and usually blackish, or black with white markings; the forelimbs have
become paddles and the tail a pair of horizontal flukes. As they are
mammals with lungs and breathe air, whales must come to the surface
frequently for that purpose. At the instant they emerge the pent-up
air is expelled from the lungs through the nostrils at the top of the
nose. In the case of the larger species this big discharge of moist
breath condenses in the cold air into a visible vapor, often mixed with
sea spray, which is called a "blowing"; but no water is expelled from
the mouth, with which the "blowholes" have no connection. The smaller
kinds of cetaceans, of which the variety is immense, are in the main
fish-eaters, but the killer seizes and devours porpoises and seals
also, and a band of them may unite to worry a big cachalot to death.
Most species go about in small bands, or "schools."
The great whales are of two distinct families: (1) baleen whales, and
(2) toothed whales. The first take their name from the blade-shaped
plates of horny material (whalebone) hanging, to the number of two or
three hundred, from the roof of the mouth, each central blade eight or
ten feet long in ordinary cases. These "right" (i. e., proper) whales,
as they are called by the men who hunt for and harpoon them, are huge
creatures often fifty to seventy-five feet long, ranging all northern
oceans, even amid arctic ice; yet, despite their bulk, they feed
exclusively on the small crustaceans and other minute creatures of the
plankton swept into the mouth by the million as the whale rushes along
the surface, the water scooped up escaping from the sides of the mouth,
and the food being caught by the fringes of baleen and swallowed like
a continuous meal. In addition to the whalebone obtained from these
whales the hunters cut away and save the thick layer of fat (blubber)
under the skin for the sake of the oil it yields. The beeflike flesh of
the muscles is good meat. This kind of whale is becoming very scarce.
The toothed whales consist of the single species called sperm whale,
or "cachalot," which is of gigantic size, a lesser cousin ("kogia"),
and an inferior genus, the beaked whales of the Antarctic. All are
more common in the tropics and South Pacific than elsewhere. The great
sperm whale differs in form from a "right" one mainly in having
a huge, flattopped, almost square-fronted head, beneath which is
hinged a somewhat shorter underjaw. The cavernous mouth is armed with
strong, pointed teeth, and these whales prey on fish and especially on
cuttlefish. They can swallow whole nothing larger than a salmon, but
can bite larger prey into manageable pieces, and have more than once
seized and crushed a boat in their jaws. The cachalot attacks the giant
squid whenever it meets one and the marks of the squid's winding arms
and cruel suckers are often seen on the hides of whales as scars of
some struggle between these Titans of the deep. The value to mankind
of the sperm whale lies in the liquid fat and the valuable substance,
spermaceti, that fill a vast cavity in the top of its skull, a single
whale yielding several barrels of it, from which the commercial
"spermaceti" and a fine oil are extracted. In their intestines are
frequently found lumps of the secretion known as "ambergris," used as
a base for perfumes, the price of which is so high in the market that
a few pounds will cover the expenses of a ship's voyage. Ambergris is
also found floating in the open sea or cast up on shore, and for a long
time its origin was unknown.