THE WHALE 125

active lot, and some of them, according to the Finnish
whalers, can remain under water for eight or twelve
hours at a time when taking their daily rest. One of
them, the blue whale (Balenoptera Sibbaldt), is the big-
gest and fastest mammal in existence, measuring from
eighty to ninety feet and more in length and travelling
thirty knots an hour. Like all the whales, he migrates
in search of food, and during the year visits many seas.
Scoresby says that rorquals a hundred and twenty
feet long have been known. In 1828 one was found
floating off Ostend which was ninety-five feet long
and had a tail 22 ft. 6 in. wide; and even larger ones
are on record.

Of the toothed cetaceans the sperm-whale is the
biggest, but he rarely exceeds fifty feet in length. He
was the only whale that was fished for until the
discovery, in the sixteenth century, of the Greenland
whale, which is about the same size. He feeds, like
most of his family, on squids and cuttles, and in the
ambergris which is formed in his intestines the horny
beaks of these cephalopods are almost invariably found ;
but he will eat almost any kind of fish. He is not
particularly prepossessing in appearance, a fourth of
his length being devoted to a head which is chiefly
noticeable for its massiveness. He has only rudimentary
teeth in his upper jaw, but in his lower jaw he has
from forty to fifty substantial stumps, all ivory and
all rounded like pegs, which fit into a groove above
them, so that when the mouth is closed there is no
escape from destruction. His mouth is white, his
tongue is white, and his throat is large, and it has
been suggested that when seeking food he remains at