feel pain to any great extent. Even when badly wounded, one will
continue whatever it has started to do, either eating, struggling to escape,
or fighting until the blood has drained from its body or it is
dismembered. (2 p. 17)

Many curious tales have been told about sharks, which in truth
are very different from most fish since they are practically all jaws and
muscle. Their great bodies are supported not by a bony skeleton but by
cartilage. Sharks, moreover, are not provided with an air bladder, an
organ most fish use as a submarine uses its ballast tanks in diving or
ascending in water. (2 p. 6)

Sharks are not always careful about their diet and, sometimes, in
their haste, eat things which are not in the least good for them. Their
stomachs can digest almost everything but it is doubtful that food tins,
which have been taken from the stomachs of captured sharks, are on the
list. The porcupine fish is another indigestible food. When swallowed
by a shark this prickly specimen secretes a reddish-like substance which
is thought to protect it against the action of the shark's digestive juices.
Then, the porcupine fish saws its way through the shark's body and so
escapes an untimely end. (1 p. 113) (6 p. 264)

The Great White Shark, one of the largest, has won the name of
"Man-eater" because it occasionally attacks humans. Adults occasionally
reach a length of 40 feet. According to Linnaeus, eminent Swedish
scientist, the Great White Shark was the creature that swal-