sea, and that the mouth and throat of this monster should be so made
that he can eat only this minute food, food like that which the tiny
Herring eats.

In some parts of those cold northern seas the water is coloured in bands
of red and blue. If you took up a bucketful, you would find that the
colour was due to myriads of tiny creatures. Amongst these are other
myriads of small animals, each of less size than a house-fly. The larger
ones are there to feed on the smaller ones. And that mass of small life
is the food of this mountain of fat and flesh, the Greenland Whale.

He swims through the sea with his mouth gaping open, like a great
cavern, and soon thousands of the little creatures are inside. Then his
tongue comes forward. It is of immense size, and it pushes out all the
sea water from his mouth. But the small animals remain inside! For the
water is forced through a wonderful sieve, made of fringed plates, which
hangs from his upper jaw. Instead of having teeth in his mouth, as many
Whales have, the Greenland Whale has this sieve of "whalebone." Of
course it is a large sieve, to fill so large a mouth. Yet it is never in
the way, being neatly packed away at the top of the mouth, one plate
over the other, when not in use.

The mass of small animals, held back by this peculiar sieve, then slides
down his throat, which is a tube about as wide as a boy's wrist! We said
just now that Nature was full of surprises. Is it not surprising to find
a gigantic Whale feeding in this way! Inside the great mouth the
_Remora_? or Sucking Fish, is often found. This fish has an oval sucker
on its head, by which it fixes itself to Whales, or even to the hull of
a ship. It has fins, and can swim perfectly well, but prefers to live in
this lazy way.