The Common Shrewmouse, who is Half as Big Again as the Pygmy
It is wonderful to think that the wee Pygmy and the huge Whale should belong to the same Class of creatures. But it is so. Nearly all the bones in the Pygmy (some are scarcely thicker than a hair) can be matched by the same sort of bones in the Blue Whale. If the Blue Whale were a fish (and he certainly looks like one) his bones would be quite different and quite differently arranged, and from this we know that the Whale is not a fish like a Shark, but an animal like a Seal, or a Pygmy Shrewmouse or one of ourselves.
Now we must look at the pictures. You will see at once what a long nose the Pygmy has got. This nose is very useful to him, for much of his food is tiny insects, and he pokes his nose into tiny holes after them.
You can't see his teeth in the pictures, which is a pity, for they are very curious teeth, and the front ones, instead of pointing up and down like ours do, point outwards rather, and come together like a pair of tweezers. This helps him to catch insects too, and to pull little snails out of their shells.
I don't think his teeth are strong enough to crack snail shells, but his dark-brown cousin, the Common Shrewmouse (his picture is on page 181), cracks snail shells quite easily, and so does his black cousin, the Water Shrewmouse.
The Water Shrewmouse, who is nearly Half as Big Again as the Common Shrewmouse
What does the great Blue Whale eat, you ask? I expect you will be surprised to hear that he eats much the same kind of things as the Pygmy—small slug-like creatures, scarcely an inch long, which swarm in parts of the sea. Of course he eats barrelfuls at once.
He catches them by a wonderful arrangement in his mouth, which is made of what we call whalebone. It is something like the gratings across drain-pipes, which let the water through but stop everything else, and he can lift it up or drop it down as he pleases. When he is hungry, he takes a huge mouthful of sea-water and lets it out again through this whalebone grating. All the small slug-like things which are swimming in the water are trapped, and, when he has got most of the water out of his mouth, he swallows them.