184 THE RING OF NATURE 



the pen or cuttle-bone which we use as an ink 

 eraser. The thunderbolt or belemnite fossil we 

 asked about is the pen of a prehistoric cuttle-fish, 

 and the ink has been found surrounded by the 

 fossil remains, so little injured by the passage of a 

 few million years that it gave full satisfaction as 

 sepia to an artist who painted with it. 



So much for the mighty kingdom of the garden 

 snail. Now we fling off boots and stockings and 

 go for a paddle in a rock pool. It is glass clear ; 

 there is no outlet to the sea ; no sooner do we 

 stir up a cloud of sand than it settles again, so 

 that we should see the movement of the tiniest 

 atom. Yet we must search it long and keenly if 

 we are to find all the animal treasures it contains. 



A little submarine eddy near a bank of bright 

 green seaweed draws attention to apparently a 

 piece of water in the water, something scarcely 

 more visible than a flake of sunken ice. It is off 

 again and again when we try to get a hand beneath 

 it, and once the eye is removed from it the 

 invisibility of the pool swallows it. But if we 

 catch it, we find that this ghostly creature is 

 clothed in mail, and furnished with the most 

 delicate and elaborate of legs, antennae and 

 mouth-parts, with the last of which it can be seen 

 tucking bunches of sea salad into its gullet in the 

 most business-like way. And every one knows 

 that when a prawn is boiled its transparency turns 

 to the most aggressive of opaque reds, visible half 

 a street away. 



