his brush out at the top of a tall round chimney.  Now if you can fancy one of our tall round manufactory chimneys to be white instead of black, and the round chimney-sweep’s brush to have lovely gay-coloured feathers all round it instead of dirty bristles, or if you can fancy the sweep letting off a monster catherine-wheel at the chimney’s mouth, you may have some idea what a tube-worm’s head is like when he pokes it out of his tube.

The Serpulae make their tubes of chalky stuff, something like egg-shell; and they stick them on to anything that comes to hand down below.  Those in the Great Aquarium came from Weymouth.  They were dredged up with the white pipes or tubes sticking to oyster-shells, old bottles, stones, and what not, like bits of maccaroni glued on to old crockery sherds.  These odds and ends are overgrown, however, with weeds and zoophytes, and (like an ugly house covered by creepers) look picturesque rather than otherwise.  The worms have small bristles down their bodies, which serve as feet, and help them to scramble up inside their tubes, when they wish to poke their heads out and breathe.  These heads are delicate, bright-coloured plumes.  Each species has its own plume of its own special shape and colour.  They are only to be seen when the animal is alive.  A good many little Serpulae have been born in the Aquarium.

Through the next window—­Tank No. 3—­you may see more tube-worms, with ray-like, daisy heads, and soft muddy tubes.  They are Sabellae.

Have you ever see a “sea-mouse”?  Probably you have:  preserved in a bottle.  It is only like a mouse from being about the size of a mouse’s body, without legs, and with a lot of rainbow-coloured hairs.  You may be astonished to hear that it is classed among the worms.  There is a sea-mouse in the Great Aquarium.  I did not see him; perhaps because he is given to burrowing.  If he is not in one of the two tanks just named he is probably in No. 21 or No. 25.  He is so handsome dead and in a bottle, that he must be gorgeous to behold alive and in a pool.  You should look out for him.

It is a disappointing feature of this water wonderland that some of the “sea-gentlemen” are apt to hide, like hobbledehoy children, when visitors call.  Indeed, a good many of them—­such as the swimming-crabs, the burrowing-crabs, the sea-scorpions, and the eels—­are night-feeders, and one cannot expect them to change their whole habits and customs to be seen of the British public.  Anyhow, whether they hide from custom or caprice, they are quite safe from interference.  Much happier, in this respect, than the beasts in the Zoological Gardens.  One may disturb the big elephant’s repose with umbrella-points, or throw buns at the brown bear, but the “sea-gentlemen” are safe in their caves, and humanity flattens its nose against the glass wall of separation in vain.