Marvels of. the Universe 
organ, which can be folded up into a small compass like a 
telescope, or be stretched out till it is nearly six inches 
long and as thin as a horsehair. 
When the grub changes into the pupal or intermediate 
stage, similar to that of the chrysalis in the butterfly, its 
skin first of all becomes hard and opaque, then appear two 
pairs of horns at the head end, the fore pair about half 
the length of the other. These are to serve as breathing- 
organs, supplying the place of the tail, which is now 
retracted, and, like the body-skin, has become quite hard. 
They are not long wanted, for, if the season be favour- 
able, the fly will be ready to emerge after eight days. 
SEA-WORMS 
THE word “worm” is generally held in abhorrence as 
indicating something ugly, slimy and wriggly. But if we 
would learn something of the wonders of Nature we must 
not be deterred by a word ; and since Darwin showed, in 
his volume on the Earthworm, how important a work that 
despised creature does for the human race, that word 
should have for ever lost its terrors for the most sensitive 
of us. But the word “worm” covers a multitude of 
lowly creatures of the most diverse form and habit, and 
the worms that dwell in the sea include some of the most 
exquisitely-coloured as well as beautifully-formed of the 
smaller animals. They are of several distinct types, and 
their habits vary as much as their forms. Some, which 
we hope to deal with on a future occasion, are sedentary, 
building fixed tubular homes of sand or porcelain. Others 
are free to rove the vast domain of the sea at will. It is 
of a few of these that we desire to speak at present. 
Several of these Sea-worms are distinctly unwormlike 
in form. Such, for example, is the beautiful Sea-mouse, 
so-called because its rounded back is completely covered 
with a kind of long hair. But no terrestrial beast was 
ever clothed in fur of so glorious a character. It is only 
when you turn it on its back that you get an idea of the 
Then you see that it is built 
up of rings with side feet ; above it is really covered with 
Sea-mouse’s real nature. 
broad, overlapping armour-plates, but these are almost 
hidden by a thick brown 
reflect almost every conceivable brilliant tint. 
« 
95 
Photo by) ‘Laugh Main, B.Sc., F’. ES. 
THE RAT-TAILED MAGGOT. 
The Maggot is remarkable for its telescopic 
“tail,”’ or breathing-tube, which within certain 
limits can be extended according to the depth of 
water in which the creature lives so that the 
aperture remains above the water and allows a 
free passage of oxygen to the Maggot. 
‘underfur”’ from which emerge long iridescent hairs and bristles that 
The despiser of worms should see this Sea-mouse ; 
but probably then he will not admit that it is a worm. Several other of the Sea-worms are 
covered with similar plates, but without the addition of the coat of fur. 
What we have spoken of as feet in the case of the Sea-mouse are shared by many other 
Sea-worms, though they are not jointed limbs, but fleshy protuberances from the sides, which, in 
turn, bear bunches of bristles—often iridescent—which are used as organs of locomotion by 
pressing them against the surface they are gliding over. 
Some of them have these feet protected 
69 
