t of the eye
they saw us; should some sly fish, from below the surface of the
water, make a rush at one, the beetle sees the enemy with his under
eye and avoids him. What have you caught now, Jack? fish him out
whatever it is. Oh! a fresh-water mussel, and a very fine specimen
too; there are plenty of these fellows in the canal all the way from
here to Newport. "Are they good to eat, papa?" asked Willy. I never
tried one, but, from having often dissected specimens, I should say
they were as tough as the sole of a boot. I never heard of anyone
eating them. These molluscs carry their eggs, myriads in number,
within their gills. The young, at the time they are ejected, are very
curious little animals with triangular shells, and, oddly enough, they
will fasten upon the fins or tails of fish, on which they will stick
for some time, but how long I do not know.

[Illustration: FRY OF SWAN-MUSSEL, PARASITIC ON A FISH'S FIN.]

[Illustration: FRY OF SWAN-MUSSEL, HIGHLY MAGNIFIED.]

This particular mollusc is known by the name of swan-mussel; the young
fry are sent into the water in April and May. There is another kind of
fresh-water mussel in rivers and streams, called the pearl-mussel,
pearls being occasionally found in them. I had one of these pearls
once given me by a lad, taken from a river in the Isle of Man. I took
it to a jeweller, in Liverpool, who valued it at a guinea. Your uncle
Arthur, to whom I gave it, had it set in gold as a pin "I wish," said
May, who had listened to this part of the story with great attention,
"I wish pearl-mussels would live in the canal, it would be so nice to
get the pearls out of them." Very few mussels are found to contain the
pearls; perhaps you might have to open many hundreds before you found
a single pearl, and I should not like to cause the death of so many
harmless animals for the sake of a single pearl.

[Illustration: FRESH-WATER MUSSEL.]

"Here is another swan-mussel, and, just look, papa," said Jack, "some
other shells are fastened on it." So there are; it is a lot of the
curious and pretty little zebra-mussel. How prettily they are marked
with zig-zag stripes of reddish brown, especially the young specimens.
The name of mussel is better suited to these molluscs than to the
large kinds upon which the "zebras" are often attached, because, like
the salt water mussel you have often seen at New Brighton, they have
the power of spinning, what is called, "a byssus"--here, you see, i