icklebacks,
like young children, are of an inquisitive turn of mind, and apt to
play truant too occasionally; but should some little fellow wander too
far from the nest, Father Stickles hurries after him, takes the little
truant in his mouth, and spits him out right over the nest. This I
repeatedly witnessed myself, and I have no doubt you will be able to
see the same thing yourselves.

"Are not sticklebacks quarrelsome little fish?" asked Willy. Yes, they
are very fond of fighting, and they are so bold that they do not fear
any enemy, whatever his size. I once kept a small pike, about ten
inches long, in an aquarium, into which I also introduced five or six
sticklebacks. I suppose the pike did not much like the look of the
prickles or spines, for he did not eat the fish. Once I saw him make
the attempt, but after getting Master Stickles into his mouth, he
quickly threw him out again, not relishing, I suppose, the _sauce
piquante_ of the spines. The sticklebacks were really masters; they
tormented Mr. Pike dreadfully; first one would take a bite at his
tail, and then another, till the tail had a woful expression indeed;
so I turned the pike into a pool of water, and I dare say the _retail_
business has long ere this been completed.

"Are there any other kinds of fish," asked Willy, "that make nests and
take care of their young ones like the three species of sticklebacks?"
Yes, there are several kinds of fish which do so, but no other British
fresh-water kinds, I believe. There is the salt-water _Lumpsucker_, a
fish of strange form and brilliant colour--you know the pickled
specimen in my study--whose young soon after birth fix themselves to
the sides and on the back of their male parent, who sails, thus
loaded, away to deeper and more safe retreats. There are the long
pipe-fishes, the males of which possess each a singular pouch on the
tail; in this the eggs of the female are deposited and matured; the
young ones occasionally leave their strange abode, and after swimming
about for a time return to it again, reminding us in this respect of
the kangaroos and opossums amongst mammalia. There are also fish which
inhabit the rivers of Demerara which make nests and show great
attachment to their young ones, and I dare say several other fish will
be found to do the same.

[Illustration: SNAIL LEECH.]

"Oh! papa, do look here; as I was turning over this bit of flat tile I
saw in the water I found a creature something like