THE STICKLEBACKS. 355

in length and is furnished with spines which it uses with great
effect when fighting with its enemies.

The Stickle. Mr. John Stark who experimented with some
back and the sticklebacks and leeches some years ago gives the

Leech. following description of his experiences.

‘*On putting the leeches into the water, the stickleback
darted round the tumbler with lively motions till it found a
leech detached, and in a proper situation for being seized.
When the leech was very small, say about half an inch in
length, it was often swallowed at once before it reached the
bottom of the vessel, but when a larger one, about an inch,
or an inch and a half in length in its expanded state, was put
in, and had fastened itself by its mouth to the glass, the efforts
of the stickleback to seize and tear it from its hold, were inces-
sant, and never failed to succeed. It darted at the loose ex-
tremity, or, when both ends were fastened, at the curve in its
middle, seized it in its mouth, rose to near the surface, and
after a hearty shake (such as a dog would give a rat) let it
drop. The leech, who evidently wished to avoid its enemy
upon its release again, attached itself by its mouth to the
glass ; but again and again the attack was repeated, till the
poor leech became exhausted, and ceased to attempt holding
itself by its disc. The stickleback then seized it by the head
in a proper position for swallowing, and after a few gulps the
leech disappeared. The flattened leech being of an oval form,
and having a hard skin, was not attacked, unless when very
young, and small ; and leeches of the other species when pretty
well grown, or larger than himself when expanded, were killed
in the manner above mentioned, but not swallowed. In one
of his attempts to seize a leech, the stickleback having got it
by the tail, the animal curled back and fixed its disc upon his
snout. The efforts of the stickleback to rid himself of this en-
cumbrance were amusing. He let go his hold of the leech,
which then hung over his mouth, and darting at the bottom
and sides of the glass with all his strength, endeavoured to rub