a leech, and on
raising it up I saw what looks like a quantity of the animal's eggs,
and she seems to be sitting upon them as a hen upon her eggs." All
right, Jack; let me look, I dare say it is one of the snail-leeches.
Yes, to be sure it is, and here are the eggs which the creature
carefully covers with her body, and upon which she will sit till the
young ones are formed; the small brood, sometimes one hundred and
fifty or more in number, then attach themselves to the under surface
of the parent, and are carried about wherever she goes. There are
various species of this interesting family; all are inhabitants of
fresh water; some incubate or sit upon their eggs, others carry them
about in a hollow formed by the contraction of the sides. They have a
long tubular proboscis, by means of which they suck out the juices of
pond-snails and other water creatures. These snail-leeches move along
in the same way as the common horse-leech and the medicinal leech,
namely, by fixing the head-part on to the surface of some substance in
the water and then drawing the hinder part up to it; they then extend
the head-portion and fix it upon another spot, again drawing up the
other extremity. But the leeches, properly so called, have all red
blood; that of the snail-leeches is colourless.

"Is the leech used to bleed people when they are ill ever found in the
ponds of this country?" asked Willy. I believe it is rarely met with
now-a-days; most of the leeches used in medicine are imported from
Spain, Hungary, the south of France, and Algeria; many millions are
brought every year to this country. The medicinal leech, was, however,
once pretty common in the lakes and pools of the north of England. The
poet Wordsworth introduces us to an old leech-gatherer lamenting the
scarcity of the animals in the following lines:

"He with a smile did then his words repeat
And said that gathering leeches far and wide
He travelled; stirring thus about his feet
The waters of the pool where they abide.
Once I could meet with them on every side;
But they have dwindled long by slow decay;
Yet still I persevere and find them where I may."

This sonnet was written in 1807, and when we consider the immense
numbers used in medicine, and the utter neglect of leech culture in
this country, we shall cease to wonder that native leeches are very
scarce. It is said that four only of the principal dealers in London
import every year more