72 NATURAL HISTORY OF BRITISH FRESH-WATER LEECHES.
gal, which used to export, are now obliged to draw supplies from abroad.
It is the same in Italy. Tuscany exports some leeches, but they are
considered of an inferior quality. Bohemia, which used to furnish supplies,
now possesses only exhausted marshes. Hungary, so rich in leech morasses,
commences to be impoverished of the kinds which the dealers used to send
as far as the frontiers of Russia and Turkey, Poland and other countries
in the north of Europe. Great Britain, which used to be rich in leeches,
is now forced to draw supplies from France, Germany and Portugal."
Legislation in France and Germany followed, relating to
exportation and closed seasons. The French encouraged the
establishment of breeding grounds, and the Societe d'Encourage-
ment pour l'Industrie Nationale gave several medals and prizes.
The first to breed leeches successfully in France was, according
to Ebrard (14), an illiterate butcher, of Dompierre, named
Micholet. He was an excellent observer, and by carefully
imitating the conditions under which the leeches lived naturally
he raised large quantities of these animals. His efforts were
rewarded by the Society named above, which gave him a medal
and a prize.
Briefly, leech-culture consisted in placing mature and overfed
leeches (termed vaches) in suitable ponds and artificial sheets
of water. Cocoons were deposited in the banks and in due
time the young (germements) hatched out. As soon as they grew
large enough to be retained in the meshes of the net used in
fishing for them, they were called filets. The young are able
to draw blood from frogs, newts and man also immediately
after escaping from the cocoon. The leeches were then fed
on blood for about three or four years, when they were ready
for market.
Several books on leech-culture were published in France,
the more notable being those of Moquin-Tandon (37), Ebrard
(14), Vayson (43), Fermond (16) and Laurens (33). From
these authors we gather that the most suitable sheets of water
are those having a sloping bottom of sandy clay. This would
allow aquatic plants to flourish in the shallower parts, and the
deeper parts would serve as retreats during periods of heat or
cold. Medicinal Leeches seem to flourish best in ponds in which
the following plants grow readily, viz. :—Glyceria fluitans,
Potamogeton natans, Carices of various species and Chara
hispida. The pond should be supplied with water
from a stream or another pond or with rain water, as water taken